import { createRouteHandlerClient } from '@supabase/auth-helpers-nextjs';
import { cookies } from 'next/headers';
import { NextResponse } from 'next/server';
import type { NextRequest } from 'next/server';

export async function GET(request: NextRequest) {
  const requestUrl = new URL(request.url);
  const code = requestUrl.searchParams.get('code');
  
  console.log('Auth callback received:', { url: request.url, hasCode: !!code });
  
  // If no code parameter found, redirect to login page
  if (!code) {
    console.log('No code parameter found, redirecting to login page');
    return NextResponse.redirect(new URL('/login', request.url));
  }

  try {
    // Create Supabase client
    const cookieStore = cookies();
    const supabaseRouteHandler = createRouteHandlerClient({ cookies: () => cookieStore });
    
    // Exchange code for session
    console.log('Starting code exchange for session');
    const { data, error } = await supabaseRouteHandler.auth.exchangeCodeForSession(code);
    
    if (error) {
      console.error('Error exchanging code for session:', error);
      throw error;
    }
    
    console.log('Successfully retrieved session, user:', data.session?.user.email);
    
    // Check if session was successfully created
    if (data.session) {
      console.log('Session created successfully:', {
        userId: data.session.user.id,
        email: data.session.user.email,
        expiresAt: data.session.expires_at ? new Date(data.session.expires_at * 1000).toISOString() : 'unknown'
      });
      
      // Set additional cookie to ensure client can detect login status
      // Use Next.js Response to set cookie
      const response = NextResponse.redirect(new URL('/', request.url));
      response.cookies.set({
        name: 'sb-auth-token',
        value: 'true',
        path: '/',
        maxAge: 60 * 60 * 24 * 7, // 7 days
        sameSite: 'lax',
        secure: process.env.NODE_ENV === 'production',
        httpOnly: false,
      });
      console.log('Set backup cookie: sb-auth-token');
      return response;
    }
    
    // Redirect to home page by default
    console.log('Redirecting to home page');
    return NextResponse.redirect(new URL('/', request.url));
  } catch (error) {
    console.error('Auth callback error:', error);
    // Redirect to login page on error
    return NextResponse.redirect(
      new URL('/login?message=Authentication failed. Please try again.', request.url)
    );
  }
}