"use strict";
const { ROOT_PATH, LIB_PATH, MODELS_PATH, API_CONFIG } = process.env;
const apiConfig = require( `${ROOT_PATH}/${API_CONFIG}` );

const { S3Client, GetObjectCommand } = require('@aws-sdk/client-s3');
const s3Client = new S3Client({
    region : apiConfig.S3.region,
    credentials : {
        accessKeyId : apiConfig.S3.accessKeyId,
        secretAccessKey : apiConfig.S3.secretAccessKey
    }
});
const s3Bucket = apiConfig.S3.bucket;
const s3BucketKey = apiConfig.S3.key;

async function downloadFile( bucket, key, obj_id ){
    const params = {
        Bucket: bucket,
		Key : `${key}/${obj_id}`
    };
    const s3resp = await s3Client.send( new GetObjectCommand( params ) );
    const chunks = []
    for await (const chunk of s3resp.Body) {
      chunks.push(chunk)
    }
    const body = Buffer.concat(chunks);
    s3resp.Body = body;
    return s3resp;
}
const getAttachmentFile = async(req, res) => {
    const attachmentId = req.params.id;
    const file = await downloadFile( s3Bucket, s3BucketKey, attachmentId );
    res.attachment( attachmentId );
    res.setHeader('Content-Type', file.ContentType );
    res.send( file.Body );
}

module.exports = { getAttachmentFile };