import re
from fastapi.responses import JSONResponse
from fastapi import HTTPException, Request
from starlette.middleware.base import BaseHTTPMiddleware
from fastapi.middleware.cors import CORSMiddleware

from src.utils import JWTUtil
from src.services import SessionService


EXEMPT_ROUTES = [
    "/",
    "/docs",
    "/openapi.json",
    "/api/v1/auth/login",
    "/api/v1/auth/logout",
    "/api/v1/auth/register",
]

EXEMPT_ROUTE_PATTERNS = []


class AuthenticationMiddleware(BaseHTTPMiddleware):
    def __init__(self, app):
        super().__init__(app)
        self._jwt = JWTUtil()
        self._session_service = SessionService()

    async def dispatch(self, request: Request, call_next):
        if request.method == "OPTIONS":
            return await call_next(request)

        if self._require_auth(request.url.path):
            try:
                user_payload = await self._validate_api_key(
                    request.headers.get("Authorization")
                )
                request.state.user = user_payload
            except HTTPException as e:
                # Create a response with CORS headers
                response = JSONResponse(
                    status_code=e.status_code, content={"detail": e.detail}
                )

                origin = request.headers.get("origin", "*")
                response.headers["Access-Control-Allow-Origin"] = origin
                response.headers["Access-Control-Allow-Credentials"] = "true"
                response.headers["Access-Control-Allow-Methods"] = "*"
                response.headers["Access-Control-Allow-Headers"] = "*"

                return response
            except Exception as e:
                response = JSONResponse(
                    status_code=500, content={"detail": "Internal server error"}
                )

                origin = request.headers.get("origin", "*")
                response.headers["Access-Control-Allow-Origin"] = origin
                response.headers["Access-Control-Allow-Credentials"] = "true"
                response.headers["Access-Control-Allow-Methods"] = "*"
                response.headers["Access-Control-Allow-Headers"] = "*"

                return response

        return await call_next(request)

    def _require_auth(self, path: str):
        if path in EXEMPT_ROUTES or any(
            re.match(pattern, path) for pattern in EXEMPT_ROUTE_PATTERNS
        ):
            return False
        return True

    async def _validate_api_key(self, api_key: str):
        if not api_key:
            raise HTTPException(status_code=401, detail="No API key provided")
        if not re.match(r"Bearer .+", api_key):
            raise HTTPException(status_code=401, detail="Invalid API key")

        token = api_key.split(" ")[1]

        is_expired = await self._session_service.is_session_expired(token)
        if is_expired:
            raise HTTPException(status_code=401, detail="Token expired")

        jwt_payload = self._jwt.validate_jwt(token)
        if not jwt_payload:
            raise HTTPException(status_code=401, detail="Invalid token")
        return jwt_payload