from __future__ import annotations

import asyncio
from contextlib import asynccontextmanager

import httpx
from fastapi import FastAPI

from app.api.routes import get_router
from app.bot.telegram_bot import TelegramBotRunner
from app.clients.lastfm import LastFmClient
from app.clients.spotify import SpotifyClient
from app.config import get_settings
from app.db.session import create_engine, create_session_factory, init_db
from app.runtime import AppRuntime
from app.services.app_services import AppServices
from app.services.playlist_job import PlaylistJobService
from app.services.recommendation import RecommendationEngine
from app.services.spotify_auth import SpotifyAuthService


def create_app() -> FastAPI:
    settings = get_settings()

    @asynccontextmanager
    async def lifespan(app: FastAPI):
        engine = create_engine(settings)
        session_factory = create_session_factory(engine)
        await init_db(engine)

        http_client = httpx.AsyncClient(headers={"User-Agent": "spotify-vibe-bot/1.0"})
        spotify = SpotifyClient(settings, http_client)
        lastfm = LastFmClient(settings.lastfm_api_key, http_client)
        auth_service = SpotifyAuthService(settings, spotify, session_factory)
        rec_engine = RecommendationEngine(settings, spotify, lastfm)
        job_service = PlaylistJobService(settings, session_factory, auth_service, rec_engine, asyncio.Lock())
        services = AppServices(auth=auth_service, recommendation=rec_engine, jobs=job_service)

        runtime = AppRuntime(
            settings=settings,
            engine=engine,
            session_factory=session_factory,
            http_client=http_client,
            spotify=spotify,
            lastfm=lastfm,
            generate_lock=job_service.generate_lock,
        )
        app.state.runtime = runtime
        app.state.services = services

        telegram_runner = TelegramBotRunner(
            token=settings.telegram_bot_token,
            session_factory=session_factory,
            services=services,
            app_base_url=settings.app_base_url,
        )
        runtime.telegram_runner = telegram_runner
        job_service.set_notifier(telegram_runner.send_message)

        await telegram_runner.start_polling()
        try:
            yield
        finally:
            await telegram_runner.stop()
            await http_client.aclose()
            await engine.dispose()

    app = FastAPI(title="Spotify Vibe Bot", lifespan=lifespan)
    app.include_router(get_router())
    return app