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

// Environment variables for S3 configuration
const S3_BUCKET_URL = process.env.MINIO_S3_UPLOAD_BUCKET_URL || 'https://dome-api.slm-lab.net/';
const S3_REGION = process.env.MINIO_AWS_REGION || 'eu-east-1';
const S3_BUCKET_NAME = process.env.MINIO_AWS_S3_UPLOAD_BUCKET_NAME || 'pages';
const S3_ACCESS_KEY = process.env.MINIO_ACCESS_KEY || process.env.AWS_ACCESS_KEY_ID;
const S3_SECRET_KEY = process.env.MINIO_SECRET_KEY || process.env.AWS_SECRET_ACCESS_KEY;

// Basic client config without credentials
const s3Config = {
  region: S3_REGION,
  endpoint: S3_BUCKET_URL,
  forcePathStyle: true, // Required for MinIO
};

// Add credentials if available
if (S3_ACCESS_KEY && S3_SECRET_KEY) {
  Object.assign(s3Config, {
    credentials: {
      accessKeyId: S3_ACCESS_KEY,
      secretAccessKey: S3_SECRET_KEY
    }
  });
}

// Create S3 client with MinIO configuration
export const s3Client = new S3Client(s3Config);

// Helper functions for S3 operations

// List objects in a "folder" for a specific user
export async function listUserObjects(userId: string, folder: string) {
  try {
    const prefix = `user-${userId}/${folder}/`;
    const command = new ListObjectsV2Command({
      Bucket: S3_BUCKET_NAME,
      Prefix: prefix,
      Delimiter: '/'
    });
    
    const response = await s3Client.send(command);
    
    // Transform S3 objects to match the expected format for the frontend
    // This ensures compatibility with existing NextCloud based components
    return response.Contents?.map(item => ({
      id: item.Key,
      title: item.Key?.split('/').pop()?.replace('.md', '') || '',
      lastModified: item.LastModified?.toISOString(),
      size: item.Size,
      type: 'file',
      mime: item.Key?.endsWith('.md') ? 'text/markdown' : 'application/octet-stream',
      etag: item.ETag
    })) || [];
  } catch (error) {
    console.error('Error listing objects:', error);
    throw error;
  }
}

// Get object content
export async function getObjectContent(key: string) {
  try {
    const command = new GetObjectCommand({
      Bucket: S3_BUCKET_NAME,
      Key: key
    });
    
    const response = await s3Client.send(command);
    
    // Convert the stream to string
    return await response.Body?.transformToString();
  } catch (error) {
    console.error('Error getting object content:', error);
    throw error;
  }
}

// Put object (create or update a file)
export async function putObject(key: string, content: string, contentType?: string) {
  try {
    const command = new PutObjectCommand({
      Bucket: S3_BUCKET_NAME,
      Key: key,
      Body: content,
      ContentType: contentType || (key.endsWith('.md') ? 'text/markdown' : 'text/plain')
    });
    
    const response = await s3Client.send(command);
    
    return {
      id: key,
      title: key.split('/').pop()?.replace('.md', '') || '',
      lastModified: new Date().toISOString(),
      size: content.length,
      type: 'file',
      mime: contentType || (key.endsWith('.md') ? 'text/markdown' : 'text/plain'),
      etag: response.ETag
    };
  } catch (error) {
    console.error('Error putting object:', error);
    throw error;
  }
}

// Delete object
export async function deleteObject(key: string) {
  try {
    const command = new DeleteObjectCommand({
      Bucket: S3_BUCKET_NAME,
      Key: key
    });
    
    await s3Client.send(command);
    return true;
  } catch (error) {
    console.error('Error deleting object:', error);
    throw error;
  }
}

// Create folder structure (In S3, folders are just prefix notations)
export async function createUserFolderStructure(userId: string) {
  try {
    console.log(`Starting folder structure creation for user: ${userId}`);
    
    // Define the standard folders to create - use lowercase for consistency with S3 operations
    // These are the canonical folder names that match what the frontend expects in the "vues" sidebar
    const folders = ['notes', 'diary', 'health', 'contacts'];
    
    // Also create capitalized versions for backward compatibility with UI components
    const capitalizedFolders = ['Notes', 'Diary', 'Health', 'Contacts'];
    
    // Results tracking
    const results = {
      lowercase: [] as string[],
      capitalized: [] as string[]
    };
    
    // For S3, creating a folder means creating an empty object with the folder name as a prefix
    // First create lowercase versions (primary storage)
    for (const folder of folders) {
      try {
        const key = `user-${userId}/${folder}/`;
        console.log(`Creating folder: ${key}`);
        await putObject(key, '', 'application/x-directory');
        results.lowercase.push(folder);
        
        // Create a placeholder file to ensure the folder is visible
        const placeholderKey = `user-${userId}/${folder}/.placeholder`;
        await putObject(placeholderKey, 'This is a placeholder file to ensure the folder exists.', 'text/plain');
      } catch (error) {
        console.error(`Error creating lowercase folder ${folder}:`, error);
      }
    }
    
    // Then create capitalized versions (for backward compatibility)
    for (const folder of capitalizedFolders) {
      try {
        const key = `user-${userId}/${folder}/`;
        console.log(`Creating capitalized folder: ${key}`);
        await putObject(key, '', 'application/x-directory');
        results.capitalized.push(folder);
        
        // Create a placeholder file to ensure the folder is visible
        const placeholderKey = `user-${userId}/${folder}/.placeholder`;
        await putObject(placeholderKey, 'This is a placeholder file to ensure the folder exists.', 'text/plain');
      } catch (error) {
        console.error(`Error creating capitalized folder ${folder}:`, error);
      }
    }
    
    console.log(`Successfully created folder structure for user: ${userId}`, results);
    return true;
  } catch (error) {
    console.error('Error creating folder structure:', error);
    throw error;
  }
}

// Generate pre-signed URL for direct browser upload (optional feature)
export async function generatePresignedUrl(key: string, expiresIn = 3600) {
  try {
    const command = new PutObjectCommand({
      Bucket: S3_BUCKET_NAME,
      Key: key
    });
    
    return await getSignedUrl(s3Client, command, { expiresIn });
  } catch (error) {
    console.error('Error generating presigned URL:', error);
    throw error;
  }
}