import { NextResponse, NextRequest } from 'next/server';
import { getServerSession } from 'next-auth';
import { authOptions } from '@/app/api/auth/[...nextauth]/route';

export async function GET(req: NextRequest) {
  try {
    const session = await getServerSession(authOptions);

    if (!session?.accessToken) {
      return NextResponse.json({ error: 'Unauthorized' }, { status: 401 });
    }

    const nextcloudUrl = process.env.NEXTCLOUD_URL;
    if (!nextcloudUrl) {
      console.error('Missing Nextcloud URL');
      return NextResponse.json(
        { error: 'Nextcloud configuration is missing' },
        { status: 500 }
      );
    }

    // Fetch unread messages from Nextcloud Mail API using OIDC token
    const response = await fetch(`${nextcloudUrl}/ocs/v2.php/apps/mail/api/v1/folders/inbox/messages?filter=unseen`, {
      headers: {
        'Authorization': `Bearer ${session.accessToken}`,
        'Accept': 'application/json',
        'OCS-APIRequest': 'true',
        'Content-Type': 'application/json',
      },
    });

    if (!response.ok) {
      console.error('Nextcloud API error:', {
        status: response.status,
        statusText: response.statusText,
        url: response.url
      });
      
      if (response.status === 401) {
        return NextResponse.json({ error: 'Nextcloud authentication failed' }, { status: 401 });
      }
      
      if (response.status === 404) {
        return NextResponse.json(
          { error: 'Mail app not available on Nextcloud' },
          { status: 404 }
        );
      }

      throw new Error(`Failed to fetch emails: ${response.status} ${response.statusText}`);
    }

    const data = await response.json();
    
    // Transform the data to match our Email interface
    const emails = (data?.ocs?.data || []).map((email: any) => ({
      id: email.id,
      subject: email.subject || '(No subject)',
      sender: {
        name: email.from?.name || email.from?.email || 'Unknown',
        email: email.from?.email || 'unknown@example.com'
      },
      date: email.sentDate,
      isUnread: true // Since we're only fetching unread messages
    }));

    // Sort by date (newest first) and limit to 5 messages
    const sortedEmails = emails
      .sort((a: any, b: any) => new Date(b.date).getTime() - new Date(a.date).getTime())
      .slice(0, 5);

    return NextResponse.json(sortedEmails);
  } catch (error) {
    console.error('Error fetching emails:', error);
    return NextResponse.json(
      { error: 'Failed to fetch emails from Nextcloud' },
      { status: 500 }
    );
  }
}