import { S3Client, PutObjectCommand, GetObjectCommand, DeleteObjectCommand, ListObjectsV2Command } from '@aws-sdk/client-s3';
import { getSignedUrl } from '@aws-sdk/s3-request-presigner';

// S3 Configuration
export const S3_CONFIG = {
  endpoint: 'https://dome-api.slm-lab.net',
  region: 'us-east-1',
  bucket: process.env.S3_BUCKET || 'pages',
  accessKey: '4aBT4CMb7JIMMyUtp4Pl',
  secretKey: 'HGn39XhCIlqOjmDVzRK9MED2Fci2rYvDDgbLFElg'
};

// Initialize S3 client for Minio
export const s3Client = new S3Client({
  region: S3_CONFIG.region,
  endpoint: S3_CONFIG.endpoint,
  credentials: {
    accessKeyId: S3_CONFIG.accessKey,
    secretAccessKey: S3_CONFIG.secretKey
  },
  forcePathStyle: true // Required for MinIO
});

/**
 * Upload a file to S3
 */
export async function putObject(
  key: string,
  content: string | Buffer,
  contentType?: string
): Promise<{ key: string; url?: string }> {
  const command = new PutObjectCommand({
    Bucket: S3_CONFIG.bucket,
    Key: key,
    Body: typeof content === 'string' ? Buffer.from(content, 'utf-8') : content,
    ContentType: contentType || 'text/plain',
  });

  await s3Client.send(command);
  return { key };
}

/**
 * Get object content from S3
 */
export async function getObjectContent(key: string): Promise<string | null> {
  try {
    const command = new GetObjectCommand({
      Bucket: S3_CONFIG.bucket,
      Key: key,
    });

    const response = await s3Client.send(command);
    if (!response.Body) {
      return null;
    }

    const chunks: Uint8Array[] = [];
    for await (const chunk of response.Body as any) {
      chunks.push(chunk);
    }
    
    const buffer = Buffer.concat(chunks);
    return buffer.toString('utf-8');
  } catch (error) {
    console.error('Error getting object content:', error);
    return null;
  }
}

/**
 * Delete an object from S3
 */
export async function deleteObject(key: string): Promise<void> {
  const command = new DeleteObjectCommand({
    Bucket: S3_CONFIG.bucket,
    Key: key,
  });

  await s3Client.send(command);
}

/**
 * List objects for a user in a specific folder
 */
export async function listUserObjects(userId: string, folder: string): Promise<Array<{ key: string; name: string; size?: number; lastModified?: Date }>> {
  const prefix = `user-${userId}/${folder}/`;
  const command = new ListObjectsV2Command({
    Bucket: S3_CONFIG.bucket,
    Prefix: prefix,
    Delimiter: '/'
  });

  const response = await s3Client.send(command);
  const objects = response.Contents || [];
  
  return objects
    .filter(obj => obj.Key && !obj.Key.endsWith('/') && !obj.Key.includes('.placeholder'))
    .map(obj => ({
      key: obj.Key!,
      name: obj.Key!.split('/').pop() || obj.Key!,
      size: obj.Size,
      lastModified: obj.LastModified
    }));
}

/**
 * Get public URL for an object
 * Simple URL construction for MinIO/S3 objects
 */
export function getPublicUrl(filePath: string, bucket?: string): string {
  if (!filePath) return '';
  if (filePath.startsWith('http')) return filePath; // Already a full URL
  
  // Remove leading slash if present
  const cleanPath = filePath.startsWith('/') ? filePath.substring(1) : filePath;
  
  // Construct the full URL
  const endpoint = S3_CONFIG.endpoint?.replace(/\/$/, ''); // Remove trailing slash if present
  const bucketName = bucket || S3_CONFIG.bucket;
  
  // Return original path if no endpoint is configured
  if (!endpoint) return cleanPath;
  
  // Construct and return the full URL
  return `${endpoint}/${bucketName}/${cleanPath}`;
}

/**
 * Create standard folder structure for a user
 */
export async function createUserFolderStructure(userId: string): Promise<void> {
  const folders = ['notes', 'diary', 'health', 'contacts'];
  
  for (const folder of folders) {
    try {
      // Create folder path (prefix in S3)
      const folderKey = `user-${userId}/${folder}/`;
      await putObject(folderKey, '', 'application/x-directory');
      
      // Create placeholder file to ensure folder is visible
      const placeholderKey = `user-${userId}/${folder}/.placeholder`;
      await putObject(placeholderKey, 'Folder placeholder', 'text/plain');
      
      console.log(`Created folder: ${folderKey}`);
    } catch (error) {
      console.error(`Error creating folder ${folder} for user ${userId}:`, error);
      // Continue with other folders even if one fails
    }
  }
}

export async function uploadMissionFile({
  missionId,
  file,
  type, // 'logo' or 'attachment'
}: {
  missionId: string;
  file: File;
  type: 'logo' | 'attachment';
}): Promise<{ success: boolean; data?: any; error?: string }> {
  const formData = new FormData();
  formData.append('missionId', missionId);
  formData.append('type', type);
  formData.append('file', file);

  const res = await fetch('/api/missions/upload', {
    method: 'POST',
    body: formData,
  });

  if (!res.ok) {
    const err = await res.json().catch(() => ({}));
    return { success: false, error: err.error || 'Upload failed' };
  }

  const data = await res.json();
  return { success: true, data };
}