FastbootUI.cs

using ChromeosUpdateEngine;
using FastbootEnhance.Core.Adb;
using FastbootEnhance.Core.Fastboot;
using FastbootEnhance.Core.Images;
using FastbootEnhance.Core.Payload;
using FastbootEnhance.Core.Usb;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Threading;
using System.Windows;

namespace FastbootEnhance
{
    class FastbootUI
    {
        /// <summary>
        /// Staging area for images on their way to the device. It lives under the user's temp
        /// directory rather than next to the executable, which may sit somewhere unwritable.
        /// </summary>
        public static readonly string PAYLOAD_TMP =
            Path.Combine(Path.GetTempPath(), "FastbootStudio", "flash");

        static List<fastboot_devices_row> devices;
        static string cur_serial;
        static FastbootData fastbootData;

        /// <summary>True while a payload is being extracted or written; the window asks before closing.</summary>
        public static volatile bool flashing;

        /// <summary>The fastboot started by <see cref="runStep"/> and still running; null otherwise.</summary>
        static volatile Fastboot activeStep;

        /// <summary>
        /// Which phone a question is about: "Phone: serial · product · slot a · fastbootd". Every
        /// flash or erase confirmation ends with it, so a phone swapped mid-way is noticed.
        /// </summary>
        internal static string deviceLine()
        {
            FastbootData data = fastbootData;
            string slot = data == null || string.IsNullOrEmpty(data.current_slot) ? "-" : data.current_slot.TrimStart('_');
            return string.Format(Properties.Resources.confirm_device_line, cur_serial ?? "?",
                data == null || string.IsNullOrEmpty(data.product) ? "?" : data.product, slot,
                data != null && data.fastbootd ? "fastbootd" : "bootloader");
        }

        /// <summary>
        /// Stops whatever fastboot command is running: a step command (flash, erase, boot…) or
        /// the payload flash. The command's own error path reports what was stopped.
        /// </summary>
        public static void cancelCurrent()
        {
            Fastboot step = activeStep;
            if (step != null)
            {
                appendLog("stopped by the user");
                step.Abort();
                return;
            }
            if (flashWorker != null)
            {
                appendLog("flash stopped by the user");
                abortFlash();
            }
        }

        static void appendLog(string logs)
        {
            LogStore.Append(logs);
        }

        enum FastbootStatus
        {
            show_devices,
            show_actions
        }

        static FastbootStatus cur_status;
        static void refreshDeviceList()
        {
            MainWindow.THIS.Dispatcher.Invoke(new Action(delegate
            {
                MainWindow.THIS.fastboot_devices_list.Items.Clear();
                foreach (fastboot_devices_row row in devices)
                {
                    MainWindow.THIS.fastboot_devices_list.Items.Add(row);
                }
                MainWindow.THIS.fastboot_devices_empty.Visibility =
                    devices.Count == 0 ? Visibility.Visible : Visibility.Collapsed;
                setStatus(string.Format(Properties.Resources.rail_devices, devices.Count));
            }));
        }

        static bool checkCurDevExist()
        {
            using (Fastboot fastboot = new Fastboot(null, "devices"))
            {
                // stderr is drained alongside: a full pipe would otherwise stall fastboot.
                System.Threading.Tasks.Task<string> errors = fastboot.stderr.ReadToEndAsync();
                while (true)
                {
                    string line = fastboot.stdout.ReadLine();
                    if (line == null)
                        break;

                    string[] param = line.Split(new char[] { '\t' }, StringSplitOptions.RemoveEmptyEntries);
                    if (param.Length > 0 && cur_serial == param[0])
                        return true;
                }
                ThemedDialog.Show(Properties.Resources.fastboot_device_not_exist);
                leaveDevice();
                return false;
            }
        }

        /// <summary>
        /// Back to the device list. The variables read from the device go too, so nothing later
        /// (a payload flash, the pre-flash checks) can act on what an earlier device reported.
        /// </summary>
        static void leaveDevice()
        {
            cur_serial = null;
            fastbootData = null;
            cur_status = FastbootStatus.show_devices;
            change_page();
        }

        static void devicesListRefresher()
        {
            while (true)
            {
                Thread.Sleep(1000);

                if (cur_status == FastbootStatus.show_actions)
                    continue;

                if (adbPolling && ++adbTick % 3 == 0)
                    pollAdbPhones();

                List<fastboot_devices_row> tmp;
                try
                {
                    tmp = listDevices();
                }
                catch (FileNotFoundException e)
                {
                    // Without fastboot.exe there is nothing to poll; say so once and stop,
                    // rather than letting the exception take the whole app down.
                    MainWindow.THIS.Dispatcher.BeginInvoke(new Action(delegate
                    {
                        setStatus(Properties.Resources.rail_no_fastboot);
                        ThemedDialog.Show(e.Message + "\n" + e.FileName, Properties.Resources.error,
                            MessageBoxButton.OK, MessageBoxImage.Error);
                    }));
                    return;
                }
                catch (Exception e)
                {
                    appendLog("device poll failed: " + e.Message);
                    continue;
                }

                if (tmp.Count != devices.Count)
                {
                    devices = tmp;
                    refreshDeviceList();
                }
                else
                {
                    int i;
                    for (i = 0; i < tmp.Count; i++)
                    {
                        if (devices[i].name != tmp[i].name || devices[i].serial != tmp[i].serial)
                            break;
                    }
                    if (i != tmp.Count)
                    {
                        devices = tmp;
                        refreshDeviceList();
                    }
                }
            }
        }

        static int adbTick;
        static bool adbPolling = true;
        static string adbNoteShown;

        /// <summary>
        /// Phones booted into Android: each is read once per run (kernel, and the Companion's
        /// report when root allows), and the device list says they are there, since fastboot
        /// cannot see them. Runs on the poller thread.
        /// </summary>
        static void pollAdbPhones()
        {
            List<AdbDevice> phones;
            try
            {
                Adb.Result list = Adb.Run("devices -l", Adb.ShortCommand);
                phones = list.Succeeded
                    ? AdbDevice.ParseList(list.Output).Where(d => d.State == "device").ToList()
                    : new List<AdbDevice>();
            }
            catch (FileNotFoundException)
            {
                adbPolling = false;   // no adb.exe: nothing to look for
                return;
            }
            catch (Exception)
            {
                return;
            }

            foreach (AdbDevice phone in phones)
                AdbFacts.ReadOnce(phone.Serial);

            string note = adbPhonesNote(phones);
            if (note == adbNoteShown)
                return;
            adbNoteShown = note;
            MainWindow.THIS.Dispatcher.BeginInvoke(new Action(delegate
            {
                MainWindow.THIS.fastboot_adb_note.Text = note ?? "";
                MainWindow.THIS.fastboot_adb_note.Visibility = note == null ? Visibility.Collapsed : Visibility.Visible;
            }));
        }

        static string adbPhonesNote(List<AdbDevice> phones)
        {
            if (phones.Count == 0)
                return null;
            List<string> lines = new List<string>();
            foreach (AdbDevice phone in phones)
            {
                DeviceFacts facts = AdbFacts.Recall(phone.Serial);
                string name = facts?.Model ?? phone.Model ?? phone.Serial;
                string kernel = facts?.Kernel != null ? Helper.ltr(facts.Kernel) : "…";
                lines.Add(facts?.Companion != null
                    ? string.Format(Properties.Resources.adb_phone_companion, name, kernel, Helper.ltr("v" + facts.Companion), facts.Root ?? "?")
                    : string.Format(Properties.Resources.adb_phone_seen, name, kernel));
            }
            lines.Add(Properties.Resources.adb_phone_hint);
            return string.Join("\n", lines);
        }

        static List<fastboot_devices_row> listDevices()
        {
            List<fastboot_devices_row> found = new List<fastboot_devices_row>();

            using (Fastboot fastboot = new Fastboot(null, "devices"))
            {
                while (true)
                {
                    string line = fastboot.stdout.ReadLine();
                    if (line == null)
                        break;

                    string[] param = line.Split(new char[] { '\t' }, StringSplitOptions.RemoveEmptyEntries);
                    if (param.Length < 2)
                        continue;

                    found.Add(new fastboot_devices_row(param[0], param[1]));
                }
            }

            return found;
        }

        class fastboot_devices_row
        {
            public string serial { get; }
            public string name { get; }
            public fastboot_devices_row(string serial, string name)
            {
                this.serial = serial;
                this.name = name;
            }
        }

        class fastboot_info_row
        {
            public string name { get; }
            public string value { get; }
            public fastboot_info_row(string name, string value)
            {
                this.name = name;
                this.value = Helper.ltr(value);
            }
        }

        class fastboot_partition_row
        {
            public string name { get; }
            public string size { get; }
            public string is_logical { get; }
            public fastboot_partition_row(string name, string size, string is_logical)
            {
                this.name = name;
                this.size = size;
                this.is_logical = is_logical;
            }
        }

        /// <summary>
        /// How many operations hold the controls. Each lock is matched by exactly one unlock,
        /// and the controls come back only when the last one finishes.
        /// </summary>
        static int lockDepth;

        static void action_lock()
        {
            lockDepth++;
            if (lockDepth > 1)
                return;
            MainWindow.THIS.fastboot_progress_bar.Value = 0;
            MainWindow.THIS.fastboot_action_bar.IsEnabled = false;
            MainWindow.THIS.fastboot_progress_bar.Visibility = Visibility.Visible;
            MainWindow.THIS.fastboot_progress_bar.IsIndeterminate = false;
            Helper.TaskbarItemHelper.start();
            MainWindow.THIS.fastboot_single_part_op.IsEnabled = false;
            MainWindow.THIS.fastboot_flash_payload.IsEnabled = false;
            // Leaving the device mid-operation would let a flash continue with no target serial.
            MainWindow.THIS.fastboot_remove.IsEnabled = false;
        }

        static void action_unlock()
        {
            if (lockDepth > 0)
                lockDepth--;
            if (lockDepth > 0)
                return;
            MainWindow.THIS.fastboot_progress_bar.Visibility = Visibility.Hidden;
            MainWindow.THIS.fastboot_action_bar.IsEnabled = true;
            Helper.TaskbarItemHelper.stop();
            MainWindow.THIS.fastboot_single_part_op.IsEnabled = true;
            MainWindow.THIS.fastboot_flash_payload.IsEnabled = true;
            MainWindow.THIS.fastboot_remove.IsEnabled = true;
        }

        static Helper.ListHelper<fastboot_partition_row> listHelper;

        /// <summary>Long enough for a phone rebooting into fastbootd to come back.</summary>
        static readonly TimeSpan GetvarTimeout = TimeSpan.FromMinutes(3);

        static void load_fastboot_vars()
        {
            //reset
            fastbootData = null;
            listHelper.clear();
            MainWindow.THIS.fastboot_partition_name_textbox.Text = "";
            MainWindow.THIS.fastboot_info_list.Items.Clear();
            MainWindow.THIS.fastboot_checks.ItemsSource = null;
            action_lock();
            MainWindow.THIS.fastboot_progress_bar.IsIndeterminate = true;

            string serial = cur_serial;
            Thread loader = new Thread(new ThreadStart(delegate
            {
                FastbootData loaded;
                try
                {
                    using (Fastboot fastboot = new Fastboot(serial, "getvar all", GetvarTimeout))
                    {
                        // fastboot bug: Must read stderr first or stdout would be blocked
                        string output = fastboot.stderr.ReadToEnd();
                        int? exitCode = fastboot.WaitForExit();
                        if (exitCode == null)
                        {
                            throw new TimeoutException("the device did not answer \"getvar all\" within "
                                + GetvarTimeout.TotalMinutes + " minutes");
                        }

                        loaded = new FastbootData(output);

