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?.user?.email) {
      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 }
      );
    }

    // Get the access token from the session
    const accessToken = session.accessToken;
    if (!accessToken) {
      console.error('Missing access token');
      return NextResponse.json(
        { error: 'Authentication token is missing' },
        { status: 401 }
      );
    }

    // First, try the unified inbox endpoint for unread messages
    const unifiedResponse = await fetch(
      `${nextcloudUrl}/apps/mail/api/messages?filter=is:unread`,
      {
        headers: {
          'Authorization': `Bearer ${accessToken}`,
          'Accept': 'application/json'
        }
      }
    );

    if (unifiedResponse.ok) {
      const unifiedData = await unifiedResponse.json();
      const messages = unifiedData.data || [];
      
      const unreadEmails = messages.map((msg: any) => ({
        id: msg.id,
        subject: msg.subject,
        sender: {
          name: msg.from[0].label || msg.from[0].email,
          email: msg.from[0].email
        },
        date: msg.date,
        isUnread: true
      }));

      return NextResponse.json({
        emails: unreadEmails,
        mailUrl: `${nextcloudUrl}/apps/mail/box/unified`
      });
    }

    // If unified inbox fails, fall back to the account-based approach
    const accountsResponse = await fetch(
      `${nextcloudUrl}/apps/mail/api/accounts`,
      {
        headers: {
          'Authorization': `Bearer ${accessToken}`,
          'Accept': 'application/json'
        }
      }
    );

    if (!accountsResponse.ok) {
      console.error('Failed to fetch mail accounts:', await accountsResponse.text());
      return NextResponse.json(
        { 
          error: "L'application Mail n'est pas disponible sur Nextcloud. Veuillez contacter votre administrateur.",
          emails: []
        },
        { status: 404 }
      );
    }

    const accountsData = await accountsResponse.json();
    const accounts = accountsData.data || [];

    const unreadEmails = [];
    for (const account of accounts) {
      // Get mailboxes for the account
      const mailboxesResponse = await fetch(
        `${nextcloudUrl}/apps/mail/api/accounts/${account.id}/mailboxes`,
        {
          headers: {
            'Authorization': `Bearer ${accessToken}`,
            'Accept': 'application/json'
          }
        }
      );

      if (!mailboxesResponse.ok) continue;

      const mailboxesData = await mailboxesResponse.json();
      const mailboxes = mailboxesData.data || [];

      // Get unread messages from each mailbox
      for (const mailbox of mailboxes) {
        const messagesResponse = await fetch(
          `${nextcloudUrl}/apps/mail/api/accounts/${account.id}/mailboxes/${mailbox.id}/messages?filter=is:unread`,
          {
            headers: {
              'Authorization': `Bearer ${accessToken}`,
              'Accept': 'application/json'
            }
          }
        );

        if (!messagesResponse.ok) continue;

        const messagesData = await messagesResponse.json();
        const messages = messagesData.data || [];

        unreadEmails.push(...messages.map((msg: any) => ({
          id: msg.id,
          subject: msg.subject,
          sender: {
            name: msg.from[0].label || msg.from[0].email,
            email: msg.from[0].email
          },
          date: msg.date,
          isUnread: true
        })));
      }
    }

    return NextResponse.json({
      emails: unreadEmails,
      mailUrl: `${nextcloudUrl}/apps/mail/box/unified`
    });
  } catch (error) {
    console.error('Error getting emails:', error);
    return NextResponse.json(
      { 
        error: "Une erreur est survenue. Veuillez contacter votre administrateur.",
        emails: []
      },
      { status: 500 }
    );
  }
}