from fastapi import FastAPI
from fastapi.middleware.cors import CORSMiddleware
from typing import List
import os
import logging

logger = logging.getLogger(__name__)


def configure_cors_open(app: FastAPI):
    app.add_middleware(
        CORSMiddleware,
        allow_origins=["*"],
        allow_credentials=False,
        allow_methods=["GET", "POST", "PUT", "DELETE", "PATCH", "OPTIONS"],
        allow_headers=["*"],
        expose_headers=["X-RateLimit-Limit", "X-RateLimit-Remaining"],
        max_age=3600,
    )

    logger.info(" CORS configuré: Mode OUVERT (sécurisé par API Keys)")
    logger.info("   - Origins: * (toutes)")
    logger.info("   - Headers: * (dont X-API-Key)")
    logger.info("   - Credentials: False")


def configure_cors_whitelist(app: FastAPI):
    allowed_origins_str = os.getenv("CORS_ALLOWED_ORIGINS", "")

    if allowed_origins_str:
        allowed_origins = [
            origin.strip()
            for origin in allowed_origins_str.split(",")
            if origin.strip()
        ]
    else:
        allowed_origins = ["*"]

    app.add_middleware(
        CORSMiddleware,
        allow_origins=allowed_origins,
        allow_credentials=True,
        allow_methods=["GET", "POST", "PUT", "DELETE", "PATCH", "OPTIONS"],
        allow_headers=["Content-Type", "Authorization", "X-API-Key"],
        expose_headers=["X-RateLimit-Limit", "X-RateLimit-Remaining"],
        max_age=3600,
    )

    logger.info(" CORS configuré: Mode WHITELIST")
    logger.info(f"   - Origins autorisées: {len(allowed_origins)}")
    for origin in allowed_origins:
        logger.info(f"     • {origin}")


def configure_cors_regex(app: FastAPI):
    origin_regex = r"*"

    app.add_middleware(
        CORSMiddleware,
        allow_origin_regex=origin_regex,
        allow_credentials=True,
        allow_methods=["GET", "POST", "PUT", "DELETE", "PATCH", "OPTIONS"],
        allow_headers=["Content-Type", "Authorization", "X-API-Key"],
        expose_headers=["X-RateLimit-Limit", "X-RateLimit-Remaining"],
        max_age=3600,
    )

    logger.info(" CORS configuré: Mode REGEX")
    logger.info(f"   - Pattern: {origin_regex}")


def configure_cors_hybrid(app: FastAPI):
    from starlette.middleware.base import BaseHTTPMiddleware

    class HybridCORSMiddleware(BaseHTTPMiddleware):
        def __init__(self, app, known_origins: List[str]):
            super().__init__(app)
            self.known_origins = set(known_origins)

        async def dispatch(self, request, call_next):
            origin = request.headers.get("origin")

            if origin in self.known_origins:
                response = await call_next(request)
                response.headers["Access-Control-Allow-Origin"] = origin
                response.headers["Access-Control-Allow-Credentials"] = "true"
                response.headers["Access-Control-Allow-Methods"] = (
                    "GET, POST, PUT, DELETE, PATCH, OPTIONS"
                )
                response.headers["Access-Control-Allow-Headers"] = (
                    "Content-Type, Authorization, X-API-Key"
                )
                return response

            response = await call_next(request)
            response.headers["Access-Control-Allow-Origin"] = "*"
            response.headers["Access-Control-Allow-Methods"] = (
                "GET, POST, PUT, DELETE, PATCH, OPTIONS"
            )
            response.headers["Access-Control-Allow-Headers"] = "*"
            return response

    known_origins = ["*"]

    app.add_middleware(HybridCORSMiddleware, known_origins=known_origins)

    logger.info(" CORS configuré: Mode HYBRIDE")
    logger.info(f"   - Whitelist: {len(known_origins)} domaines")
    logger.info("   - Fallback: * (ouvert)")


def setup_cors(app: FastAPI, mode: str = "open"):
    if mode == "open":
        configure_cors_open(app)
    elif mode == "whitelist":
        configure_cors_whitelist(app)
    elif mode == "regex":
        configure_cors_regex(app)
    elif mode == "hybrid":
        configure_cors_hybrid(app)
    else:
        logger.warning(
            f" Mode CORS inconnu: {mode}. Utilisation de 'open' par défaut."
        )
        configure_cors_open(app)