                        // Some old bootloaders reject "all" but still list a few variables; only
                        // a failure that told us nothing at all is treated as one.
                        bool learned = loaded.product != null || loaded.current_slot != null
                            || loaded.partition_size.Count > 0 || loaded.max_download_size > 0;
                        if (exitCode != 0 && !learned)
                        {
                            string[] lines = output.Split(new[] { '\n' }, StringSplitOptions.RemoveEmptyEntries);
                            throw new IOException("fastboot getvar all exited with code " + exitCode
                                + (lines.Length > 0 ? ": " + lines[lines.Length - 1].Trim() : ""));
                        }
                    }
                }
                catch (Exception e)
                {
                    appendLog("getvar all failed: " + e.Message);
                    MainWindow.THIS.Dispatcher.BeginInvoke(new Action(delegate
                    {
                        MainWindow.THIS.fastboot_progress_bar.IsIndeterminate = false;
                        action_unlock();
                        if (cur_serial != serial)
                            return;
                        ThemedDialog.Show(e.Message, Properties.Resources.error, MessageBoxButton.OK, MessageBoxImage.Error);
                        leaveDevice();
                    }));
                    return;
                }

                MainWindow.THIS.Dispatcher.Invoke(delegate
                {
                    MainWindow.THIS.fastboot_progress_bar.IsIndeterminate = false;
                    action_unlock();
                    if (cur_serial != serial)
                        return;
                    fastbootData = loaded;
                    showFastbootVars();
                });
            }));
            loader.IsBackground = true;
            loader.Start();
        }

        static void showFastbootVars()
        {
            //Partition list init

            foreach (string key in fastbootData.partition_size.Keys)
            {
                long raw_size = fastbootData.partition_size[key];
                string size_str = raw_size >= 0 ? Helper.byte2AUnit((ulong)raw_size) : Properties.Resources.fastboot_0_size;
                bool? raw_logical = null;
                fastbootData.partition_is_logical.TryGetValue(key, out raw_logical);
                string logical_str = raw_logical != null && raw_logical == true ? Properties.Resources.yes : Properties.Resources.no;
                listHelper.addItem(new fastboot_partition_row(key, size_str, logical_str));
            }
            listHelper.render();

            //info list init

            MainWindow.THIS.fastboot_info_list.Items.Add(new fastboot_info_row(Properties.Resources.fastboot_device,
                fastbootData.product ?? Properties.Resources.unknown));

            MainWindow.THIS.fastboot_info_list.Items.Add(new fastboot_info_row(Properties.Resources.fastboot_secure_boot,
                fastbootData.secure ? Properties.Resources.enabled : Properties.Resources.disabled));

            MainWindow.THIS.fastboot_info_list.Items.Add(new fastboot_info_row(Properties.Resources.fastboot_seamless_update,
                fastbootData.current_slot != null ? Properties.Resources.yes : Properties.Resources.no));

            if (fastbootData.current_slot != null)
                MainWindow.THIS.fastboot_info_list.Items.Add(new fastboot_info_row(Properties.Resources.fastboot_current_slot,
                    fastbootData.current_slot));

            MainWindow.THIS.fastboot_info_list.Items.Add(new fastboot_info_row(Properties.Resources.fastboot_is_userspace,
                fastbootData.fastbootd ? Properties.Resources.yes : Properties.Resources.no));

            if (fastbootData.max_download_size > 0)
                MainWindow.THIS.fastboot_info_list.Items.Add(new fastboot_info_row("max-download-size",
                    Helper.byte2AUnit(fastbootData.max_download_size)));

            string vab_status_str = null;
            switch (fastbootData.snapshot_update_status)
            {
                case "none":
                    vab_status_str = Properties.Resources.fastboot_update_status_none;
                    break;
                case "snapshotted":
                    vab_status_str = Properties.Resources.fastboot_update_status_snapshotted;
                    break;
                case "merging":
                    vab_status_str = Properties.Resources.fastboot_update_status_merging;
                    break;
                default:
                    vab_status_str = fastbootData.snapshot_update_status;
                    break;
            }

            if (vab_status_str != null)
                MainWindow.THIS.fastboot_info_list.Items.Add(new fastboot_info_row(Properties.Resources.fastboot_update_status,
                    vab_status_str));

            // fastboot cannot ask the kernel or the patch level; show what adb last said, if anything.
            DeviceFacts seen = DeviceFacts.Recall(Settings.Get(DeviceFactsKey), cur_serial);
            if (seen?.Kernel != null)
                MainWindow.THIS.fastboot_info_list.Items.Add(new fastboot_info_row(Properties.Resources.fastboot_row_adb_kernel,
                    Helper.ltr(seen.Kernel)));
            if (seen?.Patch != null)
                MainWindow.THIS.fastboot_info_list.Items.Add(new fastboot_info_row(Properties.Resources.fastboot_row_adb_patch,
                    Helper.ltr(seen.Patch)));
            if (seen?.Companion != null)
            {
                MainWindow.THIS.fastboot_info_list.Items.Add(new fastboot_info_row(Properties.Resources.fastboot_row_companion,
                    Helper.ltr("v" + seen.Companion) + (seen.Root != null ? "  ·  " + seen.Root : "")));
                if (seen.Avb != null)
                    MainWindow.THIS.fastboot_info_list.Items.Add(new fastboot_info_row(Properties.Resources.fastboot_row_avb,
                        seen.Avb + (seen.DeviceState != null ? "  ·  " + seen.DeviceState : "")
                        + (seen.Spoofed ? "  ·  " + Properties.Resources.fastboot_avb_spoofed : "")));
                if (seen.Conflicts != null)
                    MainWindow.THIS.fastboot_info_list.Items.Add(new fastboot_info_row(Properties.Resources.fastboot_row_conflicts,
                        seen.Conflicts == 0 ? Properties.Resources.fastboot_conflicts_none
                            : seen.Conflicts.Value.ToString(System.Globalization.CultureInfo.CurrentCulture)));
            }

            //buttons init

            MainWindow.THIS.fastboot_logical_create.IsEnabled = fastbootData.fastbootd;
            MainWindow.THIS.fastboot_reboot_d.Content = fastbootData.fastbootd ?
                Properties.Resources.fastboot_reboot_bootloader : Properties.Resources.fastboot_reboot_fastbootd;

            if (fastbootData.current_slot == "a" || fastbootData.current_slot == "b")
            {
                MainWindow.THIS.fastboot_ab_switch.Visibility = Visibility.Visible;
                MainWindow.THIS.fastboot_ab_switch.Content = fastbootData.current_slot == "a"
                    ? Properties.Resources.fastboot_setactive_b
                    : Properties.Resources.fastboot_setactive_a;
            }
            else
            {
                MainWindow.THIS.fastboot_ab_switch.Visibility = Visibility.Collapsed;
            }

            // Only offer to cancel a Virtual A/B update when there is one. The old code hid this
            // button the first time it saw "none" and never showed it again.
            MainWindow.THIS.fastboot_cancel_update.Visibility =
                fastbootData.HasPendingUpdate ? Visibility.Visible : Visibility.Collapsed;

            MainWindow.THIS.fastboot_mode_text.Text = fastbootData.fastbootd ? "fastbootd" : "bootloader";

            MainWindow.THIS.fastboot_checks.ItemsSource = buildChecks();
            showSuperSpace();
            updateDeviceBar();
        }

        /// <summary>What to look at before writing anything to this device.</summary>
        static List<CheckRow> buildChecks()
        {
            List<CheckRow> checks = new List<CheckRow>();

            if (fastbootData.unlocked == true)
                checks.Add(new CheckRow(CheckRow.Level.Ok, Properties.Resources.check_unlocked));
            else if (fastbootData.unlocked == false)
                checks.Add(new CheckRow(CheckRow.Level.Danger, Properties.Resources.check_locked));

            if (fastbootData.fastbootd)
                checks.Add(new CheckRow(CheckRow.Level.Ok, Properties.Resources.check_fastbootd));
            else
                checks.Add(new CheckRow(CheckRow.Level.Warn, Properties.Resources.check_bootloader));

            if (!fastbootData.HasPendingUpdate)
                checks.Add(new CheckRow(CheckRow.Level.Ok, Properties.Resources.check_no_update));
            else
                checks.Add(new CheckRow(CheckRow.Level.Warn,
                    string.Format(Properties.Resources.check_update_pending, fastbootData.snapshot_update_status)));

            if (fastbootData.HasCowPartitions)
                checks.Add(new CheckRow(CheckRow.Level.Warn, Properties.Resources.check_cow));

            if (fastbootData.current_slot != null)
                checks.Add(new CheckRow(CheckRow.Level.Ok,
                    string.Format(Properties.Resources.check_slot, fastbootData.current_slot)));

            DeviceFacts seen = AdbFacts.Recall(cur_serial);
            if (seen?.Conflicts > 0)
                checks.Add(new CheckRow(CheckRow.Level.Warn,
                    string.Format(Properties.Resources.check_module_conflicts, seen.Conflicts.Value)));

            return checks;
        }

        /// <summary>The "Super" card on the partition tab: what each slot takes and what is free.</summary>
        static void showSuperSpace()
        {
            SuperSpace space = SuperSpace.From(fastbootData);
            MainWindow.THIS.fastboot_super_bar.Value = 0;
            MainWindow.THIS.fastboot_super_bar.Foreground = Palette.Get("Accent");

            if (!fastbootData.fastbootd)
            {
                MainWindow.THIS.fastboot_super_text.Text = Properties.Resources.super_space_bootloader;
                return;
            }
            if (!space.Known)
            {
                MainWindow.THIS.fastboot_super_text.Text = Properties.Resources.super_space_unknown;
                return;
            }

            MainWindow.THIS.fastboot_super_bar.Value = Math.Min(100, space.Used * 100.0 / space.SuperSize);
            MainWindow.THIS.fastboot_super_bar.Foreground = Palette.Get(
                space.Free < (512L << 20) ? "Danger" : space.Free < (2L << 30) ? "Warn" : "Accent");

            List<string> lines = new List<string>();
            lines.Add(string.Format(Properties.Resources.super_space_total,
                Helper.byte2AUnit(space.SuperSize), Helper.byte2AUnit(space.Free)));
            if (space.CurrentSlot != null)
                lines.Add(string.Format(Properties.Resources.super_space_slot, space.CurrentSlot,
                    Helper.byte2AUnit(space.CurrentSlotBytes)) + "  " + Properties.Resources.super_space_in_use);
            if (space.OtherSlot != null)
                lines.Add(string.Format(Properties.Resources.super_space_slot, space.OtherSlot,
                    Helper.byte2AUnit(space.OtherSlotBytes)));
            if (space.CowBytes > 0)
                lines.Add(string.Format(Properties.Resources.super_space_cow, Helper.byte2AUnit(space.CowBytes)));
            if (space.UnslottedBytes > 0)
                lines.Add(string.Format(Properties.Resources.super_space_unslotted, Helper.byte2AUnit(space.UnslottedBytes)));
            MainWindow.THIS.fastboot_super_text.Text = string.Join("\n", lines);
        }

        /// <summary>
        /// Before writing to logical partitions in fastbootd: when super is known to be too
        /// small for the images, says by how much and what could make room, and asks.
        /// True to go ahead.
        /// </summary>
        static bool superSpaceAllowed(IEnumerable<KeyValuePair<string, long>> writes, IEnumerable<string> created = null)
        {
            string problem = superSpaceProblem(writes, created);
            return problem == null || Helper.confirm(problem + "\n\n" + Properties.Resources.super_full_ask + "\n\n" + deviceLine(),
                Properties.Resources.super_full_title, true);
        }

        /// <summary>
        /// When super is known to be too small for the images: by how much, and what could make
        /// room. Null when they fit (or the phone is not in fastbootd, where nothing is resized).
        /// </summary>
        static string superSpaceProblem(IEnumerable<KeyValuePair<string, long>> writes, IEnumerable<string> created = null)
        {
            if (fastbootData == null || !fastbootData.fastbootd)
                return null;

