feat(api): add memoir image prompt settings and optimization service

Made-with: Cursor

api/services/memoir_images/prompting.py

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+import json
+from typing import Any, Optional
+
+from .settings import MemoirImageSettings
+
+
+class MemoirImagePromptService:
+    CATEGORY_STYLE_MAP = {
+        "childhood": "watercolor",
+        "family": "watercolor",
+        "career_early": "realistic",
+        "career_achievement": "realistic",
+        "career_challenge": "realistic",
+        "beliefs": "editorial illustration",
+        "summary": "editorial illustration",
+    }
+
+    def __init__(self, llm: Optional[Any], settings: MemoirImageSettings):
+        self.llm = llm
+        self.settings = settings
+
+    def build_prompt(
+        self,
+        chapter_title: str,
+        chapter_category: str,
+        description: str,
+        context_excerpt: str,
+    ) -> dict[str, str]:
+        style = self.CATEGORY_STYLE_MAP.get(chapter_category, self.settings.default_style)
+        prompt_context = f"{chapter_category}: {chapter_title}"
+
+        llm_input = {
+            "chapter_title": chapter_title,
+            "chapter_category": chapter_category,
+            "description": description,
+            "context_excerpt": context_excerpt,
+            "default_style": style,
+            "default_size": self.settings.default_size,
+        }
+
+        if self.llm:
+            try:
+                response = self.llm.invoke(
+                    "Return JSON only with keys prompt, style, size. "
+                    "Convert the memoir scene into an image-generation prompt.\n"
+                    + json.dumps(llm_input, ensure_ascii=False)
+                )
+                parsed = json.loads(response.content)
+                return {
+                    "prompt": parsed["prompt"],
+                    "style": parsed.get("style", style),
+                    "size": parsed.get("size", self.settings.default_size),
+                    "prompt_context": prompt_context,
+                }
+            except Exception:
+                pass
+
+        return {
+            "prompt": f"{description}\n\nScene context: {context_excerpt}",
+            "style": style,
+            "size": self.settings.default_size,
+            "prompt_context": prompt_context,
+        }

api/services/memoir_images/settings.py

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+import os
+from dataclasses import dataclass
+
+
+@dataclass(frozen=True)
+class MemoirImageSettings:
+    enabled: bool
+    max_per_chapter: int
+    provider: str
+    default_style: str
+    default_size: str
+    poll_interval_seconds: int
+    max_attempts: int
+
+    @classmethod
+    def from_env(cls) -> "MemoirImageSettings":
+        return cls(
+            enabled=os.getenv("MEMOIR_IMAGE_ENABLED", "").lower() in {"1", "true", "yes"},
+            max_per_chapter=int(os.getenv("MEMOIR_IMAGE_MAX_PER_CHAPTER", "2")),
+            provider=os.getenv("MEMOIR_IMAGE_PROVIDER", "liblib"),
+            default_style=os.getenv("MEMOIR_IMAGE_STYLE_DEFAULT", "watercolor"),
+            default_size=os.getenv("MEMOIR_IMAGE_SIZE_DEFAULT", "1024x1024"),
+            poll_interval_seconds=int(os.getenv("MEMOIR_IMAGE_POLL_INTERVAL", "3")),
+            max_attempts=int(os.getenv("MEMOIR_IMAGE_MAX_ATTEMPTS", "20")),
+        )

api/tests/test_memoir_image_prompting.py

@@ -0,0 +1,59 @@
+import unittest
+from unittest.mock import Mock
+
+from api.services.memoir_images.prompting import MemoirImagePromptService
+from api.services.memoir_images.settings import MemoirImageSettings
+
+
+class MemoirImagePromptingTest(unittest.TestCase):
+    def test_prompt_service_uses_category_style_and_plain_fallback_without_llm(self):
+        settings = MemoirImageSettings(
+            enabled=True,
+            max_per_chapter=2,
+            provider="liblib",
+            default_style="watercolor",
+            default_size="1024x1024",
+            poll_interval_seconds=3,
+            max_attempts=20,
+        )
+        service = MemoirImagePromptService(llm=None, settings=settings)
+
+        result = service.build_prompt(
+            chapter_title="童年的夏天",
+            chapter_category="childhood",
+            description="奶奶坐在院子里的藤椅上",
+            context_excerpt="梧桐树下很安静，夏天总有蝉鸣。",
+        )
+
+        self.assertEqual(result["style"], "watercolor")
+        self.assertEqual(result["size"], "1024x1024")
+        self.assertIn("奶奶坐在院子里的藤椅上", result["prompt"])
+        self.assertIn("childhood", result["prompt_context"])
+
+    def test_prompt_service_parses_structured_llm_response(self):
+        settings = MemoirImageSettings(
+            enabled=True,
+            max_per_chapter=2,
+            provider="liblib",
+            default_style="watercolor",
+            default_size="1024x1024",
+            poll_interval_seconds=3,
+            max_attempts=20,
+        )
+        llm = Mock()
+        llm.invoke.return_value.content = (
+            '{"prompt":"A grandmother in a quiet courtyard, summer cicadas, soft watercolor",'
+            '"style":"watercolor","size":"1024x1024"}'
+        )
+        service = MemoirImagePromptService(llm=llm, settings=settings)
+
+        result = service.build_prompt(
+            chapter_title="童年的夏天",
+            chapter_category="childhood",
+            description="奶奶坐在院子里的藤椅上",
+            context_excerpt="梧桐树下很安静，夏天总有蝉鸣。",
+        )
+
+        self.assertEqual(result["prompt"], "A grandmother in a quiet courtyard, summer cicadas, soft watercolor")
+        self.assertEqual(result["style"], "watercolor")
+        self.assertEqual(result["size"], "1024x1024")