from fastapi import FastAPI, Request, Depends
from fastapi.templating import Jinja2Templates
from fastapi.staticfiles import StaticFiles
from fastapi.responses import HTMLResponse, JSONResponse
from sqlalchemy.ext.asyncio import AsyncSession
from sqlalchemy import select
from contextlib import asynccontextmanager
import json
from datetime import datetime

from app.database import init_db, get_db
from app.models import Book, ListeningSession, Recommendation
from app.abs_client import AudiobookshelfClient
from app.recommender import BookRecommender
from app.config import get_settings


@asynccontextmanager
async def lifespan(app: FastAPI):
    """Initialize database on startup."""
    await init_db()
    yield


# Initialize FastAPI app
app = FastAPI(
    title="Audiobookshelf Recommendations",
    description="AI-powered book recommendations based on your listening history",
    lifespan=lifespan
)

# Setup templates and static files
templates = Jinja2Templates(directory="app/templates")
app.mount("/static", StaticFiles(directory="app/static"), name="static")

# Initialize clients
abs_client = AudiobookshelfClient()
recommender = BookRecommender()


@app.get("/", response_class=HTMLResponse)
async def home(request: Request, db: AsyncSession = Depends(get_db)):
    """Home page showing dashboard."""
    # Get recent books and recommendations
    recent_sessions = await db.execute(
        select(ListeningSession)
        .order_by(ListeningSession.last_update.desc())
        .limit(10)
    )
    sessions = recent_sessions.scalars().all()

    # Get book details for sessions
    books = []
    for session in sessions:
        book_result = await db.execute(
            select(Book).where(Book.id == session.book_id)
        )
        book = book_result.scalar_one_or_none()
        if book:
            books.append({
                "book": book,
                "session": session
            })

    # Get recent recommendations
    recs_result = await db.execute(
        select(Recommendation)
        .where(Recommendation.dismissed == False)
        .order_by(Recommendation.created_at.desc())
        .limit(5)
    )
    recommendations = recs_result.scalars().all()

    return templates.TemplateResponse(
        "index.html",
        {
            "request": request,
            "books": books,
            "recommendations": recommendations
        }
    )


@app.get("/api/sync")
async def sync_with_audiobookshelf(db: AsyncSession = Depends(get_db)):
    """Sync library and progress from Audiobookshelf."""
    try:
        # Get user info which includes all media progress
        user_info = await abs_client.get_user_info()
        media_progress = user_info.get("mediaProgress", [])

        synced_count = 0
        for progress_item in media_progress:
            # Skip podcast episodes, only process books
            if progress_item.get("mediaItemType") != "book":
                continue

            library_item_id = progress_item.get("libraryItemId")
            if not library_item_id:
                continue

            # Fetch full library item details
            try:
                item = await abs_client.get_item_details(library_item_id)
            except:
                # Skip if item not found
                continue
            # Extract book info
            media = item.get("media", {})
            metadata = media.get("metadata", {})

            book_id = item.get("id")
            if not book_id:
                continue

            # Check if book exists in DB
            result = await db.execute(select(Book).where(Book.id == book_id))
            book = result.scalar_one_or_none()

            # Create or update book
            if not book:
                book = Book(
                    id=book_id,
                    title=metadata.get("title", "Unknown"),
                    author=metadata.get("authorName", "Unknown"),
                    narrator=metadata.get("narratorName"),
                    description=metadata.get("description"),
                    genres=json.dumps(metadata.get("genres", [])),
                    tags=json.dumps(media.get("tags", [])),
                    duration=media.get("duration", 0),
                    cover_url=media.get("coverPath")
                )
                db.add(book)
            else:
                # Update existing book
                book.title = metadata.get("title", book.title)
                book.author = metadata.get("authorName", book.author)
                book.updated_at = datetime.now()