            SuperSpace space = SuperSpace.From(fastbootData);
            SuperFit fit = space.Check(writes, created);
            appendLog("super space: " + (space.Known ? Helper.byte2AUnit(space.Free) + " free" : "size unknown")
                + ", writes need " + Helper.byte2AUnit(fit.Needed) + (fit.Fits ? "" : " (does not fit)"));
            if (fit.Fits)
                return null;

            List<string> ways = new List<string>();
            if (space.OtherSlotPartitions.Count > 0)
                ways.Add(string.Format(Properties.Resources.super_full_other_slot, space.OtherSlot,
                    string.Join(", ", space.OtherSlotPartitions.Take(6)
                        .Select(p => p.Name + " (" + Helper.byte2AUnit(p.Size) + ")"))));
            if (space.CowPartitions.Count > 0 || fastbootData.HasPendingUpdate)
                ways.Add(Properties.Resources.super_full_cow);
            if (ways.Count == 0)
                ways.Add(Properties.Resources.super_full_nothing);

            return string.Format(Properties.Resources.super_full,
                    Helper.byte2AUnit(fit.Needed), string.Join(", ", fit.Growing), Helper.byte2AUnit(fit.Free))
                + "\n" + string.Join("\n", ways.Select(w => "•  " + w));
        }

        /// <summary>
        /// The USB check: looks at what Windows sees on USB and explains why a phone may be
        /// missing from the list (no driver, a broken driver, a download mode, Android mode).
        /// </summary>
        internal static void checkUsb()
        {
            MainWindow.THIS.fastboot_usb_check.IsEnabled = false;
            IReadOnlyList<UsbFinding> findings = null;
            Exception failure = null;
            bool samsungDriver = true;
            bool googleDriver = true;

            Helper.offloadAndRun(new Action(delegate
            {
                try
                {
                    findings = UsbDiagnosis.Diagnose(UsbScan.Read());
                    samsungDriver = DriverUI.SamsungInstalled();
                    googleDriver = DriverUI.GoogleInstalled();
                }
                catch (Exception e)
                {
                    failure = e;
                }
            }), new Action(delegate
            {
                MainWindow.THIS.fastboot_usb_check.IsEnabled = true;
                if (failure != null)
                {
                    appendLog("usb check failed: " + failure.Message);
                    ThemedDialog.Show(failure.Message, Properties.Resources.error, MessageBoxButton.OK, MessageBoxImage.Error);
                    return;
                }
                showUsbFindings(findings, samsungDriver, googleDriver);
            }));
        }

        static void showUsbFindings(IReadOnlyList<UsbFinding> findings, bool samsungDriver, bool googleDriver)
        {
            List<string> lines = new List<string>();
            bool driverTrouble = false;
            bool adbReady = false;

            foreach (UsbFinding finding in findings)
            {
                appendLog("usb: " + finding.Kind + ", " + finding.Device.Name + " " + finding.UsbId
                    + ", code " + finding.Device.ErrorCode);
                string device = finding.Device.Name + (finding.UsbId != null ? "  (" + finding.UsbId + ")" : "");
                switch (finding.Kind)
                {
                    case UsbFindingKind.MissingDriver:
                        lines.Add(string.Format(Properties.Resources.usb_missing_driver, device));
                        driverTrouble = true;
                        break;
                    case UsbFindingKind.DriverProblem:
                        lines.Add(string.Format(Properties.Resources.usb_driver_problem, device, finding.Device.ErrorCode));
                        driverTrouble = true;
                        break;
                    case UsbFindingKind.QualcommEdl:
                        lines.Add(string.Format(Properties.Resources.usb_edl, device));
                        break;
                    case UsbFindingKind.MediaTekDownload:
                        lines.Add(string.Format(Properties.Resources.usb_mediatek, device));
                        break;
                    case UsbFindingKind.UnisocDownload:
                        lines.Add(string.Format(Properties.Resources.usb_unisoc, device));
                        break;
                    case UsbFindingKind.SamsungDownload:
                        lines.Add(string.Format(Properties.Resources.usb_samsung, device));
                        break;
                    case UsbFindingKind.FastbootReady:
                        lines.Add(string.Format(Properties.Resources.usb_fastboot_ready, device));
                        break;
                    case UsbFindingKind.AdbReady:
                        lines.Add(string.Format(Properties.Resources.usb_adb_ready, device));
                        adbReady = true;
                        break;
                }
            }

            if (lines.Count == 0)
            {
                ThemedDialog.Show(Properties.Resources.usb_nothing, Properties.Resources.usb_check_title,
                    MessageBoxButton.OK, MessageBoxImage.Information);
                return;
            }

            string text = string.Join("\n\n", lines.Select(line => "•  " + line));

            // A Samsung in Download mode, or one without a working driver: Samsung's own driver is
            // what it needs, and the app can fetch it.
            bool samsungPhone = findings.Any(f => f.Kind == UsbFindingKind.SamsungDownload
                || ((f.Kind == UsbFindingKind.MissingDriver || f.Kind == UsbFindingKind.DriverProblem) && f.Vid == "04E8"));
            if (samsungPhone && !samsungDriver)
            {
                if (ThemedDialog.Show(text + "\n\n" + Properties.Resources.usb_samsung_driver_ask,
                        Properties.Resources.usb_check_title, MessageBoxButton.YesNo, MessageBoxImage.Warning) == MessageBoxResult.Yes)
                {
                    DriverUI.InstallSamsung();
                    return;
                }
                // Declined: the advice for the other phones still follows.
                bool others = findings.Any(f => f.Vid != "04E8" && (f.Kind == UsbFindingKind.MissingDriver
                    || f.Kind == UsbFindingKind.DriverProblem || f.Kind == UsbFindingKind.AdbReady));
                if (!others)
                    return;
            }

            // A phone on Google's USB ids without a working driver: Google's driver fits it.
            bool googlePhone = findings.Any(f => (f.Kind == UsbFindingKind.MissingDriver || f.Kind == UsbFindingKind.DriverProblem)
                && GoogleDriver.Covers(f.Vid));
            if (googlePhone && !googleDriver)
            {
                if (ThemedDialog.Show(text + "\n\n" + Properties.Resources.usb_google_driver_ask,
                        Properties.Resources.usb_check_title, MessageBoxButton.YesNo, MessageBoxImage.Warning) == MessageBoxResult.Yes)
                {
                    DriverUI.InstallGoogle();
                    return;
                }
            }

            if (driverTrouble)
            {
                if (ThemedDialog.Show(text + "\n\n" + Properties.Resources.usb_driver_howto
                        + "\n\n" + Properties.Resources.usb_open_device_manager,
                        Properties.Resources.usb_check_title, MessageBoxButton.YesNo, MessageBoxImage.Warning) == MessageBoxResult.Yes)
                {
                    try
                    {
                        System.Diagnostics.Process.Start(new System.Diagnostics.ProcessStartInfo("devmgmt.msc") { UseShellExecute = true });
                    }
                    catch (Exception e)
                    {
                        ThemedDialog.Show(e.Message, Properties.Resources.error, MessageBoxButton.OK, MessageBoxImage.Error);
                    }
                }
                return;
            }

            if (adbReady)
            {
                if (!Helper.confirm(text + "\n\n" + Properties.Resources.usb_reboot_bootloader_ask, Properties.Resources.usb_check_title))
                    return;

                string problem = null;
                Helper.offloadAndRun(new Action(delegate
                {
                    try
                    {
                        // Only a phone named by its serial is restarted: with several connected,
                        // the user unplugs the others rather than the app guessing.
                        List<AdbDevice> phones = AdbDevice.ParseList(Adb.Run("devices -l", Adb.ShortCommand).Output)
                            .Where(d => d.Usable).ToList();
                        if (phones.Count == 0)
                        {
                            problem = Properties.Resources.usb_reboot_none;
                            return;
                        }
                        if (phones.Count > 1)
                        {
                            problem = string.Format(Properties.Resources.usb_reboot_more_than_one,
                                string.Join(", ", phones.Select(d => d.Serial)));
                            return;
                        }
                        // Last chance to note the kernel before the phone leaves Android.
                        AdbFacts.ReadConnected();
                        Adb.Result result = Adb.Run(AdbCommand.Reboot(phones[0].Serial, "bootloader"), Adb.ShortCommand);
                        if (!result.Succeeded)
                            problem = result.Problem;
                    }
                    catch (Exception e)
                    {
                        problem = e.Message;
                    }
                }), new Action(delegate
                {
                    appendLog("adb reboot bootloader (USB check): " + (problem ?? "ok"));
                    if (problem != null)
                        ThemedDialog.Show(problem, Properties.Resources.error, MessageBoxButton.OK, MessageBoxImage.Error);
                }));
                return;
            }

            ThemedDialog.Show(text, Properties.Resources.usb_check_title, MessageBoxButton.OK, MessageBoxImage.Information);
        }

        static void change_page()
        {
            bool showActions = cur_status == FastbootStatus.show_actions;

            if (showActions)
                load_fastboot_vars();
            else
                MainWindow.THIS.fastboot_mode_badge.Visibility = Visibility.Collapsed;

            MainWindow.THIS.fastboot_devices_page.Visibility = showActions ? Visibility.Collapsed : Visibility.Visible;
            MainWindow.THIS.fastboot_actions_page.Visibility = showActions ? Visibility.Visible : Visibility.Collapsed;
            // The device bar above the page shows the phone, its mode and Disconnect; the page header no longer repeats them.
            MainWindow.THIS.flash_target_device.Text = showActions && cur_serial != null
                ? string.Format(Properties.Resources.flash_target, cur_serial)
                : Properties.Resources.flash_target_none;
            updateDeviceBar();
        }

        /// <summary>The status bar's device count, the same text the rail used to show.</summary>
        static void setStatus(string text)
        {
            MainWindow.THIS.status_devices.Text = text;
            if (cur_status != FastbootStatus.show_actions)
                MainWindow.THIS.bar_device_detail.Text = text + " · " + Properties.Resources.bar_no_device_hint;
        }

        /// <summary>
        /// The bar above every page: the phone that is open (product, serial, slot, mode,
        /// lock state) and what can be done to it; or that none is.
        /// </summary>
        static void updateDeviceBar()
        {
            MainWindow window = MainWindow.THIS;
            bool open = cur_status == FastbootStatus.show_actions && cur_serial != null;
            FastbootData data = fastbootData;

            window.bar_disconnect.Visibility = open ? Visibility.Visible : Visibility.Collapsed;
            window.bar_reboot.Visibility = open ? Visibility.Visible : Visibility.Collapsed;
            window.bar_usb_check.Visibility = open ? Visibility.Collapsed : Visibility.Visible;
            window.bar_icon.Stroke = Palette.Get(open ? "Accent" : "Dim");

            if (!open)
            {
                window.bar_device_name.Text = Properties.Resources.bar_no_device;
                window.bar_device_detail.Text = window.status_devices.Text.Length > 0
                    ? window.status_devices.Text + " · " + Properties.Resources.bar_no_device_hint
                    : Properties.Resources.bar_no_device_hint;
                window.bar_mode_chip.Visibility = Visibility.Collapsed;
                window.bar_lock_chip.Visibility = Visibility.Collapsed;
                return;
            }

            string product = data != null && !string.IsNullOrEmpty(data.product) ? data.product : null;
            window.bar_device_name.Text = product ?? cur_serial;
            List<string> detail = new List<string>();
            if (product != null)
                detail.Add(string.Format(Properties.Resources.bar_serial, cur_serial));
            if (data != null && !string.IsNullOrEmpty(data.current_slot))
                detail.Add(string.Format(Properties.Resources.bar_slot, data.current_slot.TrimStart('_')));
            window.bar_device_detail.Text = detail.Count > 0 ? string.Join(" · ", detail) : cur_serial;

            if (data != null)
            {
                window.bar_mode_text.Text = data.fastbootd ? "fastbootd" : "bootloader";
                window.bar_mode_chip.Visibility = Visibility.Visible;
                window.bar_lock_text.Text = data.unlocked == true ? Properties.Resources.bar_unlocked
                    : data.unlocked == false ? Properties.Resources.bar_locked : null;
                window.bar_lock_text.Foreground = Palette.Get(data.unlocked == false ? "Warn" : "Dim");
                window.bar_lock_chip.Visibility = window.bar_lock_text.Text == null ? Visibility.Collapsed : Visibility.Visible;
            }
            else
            {
                window.bar_mode_chip.Visibility = Visibility.Collapsed;
                window.bar_lock_chip.Visibility = Visibility.Collapsed;
            }
        }

