import { NextResponse } from 'next/server';
import { getServerSession } from 'next-auth';
import { authOptions } from '@/app/api/auth/[...nextauth]/route';
import { DOMParser } from '@xmldom/xmldom';
import { Buffer } from 'buffer';

async function sleep(ms: number) {
  return new Promise(resolve => setTimeout(resolve, ms));
}

async function getWebDAVCredentials(nextcloudUrl: string, username: string, adminUsername: string, adminPassword: string) {
  // First, try to get the user's WebDAV password
  const userInfoResponse = await fetch(`${nextcloudUrl}/ocs/v1.php/cloud/users/${encodeURIComponent(username)}`, {
    headers: {
      'Authorization': `Basic ${Buffer.from(`${adminUsername}:${adminPassword}`).toString('base64')}`,
      'OCS-APIRequest': 'true',
    },
  });

  if (!userInfoResponse.ok) {
    console.error('Failed to get user info:', await userInfoResponse.text());
    return null;
  }

  const userInfo = await userInfoResponse.json();
  const webdavPassword = userInfo.ocs.data?.webdav_password;

  if (!webdavPassword) {
    // If no WebDAV password exists, create one
    const createPasswordResponse = await fetch(`${nextcloudUrl}/ocs/v1.php/cloud/users/${encodeURIComponent(username)}`, {
      method: 'PUT',
      headers: {
        'Authorization': `Basic ${Buffer.from(`${adminUsername}:${adminPassword}`).toString('base64')}`,
        'OCS-APIRequest': 'true',
        'Content-Type': 'application/x-www-form-urlencoded',
      },
      body: new URLSearchParams({
        key: 'webdav_password',
        value: Math.random().toString(36).slice(-8), // Generate a random password
      }).toString(),
    });

    if (!createPasswordResponse.ok) {
      console.error('Failed to create WebDAV password:', await createPasswordResponse.text());
      return null;
    }

    // Get the new WebDAV password
    const newUserInfoResponse = await fetch(`${nextcloudUrl}/ocs/v1.php/cloud/users/${encodeURIComponent(username)}`, {
      headers: {
        'Authorization': `Basic ${Buffer.from(`${adminUsername}:${adminPassword}`).toString('base64')}`,
        'OCS-APIRequest': 'true',
      },
    });

    if (!newUserInfoResponse.ok) {
      console.error('Failed to get new user info:', await newUserInfoResponse.text());
      return null;
    }

    const newUserInfo = await newUserInfoResponse.json();
    return newUserInfo.ocs.data?.webdav_password;
  }

  return webdavPassword;
}

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

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

    const nextcloudUrl = process.env.NEXTCLOUD_URL;
    const adminUsername = process.env.NEXTCLOUD_ADMIN_USERNAME;
    const adminPassword = process.env.NEXTCLOUD_ADMIN_PASSWORD;

    if (!nextcloudUrl || !adminUsername || !adminPassword) {
      console.error('Missing Nextcloud configuration');
      return NextResponse.json(
        { error: 'Nextcloud configuration is missing' },
        { status: 500 }
      );
    }

    // Test Nextcloud connectivity
    const testResponse = await fetch(`${nextcloudUrl}/status.php`);
    if (!testResponse.ok) {
      console.error('Nextcloud is not accessible:', await testResponse.text());
      return NextResponse.json(
        { error: "Nextcloud n'est pas accessible" },
        { status: 503 }
      );
    }

    try {
      // Get or create WebDAV credentials
      const webdavPassword = await getWebDAVCredentials(
        nextcloudUrl,
        session.user.email,
        adminUsername,
        adminPassword
      );

      if (!webdavPassword) {
        throw new Error('Failed to get WebDAV credentials');
      }

      // Get user's folders using WebDAV with Basic authentication
      const webdavUrl = `${nextcloudUrl}/remote.php/dav/files/${encodeURIComponent(session.user.email)}/`;
      console.log('Requesting WebDAV URL:', webdavUrl);

      const foldersResponse = await fetch(webdavUrl, {
        headers: {
          'Authorization': `Basic ${Buffer.from(`${session.user.email}:${webdavPassword}`).toString('base64')}`,
          'Depth': '1',
          'Content-Type': 'application/xml',
        },
      });

      if (foldersResponse.status === 429) {
        // Rate limited, wait and retry
        const retryAfter = foldersResponse.headers.get('Retry-After');
        await sleep((retryAfter ? parseInt(retryAfter) : 5) * 1000);
        return GET(); // Retry the entire request
      }

      if (!foldersResponse.ok) {
        const errorText = await foldersResponse.text();
        console.error('Failed to fetch folders. Status:', foldersResponse.status);
        console.error('Response:', errorText);
        console.error('Response headers:', Object.fromEntries(foldersResponse.headers.entries()));
        throw new Error(`Failed to fetch folders: ${errorText}`);
      }

      const folderData = await foldersResponse.text();
      console.log('Folder data:', folderData);

      // Parse the XML response to get folder names and filter only directories
      const parser = new DOMParser();
      const xmlDoc = parser.parseFromString(folderData, 'text/xml');
      const responses = Array.from(xmlDoc.getElementsByTagName('d:response'));
      
      const folders: string[] = [];
      for (const response of responses) {
        const resourceType = response.getElementsByTagName('d:resourcetype')[0];
        const isCollection = resourceType?.getElementsByTagName('d:collection').length > 0;
        
        if (isCollection) {
          const displayName = response.getElementsByTagName('d:displayname')[0]?.textContent;
          if (displayName && displayName !== session.user.email) {
            folders.push(displayName);
          }
        }
      }

      console.log('Parsed folders:', folders);

      return NextResponse.json({
        isConnected: true,
        folders
      });
    } catch (error: any) {
      console.error('Error accessing Nextcloud WebDAV:', error);
      return NextResponse.json(
        { error: "Erreur d'accès aux dossiers Nextcloud", details: error?.message || String(error) },
        { status: 503 }
      );
    }
  } catch (error: any) {
    console.error('Error checking Nextcloud status:', error);
    return NextResponse.json(
      { error: 'Failed to check Nextcloud status', details: error?.message || String(error) },
      { status: 500 }
    );
  }
}