"""Точка входа: сборка FastAPI-приложения, lifespan, роутеры, отдача статики."""

from __future__ import annotations

import logging
from contextlib import asynccontextmanager

from fastapi import FastAPI
from fastapi.middleware.cors import CORSMiddleware
from fastapi.responses import FileResponse
from fastapi.staticfiles import StaticFiles
from starlette.requests import Request
from starlette.responses import JSONResponse, Response

from app.api import downloads, events
from app.config import settings
from app.core.events import EventBus
from app.core.queue import DownloadQueue
from app.core.storage import SqliteStorage
from app.models import DownloadStatus
from app.services.worker import WorkerPool

logging.basicConfig(level=logging.INFO, format="%(asctime)s %(levelname)s %(name)s: %(message)s")
logger = logging.getLogger("pvideodl")


@asynccontextmanager
async def lifespan(app: FastAPI):
    storage = SqliteStorage(settings.db_path)
    await storage.init()

    queue = DownloadQueue()
    event_bus = EventBus()
    pool = WorkerPool(queue, storage, event_bus, settings.workers)

    app.state.storage = storage
    app.state.queue = queue
    app.state.events = event_bus
    app.state.pool = pool

    # Перезаливаем в очередь всё, что осталось в pending с прошлого запуска.
    for download in await storage.list():
        if download.status == DownloadStatus.PENDING:
            await queue.add(download.id)

    await pool.start()
    settings.download_dir.mkdir(parents=True, exist_ok=True)
    logger.info("PVideoDl запущен. Файлы → %s", settings.download_dir)
    try:
        yield
    finally:
        await pool.stop()
        await storage.close()


def create_app() -> FastAPI:
    app = FastAPI(title="PVideoDl", version="0.1.0", lifespan=lifespan)

    # В деве фронт крутится на Vite (5173) и ходит на /api — пускаем его.
    app.add_middleware(
        CORSMiddleware,
        allow_origins=["http://localhost:5173", "http://127.0.0.1:5173"],
        allow_methods=["*"],
        allow_headers=["*"],
    )

    app.include_router(downloads.router)
    app.include_router(events.router)

    @app.get("/api/health")
    async def health() -> dict:
        return {"status": "ok"}

    _mount_frontend(app)
    return app


def _mount_frontend(app: FastAPI) -> None:
    """Отдаём собранную статику SvelteKit, если она есть. SPA-fallback на index.html."""
    static_dir = settings.static_dir
    index = static_dir / "index.html"
    if not index.exists():
        @app.get("/")
        async def no_frontend() -> JSONResponse:
            return JSONResponse(
                {
                    "message": "Фронтенд не собран. Соберите его (npm run build в frontend/) "
                    "или откройте API напрямую.",
                    "api": "/api/downloads",
                }
            )
        return

    app.mount("/_app", StaticFiles(directory=static_dir / "_app"), name="_app")

    @app.get("/{full_path:path}")
    async def spa(full_path: str, request: Request) -> Response:
        # Несуществующий /api путь — это 404, а не SPA-страница.
        if full_path.startswith("api/"):
            return JSONResponse({"detail": "Not Found"}, status_code=404)
        # Реальный файл из статики (favicon, изображения и т.п.) — отдаём как есть.
        candidate = (static_dir / full_path).resolve()
        if candidate.is_file() and static_dir.resolve() in candidate.parents:
            return FileResponse(candidate)
        return FileResponse(index)


app = create_app()


def run() -> None:
    """Запуск одной командой: `pvideodl` или `python -m app.main`."""
    import uvicorn

    uvicorn.run(app, host=settings.host, port=settings.port)


if __name__ == "__main__":
    run()