        /// <summary>The status bar's "last: fastboot flash boot · 1.2 s".</summary>
        static void setLastCommand(string command, TimeSpan took)
        {
            string shown = command.Length > 48 ? command.Substring(0, 45) + "…" : command;
            MainWindow.THIS.status_last.Text = string.Format(Properties.Resources.status_last, shown,
                string.Format(Properties.Resources.status_seconds, took.TotalSeconds.ToString("0.0", System.Globalization.CultureInfo.InvariantCulture)));
        }

        /// <summary>Reads "fastboot --version" and "adb --version" once, for the status bar.</summary>
        static void readToolVersions()
        {
            Thread reader = new Thread(delegate ()
            {
                string fastbootVersion = null, adbVersion = null;
                try
                {
                    string output;
                    Fastboot.Run(null, "--version", Fastboot.ShortCommand, out output);
                    fastbootVersion = firstVersion(output);
                }
                catch (Exception)
                {
                }
                try
                {
                    adbVersion = firstVersion(Adb.Run("--version", Adb.ShortCommand).Output);
                }
                catch (Exception)
                {
                }
                string text = string.Join(" · ", new[] { fastbootVersion != null ? "fastboot " + fastbootVersion : null,
                    adbVersion != null ? "adb " + adbVersion : null }.Where(v => v != null));
                MainWindow.THIS.Dispatcher.BeginInvoke(new Action(delegate { MainWindow.THIS.status_tools.Text = text; }));
            });
            reader.IsBackground = true;
            reader.Start();
        }

        /// <summary>"35.0.2" out of "fastboot version 35.0.2-12147458" or "Android Debug Bridge version 1.0.41 / Version 35.0.2-…".</summary>
        static string firstVersion(string output)
        {
            if (string.IsNullOrEmpty(output))
                return null;
            System.Text.RegularExpressions.Match match = System.Text.RegularExpressions.Regex.Match(output, @"(?im)^(?:Version|fastboot version)\s+(\d+(?:\.\d+)+)");
            if (!match.Success)
                match = System.Text.RegularExpressions.Regex.Match(output, @"(\d+\.\d+\.\d+)");
            return match.Success ? match.Groups[1].Value : null;
        }

        class StepCmdRunnerParam
        {
            public string cmd;
            public int step_count;
            public bool show_dialog_on_done;
            public bool skip_var_refresh;

            /// <summary>
            /// Captured on the UI thread when the command is created. Reboot clears cur_serial
            /// straight after starting the worker, so reading it there could send the command
            /// without -s, and fastboot would then act on whichever device it found first.
            /// </summary>
            public string serial;

            /// <summary>Control commands get a limit; anything that writes is left to finish.</summary>
            public TimeSpan timeout;

            /// <summary>Shown instead of "operation completed" when set.</summary>
            public string done_message;

            /// <summary>Back to the device list once the command succeeded (the phone left fastboot).</summary>
            public bool leave_after;

            public StepCmdRunnerParam(string cmd, int step_count, bool hint_on_done, bool skip_var_refresh = false)
            {
                // Every step command gets a deadline: a phone that stops answering mid-flash no
                // longer hangs the app for good. Fifteen minutes is far beyond any image over USB.
                this.timeout = Fastboot.LongCommand;
                this.cmd = cmd;
                this.step_count = step_count;
                this.show_dialog_on_done = hint_on_done;
                this.skip_var_refresh = skip_var_refresh;
                this.serial = cur_serial;
            }
        }

        static void runStep(StepCmdRunnerParam param)
        {
            // Locked here, on the click, so a second click cannot start the command again
            // before the worker gets going.
            action_lock();
            flashing = true;
            MainWindow.THIS.bar_cancel.Visibility = Visibility.Visible;
            if (param.step_count <= 0)
                MainWindow.THIS.fastboot_progress_bar.IsIndeterminate = true;

            Thread worker = new Thread(new ParameterizedThreadStart(step_cmd_runner_err));
            worker.IsBackground = true;
            worker.Start(param);
        }

        static void step_cmd_runner_err(object raw_param)
        {
            StepCmdRunnerParam param = (StepCmdRunnerParam)raw_param;

            appendLog("> fastboot " + param.cmd);
            string failure = null;
            System.Diagnostics.Stopwatch took = System.Diagnostics.Stopwatch.StartNew();

            try
            {
                using (Fastboot fastboot = new Fastboot(param.serial, param.cmd, param.timeout))
                {
                    activeStep = fastboot;
                    int count = 0;
                    while (true)
                    {
                        string err = fastboot.stderr.ReadLine();

                        if (err == null)
                            break;

                        appendLog(err);

                        if (param.step_count > 0)
                            MainWindow.THIS.Dispatcher.BeginInvoke(new Action(delegate
                            {
                                count++;
                                int percent = Math.Min(100, count * 100 / param.step_count);
                                MainWindow.THIS.fastboot_progress_bar.Value = percent;
                                Helper.TaskbarItemHelper.update(percent);
                            }));
                    }

                    int? exitCode = fastboot.WaitForExit();
                    activeStep = null;
                    if (exitCode != 0)
                    {
                        failure = "fastboot " + param.cmd + ": " + (exitCode == null
                            ? "did not finish within " + param.timeout.TotalMinutes + " minutes and was stopped"
                            : "exited with code " + exitCode);
                        if (fastboot.Aborted)
                            failure = Properties.Resources.step_cancelled;
                        appendLog(failure);
                    }
                }
            }
            catch (Exception e)
            {
                failure = e.Message;
                appendLog("fastboot " + param.cmd + " failed: " + e.Message);
            }
            activeStep = null;

            took.Stop();
            MainWindow.THIS.Dispatcher.BeginInvoke(new Action(delegate
            {
                flashing = false;
                MainWindow.THIS.fastboot_progress_bar.IsIndeterminate = false;
                MainWindow.THIS.bar_cancel.Visibility = Visibility.Collapsed;
                setLastCommand(param.cmd, took.Elapsed);
                action_unlock();

                if (failure != null)
                {
                    ThemedDialog.Show(failure, Properties.Resources.error, MessageBoxButton.OK, MessageBoxImage.Error);
                    return;
                }

                if (param.leave_after && cur_serial == param.serial)
                    leaveDevice();
                else if (!param.skip_var_refresh && cur_serial != null && cur_serial == param.serial)
                    load_fastboot_vars();
                if (param.show_dialog_on_done)
                    ThemedDialog.Done(param.done_message ?? Properties.Resources.operation_completed);
            }));
        }

        /// <summary>
        /// Checks the target slot's boot state and, in fastbootd, its logical partitions, then
        /// asks (or refuses) accordingly. True when the switch may go ahead.
        /// </summary>
        static bool slotSwitchAllowed(string target)
        {
            SlotSwitchCheck check = SlotSwitchCheck.Evaluate(fastbootData, target);
            appendLog("slot " + target + " check: " + check.Level
                + (check.Findings.Count > 0 ? " (" + string.Join(", ", check.Findings.Select(f => f.Reason)) + ")" : ""));

            List<string> lines = new List<string>();
            foreach (SlotCheckFinding finding in check.Findings.Where(f => f.Level != SlotCheckLevel.Ok))
            {
                switch (finding.Reason)
                {
                    case SlotCheckReason.NeverBooted:
                        lines.Add(string.Format(Properties.Resources.slot_reason_never_booted, target));
                        break;
                    case SlotCheckReason.Unbootable:
                        lines.Add(string.Format(Properties.Resources.slot_reason_unbootable, target));
                        break;
                    case SlotCheckReason.NoRetriesLeft:
                        lines.Add(string.Format(Properties.Resources.slot_reason_no_retries, target));
                        break;
                    case SlotCheckReason.EmptyPartitions:
                        lines.Add(string.Format(Properties.Resources.slot_reason_empty, target, string.Join(", ", finding.Partitions)));
                        break;
                }
            }
            string details = string.Join("\n\n", lines.Select(l => "•  " + l));

            switch (check.Level)
            {
                case SlotCheckLevel.Block:
                    ThemedDialog.Show(string.Format(Properties.Resources.slot_switch_blocked, target) + "\n\n" + details,
                        Properties.Resources.slot_switch_title, MessageBoxButton.OK, MessageBoxImage.Error);
                    return false;
                case SlotCheckLevel.Danger:
                    return Helper.confirm(string.Format(Properties.Resources.slot_switch_danger, target) + "\n\n" + details
                        + "\n\n" + deviceLine(), Properties.Resources.slot_switch_title, true);
                case SlotCheckLevel.Warn:
                    return Helper.confirm(string.Format(Properties.Resources.slot_switch_warn, target) + "\n\n" + details
                        + "\n\n" + deviceLine(), Properties.Resources.slot_switch_title);
                default:
                    return true;
            }
        }

        /// <summary>
        /// "fastboot boot": starts an image once from memory. Only an image with a kernel can
        /// start, and only the bootloader (not fastbootd) can do it.
        /// </summary>
        static void bootOnce(string path)
        {
            BootImageHeader header;
            try
            {
                header = BootImageHeader.Read(path);
            }
            catch (Exception e)
            {
                ThemedDialog.Show(e.Message, Properties.Resources.error, MessageBoxButton.OK, MessageBoxImage.Error);
                return;
            }

            string refusal = header.Kind == BootImageKind.NoKernel ? Properties.Resources.boot_once_no_kernel
                : header.Kind == BootImageKind.VendorBoot ? Properties.Resources.boot_once_vendor_boot
                : header.Kind == BootImageKind.NotBootImage ? Properties.Resources.boot_once_not_boot
                : null;
            if (refusal != null)
            {
                appendLog("boot once refused for " + path + ": " + header.Kind);
                ThemedDialog.Show(refusal, Properties.Resources.fastboot_boot_once_title, MessageBoxButton.OK, MessageBoxImage.Warning);
                return;
            }

            if (fastbootData.fastbootd)
            {
                if (Helper.confirm(Properties.Resources.boot_once_fastbootd + "\n\n" + deviceLine(), Properties.Resources.fastboot_boot_once_title))
                    runStep(new StepCmdRunnerParam("reboot bootloader", 2, false));
                return;
            }

            runStep(new StepCmdRunnerParam("boot \"" + path + "\"", 0, true, true)
            {
                done_message = Properties.Resources.boot_once_started,
                leave_after = true,
            });
        }

        /// <summary>
        /// Before a boot, init_boot, recovery or vendor_boot partition is written: reads the
        /// image (kernel version and KMI, patch level, root) and checks it fits the partition and
        /// the phone, as it reported itself over adb. Calls flash when nothing is wrong, or
        /// when the user goes ahead anyway.
        /// </summary>
        static void checkBootImage(string target, string path, Action flash)
        {
            if (!BootFlashCheck.Applies(target))
            {
                flash();
                return;
            }

