feat(api): add memoir image placeholder parsing

Made-with: Cursor

api/services/memoir_images/parser.py

@@ -0,0 +1,49 @@
+import re
+from typing import Any
+
+PLACEHOLDER_RE = re.compile(r"\{\{\{\{IMAGE:(.*?)\}\}\}\}")
+
+
+def parse_image_placeholders(content: str, max_images: int) -> list[dict[str, Any]]:
+    items: list[dict[str, Any]] = []
+    for match in PLACEHOLDER_RE.finditer(content or ""):
+        description = match.group(1).strip()
+        if not description:
+            continue
+        items.append(
+            {
+                "index": len(items),
+                "description": description,
+                "placeholder": match.group(0),
+                "start_offset": match.start(),
+            }
+        )
+        if len(items) >= max_images:
+            break
+    return items
+
+
+def build_initial_image_assets(
+    placeholders: list[dict[str, Any]],
+    provider: str,
+    style: str,
+    size: str,
+    now_iso: str,
+) -> list[dict[str, Any]]:
+    return [
+        {
+            "index": item["index"],
+            "placeholder": item["placeholder"],
+            "description": item["description"],
+            "prompt": None,
+            "url": None,
+            "status": "pending",
+            "provider": provider,
+            "style": style,
+            "size": size,
+            "error": None,
+            "created_at": now_iso,
+            "updated_at": now_iso,
+        }
+        for item in placeholders
+    ]

api/tests/test_memoir_image_parser.py

@@ -0,0 +1,45 @@
+import unittest
+
+from api.services.memoir_images.parser import (
+    build_initial_image_assets,
+    parse_image_placeholders,
+)
+
+
+class MemoirImageParserTest(unittest.TestCase):
+    def test_parse_image_placeholders_preserves_order_and_offsets(self):
+        content = (
+            "那条路我一直记得。\n\n"
+            "{{{{IMAGE:南方小镇的青石板路}}}}\n\n"
+            "奶奶总坐在门口。\n\n"
+            "{{{{IMAGE:奶奶坐在院子里的藤椅上}}}}"
+        )
+
+        items = parse_image_placeholders(content, max_images=3)
+
+        self.assertEqual([item["index"] for item in items], [0, 1])
+        self.assertEqual(items[0]["description"], "南方小镇的青石板路")
+        self.assertEqual(items[1]["placeholder"], "{{{{IMAGE:奶奶坐在院子里的藤椅上}}}}")
+        self.assertLess(items[0]["start_offset"], items[1]["start_offset"])
+
+    def test_build_initial_image_assets_marks_every_item_pending(self):
+        placeholders = [
+            {
+                "index": 0,
+                "description": "南方小镇的青石板路",
+                "placeholder": "{{{{IMAGE:南方小镇的青石板路}}}}",
+                "start_offset": 10,
+            }
+        ]
+
+        assets = build_initial_image_assets(
+            placeholders=placeholders,
+            provider="liblib",
+            style="watercolor",
+            size="1024x1024",
+            now_iso="2026-03-10T10:00:00Z",
+        )
+
+        self.assertEqual(assets[0]["status"], "pending")
+        self.assertEqual(assets[0]["provider"], "liblib")
+        self.assertEqual(assets[0]["url"], None)