import { NextResponse } from 'next/server';
import { getServerSession } from 'next-auth';
import { authOptions } from '@/app/api/auth/[...nextauth]/route';
import { getMicrosoftAuthUrl } from '@/lib/services/microsoft-oauth';

// Endpoint to initiate Microsoft OAuth flow
export async function GET(request: Request) {
  try {
    // Authenticate user
    const session = await getServerSession(authOptions);
    if (!session?.user?.id) {
      return NextResponse.json(
        { error: 'Unauthorized' },
        { status: 401 }
      );
    }

    // Create a state parameter with the user's ID to prevent CSRF
    const state = Buffer.from(JSON.stringify({
      userId: session.user.id,
      timestamp: Date.now()
    })).toString('base64');

    // Generate the authorization URL
    const authUrl = getMicrosoftAuthUrl(state);

    return NextResponse.json({
      authUrl,
      state
    });
  } catch (error) {
    console.error('Error initiating Microsoft OAuth flow:', error);
    return NextResponse.json(
      { 
        error: 'Failed to initiate Microsoft OAuth flow',
        details: error instanceof Error ? error.message : 'Unknown error'
      },
      { status: 500 }
    );
  }
}