            BootImageAnalysis image = null;
            Exception failure = null;
            // Locked, and the phone remembered: while the image is read nothing else may run,
            // and if the phone was removed or swapped meanwhile the flash does not start.
            string serial = cur_serial;
            action_lock();
            Helper.offloadAndRun(delegate
            {
                try
                {
                    image = BootImageAnalysis.Analyze(path);
                }
                catch (Exception e)
                {
                    failure = e;
                }
            }, delegate
            {
                action_unlock();
                if (serial == null || serial != cur_serial || fastbootData == null)
                {
                    appendLog("boot image check: the phone changed while " + path + " was being read; nothing flashed");
                    ThemedDialog.Show(Properties.Resources.fastboot_device_not_exist);
                    return;
                }
                if (failure != null)
                {
                    appendLog("boot image check: cannot read " + path + ": " + failure.Message);
                    ThemedDialog.Show(string.Format(Properties.Resources.boot_check_failed, failure.Message),
                        Properties.Resources.error, MessageBoxButton.OK, MessageBoxImage.Error);
                    return;
                }

                DeviceFacts phone = DeviceFacts.Recall(Settings.Get(DeviceFactsKey), cur_serial);
                bool hasInitBoot = fastbootData.partition_size.Keys.Any(k => BootFlashCheck.BaseName(k) == "init_boot");
                List<Finding> findings = BootFlashCheck.Check(image, target, phone, hasInitBoot);
                foreach (Finding f in findings)
                    appendLog("boot image check (" + target + "): " + f.Level + " " + f.Code + " " + string.Join(" / ", f.Values));

                FindingLevel worst = BootFlashCheck.Worst(findings);
                if (worst == FindingLevel.Info)
                {
                    flash();
                    return;
                }

                List<string> paragraphs = new List<string>();
                foreach (Finding f in findings.Where(f => f.Level != FindingLevel.Info))
                    paragraphs.Add("• " + describe(f));
                List<string> facts = findings.Where(f => f.Level == FindingLevel.Info).Select(describe).ToList();
                if (facts.Count > 0)
                    paragraphs.Add(string.Join("\n", facts));
                paragraphs.Add(phone != null
                    ? string.Format(Properties.Resources.boot_check_phone_known, phone.Model ?? phone.Serial,
                        phone.Seen.ToLocalTime().ToString("yyyy-MM-dd"))
                    : Properties.Resources.boot_check_phone_unknown);
                // Only notices (a rooted image, a recovery): nothing looks wrong, so it is a plain question.
                paragraphs.Add(string.Format(worst == FindingLevel.Notice
                    ? Properties.Resources.boot_check_question_notice : Properties.Resources.boot_check_question, target));
                string text = string.Join("\n\n", paragraphs);
                string title = string.Format(Properties.Resources.boot_check_title, target);

                bool go = worst == FindingLevel.Block
                    ? ThemedDialog.ConfirmTyped(text, title, target)
                    : Helper.confirm(text, title, worst != FindingLevel.Notice);
                if (go)
                    flash();
                else
                    appendLog("flash of " + target + " stopped after the boot image check");
            });
        }

        /// <summary>Where the phones' kernel and patch level, as seen over adb, are kept.</summary>
        public const string DeviceFactsKey = "device_facts";

        static string describe(Finding f)
        {
            IReadOnlyList<string> v = f.Values;
            switch (f.Code)
            {
                case FindingCode.NotBootImage:
                    return string.Format(Properties.Resources.boot_find_not_boot, v[0]);
                case FindingCode.NoKernelForBoot:
                    return string.Format(Properties.Resources.boot_find_no_kernel, v[0])
                        + (v[1].Length > 0 ? " " + string.Format(Properties.Resources.boot_find_no_kernel_hint, v[1]) : "");
                case FindingCode.KernelInInitBoot:
                    return string.Format(Properties.Resources.boot_find_kernel_in_init_boot, v[0]);
                case FindingCode.VendorBootMismatch:
                    return string.Format(Properties.Resources.boot_find_vendor_mismatch, v[0]);
                case FindingCode.KmiMismatch:
                    return string.Format(Properties.Resources.boot_find_kmi, Helper.ltr(v[0]), Helper.ltr(v[1]));
                case FindingCode.KernelVersionMismatch:
                    return string.Format(Properties.Resources.boot_find_kernel_version, v[0], v[1]);
                case FindingCode.OlderPatchLevel:
                    return string.Format(Properties.Resources.boot_find_older_patch, Helper.ltr(v[0]), Helper.ltr(v[1]));
                case FindingCode.KernelSummary:
                    return string.Format(Properties.Resources.boot_find_kernel, Helper.ltr(v[0] + (v[1].Length > 0 ? "  ·  KMI " + v[1] : "")));
                case FindingCode.RootSummary:
                    return string.Format(f.Level == FindingLevel.Notice ? Properties.Resources.boot_find_rooted
                        : Properties.Resources.boot_find_root, v[0]);
                case FindingCode.RecoveryTryFirst:
                    return string.Format(Properties.Resources.boot_find_recovery_try, v[0]);
                case FindingCode.Stock:
                    return Properties.Resources.boot_find_stock;
                case FindingCode.RootManagerChange:
                    return string.Format(Properties.Resources.boot_find_root_change, v[0], v[1]);
                default:
                    return f.Code.ToString();
            }
        }

        static bool singlePartitionCheck()
        {
            if (MainWindow.THIS.fastboot_partition_list.SelectedItems.Count == 0)
            {
                ThemedDialog.Show(Properties.Resources.fastboot_target_partition_not_selected);
                return true;
            }

            if (MainWindow.THIS.fastboot_partition_list.SelectedItems.Count > 1)
            {
                ThemedDialog.Show(Properties.Resources.fastboot_not_support_multiselect);
                return true;
            }

            return false;
        }

        static bool logicalCheck()
        {
            bool? ret = null;
            fastbootData.partition_is_logical.TryGetValue(
                ((fastboot_partition_row)
                MainWindow.THIS.fastboot_partition_list.SelectedItem).name, out ret);
            if (ret == null || ret == false)
            {
                ThemedDialog.Show(Properties.Resources.fastboot_only_logical);
                return true;
            }

            return false;
        }

        /// <summary>True when the user said no to one of the pending-update questions.</summary>
        static bool vabStagingCheck()
        {
            foreach (KeyValuePair<string, string> problem in vabStagingProblems())
            {
                if (!Helper.confirm(problem.Value + "\n\n" + deviceLine(), problem.Key, true))
                    return true;
            }
            return false;
        }

        /// <summary>
        /// A Virtual A/B update still pending on the phone, and COW partitions left in super:
        /// each as (title, text), empty when neither applies.
        /// </summary>
        static List<KeyValuePair<string, string>> vabStagingProblems()
        {
            List<KeyValuePair<string, string>> problems = new List<KeyValuePair<string, string>>();
            if (fastbootData.HasPendingUpdate)
                problems.Add(new KeyValuePair<string, string>(Properties.Resources.fastboot_vab_staging_str0,
                    Properties.Resources.fastboot_vab_staging_str1 + "\n" +
                    Properties.Resources.fastboot_vab_staging_str2 + "\n" +
                    Properties.Resources.fastboot_vab_staging_str3));
            if (fastbootData.HasCowPartitions)
                problems.Add(new KeyValuePair<string, string>(Properties.Resources.fastboot_cow_exist_str0,
                    Properties.Resources.fastboot_cow_exist_str1 + "\n" +
                    Properties.Resources.fastboot_cow_exist_str2 + "\n" +
                    Properties.Resources.fastboot_cow_exist_str3));
            return problems;
        }

        /// <summary>
        /// Opens a payload, makes sure the device can take it, then hands over to the flasher.
        /// </summary>
        static void openPayloadThenFlash(string path, string serial)
        {
            PayloadFile opened = null;
            Exception failure = null;

            action_lock();
            MainWindow.THIS.fastboot_progress_bar.IsIndeterminate = true;

            Helper.offloadAndRun(
                new Action(delegate
                {
                    try
                    {
                        opened = PayloadFile.Open(path, PAYLOAD_TMP);
                    }
                    catch (Exception e)
                    {
                        failure = e;
                    }
                }),
                new Action(delegate
                {
                    MainWindow.THIS.fastboot_progress_bar.IsIndeterminate = false;

                    if (failure != null)
                    {
                        action_unlock();
                        ThemedDialog.Show(Properties.Resources.payload_unsupported_format
                            + "\n" + failure.Message);
                        return;
                    }

                    MissingPartitions missing = findMissingPartitions(opened);
                    if (missing.Unknown.Count > 0)
                    {
                        opened.Dispose();
                        action_unlock();
                        string hint = fastbootData.fastbootd
                            ? "\n" + Properties.Resources.fastboot_unknown_partition_str1
                            : "\n" + Properties.Resources.fastboot_unknown_partition_str2;
                        ThemedDialog.Show(Properties.Resources.fastboot_unknown_partition_str0
                            + "\n" + string.Join(" ", missing.Unknown) + hint);
                        return;
                    }

                    // Everything worth knowing is gathered here and asked once, at the end.
                    List<ThemedDialog.SummaryItem> points = new List<ThemedDialog.SummaryItem>();
                    foreach (KeyValuePair<string, string> problem in vabStagingProblems())
                        points.Add(new ThemedDialog.SummaryItem { Text = problem.Key + "\n" + problem.Value, Destructive = true });

                    // Logical partitions the update adds (or the phone lost) are created first.
                    if (missing.Create.Count > 0)
                    {
                        appendLog("missing logical partitions: " + string.Join(", ", missing.Create));
                        points.Add(new ThemedDialog.SummaryItem
                        {
                            Text = string.Format(Properties.Resources.create_missing, string.Join(", ", missing.Create)),
                        });
                    }

                    List<string> odd = opened.Partitions.Select(part => part.Name)
                        .Where(name => !AdbCommand.IsSafePartitionName(name)).ToList();
                    if (odd.Count > 0)
                    {
                        appendLog("payload refused: partition names that cannot go on a command line: " + string.Join(", ", odd));
                        ThemedDialog.Show(string.Format(Properties.Resources.payload_bad_names, string.Join(", ", odd)),
                            Properties.Resources.error, MessageBoxButton.OK, MessageBoxImage.Error);
                        opened.Dispose();
                        action_unlock();
                        return;
                    }

                    List<string> blocked = opened.Partitions
                        .Where(part => !part.CanExtract)
                        .Select(part => part.Name)
                        .ToList();

                    if (blocked.Count > 0)
                    {
                        opened.Dispose();
                        action_unlock();
                        ThemedDialog.Show(Properties.Resources.payload_incremental_warning
                            + "\n\n" + string.Join(", ", blocked));
                        return;
                    }

                    List<string> unverifiable = opened.Partitions
                        .Where(part => string.IsNullOrEmpty(part.ExpectedSha256))
                        .Select(part => part.Name)
                        .ToList();

                    if (unverifiable.Count > 0)
                        points.Add(new ThemedDialog.SummaryItem
                        {
                            Text = string.Format(Properties.Resources.flash_unverified, string.Join(", ", unverifiable)),
                            Destructive = true,
                        });

                    // The device must still be the one the user picked when they clicked flash.
                    if (serial == null || serial != cur_serial || fastbootData == null)
                    {
                        opened.Dispose();
                        action_unlock();
                        ThemedDialog.Show(Properties.Resources.flash_no_device);
                        return;
                    }

