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

from fastapi import FastAPI, Request
from fastapi.responses import JSONResponse, RedirectResponse
from fastapi.staticfiles import StaticFiles
from slowapi.errors import RateLimitExceeded
from slowapi.middleware import SlowAPIMiddleware

from app.config import get_settings
from app.db import close_pool, get_pool
from app.health import router as health_router
from app.logging_setup import configure_logging
from app.rate_limit import limiter
from app.routers.auth import router as auth_router
from app.routers.push import router as push_router
from app.routers.views import router as views_router

WEB_DIR = Path("/srv/web")


@asynccontextmanager
async def lifespan(_: FastAPI) -> AsyncIterator[None]:
    configure_logging()
    await get_pool()
    try:
        yield
    finally:
        await close_pool()


def _rate_limit_handler(request: Request, exc: Exception) -> JSONResponse:
    _ = request, exc
    return JSONResponse(status_code=429, content={"detail": "rate limit exceeded"})


def create_app(role: str) -> FastAPI:
    settings = get_settings()
    app = FastAPI(
        title=f"fleet-platform [{role}]",
        version=settings.app_git_sha,
        lifespan=lifespan,
    )
    app.state.limiter = limiter
    app.add_exception_handler(RateLimitExceeded, _rate_limit_handler)
    app.add_middleware(SlowAPIMiddleware)

    app.include_router(health_router)

    if role == "gateway":
        app.include_router(auth_router)
        app.include_router(push_router)
        app.include_router(views_router)

        @app.get("/", include_in_schema=False)
        async def _root() -> RedirectResponse:
            return RedirectResponse(url="/index-live.html", status_code=307)

        if WEB_DIR.is_dir():
            app.mount("/", StaticFiles(directory=str(WEB_DIR), html=True), name="web")

    return app