#!/usr/bin/node

const fs			= require('fs');
const path			= require('path');
const AWS			= require('aws-sdk');
const Promise			= require('bluebird');
const imagemin 			= require('imagemin');
const imageminJpegRecompress 	= require('imagemin-jpeg-recompress');

const config = {
	sslEnabled: 		true,
	bucket: 		process.env.AWS_BUCKET,
	region: 		process.env.AWS_REGION,
	accessKeyId: 		process.env.AWS_ACCESS_KEY,
	secretAccessKey: 	process.env.AWS_SECRET_ACCESS_KEY
};

AWS.config.update(config);

const s3Bucket			= config.bucket;
const s3Endpoint		= 's3.' + config.region + '.amazonaws.com';
const s3PublicEndpoint 		= 'https://' + config.bucket + '.s3.amazonaws.com/';
const s3			= new AWS.S3({ signatureVersion: 'v4', endpoint: s3Endpoint });

const optimizeImage = (image) => {
	let imageminOptions = {
		plugins: [
			imageminJpegRecompress({
				progressive: true,
				quality: 'high',
				accuracy: true,
				target: 0.995,
				min: 60,
				max: 95
			})
		]
	};
	
	return imagemin.buffer(image.Body, imageminOptions)
		.then((buffer) => {
			console.info('Optimizing Image Finished:', image.Key);
			console.log('Prev Size', Math.round(image.Body.toString().length / 1000) + 'KB');
			console.log('New Size', Math.round(buffer.toString().length / 1000) + 'KB\n');
			return { Body: buffer, Key: image.Key };
		})
		.catch((error) => {
			console.error('Image Optimization Error:', image.Key, error);
		});
};

const listImages = (params) => {
	return new Promise((resolve, reject) => {
		s3.listObjects(params, (error, images) => {
			return error ? reject(error) : resolve(images);
		});
	});
};

const getImage = (image) => {
	let params = { Bucket: config.bucket, Key: image.Key };
	return new Promise((resolve, reject) => {
		s3.getObject(params, (error, image) => {
			image ? image.Key = params.Key : null;
			return error ? reject(error) : resolve(image);
		});
	});
};

const setImage = (image) => {
	if(!(image && image.Key && image.Body)) {
		return Promise.resolve();
	}

	let params = {
		Body: image.Body,
		Key: image.Key,
		Bucket: config.bucket,
		ACL: "public-read",
		ContentType: "image/jpeg",
		CacheControl: "max-age=86400, public"
	};

	return new Promise((resolve, reject) => {
		s3.putObject(params, (error) => {
			console.log('\nUploaded', params.Key, error ? error : '');
			return error ? reject(error) : resolve();
		});
	});
};

const optimize = (image) => {
	return getImage(image)
		.then(optimizeImage)
		.then(setImage)
		.catch(console.error);
};

const run = (Marker, oneRun) => {
	let params = { Bucket: config.bucket, MaxKeys: oneRun ? 1 : 100 };
	params.Marker = Marker;

	console.log('\nNext Marker', Marker);

	return listImages(params)
		.then((data) => {
			console.log('\nTotal Length:', data.Contents.length);

			return Promise.map(data.Contents, optimize)
			.then(() => data.IsTruncated && !oneRun ? run(data.Contents.slice(-1)[0].Key) : null);
		});
};

return run(process.argv[2], process.argv[3]);