                    // In fastbootd each logical partition is resized to its image as it is
                    // written; make sure super can take them, in the order they are written.
                    Dictionary<string, string> createdAs = new Dictionary<string, string>(StringComparer.Ordinal);
                    for (int i = 0; i < missing.Create.Count; i++)
                        createdAs[missing.CreateFrom[i]] = missing.Create[i];
                    List<KeyValuePair<string, long>> writes = opened.Partitions
                        .Select(part => new KeyValuePair<string, long>(
                            createdAs.ContainsKey(part.Name) ? createdAs[part.Name] : part.Name, part.UnpackedSize))
                        .ToList();
                    string superProblem = superSpaceProblem(writes, missing.Create);
                    if (superProblem != null)
                        points.Add(new ThemedDialog.SummaryItem { Text = superProblem, Destructive = true });

                    // "Flash both slots": physical A/B partitions also go to the other slot.
                    IReadOnlyDictionary<string, string> otherSlot = new Dictionary<string, string>();
                    if (MainWindow.THIS.flash_both_slots.IsChecked == true)
                    {
                        otherSlot = BothSlots.OtherSlotTargets(fastbootData, opened.Partitions.Select(part => part.Name),
                            new HashSet<string>(opened.LogicalPartitionNames(), StringComparer.Ordinal));
                        if (otherSlot.Count == 0)
                            appendLog("flash both slots: nothing to write to another slot on this phone");
                        else
                            points.Add(new ThemedDialog.SummaryItem
                            {
                                Text = string.Format(Properties.Resources.flash_both_slots_confirm,
                                    BothSlots.Other(fastbootData.current_slot.TrimStart('_')), string.Join(", ", otherSlot.Keys)),
                            });
                    }

                    long total = opened.Partitions.Sum(part => part.UnpackedSize);
                    string summary = string.Format(Properties.Resources.flash_summary, Path.GetFileName(path),
                        opened.Partitions.Count, Helper.byte2AUnit(total));
                    if (!ThemedDialog.Summary(Properties.Resources.flash_summary_title, summary, deviceLine(), points,
                            Properties.Resources.flash_summary_go))
                    {
                        appendLog("flash not confirmed");
                        opened.Dispose();
                        action_unlock();
                        return;
                    }

                    // The phone may have gone while the summary was open.
                    if (serial != cur_serial || fastbootData == null)
                    {
                        opened.Dispose();
                        action_unlock();
                        ThemedDialog.Show(Properties.Resources.flash_no_device);
                        return;
                    }

                    flashPayload(opened, serial, missing.Create, otherSlot);
                }));
        }

        /// <summary>
        /// The partitions of the payload the phone does not have, split into those that can
        /// be created in super and those that cannot. Nothing when the user chose to ignore them.
        /// </summary>
        static MissingPartitions findMissingPartitions(PayloadFile payload)
        {
            if (MainWindow.THIS.ignore_unknown_part.IsChecked == true)
                return MissingPartitions.Find(fastbootData, new string[0], new string[0]);

            return MissingPartitions.Find(fastbootData, payload.Partitions.Select(part => part.Name),
                payload.LogicalPartitionNames());
        }

        /// <summary>
        /// "create-logical-partition NAME 0" for each partition; fastbootd then sizes each one to
        /// the image written to it. Returns the error, or null when all were created.
        /// </summary>
        static string createLogicalPartitions(string serial, IReadOnlyList<string> names, CancellationToken cancel)
        {
            foreach (string name in names)
            {
                cancel.ThrowIfCancellationRequested();
                appendLog("Creating logical partition " + name);
                int? exitCode;
                using (Fastboot fastboot = new Fastboot(serial,
                    "create-logical-partition " + AdbCommand.WindowsArgument(name) + " 0", Fastboot.LongCommand))
                {
                    while (true)
                    {
                        string line = fastboot.stderr.ReadLine();
                        if (line == null)
                            break;
                        appendLog(line);
                    }
                    exitCode = fastboot.WaitForExit();
                }
                if (exitCode != 0)
                    return name + ": create-logical-partition " + (exitCode == null
                        ? "did not finish in time"
                        : "exited with code " + exitCode);
            }
            return null;
        }

        /// <summary>
        /// Extracts the whole payload first, in parallel, and only then writes it to the device.
        /// Nothing reaches the device until every image is present and its hash checks out, so a
        /// payload that turns out to be damaged cannot leave the phone half written. Each image
        /// is deleted as soon as it is flashed to keep the staging directory small.
        /// </summary>
        static void flashPayload(PayloadFile payload, string serial, IReadOnlyList<string> create,
            IReadOnlyDictionary<string, string> otherSlot)
        {
            if (serial == null)
                throw new ArgumentNullException(nameof(serial));

            string staging = Path.Combine(PAYLOAD_TMP, "stage-" + Guid.NewGuid().ToString("N"));

            List<PayloadPartitionInfo> parts = payload.Partitions.ToList();
            long totalBytes = Math.Max(1, parts.Sum(part => part.UnpackedSize));

            ExtractionOptions options = new ExtractionOptions
            {
                VerifyOperationHashes = true,
                VerifyImageHash = true,
                IgnoreUnsupportedOperations = false,
                MaxDegreeOfParallelism = Math.Max(1, Environment.ProcessorCount)
            };

            // The Flash page's queue: one row per partition, updated as work moves along.
            System.Collections.ObjectModel.ObservableCollection<FlashRow> rows =
                new System.Collections.ObjectModel.ObservableCollection<FlashRow>();
            Dictionary<string, FlashRow> rowByName = new Dictionary<string, FlashRow>(StringComparer.Ordinal);
            foreach (PayloadPartitionInfo part in parts)
            {
                FlashRow row = new FlashRow(part.Name, Helper.byte2AUnit(part.UnpackedSize));
                rows.Add(row);
                rowByName[part.Name] = row;
            }

            MainWindow.THIS.flash_queue.ItemsSource = rows;
            MainWindow.THIS.flash_file_name.Text = Path.GetFileName(payload.Source.ContainerPath);
            MainWindow.THIS.flash_file_detail.Text = string.Format(Properties.Resources.flash_file_detail,
                parts.Count, Helper.byte2AUnit(totalBytes), payload.Source.FromZip ? "OTA zip" : "payload.bin");
            MainWindow.THIS.flash_count.Text = "0 / " + parts.Count;
            MainWindow.THIS.flash_overall_progress.Value = 0;
            MainWindow.THIS.flash_log.Clear();
            MainWindow.forgetLength(MainWindow.THIS.flash_log);
            MainWindow.THIS.flash_result.Visibility = Visibility.Collapsed;
            string logFile = LogStore.BeginFile(serial);
            appendLog("flash of " + Path.GetFileName(payload.Source.ContainerPath) + " to " + serial
                + (fastbootData != null && !string.IsNullOrEmpty(fastbootData.product) ? " (" + fastbootData.product + ")" : "")
                + (logFile != null ? "; log file " + logFile : ""));
            setPhase(Properties.Resources.flash_phase_extract, "Accent");
            MainWindow.THIS.main_tabs.SelectedItem = MainWindow.THIS.flash_tab;

            System.Diagnostics.Stopwatch clock = System.Diagnostics.Stopwatch.StartNew();
            System.Windows.Threading.DispatcherTimer ticker = new System.Windows.Threading.DispatcherTimer
            {
                Interval = TimeSpan.FromSeconds(1)
            };
            ticker.Tick += delegate { MainWindow.THIS.flash_elapsed.Text = clock.Elapsed.ToString(@"mm\:ss"); };
            ticker.Start();

            // Extraction counts for the first half of the bar, flashing for the second. The bar
            // only moves forward: the extraction phase finishes before the flashing phase reports.
            int lastPercent = -1;

            Action<int> showPercent = new Action<int>(delegate (int percent)
            {
                if (percent <= lastPercent)
                    return;
                lastPercent = percent;

                MainWindow.THIS.Dispatcher.BeginInvoke(new Action(delegate
                {
                    MainWindow.THIS.fastboot_progress_bar.Value = percent;
                    MainWindow.THIS.flash_overall_progress.Value = percent;
                    Helper.TaskbarItemHelper.update(percent);
                }));
            });

            ProgressAggregator progress = new ProgressAggregator(totalBytes,
                delegate (int percent) { showPercent(percent / 2); },
                delegate (string partition, int percent)
                {
                    FlashRow row;
                    if (!rowByName.TryGetValue(partition, out row))
                        return;
                    MainWindow.THIS.Dispatcher.BeginInvoke(new Action(delegate
                    {
                        row.Current = FlashRow.Stage.Extracting;
                        row.Progress = percent / 2.0;
                    }));
                });

            Action<string, FlashRow.Stage, double?> updateRow = new Action<string, FlashRow.Stage, double?>(
                delegate (string name, FlashRow.Stage stage, double? value)
                {
                    FlashRow row;
                    if (!rowByName.TryGetValue(name, out row))
                        return;
                    MainWindow.THIS.Dispatcher.BeginInvoke(new Action(delegate
                    {
                        row.Current = stage;
                        if (value != null)
                            row.Progress = value.Value;
                    }));
                });

            // Logical partitions exist only in fastbootd; any other partition fastbootd refuses
            // is written from the bootloader after the rest.
            bool inFastbootd = fastbootData != null && fastbootData.fastbootd;
            HashSet<string> logical = new HashSet<string>(payload.LogicalPartitionNames(), StringComparer.Ordinal);

            // The lock taken by openPayloadThenFlash carries over and is released when this ends.
            flashing = true;
            MainWindow.THIS.bar_cancel.Visibility = Visibility.Visible;

            CancellationTokenSource cancel = new CancellationTokenSource();
            flashCancel = cancel;

            Thread worker = new Thread(new ThreadStart(delegate
            {
                string error = null;
                int flashed = 0;
                // The partitions written from the bootloader after fastbootd refused them, for the summary.
                string fromBootloader = null;

                try
                {
                    Directory.CreateDirectory(staging);

                    appendLog("Extracting " + parts.Count + " partitions with "
                        + options.MaxDegreeOfParallelism + " workers");

                    ExtractionReport report = PayloadExtractor.ExtractAll(
                        payload, staging, parts.Select(part => part.Name), options, progress,
                        cancel.Token);

                    foreach (PartitionResult result in report.Results)
                    {
                        if (result.Succeeded)
                            updateRow(result.Partition, FlashRow.Stage.Verified, 50.0);
                        else
                            updateRow(result.Partition, FlashRow.Stage.Failed, null);
                    }

                    if (!report.AllSucceeded)
                    {
                        error = string.Join("\n", report.Results
                            .Where(result => !result.Succeeded)
                            .Select(result => result.Partition + ": " + result.Error));
                        foreach (PartitionResult result in report.Results.Where(r => r.Succeeded))
                            updateRow(result.Partition, FlashRow.Stage.NotWritten, null);
                    }
                    else
                    {
                        appendLog("Extracted " + Helper.byte2AUnit(report.TotalBytes)
                            + " in " + report.Elapsed.TotalSeconds.ToString("F1") + " s");

                        MainWindow.THIS.Dispatcher.BeginInvoke(new Action(delegate
                        {
                            setPhase(Properties.Resources.flash_phase_flash, "Accent");
                        }));

                        long flashedBytes = 0;
                        List<PartitionResult> results = report.Results.ToList();

                        // Only now, with every image extracted and verified, is super touched.
                        error = createLogicalPartitions(serial, create, cancel.Token);
                        if (error != null)
                        {
                            appendLog(error);
                            foreach (PartitionResult result in results)
                                updateRow(result.Partition, FlashRow.Stage.NotWritten, null);
                        }

                        // Where each image goes: the slot in use, then the other slot with "flash both slots".
                        Dictionary<string, Queue<string>> targets = new Dictionary<string, Queue<string>>(StringComparer.Ordinal);
                        foreach (PartitionResult result in results)
                        {
                            Queue<string> queue = new Queue<string>();
                            queue.Enqueue(result.Partition);
                            string other;
                            if (otherSlot.TryGetValue(result.Partition, out other))
                                queue.Enqueue(other);
                            targets[result.Partition] = queue;
                        }

