const { createBackup, listBackups, restoreBackup, cleanupOldBackups } = require('../../../maintenance/backup');
const { logError } = require('../../../infrastructure/logger');
const { trackRequest, trackRequestWithTiming } = require('../../../maintenance/metrics');
const { createErrorResponse } = require('../../../infrastructure/error_handler');
const sdk = require('../../../plugins/sdk');
const fs = require('fs').promises;
const path = require('path');

async function handleBackupsRoutes(req, res) {
  const urlPath = req.urlPath || new URL(req.url, `https://${req.headers.host}`).pathname;
  const method = req.method;

  // GET /api/backups - List all backups
  if (method === 'GET' && urlPath === '/api/backups') {
    try {
      const startTime = Date.now();
      const backups = await listBackups();
      
      // Add formatted size to each backup (size is already calculated in listBackups for tar.gz)
      const backupsWithSize = backups.map((backup) => {
        return {
          ...backup,
          size: backup.size || 0,
          sizeFormatted: sdk.utils.format.formatBytes(backup.size || 0)
        };
      });
      
      const responseTime = Date.now() - startTime;
      trackRequestWithTiming('/api/backups', true, responseTime);
      res.writeHead(200, { 'Content-Type': 'application/json' });
      res.end(JSON.stringify(backupsWithSize));
    } catch (err) {
      logError('Admin', `Failed to list backups: ${err.message}`);
      trackRequest('/api/backups', false);
      const errorResponse = createErrorResponse(err, 500);
      res.writeHead(errorResponse.statusCode, errorResponse.headers);
      res.end(errorResponse.body);
    }
    return true;
  }

  // POST /api/backups/create - Create manual backup
  if (method === 'POST' && urlPath === '/api/backups/create') {
    try {
      const startTime = Date.now();
      // Cleanup before creating backup
      await cleanupOldBackups();
      const backupPath = await createBackup();
      const responseTime = Date.now() - startTime;
      trackRequestWithTiming('/api/backups/create', true, responseTime);
      res.writeHead(200, { 'Content-Type': 'application/json' });
      res.end(JSON.stringify({ success: true, path: backupPath }));
    } catch (err) {
      logError('Admin', `Failed to create backup: ${err.message}`);
      trackRequest('/api/backups/create', false);
      const errorResponse = createErrorResponse(err, 500);
      res.writeHead(errorResponse.statusCode, errorResponse.headers);
      res.end(errorResponse.body);
    }
    return true;
  }

  // POST /api/backups/restore - Restore from backup
  if (method === 'POST' && urlPath === '/api/backups/restore') {
    try {
      let body = '';
      for await (const chunk of req) {
        body += chunk.toString();
      }
      const data = JSON.parse(body);
      const { backupName } = data;
      
      if (!backupName) {
        res.writeHead(400, { 'Content-Type': 'application/json' });
        res.end(JSON.stringify({ error: 'backupName is required' }));
        trackRequest('/api/backups/restore', false);
        return true;
      }
      
      const startTime = Date.now();
      await restoreBackup(backupName);
      const responseTime = Date.now() - startTime;
      trackRequestWithTiming('/api/backups/restore', true, responseTime);
      res.writeHead(200, { 'Content-Type': 'application/json' });
      res.end(JSON.stringify({ success: true, message: 'Backup restored successfully' }));
    } catch (err) {
      logError('Admin', `Failed to restore backup: ${err.message}`);
      trackRequest('/api/backups/restore', false);
      const errorResponse = createErrorResponse(err, 500);
      res.writeHead(errorResponse.statusCode, errorResponse.headers);
      res.end(errorResponse.body);
    }
    return true;
  }

  // DELETE /api/backups/:id - Delete backup
  if (method === 'DELETE' && urlPath.startsWith('/api/backups/')) {
    try {
      const backupName = urlPath.split('/api/backups/')[1];
      if (!backupName) {
        res.writeHead(400, { 'Content-Type': 'application/json' });
        res.end(JSON.stringify({ error: 'Backup name is required' }));
        trackRequest(urlPath, false);
        return true;
      }
      
      const BACKUP_DIR = process.env.BACKUP_DIR || './backups';
      const backupPath = path.join(BACKUP_DIR, backupName);
      
