life-echo/api/app/features/memoir/service.py

"""Memoir service — 回忆录编排（章节生成、状态流转）；通过 MemoryService 获取 evidence。"""

from app.core.logging import get_logger
from typing import List, Optional

from fastapi import HTTPException
from sqlalchemy import select
from sqlalchemy.ext.asyncio import AsyncSession
from sqlalchemy.orm import joinedload

from app.agents.prompts.memory_prompts import (
    CHAPTER_CATEGORIES,
    CHAPTER_ORDER,
    STAGE_TO_ORDER,
)
from app.features.memoir import repo
from app.features.memoir.helpers import (
    chapter_to_dict,
    is_image_permanently_unavailable,
)
from app.features.memoir.models import Book, Chapter, ChapterSection
from app.features.memory.service import MemoryService

logger = get_logger(__name__)


async def get_or_create_book(user_id: str, db: AsyncSession):
    """Get the user's current book or return None."""
    return await repo.get_current_book(user_id, db)


class MemoirService:
    def __init__(
        self,
        db: AsyncSession,
        memory_service: Optional[MemoryService] = None,
    ):
        self._db = db
        self._memory = memory_service

    async def get_evidence(self, user_id: str, query: str, *, top_k: int = 10) -> dict:
        """通过 MemoryService 获取检索证据（章节生成时优先使用）。"""
        if self._memory is None:
            return {
                "relevant_chunks": [],
                "relevant_summaries": [],
                "relevant_facts": [],
                "timeline_hints": [],
            }
        return await self._memory.retrieve(user_id, query, top_k=top_k)

    async def _cleanup_unavailable_images(self, ch: Chapter) -> None:
        sections = getattr(ch, "sections", None) or []
        cleaned = False
        for s in sections:
            rec = getattr(s, "image_record", None)
            if rec and is_image_permanently_unavailable(rec):
                logger.info("清理不可用配图: chapter=%s, section=%s", ch.id, s.id)
                s.image_id = None
                await self._db.delete(rec)
                cleaned = True
        if cleaned:
            await self._db.commit()
            await self._db.refresh(ch)

    async def get_current_book(self, user_id: str) -> dict:
        book = await repo.get_current_book(user_id, self._db)
        if not book:
            return {"message": "No book found"}
        return {
            "id": book.id,
            "title": book.title,
            "total_pages": book.total_pages,
            "total_words": book.total_words,
            "cover_image_url": book.cover_image_url,
            "has_update": book.has_update,
            "last_update_chapter_id": book.last_update_chapter_id,
        }

    async def clear_book_update(self, user_id: str) -> dict:
        book = await repo.get_current_book(user_id, self._db)
        if not book:
            return {"status": "ok", "message": "No book found"}
        book.has_update = False
        await self._db.commit()
        return {"status": "ok"}

    async def update_book(self, book_id: str, user_id: str, title: str) -> dict:
        book = await self._db.get(Book, book_id)
        if not book:
            raise HTTPException(status_code=404, detail="Book not found")
        if book.user_id != user_id:
            raise HTTPException(status_code=403, detail="无权更新此回忆录")
        book.title = title
        await self._db.commit()
        await self._db.refresh(book)
        return {
            "id": book.id,
            "title": book.title,
            "total_pages": book.total_pages,
            "total_words": book.total_words,
            "cover_image_url": book.cover_image_url,
            "has_update": book.has_update,
            "last_update_chapter_id": book.last_update_chapter_id,
        }

    async def export_pdf(self, user_id: str, book_id: str) -> dict:
        from app.features.memoir.pdf_service import pdf_service

        book = await self._db.get(Book, book_id)
        if not book:
            raise HTTPException(status_code=404, detail="Book not found")
        if book.user_id != user_id:
            raise HTTPException(status_code=403, detail="无权导出此回忆录")
        stmt = (
            select(Chapter)
            .where(Chapter.user_id == user_id, Chapter.is_active == True)
            .options(joinedload(Chapter.sections))
            .order_by(Chapter.order_index)
        )
        result = await self._db.execute(stmt)
        chapters = list(result.unique().scalars().all())
        pdf_bytes = await pdf_service.generate_pdf(book, chapters)
        return {
            "pdf_base64": pdf_bytes.decode("latin1"),
            "filename": f"{book.title}.pdf",
        }