            # Update or create listening session
            progress_data = progress_item.get("progress", 0)
            current_time = progress_item.get("currentTime", 0)
            is_finished = progress_item.get("isFinished", False)
            started_at_ts = progress_item.get("startedAt")
            finished_at_ts = progress_item.get("finishedAt")

            session_result = await db.execute(
                select(ListeningSession)
                .where(ListeningSession.book_id == book_id)
                .order_by(ListeningSession.last_update.desc())
                .limit(1)
            )
            session = session_result.scalar_one_or_none()

            if not session:
                session = ListeningSession(
                    book_id=book_id,
                    progress=progress_data,
                    current_time=current_time,
                    is_finished=is_finished,
                    started_at=datetime.fromtimestamp(started_at_ts / 1000) if started_at_ts else datetime.now(),
                    finished_at=datetime.fromtimestamp(finished_at_ts / 1000) if finished_at_ts else None
                )
                db.add(session)
            else:
                # Update existing session
                session.progress = progress_data
                session.current_time = current_time
                session.is_finished = is_finished
                if finished_at_ts and not session.finished_at:
                    session.finished_at = datetime.fromtimestamp(finished_at_ts / 1000)

            synced_count += 1

        await db.commit()

        return JSONResponse({
            "status": "success",
            "synced": synced_count,
            "message": f"Synced {synced_count} books from Audiobookshelf"
        })

    except Exception as e:
        return JSONResponse(
            {"status": "error", "message": str(e)},
            status_code=500
        )


@app.get("/api/recommendations/generate")
async def generate_recommendations(db: AsyncSession = Depends(get_db)):
    """Generate new AI recommendations based on reading history."""
    try:
        # Get finished books for context
        finished_result = await db.execute(
            select(ListeningSession, Book)
            .join(Book, ListeningSession.book_id == Book.id)
            .where(ListeningSession.is_finished == True)
            .order_by(ListeningSession.finished_at.desc())
            .limit(20)
        )
        finished_items = finished_result.all()

        if not finished_items:
            return JSONResponse({
                "status": "error",
                "message": "No reading history found. Please sync with Audiobookshelf first."
            })

        # Format reading history
        reading_history = []
        for session, book in finished_items:
            reading_history.append({
                "title": book.title,
                "author": book.author,
                "genres": json.loads(book.genres) if book.genres else [],
                "progress": session.progress,
                "is_finished": session.is_finished
            })

        # Generate recommendations
        new_recs = await recommender.generate_recommendations(
            reading_history, num_recommendations=5
        )

        # Save to database
        for rec in new_recs:
            recommendation = Recommendation(
                title=rec.get("title"),
                author=rec.get("author"),
                description=rec.get("description"),
                reason=rec.get("reason"),
                genres=json.dumps(rec.get("genres", []))
            )
            db.add(recommendation)

        await db.commit()

        return JSONResponse({
            "status": "success",
            "recommendations": new_recs,
            "count": len(new_recs)
        })

    except Exception as e:
        return JSONResponse(
            {"status": "error", "message": str(e)},
            status_code=500
        )


@app.get("/api/recommendations")
async def get_recommendations(db: AsyncSession = Depends(get_db)):
    """Get saved recommendations."""
    result = await db.execute(
        select(Recommendation)
        .where(Recommendation.dismissed == False)
        .order_by(Recommendation.created_at.desc())
    )
    recommendations = result.scalars().all()

    return JSONResponse({
        "recommendations": [
            {
                "id": rec.id,
                "title": rec.title,
                "author": rec.author,
                "description": rec.description,
                "reason": rec.reason,
                "genres": json.loads(rec.genres) if rec.genres else [],
                "created_at": rec.created_at.isoformat()
            }
            for rec in recommendations
        ]
    })


@app.get("/api/history")
async def get_listening_history(db: AsyncSession = Depends(get_db)):
    """Get listening history."""
    result = await db.execute(
        select(ListeningSession, Book)
        .join(Book, ListeningSession.book_id == Book.id)
        .order_by(ListeningSession.last_update.desc())
    )
    items = result.all()

    return JSONResponse({
        "history": [
            {
                "book": {
                    "id": book.id,
                    "title": book.title,
                    "author": book.author,
                    "cover_url": book.cover_url,
                },
                "session": {
                    "progress": session.progress,
                    "is_finished": session.is_finished,
                    "started_at": session.started_at.isoformat() if session.started_at else None,
                    "finished_at": session.finished_at.isoformat() if session.finished_at else None,
                }
            }
            for session, book in items
        ]
    })


@app.get("/health")
async def health_check():
    """Health check endpoint."""
    return {"status": "healthy"}