from fastapi import APIRouter, Request, Response, status
from fastapi.responses import RedirectResponse, HTMLResponse
from starlette.middleware.sessions import SessionMiddleware
from google_auth_oauthlib.flow import Flow
from googleapiclient.discovery import build
import os

from app.config import GOOGLE_CLIENT_ID, GOOGLE_CLIENT_SECRET, GOOGLE_REDIRECT_URI, YOUTUBE_SCOPES
from app.models import UserDatabase
router = APIRouter()


def create_flow():
    return Flow.from_client_config(
        {
            "web": {
                "client_id": GOOGLE_CLIENT_ID,
                "project_id": "youtube-fastapi-sample",
                "auth_uri": "https://accounts.google.com/o/oauth2/auth",
                "token_uri": "https://oauth2.googleapis.com/token",
                "client_secret": GOOGLE_CLIENT_SECRET,
            }
        },
        scopes=YOUTUBE_SCOPES,
    )

@router.get("/auth")
async def login(request: Request):
    flow = create_flow()
    flow.redirect_uri = GOOGLE_REDIRECT_URI  # must set the redirect_uri separately
    authorization_url, state = flow.authorization_url(
        access_type="offline",
        include_granted_scopes="true",
        prompt="select_account"
    )
    request.session["state"] = state
    return RedirectResponse(authorization_url)


@router.get("/auth/callback") 
async def auth_callback(request: Request):
    """Handle OAuth callback from Google with ?code= and ?state=."""
    state = request.session.get("state")
    if not state:
        return HTMLResponse("<h1>Session state not found. Please /login again.</h1>", status_code=400)
    
    flow = create_flow()
    flow.redirect_uri = GOOGLE_REDIRECT_URI  # Set the redirect_uri here instead
    
    # Remove the redirect_uri parameter from fetch_token
    flow.fetch_token(
        authorization_response=str(request.url)
        # Don't pass redirect_uri here, as it's already set on the flow object
    )
    
    # Rest of your code remains the same
    credentials = flow.credentials
    if not credentials or not credentials.valid:
        return HTMLResponse("<h1>Invalid credentials. Please /login again.</h1>", status_code=400)
    
    request.session["credentials"] = {
        "token": credentials.token,
        "refresh_token": credentials.refresh_token,
        "token_uri": credentials.token_uri,
        "client_id": credentials.client_id,
        "client_secret": credentials.client_secret,
        "scopes": credentials.scopes
    }

    youtube = build("youtube", "v3", credentials=credentials)
    channel_response = youtube.channels().list(part="snippet", mine=True).execute()
    if channel_response.get("items") and len(channel_response["items"]) > 0:
        channel_username = channel_response["items"][0]["snippet"]["title"]
    else:
        channel_username = "unknown_user"
    

    user = UserDatabase.create_user(channel_username, request.session["credentials"])
    response = RedirectResponse(url="/videos", status_code=status.HTTP_302_FOUND)
    
    # Set cookie settings based on your environment
    import os
    if os.getenv("HF_SPACE") == "true":
        secure_cookie = True
        samesite_value = "none"
    else:
        secure_cookie = False
        samesite_value = "lax"
    
    # Redirect to /videos with a cookie token
    response = RedirectResponse(url="/videos", status_code=303)
    response.set_cookie(
        key="token", 
        value=channel_username, 
        max_age=1800, 
        httponly=True, 
        secure=secure_cookie, 
        samesite=samesite_value
    )
    return response