      // Verify it's a backup (directory or tar.gz)
      if (!backupName.startsWith('backup-')) {
        res.writeHead(400, { 'Content-Type': 'application/json' });
        res.end(JSON.stringify({ error: 'Invalid backup name' }));
        trackRequest(urlPath, false);
        return true;
      }
      
      const startTime = Date.now();
      // Check if it's a file (tar.gz) or directory
      const stats = await fs.stat(backupPath).catch(() => null);
      if (stats) {
        if (stats.isFile()) {
          // Delete tar.gz file
          await fs.unlink(backupPath);
        } else {
          // Delete directory
          await fs.rm(backupPath, { recursive: true, force: true });
        }
      }
      const responseTime = Date.now() - startTime;
      trackRequestWithTiming(urlPath, true, responseTime);
      res.writeHead(200, { 'Content-Type': 'application/json' });
      res.end(JSON.stringify({ success: true, message: 'Backup deleted successfully' }));
    } catch (err) {
      logError('Admin', `Failed to delete backup: ${err.message}`);
      trackRequest(urlPath, false);
      const errorResponse = createErrorResponse(err, 500);
      res.writeHead(errorResponse.statusCode, errorResponse.headers);
      res.end(errorResponse.body);
    }
    return true;
  }

  // GET /api/backups/:id/metadata - Get backup metadata
  if (method === 'GET' && urlPath.startsWith('/api/backups/') && urlPath.endsWith('/metadata')) {
    try {
      const backupName = urlPath.split('/api/backups/')[1].replace('/metadata', '');
      if (!backupName) {
        res.writeHead(400, { 'Content-Type': 'application/json' });
        res.end(JSON.stringify({ error: 'Backup name is required' }));
        trackRequest(urlPath, false);
        return true;
      }
      
      const BACKUP_DIR = process.env.BACKUP_DIR || './backups';
      const backupPath = path.join(BACKUP_DIR, backupName);
      
      const startTime = Date.now();
      let metadata, restoreSource, extractDir = null;
      
      try {
        // Check if it's a tar.gz file
        const stats = await fs.stat(backupPath);
        const isTarGz = backupName.endsWith('.tar.gz') && stats.isFile();
        
        if (isTarGz) {
          // Extract tar.gz to read metadata
          const { exec } = require('child_process');
          const { promisify } = require('util');
          const execAsync = promisify(exec);
          
          extractDir = path.join(BACKUP_DIR, `extract-metadata-${Date.now()}`);
          await fs.mkdir(extractDir, { recursive: true });
          
          try {
            await execAsync(`tar -xzf "${backupPath}" -C "${extractDir}"`);
            const entries = await fs.readdir(extractDir, { withFileTypes: true });
            if (entries.length === 1 && entries[0].isDirectory()) {
              restoreSource = path.join(extractDir, entries[0].name);
            } else {
              restoreSource = extractDir;
            }
            const metadataPath = path.join(restoreSource, 'metadata.json');
            metadata = JSON.parse(await fs.readFile(metadataPath, 'utf8'));
          } finally {
            // Clean up extraction
            if (extractDir) {
              await fs.rm(extractDir, { recursive: true, force: true }).catch(() => {});
            }
          }
        } else {
          // Directory format
          restoreSource = backupPath;
          const metadataPath = path.join(backupPath, 'metadata.json');
          metadata = JSON.parse(await fs.readFile(metadataPath, 'utf8'));
        }
        
        // Get file sizes (only for directory format, tar.gz files are already compressed)
        const filesWithSize = await Promise.all(
          (metadata.files || []).map(async (fileName) => {
            if (isTarGz) {
              // For tar.gz, we can't easily get individual file sizes without extracting
              return {
                name: fileName,
                size: 0,
                sizeFormatted: 'N/A (compressed)',
                modified: null
              };
            } else {
              const filePath = path.join(restoreSource, 'cache', fileName);
              const altPath = path.join(restoreSource, fileName);
              try {
                let stats;
                try {
                  stats = await fs.stat(filePath);
                } catch {
                  stats = await fs.stat(altPath);
                }
                return {
                  name: fileName,
                  size: stats.size,
                  sizeFormatted: sdk.utils.format.formatBytes(stats.size),
                  modified: stats.mtime.toISOString()
                };
              } catch (err) {
                return {
                  name: fileName,
                  size: 0,
                  sizeFormatted: '0 Bytes',
                  modified: null
                };
              }
            }
          })
        );
        
        const responseTime = Date.now() - startTime;
        trackRequestWithTiming(urlPath, true, responseTime);
        res.writeHead(200, { 'Content-Type': 'application/json' });
        res.end(JSON.stringify({
          ...metadata,
          files: filesWithSize
        }));
      } catch (readErr) {
        if (extractDir) {
          await fs.rm(extractDir, { recursive: true, force: true }).catch(() => {});
        }
        throw readErr;
      }
    } catch (err) {
      if (err.code === 'ENOENT') {
        res.writeHead(404, { 'Content-Type': 'application/json' });
        res.end(JSON.stringify({ error: 'Backup not found' }));
      } else {
        logError('Admin', `Failed to get backup metadata: ${err.message}`);
        const errorResponse = createErrorResponse(err, 500);
        res.writeHead(errorResponse.statusCode, errorResponse.headers);
        res.end(errorResponse.body);
      }
      trackRequest(urlPath, false);
    }
    return true;
  }

  return false;
}

module.exports = { handleBackupsRoutes };