"""
回忆录相关 API 路由
"""
from fastapi import APIRouter, Depends, HTTPException, Query, Body
from pydantic import BaseModel
from sqlalchemy import select
from sqlalchemy.ext.asyncio import AsyncSession

from database import get_async_db
from database.models import Book as BookModel
from database.models import User as UserModel
from services.pdf_service import pdf_service
from middleware.auth import get_current_user

router = APIRouter(prefix="/api/books", tags=["books"])


@router.get("/current")
async def get_current_book(
    current_user: UserModel = Depends(get_current_user),
    db: AsyncSession = Depends(get_async_db)
):
    """获取当前回忆录（需要认证）"""
    stmt = select(BookModel).where(BookModel.user_id == current_user.id).order_by(BookModel.updated_at.desc()).limit(1)
    result = await db.execute(stmt)
    book = result.scalar_one_or_none()
    
    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,
    }


@router.post("/clear-update")
async def clear_book_update(
    current_user: UserModel = Depends(get_current_user),
    db: AsyncSession = Depends(get_async_db),
):
    """清除回忆录更新标记"""
    stmt = select(BookModel).where(BookModel.user_id == current_user.id).order_by(BookModel.updated_at.desc()).limit(1)
    result = await db.execute(stmt)
    book = result.scalar_one_or_none()
    if not book:
        return {"status": "ok", "message": "No book found"}
    book.has_update = False
    await db.commit()
    return {"status": "ok"}


class UpdateBookRequest(BaseModel):
    title: str
    subtitle: str | None = None  # 目前数据库不支持subtitle，但保留字段以便将来扩展


@router.put("/{book_id}")
async def update_book(
    book_id: str,
    request: UpdateBookRequest = Body(...),
    current_user: UserModel = Depends(get_current_user),
    db: AsyncSession = Depends(get_async_db)
):
    """更新书籍标题（需要认证，只能更新自己的回忆录）"""
    book = await db.get(BookModel, book_id)
    if not book:
        raise HTTPException(status_code=404, detail="Book not found")
    
    # 验证用户权限
    if book.user_id != current_user.id:
        raise HTTPException(status_code=403, detail="无权更新此回忆录")
    
    # 更新标题
    book.title = request.title
    # subtitle字段目前数据库不支持，暂时忽略
    await db.commit()
    await 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,
    }


class ExportPdfRequest(BaseModel):
    book_id: str


@router.post("/export-pdf")
async def export_pdf(
    request: ExportPdfRequest = Body(...),
    current_user: UserModel = Depends(get_current_user),
    db: AsyncSession = Depends(get_async_db)
):
    """导出 PDF（需要认证，只能导出自己的回忆录）"""
    book = await db.get(BookModel, request.book_id)
    if not book:
        raise HTTPException(status_code=404, detail="Book not found")
    
    # 验证用户权限
    if book.user_id != current_user.id:
        raise HTTPException(status_code=403, detail="无权导出此回忆录")
    
    # 获取所有 active 章节
    from database.models import Chapter
    stmt = select(Chapter).where(
        Chapter.user_id == current_user.id,
        Chapter.is_active == True
    ).order_by(Chapter.order_index)
    result = await db.execute(stmt)
    chapters = result.scalars().all()
    
    # 生成 PDF
    pdf_bytes = await pdf_service.generate_pdf(book, chapters)
    
    return {
        "pdf_base64": pdf_bytes.decode('latin1'),  # 简化处理，实际应该用 base64
        "filename": f"{book.title}.pdf"
    }