                        // Writes one image to each of its targets: the exit code (null when stopped) and
                        // what fastboot said. A target that fails stays first in the queue, so a write
                        // deferred to the bootloader picks up where it stopped.
                        (int? code, string said) flashOne(PartitionResult result)
                        {
                            updateRow(result.Partition, FlashRow.Stage.Flashing, 75.0);
                            Queue<string> queue = targets[result.Partition];
                            System.Text.StringBuilder output = new System.Text.StringBuilder();

                            while (queue.Count > 0)
                            {
                                string target = queue.Peek();
                                appendLog("Flashing " + target);

                                int? exitCode;
                                output.Clear();
                                cancel.Token.ThrowIfCancellationRequested();
                                using (Fastboot fastboot = new Fastboot(serial,
                                    "flash " + AdbCommand.WindowsArgument(target) + " " + AdbCommand.WindowsArgument(result.OutputPath), Fastboot.NoLimit))
                                {
                                    activeFlash = fastboot;
                                    // abortFlash may have looked for a process just before this one started.
                                    if (cancel.IsCancellationRequested)
                                        fastboot.Abort();
                                    while (true)
                                    {
                                        string line = fastboot.stderr.ReadLine();
                                        if (line == null)
                                            break;
                                        appendLog(line);
                                        output.AppendLine(line);
                                    }

                                    exitCode = fastboot.WaitForExit();
                                    activeFlash = null;
                                }
                                if (exitCode != 0)
                                    return (exitCode, output.ToString());
                                queue.Dequeue();
                            }

                            flashed++;
                            flashedBytes += result.Size;
                            updateRow(result.Partition, FlashRow.Stage.Flashed, 100.0);
                            showPercent(50 + (int)(flashedBytes * 50 / totalBytes));

                            int written = flashed;
                            MainWindow.THIS.Dispatcher.BeginInvoke(new Action(delegate
                            {
                                MainWindow.THIS.flash_count.Text = written + " / " + parts.Count;
                            }));

                            try
                            {
                                File.Delete(result.OutputPath);
                            }
                            catch (Exception e) when (e is IOException || e is UnauthorizedAccessException)
                            {
                                appendLog("could not delete " + result.OutputPath + ": " + e.Message);
                            }
                            return (0, output.ToString());
                        }

                        string failure(PartitionResult result, int? code) => targets[result.Partition].Peek() + ": fastboot " + (code == null
                            ? "was stopped before it finished"
                            : "exited with code " + code);

                        // Partitions fastbootd refuses (a OnePlus 11's modem) wait for the bootloader.
                        List<PartitionResult> later = new List<PartitionResult>();

                        for (int i = 0; error == null && i < results.Count; i++)
                        {
                            PartitionResult result = results[i];
                            (int? code, string said) = flashOne(result);
                            if (code == 0)
                                continue;

                            if (code != null && FastbootdRefusal.CanDefer(inFastbootd, logical.Contains(result.Partition), said))
                            {
                                later.Add(result);
                                updateRow(result.Partition, FlashRow.Stage.Later, 75.0);
                                appendLog(result.Partition + ": fastbootd refuses it; it is written from the bootloader after the rest");
                                continue;
                            }

                            // Without this the dialog reported success even when every write failed.
                            error = failure(result, code);
                            appendLog(error);
                            updateRow(result.Partition, FlashRow.Stage.Failed, null);
                            for (int rest = i + 1; rest < results.Count; rest++)
                                updateRow(results[rest].Partition, FlashRow.Stage.NotWritten, null);
                            foreach (PartitionResult waiting in later)
                                updateRow(waiting.Partition, FlashRow.Stage.NotWritten, null);
                            break;
                        }

                        if (error == null && later.Count > 0)
                        {
                            string names = string.Join(", ", later.Select(r => r.Partition));
                            MainWindow.THIS.Dispatcher.BeginInvoke(new Action(delegate
                            {
                                setPhase(Properties.Resources.flash_phase_bootloader, "Warn");
                            }));
                            appendLog("Restarting to the bootloader for " + names);
                            string said;
                            int? code = Fastboot.Run(serial, "reboot bootloader", Fastboot.ShortCommand, out said);
                            foreach (string line in said.Split('\n').Where(l => l.Trim().Length > 0))
                                appendLog(line.TrimEnd());

                            if (code != 0 || !waitForBootloader(serial, TimeSpan.FromMinutes(2), cancel.Token))
                            {
                                error = string.Format(Properties.Resources.flash_bootloader_timeout, names);
                                appendLog(error);
                                foreach (PartitionResult waiting in later)
                                    updateRow(waiting.Partition, FlashRow.Stage.NotWritten, null);
                            }
                            else
                            {
                                appendLog("In the bootloader: writing " + names);
                                for (int i = 0; i < later.Count; i++)
                                {
                                    (int? lateCode, string lateSaid) = flashOne(later[i]);
                                    if (lateCode == 0)
                                        continue;
                                    error = failure(later[i], lateCode);
                                    appendLog(error);
                                    updateRow(later[i].Partition, FlashRow.Stage.Failed, null);
                                    for (int rest = i + 1; rest < later.Count; rest++)
                                        updateRow(later[rest].Partition, FlashRow.Stage.NotWritten, null);
                                    break;
                                }
                                if (error == null)
                                    fromBootloader = names;
                            }
                        }
                    }
                }
                catch (Exception e)
                {
                    error = e.Message;
                    appendLog("flash failed: " + e.Message);
                }
                finally
                {
                    payload.Dispose();
                    try
                    {
                        if (Directory.Exists(staging))
                            Directory.Delete(staging, true);
                    }
                    catch (IOException)
                    {
                    }
                    catch (UnauthorizedAccessException)
                    {
                    }
                }

                string summary = error;
                int flashedCount = flashed;
                string lateNames = fromBootloader;

                MainWindow.THIS.Dispatcher.BeginInvoke(new Action(delegate
                {
                    flashing = false;
                    flashWorker = null;
                    flashCancel = null;
                    ticker.Stop();
                    clock.Stop();
                    MainWindow.THIS.flash_elapsed.Text = clock.Elapsed.ToString(@"mm\:ss");
                    MainWindow.THIS.bar_cancel.Visibility = Visibility.Collapsed;
                    setLastCommand("flash (" + parts.Count + " partitions)", clock.Elapsed);
                    action_unlock();
                    appendLog(summary == null ? "flash finished: " + flashedCount + " of " + parts.Count + " written in "
                        + clock.Elapsed.ToString(@"mm\:ss") : "flash failed after " + flashedCount + " of " + parts.Count);
                    LogStore.EndFile();
                    if (cur_serial == serial)
                        load_fastboot_vars();

                    if (summary == null)
                    {
                        setPhase(Properties.Resources.flash_phase_done, "Ok");
                        MainWindow.THIS.flash_overall_progress.Value = 100;
                        // The result stays on the page, over the log, instead of a box that hides it.
                        List<string> detail = new List<string>();
                        detail.Add(clock.Elapsed.ToString(@"mm\:ss"));
                        if (otherSlot.Count > 0)
                            detail.Add(string.Format(Properties.Resources.flash_both_slots_done, string.Join(", ", otherSlot.Values)));
                        if (lateNames != null)
                            detail.Add(string.Format(Properties.Resources.flash_deferred_done, lateNames));
                        MainWindow.THIS.flash_result_title.Text = string.Format(Properties.Resources.flash_result_title, flashedCount, parts.Count);
                        MainWindow.THIS.flash_result_detail.Text = string.Join(" · ", detail);
                        MainWindow.THIS.flash_result_reboot.IsEnabled = cur_serial == serial;
                        MainWindow.THIS.flash_result.Visibility = Visibility.Visible;
                        return;
                    }

                    setPhase(Properties.Resources.flash_phase_failed, "Danger");
                    Helper.TaskbarItemHelper.error();
                    ThemedDialog.Show(Properties.Resources.payload_error_occur
                        + "\n\n" + summary
                        + "\n\n" + string.Format(Properties.Resources.flash_written_count, flashedCount, parts.Count));
                }));
            }));

            worker.IsBackground = true;
            flashWorker = worker;
            worker.Start();
        }

        /// <summary>
        /// After "reboot bootloader": true once the phone with this serial is back and is not in
        /// fastbootd (is-userspace is not "yes"; a bootloader may not know the variable at all).
        /// </summary>
        static bool waitForBootloader(string serial, TimeSpan limit, CancellationToken cancel)
        {
            DateTime end = DateTime.UtcNow + limit;
            Thread.Sleep(3000);
            while (DateTime.UtcNow < end)
            {
                cancel.ThrowIfCancellationRequested();
                if (Fastboot.ListSerials().Contains(serial))
                {
                    string said;
                    Fastboot.Run(serial, "getvar is-userspace", Fastboot.ShortCommand, out said);
                    if (!System.Text.RegularExpressions.Regex.IsMatch(said ?? "", @"is-userspace:\s*yes"))
                        return true;
                }
                Thread.Sleep(2000);
            }
            return false;
        }

        static volatile Fastboot activeFlash;
        static volatile CancellationTokenSource flashCancel;
        static volatile Thread flashWorker;

        /// <summary>
        /// Called when the window closes mid-flash, after the user agreed to stop. Stops the
        /// extraction and the fastboot process writing the current image, then waits for the
        /// worker to remove its staging images, so neither a stray fastboot.exe nor gigabytes
        /// of images outlive the app.
        /// </summary>
        public static void abortFlash()
        {
            CancellationTokenSource cancel = flashCancel;
            if (cancel != null)
                cancel.Cancel();

            Fastboot running = activeFlash;
            if (running != null)
                running.Abort();

            Thread worker = flashWorker;
            if (worker != null)
                worker.Join(TimeSpan.FromSeconds(10));
        }

        static void setPhase(string text, string brushKey)
        {
            MainWindow.THIS.flash_phase.Text = text;
            MainWindow.THIS.flash_phase.Foreground = Palette.Get(brushKey);
        }

        static void openSelectedDevice()
        {
            if (MainWindow.THIS.fastboot_devices_list.SelectedItems.Count != 1)
                return;

            fastboot_devices_row cur = (fastboot_devices_row)MainWindow.THIS.fastboot_devices_list.SelectedItem;
            cur_serial = cur.serial;
            if (!checkCurDevExist())
                return;
            cur_status = FastbootStatus.show_actions;
            MainWindow.THIS.fastboot_cur_device.Content = cur.serial;
            appendLog("Opened device " + cur.serial + " (" + cur.name + ")");
            change_page();
        }

        public static void init()
        {
            devices = new List<fastboot_devices_row>();
            cur_status = FastbootStatus.show_devices;
            change_page();

            // Background, so it never keeps the process alive after the window closes.
            Thread refresher = new Thread(new ThreadStart(devicesListRefresher));
            refresher.IsBackground = true;
            refresher.Start();
            setStatus(string.Format(Properties.Resources.rail_devices, 0));

            MainWindow.THIS.fastboot_usb_check.Click += delegate
            {
                checkUsb();
            };

            MainWindow.THIS.fastboot_devices_list.MouseDoubleClick += delegate
            {
                openSelectedDevice();
            };

            // Keyboard users (and UI automation) open a device with Enter.
            MainWindow.THIS.fastboot_devices_list.KeyDown += delegate (object sender, System.Windows.Input.KeyEventArgs e)
            {
                if (e.Key != System.Windows.Input.Key.Enter)
                    return;
                e.Handled = true;
                openSelectedDevice();
            };

