import logging
import time
from collections.abc import Awaitable, Callable

from fastapi import FastAPI, Request, Response
from fastapi.exceptions import RequestValidationError
from fastapi.responses import JSONResponse
from fastapi.staticfiles import StaticFiles

from src.routes import top_level_router
from src.settings import CONFIG

log = logging.getLogger(__name__)

fastapi_app = FastAPI(debug=CONFIG.debug, root_path=CONFIG.app_prefix)
fastapi_app.mount("/static", StaticFiles(directory="src/static"), name="static")
fastapi_app.include_router(top_level_router)


@fastapi_app.get("/heartbeat")
def health_check() -> JSONResponse:
    """Return basic response, for use as a health check."""
    return JSONResponse({"detail": "I am alive!"})


@fastapi_app.exception_handler(RequestValidationError)
def pydantic_validation_error(request: Request, error: RequestValidationError) -> JSONResponse:
    """Raise a warning for pydantic validation errors, before returning."""
    log.warning("Error from %s: %s", request.url, error)
    return JSONResponse({"error": str(error)}, status_code=422)


@fastapi_app.middleware("http")
async def add_process_time_and_security_headers(
    request: Request,
    call_next: Callable[[Request], Awaitable[Response]],
) -> Response:
    """Add process time and some security headers before sending the response."""
    start_time = time.perf_counter()
    response = await call_next(request)
    response.headers["X-Process-Time"] = str(time.perf_counter() - start_time)
    response.headers["X-Frame-Options"] = "DENY"
    response.headers["X-XSS-Protection"] = "1; mode=block"
    response.headers["Strict-Transport-Security"] = "max-age=31536000"
    response.headers["X-Content-Type-Options"] = "nosniff"
    response.headers["Content-Security-Policy"] = (
        "default-src 'self';"
        " script-src 'unsafe-inline' https://cdn.jsdelivr.net/ https://unpkg.com/;"
        " style-src 'self' https://cdn.jsdelivr.net/ https://fonts.googleapis.com/;"
        " font-src https://fonts.gstatic.com/;"
        " img-src 'self' data:;"
    )
    response.headers["Referrer-Policy"] = "no-referrer"
    response.headers["Permissions-Policy"] = (
        "camera=(), display-capture=(), fullscreen=(), geolocation=(), microphone=(), screen-wake-lock=(), web-share=()"
    )
    return response