"""Application factory and wiring. No logic lives here."""

from collections.abc import AsyncIterator
from contextlib import asynccontextmanager
from pathlib import Path

import httpx2
from fastapi import FastAPI
from fastapi.staticfiles import StaticFiles

from app.adapters.spotify.session import PendingLogins, SessionStore
from app.api.routes import router
from app.config import AppMode, Settings, settings

FRONTEND_DIST = Path(__file__).parent / "static"


def create_app(
    application_settings: Settings | None = None,
    http_transport: httpx2.AsyncBaseTransport | None = None,
) -> FastAPI:
    """Build the FastAPI app: API routes plus the built SPA on one port."""
    active_settings = application_settings or settings

    @asynccontextmanager
    async def lifespan(application: FastAPI) -> AsyncIterator[None]:
        if active_settings.app_mode is AppMode.LIVE and not active_settings.spotify_client_id:
            raise RuntimeError("SPOTIFY_CLIENT_ID is required in live mode")
        async with httpx2.AsyncClient(
            timeout=active_settings.spotify_timeout_seconds,
            transport=http_transport,
        ) as http:
            application.state.http = http
            application.state.session_store = SessionStore()
            application.state.pending_logins = PendingLogins()
            application.state.settings = active_settings
            yield

    app = FastAPI(
        title="discovery-by-llm",
        docs_url=None,
        redoc_url=None,
        lifespan=lifespan,
    )

    @app.get("/api/health")
    def health() -> dict[str, str]:
        return {"status": "ok", "mode": active_settings.app_mode}

    app.include_router(router)
    if FRONTEND_DIST.is_dir():
        app.mount("/", StaticFiles(directory=FRONTEND_DIST, html=True), name="spa")

    return app


app = create_app()