            MainWindow.THIS.fastboot_remove.Click += delegate
            {
                leaveDevice();
            };
            MainWindow.THIS.flash_result_log.Click += delegate { MainWindow.THIS.main_tabs.SelectedItem = MainWindow.THIS.logs_tab; };
            MainWindow.THIS.flash_result_reboot.Click += delegate
            {
                MainWindow.THIS.flash_result.Visibility = Visibility.Collapsed;
                if (!checkCurDevExist())
                    return;
                runStep(new StepCmdRunnerParam("reboot", 0, false, true));
                leaveDevice();
            };
            MainWindow.THIS.bar_disconnect.Click += delegate { leaveDevice(); };
            MainWindow.THIS.bar_usb_check.Click += delegate { checkUsb(); };
            MainWindow.THIS.bar_cancel.Click += delegate { cancelCurrent(); };
            MainWindow.THIS.bar_reboot.Click += delegate
            {
                System.Windows.Controls.ContextMenu menu = MainWindow.THIS.bar_reboot.ContextMenu;
                menu.PlacementTarget = MainWindow.THIS.bar_reboot;
                menu.IsOpen = true;
            };
            MainWindow.THIS.bar_reboot_system.Click += delegate
            {
                if (!checkCurDevExist())
                    return;
                runStep(new StepCmdRunnerParam("reboot", 0, false, true));
                leaveDevice();
            };
            MainWindow.THIS.bar_reboot_recovery.Click += delegate
            {
                if (!checkCurDevExist())
                    return;
                runStep(new StepCmdRunnerParam("reboot recovery", 0, false, true));
                leaveDevice();
            };
            MainWindow.THIS.bar_reboot_bootloader.Click += delegate
            {
                if (!checkCurDevExist())
                    return;
                runStep(new StepCmdRunnerParam("reboot bootloader", 2, false));
            };
            MainWindow.THIS.bar_reboot_fastbootd.Click += delegate
            {
                if (!checkCurDevExist())
                    return;
                runStep(new StepCmdRunnerParam("reboot fastboot", 3, false));
            };
            readToolVersions();

            MainWindow.THIS.fastboot_reboot_d.Click += delegate
            {
                if (!checkCurDevExist())
                    return;

                if (fastbootData.fastbootd)
                {
                    runStep(new StepCmdRunnerParam("reboot bootloader", 2, false));
                }
                else
                {
                    runStep(new StepCmdRunnerParam("reboot fastboot", 3, false));
                }
            };

            MainWindow.THIS.fastboot_reboot_system.Click += delegate
            {
                if (!checkCurDevExist())
                    return;

                runStep(new StepCmdRunnerParam("reboot", 0, false, true));

                leaveDevice();
            };

            MainWindow.THIS.fastboot_reboot_recovery.Click += delegate
            {
                if (!checkCurDevExist())
                    return;

                runStep(new StepCmdRunnerParam("reboot recovery", 0, false, true));

                leaveDevice();
            };

            MainWindow.THIS.fastboot_ab_switch.Click += delegate
            {
                if (!checkCurDevExist())
                    return;

                string slot = fastbootData.current_slot?.TrimStart('_');
                string target = slot == "a" ? "b" : slot == "b" ? "a" : null;
                if (target == null)
                {
                    ThemedDialog.Show(Properties.Resources.operation_not_supported);
                    return;
                }
                if (!slotSwitchAllowed(target))
                    return;
                runStep(new StepCmdRunnerParam("set_active " + target, 2, false));
            };

            MainWindow.THIS.fastboot_boot_once.Click += delegate
            {
                if (!checkCurDevExist())
                    return;
                Helper.fileSelect(new Helper.PathSelectCallback(bootOnce), "Boot / recovery images|*.img;*.bin|All files|*.*");
            };

            // Cancel a staged Virtual A/B update.
            MainWindow.THIS.fastboot_cancel_update.Click += delegate
            {
                if (!checkCurDevExist())
                    return;

                runStep(new StepCmdRunnerParam("snapshot-update cancel", 2, true));
            };

            MainWindow.THIS.fastboot_flash.Click += delegate
            {
                if (!checkCurDevExist())
                    return;

                if (singlePartitionCheck())
                    return;

                if (vabStagingCheck())
                    return;

                string target = ((fastboot_partition_row)MainWindow.THIS.fastboot_partition_list.SelectedItem).name;

                if (PartitionSafety.IsBrickRisk(target) && !ThemedDialog.ConfirmTyped(
                        string.Format(Properties.Resources.confirm_critical_flash, target) + "\n\n" + deviceLine(),
                        Properties.Resources.critical_title, target))
                {
                    appendLog("flash of critical partition " + target + " not confirmed");
                    return;
                }

                Helper.fileSelect(new Helper.PathSelectCallback(delegate (string path)
                {
                    // fastbootd resizes a logical partition to its image: check super has room.
                    bool? isLogical;
                    if (fastbootData.partition_is_logical.TryGetValue(target, out isLogical) && isLogical == true)
                    {
                        long imageSize;
                        try
                        {
                            imageSize = SuperSpace.WrittenSize(path);
                        }
                        catch (Exception e)
                        {
                            ThemedDialog.Show(e.Message, Properties.Resources.error, MessageBoxButton.OK, MessageBoxImage.Error);
                            return;
                        }
                        if (!superSpaceAllowed(new[] { new KeyValuePair<string, long>(target, imageSize) }))
                            return;
                    }

                    string ext_arg = "";

                    if (target == "vbmeta" || target == "vbmeta_" + fastbootData.current_slot?.TrimStart('_')
                    || target == "vbmeta_a" || target == "vbmeta_b")
                    {
                        if (Helper.confirm(Properties.Resources.fastboot_vbmeta_disable_verify + "\n\n" + deviceLine(),
                                Properties.Resources.fastboot_vbmeta_disable_verify_title))
                        {
                            ext_arg += "--disable-verity --disable-verification";
                        }
                    }
                    string command = "flash " + ext_arg + " " + AdbCommand.WindowsArgument(target) + " " + AdbCommand.WindowsArgument(path);
                    checkBootImage(target, path, delegate { runStep(new StepCmdRunnerParam(command, -1, true)); });
                }), "Image File|*.img;*.image");
            };

            MainWindow.THIS.fastboot_erase.Click += delegate
            {
                if (!checkCurDevExist())
                    return;

                if (singlePartitionCheck())
                    return;

                string target = ((fastboot_partition_row)MainWindow.THIS.fastboot_partition_list.SelectedItem).name;

                bool confirmed = PartitionSafety.IsBrickRisk(target)
                    ? ThemedDialog.ConfirmTyped(string.Format(Properties.Resources.confirm_critical_erase, target) + "\n\n" + deviceLine(),
                        Properties.Resources.critical_title, target)
                    : Helper.confirm(string.Format(Properties.Resources.confirm_erase, target) + "\n\n" + deviceLine(),
                        Properties.Resources.confirm_title, true);
                if (!confirmed)
                    return;

                runStep(new StepCmdRunnerParam("erase " + AdbCommand.WindowsArgument(target), 2, false));
            };

            MainWindow.THIS.fastboot_partition_list.SelectionChanged += delegate
            {
                MainWindow.THIS.fastboot_flash.IsEnabled = true;
                MainWindow.THIS.fastboot_erase.IsEnabled = true;
                MainWindow.THIS.fastboot_logical_delete.IsEnabled = true;
                MainWindow.THIS.fastboot_logical_resize.IsEnabled = true;

                if (MainWindow.THIS.fastboot_partition_list.SelectedItems.Count > 1)
                {
                    MainWindow.THIS.fastboot_flash.IsEnabled = false;
                    MainWindow.THIS.fastboot_erase.IsEnabled = false;
                    MainWindow.THIS.fastboot_logical_delete.IsEnabled = false;
                    MainWindow.THIS.fastboot_logical_resize.IsEnabled = false;
                    return;
                }

                if (fastbootData == null)
                    return;

                if (!fastbootData.fastbootd)
                {
                    MainWindow.THIS.fastboot_logical_delete.IsEnabled = false;
                    MainWindow.THIS.fastboot_logical_resize.IsEnabled = false;
                    return;
                }

                bool? ret = null;

                if (MainWindow.THIS.fastboot_partition_list.SelectedItem == null)
                {
                    MainWindow.THIS.fastboot_logical_delete.IsEnabled = true;
                    MainWindow.THIS.fastboot_logical_resize.IsEnabled = true;
                    return;
                }
                fastbootData.partition_is_logical.TryGetValue(
                    ((fastboot_partition_row)
                    MainWindow.THIS.fastboot_partition_list.SelectedItem).name, out ret);
                if (ret == null || ret == false)
                {
                    MainWindow.THIS.fastboot_logical_delete.IsEnabled = false;
                    MainWindow.THIS.fastboot_logical_resize.IsEnabled = false;
                }
            };

            MainWindow.THIS.fastboot_logical_delete.Click += delegate
            {
                if (!checkCurDevExist())
                    return;

                if (singlePartitionCheck() || logicalCheck())
                    return;

                string target = ((fastboot_partition_row)MainWindow.THIS.fastboot_partition_list.SelectedItem).name;

                if (!Helper.confirm(string.Format(Properties.Resources.confirm_delete, target) + "\n\n" + deviceLine(),
                        Properties.Resources.confirm_title, true))
                    return;

                runStep(new StepCmdRunnerParam("delete-logical-partition " + AdbCommand.WindowsArgument(target), 2, false));
            };

            MainWindow.THIS.fastboot_logical_create.Click += delegate
            {
                if (!checkCurDevExist())
                    return;

                new FastbootActionWindow(FastbootActionWindow.StartType.CREATE, "", 0,
                    delegate (string name, ulong size)
                   {
                       if (!AdbCommand.IsSafePartitionName(name))
                       {
                           ThemedDialog.Show(Properties.Resources.operation_not_supported);
                           return;
                       }
                       runStep(new StepCmdRunnerParam(
                            "create-logical-partition " + AdbCommand.WindowsArgument(name) + " " + size.ToString(), 2, false));
                   }).ShowDialog();
            };

            MainWindow.THIS.fastboot_logical_resize.Click += delegate
            {
                if (!checkCurDevExist())
                    return;

                if (singlePartitionCheck() || logicalCheck())
                    return;

                string target = ((fastboot_partition_row)MainWindow.THIS.fastboot_partition_list.SelectedItem).name;

                new FastbootActionWindow(FastbootActionWindow.StartType.RESIZE, target,
                    fastbootData.partition_size[target],
                    delegate (string name, ulong size)
                    {
                        runStep(new StepCmdRunnerParam(
                             "resize-logical-partition \"" + name + "\" \"" + size.ToString() + "\"", 2, false));
                    }).ShowDialog();
            };

            MainWindow.THIS.fastboot_flash_payload.Click += delegate
            {
                if (cur_status != FastbootStatus.show_actions || cur_serial == null || fastbootData == null)
                {
                    ThemedDialog.Show(Properties.Resources.flash_no_device);
                    MainWindow.THIS.main_tabs.SelectedItem = MainWindow.THIS.device_tab;
                    return;
                }

                if (!checkCurDevExist())
                    return;

                // The pending-update questions are part of the one summary shown before the flash.
                string serial = cur_serial;
                Helper.fileSelect(new Helper.PathSelectCallback(delegate (string path)
                {
                    openPayloadThenFlash(path, serial);
                }), "Payload or OTA package|*.bin;*.zip|All Files|*.*");
            };

            listHelper = new Helper.ListHelper<fastboot_partition_row>(MainWindow.THIS.fastboot_partition_list,
                new Helper.ListHelper<fastboot_partition_row>.Filter(delegate (fastboot_partition_row row)
                {
                    if (MainWindow.THIS.fastboot_partition_name_textbox.Text == "")
                        return true;

                    if (row.name.Contains(MainWindow.THIS.fastboot_partition_name_textbox.Text))
                        return true;
                    return false;
                }));

            MainWindow.THIS.fastboot_partition_name_textbox.TextChanged += delegate
            {
                listHelper.doFilter();
            };
        }
    }
}