import os
from typing import Optional

import httpx
from fastapi import Depends, HTTPException, Request
from fastapi.responses import RedirectResponse
from sqlmodel import Session, select

from app.database import get_session
from app.models import User

TWITCH_CLIENT_ID = os.getenv("TWITCH_CLIENT_ID", "")
TWITCH_CLIENT_SECRET = os.getenv("TWITCH_CLIENT_SECRET", "")
TWITCH_REDIRECT_URI = os.getenv("TWITCH_REDIRECT_URI", "http://localhost:8000/auth/callback")

SCOPES = "channel:read:subscriptions bits:read channel:read:redemptions moderator:read:followers"

TWITCH_AUTH_URL = (
    "https://id.twitch.tv/oauth2/authorize"
    f"?client_id={TWITCH_CLIENT_ID}"
    f"&redirect_uri={TWITCH_REDIRECT_URI}"
    "&response_type=code"
    f"&scope={SCOPES.replace(' ', '+')}"
)


async def exchange_code(code: str) -> dict:
    async with httpx.AsyncClient() as client:
        r = await client.post("https://id.twitch.tv/oauth2/token", data={
            "client_id": TWITCH_CLIENT_ID,
            "client_secret": TWITCH_CLIENT_SECRET,
            "code": code,
            "grant_type": "authorization_code",
            "redirect_uri": TWITCH_REDIRECT_URI,
        })
        r.raise_for_status()
        return r.json()


async def get_twitch_user(access_token: str) -> dict:
    async with httpx.AsyncClient() as client:
        r = await client.get(
            "https://api.twitch.tv/helix/users",
            headers={"Authorization": f"Bearer {access_token}", "Client-Id": TWITCH_CLIENT_ID},
        )
        r.raise_for_status()
        return r.json()["data"][0]


def get_current_user(request: Request, session: Session = Depends(get_session)) -> Optional[User]:
    user_id = request.session.get("user_id")
    if not user_id:
        return None
    return session.get(User, user_id)


def require_user(request: Request, session: Session = Depends(get_session)) -> User:
    user_id = request.session.get("user_id")
    if not user_id:
        raise HTTPException(status_code=307, headers={"Location": "/auth/login"})
    user = session.get(User, user_id)
    if not user:
        raise HTTPException(status_code=307, headers={"Location": "/auth/login"})
    return user