src/middlewares/multer.ts

import multer from 'multer';
import AWS from 'aws-sdk';
import { GenerateDownloadUrlParams, GenerateSignedUrlParams } from 'shared/interfaces/s3.interface';

export const s3 = new AWS.S3({
    accessKeyId: process.env.AWS_ACCESS_KEY_ID,
    secretAccessKey: process.env.AWS_SECRET_ACCESS_KEY,
    region: process.env.AWS_REGION,
});


const storage = multer.memoryStorage();
const upload = multer({ storage });

export const multipleUpload = upload.array('files');

export const generateSignedUrl = async ({
  bucketName,
  objectKey,
  expiration = 3600,
  contentType = 'application/octet-stream',
}: GenerateSignedUrlParams): Promise<string> => {
  const params = {
    Bucket: bucketName,
    Key: objectKey,
    Expires: expiration, 
    ContentType: contentType,
  };

  try {
    const url = await s3.getSignedUrlPromise('putObject', params);
    
    return url;
  } catch (err) {
    console.error('Error generating signed URL', err);
    throw err;
  }
};

export const generateDownloadUrl = async ({
  bucketName,
  objectKey,
  expiration = 60 * 60 * 24 * 365 * 10 // URL EXPIRY is set to 10 years for now, TODO: change the logic in frontend to get file download url run time
}: GenerateDownloadUrlParams): Promise<string> => {
  const params = {
    Bucket: bucketName,
    Key: objectKey,
    Expires: expiration,
  };

  try {
    const url = await s3.getSignedUrlPromise('getObject', params);
    return url;
  } catch (err) {
    console.error('Error generating signed URL', err);
    throw err;
  }
};