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

Made-with: Cursor

api/services/memoir_images/prompting.py

@@ -0,0 +1,63 @@
+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

@@ -0,0 +1,25 @@
+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")),
+        )