/**
 * MinIO Storage Service
 * S3-compatible object storage for media files
 *
 * MinIO Console: https://minio-console.eluxnetworks.net
 * S3 Endpoint: https://minio.eluxnetworks.net
 */

const { S3Client, PutObjectCommand, DeleteObjectCommand } = require('@aws-sdk/client-s3');
const crypto = require('crypto');

// MinIO Configuration
const MINIO_ENDPOINT = process.env.MINIO_ENDPOINT || 'https://minio.eluxnetworks.net';
const MINIO_ACCESS_KEY = process.env.MINIO_ACCESS_KEY;
const MINIO_SECRET_KEY = process.env.MINIO_SECRET_KEY;
const MINIO_BUCKET = process.env.MINIO_BUCKET || 'wellnuo';

// Public URL for accessing files
const PUBLIC_URL = process.env.MINIO_PUBLIC_URL || MINIO_ENDPOINT;

// Create S3 client for MinIO
const s3Client = new S3Client({
  endpoint: MINIO_ENDPOINT,
  region: 'us-east-1', // MinIO ignores this but requires it
  credentials: {
    accessKeyId: MINIO_ACCESS_KEY,
    secretAccessKey: MINIO_SECRET_KEY,
  },
  forcePathStyle: true, // Required for MinIO
});

/**
 * Upload a base64 image to MinIO
 * @param {string} base64Data - Base64 data URI (data:image/png;base64,...)
 * @param {string} folder - Folder path (e.g., 'avatars/beneficiaries')
 * @param {string} [filename] - Optional filename, generated if not provided
 * @returns {Promise<{url: string, key: string}>}
 */
async function uploadBase64Image(base64Data, folder, filename = null) {
  if (!MINIO_ACCESS_KEY || !MINIO_SECRET_KEY) {
    throw new Error('MinIO credentials not configured');
  }

  // Parse base64 data URI
  const matches = base64Data.match(/^data:image\/(\w+);base64,(.+)$/);
  if (!matches) {
    throw new Error('Invalid base64 image format');
  }

  const [, extension, base64Content] = matches;
  const buffer = Buffer.from(base64Content, 'base64');

  // Generate filename if not provided
  const finalFilename = filename || `${crypto.randomUUID()}.${extension}`;
  const key = `${folder}/${finalFilename}`;

  // Determine content type
  const contentType = `image/${extension === 'jpg' ? 'jpeg' : extension}`;


  // Upload to MinIO
  const command = new PutObjectCommand({
    Bucket: MINIO_BUCKET,
    Key: key,
    Body: buffer,
    ContentType: contentType,
    ACL: 'public-read', // Make file publicly accessible
  });

  await s3Client.send(command);

  // Return public URL
  const url = `${PUBLIC_URL}/${MINIO_BUCKET}/${key}`;


  return { url, key };
}

/**
 * Delete a file from MinIO
 * @param {string} key - Object key (path in bucket)
 */
async function deleteFile(key) {
  if (!MINIO_ACCESS_KEY || !MINIO_SECRET_KEY) {
    throw new Error('MinIO credentials not configured');
  }


  const command = new DeleteObjectCommand({
    Bucket: MINIO_BUCKET,
    Key: key,
  });

  await s3Client.send(command);

}

/**
 * Extract key from MinIO URL
 * @param {string} url - Full MinIO URL
 * @returns {string|null} - Object key or null
 */
function extractKeyFromUrl(url) {
  if (!url) return null;

  // URL format: https://minio.eluxnetworks.net/wellnuo/avatars/xxx.png
  const match = url.match(/\/wellnuo\/(.+)$/);
  return match ? match[1] : null;
}

/**
 * Check if storage is configured
 */
function isConfigured() {
  return !!(MINIO_ACCESS_KEY && MINIO_SECRET_KEY);
}

module.exports = {
  uploadBase64Image,
  deleteFile,
  extractKeyFromUrl,
  isConfigured,
  MINIO_BUCKET,
  PUBLIC_URL,
};