Story wire: read a step's structured args

data/story/wire-conformance.json

@@ -255,6 +255,50 @@
         "value": {"map": "M", "certainty": "unknown", "where": {"kind": "gps"}}
       },
       "expectation": {"rejected": true}
+    },
+    {
+      "input": {
+        "name": "args",
+        "record": "step",
+        "value": {
+          "id": "buy",
+          "kind": "game_action",
+          "variant": "mart",
+          "args": {"map": "CeruleanCity_Mart", "budget": 3000, "if_present": true}
+        }
+      },
+      "expectation": {
+        "canonical": {
+          "id": "buy",
+          "kind": "game_action",
+          "variant": "mart",
+          "args": {"map": "CeruleanCity_Mart", "budget": 3000, "if_present": true}
+        }
+      }
+    },
+    {
+      "input": {
+        "name": "fractional arg",
+        "record": "step",
+        "value": {"id": "a", "kind": "game_action", "variant": "mart", "args": {"budget": 1.5}}
+      },
+      "expectation": {"rejected": true}
+    },
+    {
+      "input": {
+        "name": "nested arg",
+        "record": "step",
+        "value": {"id": "a", "kind": "game_action", "variant": "mart", "args": {"items": [1]}}
+      },
+      "expectation": {"rejected": true}
+    },
+    {
+      "input": {
+        "name": "args not an object",
+        "record": "step",
+        "value": {"id": "a", "kind": "game_action", "variant": "mart", "args": ["map"]}
+      },
+      "expectation": {"rejected": true}
     }
   ]
 }

schemas/story-checkpoint.schema.json

@@ -120,6 +120,7 @@
           }
         },
         "variant": {"type": "string"},
+        "args": {"type": "object", "additionalProperties": {"type": ["boolean", "integer", "string"]}},
         "skip_if": {"type": "array", "items": {"type": "string"}},
         "once_per_save": {"type": "boolean"},
         "notes": {"$ref": "#/$defs/notes"}

src/pokesim/story/checkpoint_wire.py

@@ -49,6 +49,22 @@ def array(value):
     return value
 
 
+def read_args(value):
+    """A step's args: flags, whole numbers and words by name, as the step's
+    action declares them in the game's C++ (StoryArgSpec); this reader checks
+    only the value types."""
+    if not isinstance(value, dict):
+        raise ValueError('expected args object')
+    result = {}
+    for key, item in value.items():
+        if type(item) is int:
+            integer(item, -9223372036854775808, 9223372036854775807)
+        elif type(item) is not bool and not isinstance(item, str):
+            raise ValueError('arg is not a flag, whole number or word: ' + key)
+        result[key] = item
+    return result
+
+
 def read_notes(root, result):
     """Copy non-empty `notes` paragraphs; no executor reads them."""
     notes = [text(v) for v in array(root.get('notes', []))]
@@ -79,7 +95,7 @@ def read_pose(value):
 
 def read_step(value):
     root = fields(value, ('id', 'kind', 'why', 'target', 'direction', 'legs', 'fight_wild',
-                         'yes', 'may_lose', 'battles', 'items', 'variant', 'skip_if', 'declared_after',
+                         'yes', 'may_lose', 'battles', 'items', 'variant', 'args', 'skip_if', 'declared_after',
                          'once_per_save', 'notes'))
     result = dict(id=text(root['id']), kind=choice(root['kind'], KINDS))
     if not result['id']:
@@ -115,6 +131,9 @@ def read_step(value):
         items.append(dict(item=text(item['item']), quantity=integer(item['quantity'], 0, 9223372036854775807)))
     if items:
         result['items'] = items
+    args = read_args(root.get('args', {}))
+    if args:
+        result['args'] = args
     skip = [text(v) for v in array(root.get('skip_if', []))]
     if skip:
         result['skip_if'] = skip