    async def get_chapters(
        self, user_id: str, is_new: bool | None = None
    ) -> List[dict]:
        chapters = await repo.get_chapters_with_sections(
            user_id, self._db, is_new_only=is_new
        )
        chapter_by_category: dict[str, Chapter] = {}
        for ch in chapters:
            if ch.category and ch.category not in chapter_by_category:
                chapter_by_category[ch.category] = ch
        all_chapters: List[dict] = []
        for category in CHAPTER_ORDER:
            ch = chapter_by_category.pop(category, None)
            if ch:
                await self._cleanup_unavailable_images(ch)
                all_chapters.append(chapter_to_dict(ch))
            else:
                if is_new is True:
                    continue
                all_chapters.append({
                    "id": f"placeholder_{category}",
                    "title": CHAPTER_CATEGORIES[category],
                    "content": "",
                    "order_index": STAGE_TO_ORDER.get(category, 999),
                    "status": "empty",
                    "category": category,
                    "images": [],
                    "cover_image": None,
                    "sections": [],
                    "updated_at": None,
                    "is_new": False,
                    "source_segments": [],
                })
        for ch in chapter_by_category.values():
            await self._cleanup_unavailable_images(ch)
            all_chapters.append(chapter_to_dict(ch))
        return all_chapters

    async def get_chapter(self, chapter_id: str, user_id: str) -> dict:
        chapter = await repo.get_chapter_by_id(chapter_id, self._db)
        if not chapter:
            raise HTTPException(status_code=404, detail="Chapter not found")
        if chapter.user_id != user_id:
            raise HTTPException(status_code=403, detail="无权访问此章节")
        if not chapter.is_active:
            raise HTTPException(status_code=404, detail="Chapter not found")
        await self._cleanup_unavailable_images(chapter)
        return chapter_to_dict(chapter)

    async def disable_chapter(self, chapter_id: str, user_id: str) -> dict:
        chapter = await self._db.get(Chapter, chapter_id)
        if not chapter:
            raise HTTPException(status_code=404, detail="Chapter not found")
        if chapter.user_id != user_id:
            raise HTTPException(status_code=403, detail="无权操作此章节")
        chapter.is_active = False
        await self._db.commit()
        return {"status": "ok", "message": "章节已清除"}

    async def regenerate_chapter(self, chapter_id: str, user_id: str) -> dict:
        chapter = await self._db.get(Chapter, chapter_id)
        if not chapter:
            raise HTTPException(status_code=404, detail="Chapter not found")
        if chapter.user_id != user_id:
            raise HTTPException(status_code=403, detail="无权操作此章节")
        # TODO: 实现重新整理逻辑
        return {"status": "ok", "message": "Chapter regeneration triggered"}

    async def get_memoir_state(self, user_id: str) -> dict:
        from app.features.memoir.state_service import get_or_create_state

        state = await get_or_create_state(user_id, self._db)
        return state.model_dump()

    async def get_next_question_context(self, user_id: str) -> dict:
        from app.features.memoir.state_service import get_or_create_state

        state = await get_or_create_state(user_id, self._db)
        return {
            "current_stage": state.current_stage,
            "empty_slots": state.empty_slots_for_current_stage(),
            "covered_stages": state.covered_stages,
        }

    async def mark_memoir_read(self, user_id: str) -> dict:
        stmt = select(Chapter).where(
            Chapter.user_id == user_id, Chapter.is_new == True
        )
        result = await self._db.execute(stmt)
        for chapter in result.scalars().all():
            chapter.is_new = False
        stmt_book = (
            select(Book)
            .where(Book.user_id == user_id)
            .order_by(Book.updated_at.desc())
        )
        result_book = await self._db.execute(stmt_book)
        book = result_book.scalar_one_or_none()
        if book:
            book.has_update = False
        await self._db.commit()
        return {"status": "ok"}