import os
import time
from flask import Blueprint, render_template, request, jsonify, redirect, url_for, session, current_app
from flask_login import LoginManager, login_user, logout_user, login_required, current_user
import requests
from requests_oauthlib import OAuth2Session
from models.user import User

# Disable SSL requirement for local development
os.environ['OAUTHLIB_INSECURE_TRANSPORT'] = '1'
# Ensure OAuthlib allows HTTP for local development
os.environ['OAUTHLIB_RELAX_TOKEN_SCOPE'] = '1'
os.environ['OAUTHLIB_IGNORE_SCOPE_CHANGE'] = '1'

auth_bp = Blueprint('auth', __name__)

# Google OAuth configuration with your provided credentials
GOOGLE_CLIENT_ID = os.environ.get('GOOGLE_CLIENT_ID')
GOOGLE_CLIENT_SECRET = os.environ.get('GOOGLE_CLIENT_SECRET')
GOOGLE_REDIRECT_URI = os.environ.get('GOOGLE_REDIRECT_URI', 'http://localhost:5000/auth/google/callback')

print(f"OAuth Configuration Loaded - Client ID: {GOOGLE_CLIENT_ID[:10] if GOOGLE_CLIENT_ID else 'None'}...")

def validate_oauth_config():
    """Validate OAuth configuration and raise error if missing"""
    if not GOOGLE_CLIENT_ID or not GOOGLE_CLIENT_SECRET:
        raise ValueError("Google OAuth credentials not found in environment variables. Please check your .env file.")

# Google OAuth URLs
GOOGLE_AUTHORIZATION_BASE_URL = "https://accounts.google.com/o/oauth2/v2/auth"
GOOGLE_TOKEN_URL = "https://oauth2.googleapis.com/token"
GOOGLE_USER_INFO_URL = "https://www.googleapis.com/oauth2/v2/userinfo"

# Initialize login manager
login_manager = LoginManager()

def init_app(app):
    """Initialize the login manager with the app"""
    login_manager.init_app(app)
    # Set login view - using setattr to avoid type checking issues
    setattr(login_manager, 'login_view', 'auth.login')
    return login_manager

@login_manager.user_loader
def load_user(user_id):
    return User.get(user_id)


@auth_bp.route("/login")
def login():
    """Display the login page"""
    return render_template('login.html')


@auth_bp.route("/google/login")
def google_login():
    """Redirect to Google OAuth login"""
    try:
        # Validate OAuth configuration
        validate_oauth_config()
        
        # Clear any existing OAuth state to prevent conflicts
        session.pop('oauth_state', None)
        
        # Create OAuth2Session with Google
        google = OAuth2Session(
            GOOGLE_CLIENT_ID,
            scope=["openid", "email", "profile"],
            redirect_uri=GOOGLE_REDIRECT_URI
        )
        
        # Generate authorization URL
        authorization_url, state = google.authorization_url(
            GOOGLE_AUTHORIZATION_BASE_URL,
            access_type="offline",
            prompt="select_account"
        )
        
        # Store state in session for security
        session['oauth_state'] = state
        print(f"Stored OAuth state: {state}")
        print(f"Authorization URL: {authorization_url}")
        
        # Redirect user to Google for authorization
        return redirect(authorization_url)
        
    except Exception as e:
        print(f"Error in Google OAuth login: {e}")
        import traceback
        traceback.print_exc()
        return redirect(url_for('auth.login'))


@auth_bp.route("/google/callback")
def google_callback():
    """Handle Google OAuth callback"""
    try:
        # Validate OAuth configuration
        validate_oauth_config()
        
        # Get state parameters
        received_state = request.args.get('state')
        stored_state = session.get('oauth_state')
        
        # Log state values for debugging
        print(f"Received state: {received_state}")
        print(f"Stored state: {stored_state}")
        
        # Verify state parameter (allow None for development/testing)
        if stored_state and received_state != stored_state:
            print("State parameter mismatch")
            return redirect(url_for('auth.login'))
        
        # Create OAuth2Session with Google
        google = OAuth2Session(
            GOOGLE_CLIENT_ID,
            state=stored_state,  # Use stored state if available
            redirect_uri=GOOGLE_REDIRECT_URI
        )
        
        # Fetch token
        token = google.fetch_token(
            GOOGLE_TOKEN_URL,
            client_secret=GOOGLE_CLIENT_SECRET,
            authorization_response=request.url,
            # Include these parameters to handle token fetching properly
            include_client_id=True
        )
        
        # Fetch user info
        user_info = google.get(GOOGLE_USER_INFO_URL).json()
        print(f"User info: {user_info}")
        
        # Create or update user in our database
        user = User.create_or_update(
            id=f"google_{user_info['id']}",
            email=user_info['email'],
            name=user_info.get('name', user_info['email'].split('@')[0]),
            picture=user_info.get('picture')
        )
        
        if user:
            login_user(user)
            # Clean up session
            session.pop('oauth_state', None)
            return redirect(url_for('index'))
        else:
            return redirect(url_for('auth.login'))
            
    except Exception as e:
        print(f"Error in Google OAuth callback: {e}")
        import traceback
        traceback.print_exc()
        # Log additional debugging information
        print(f"Request args: {request.args}")
        print(f"Session data: {dict(session)}")
        return redirect(url_for('auth.login'))


@auth_bp.route("/guest/login", methods=['POST'])
def guest_login():
    """Login as a guest user"""
    name = request.form.get('name')
    if not name:
        return "Name is required", 400
    
    # Create a guest user
    user = User.create_or_update(
        id=f"guest_{name.lower().replace(' ', '_')}_{int(time.time())}",
        email=f"{name.lower().replace(' ', '.')}@guest.texlab.com",
        name=name,
        picture=None
    )
    
    if user:
        login_user(user)
        return redirect(url_for('index'))
    else:
        return "Failed to create user", 500


@auth_bp.route("/logout")
@login_required
def logout():
    logout_user()
    return redirect(url_for('auth.login'))


@auth_bp.route("/user")
def get_current_user():
    if current_user.is_authenticated:
        return jsonify({
            'authenticated': True,
            'user': {
                'id': current_user.id,
                'email': current_user.email,
                'name': current_user.name,
                'picture': current_user.picture
            }
        })
    else:
        return jsonify({'authenticated': False})