thumbnail-microservice-route.js

'use strict'


// Load in Route Class
const Route 	= require('restify-loader/route')
const lodash 	= require('lodash')
const sharp 	= require('sharp')
const Promise 	= require('bluebird')
const request 	= require('request-promise')

const S3_HOST = process.env.S3_HOST || 'https://s3.stackdot.com/sketch-storage'
console.log('S3 HOST:', S3_HOST)


// Create Route
module.exports = class Thumbnail extends Route {

	init(){
		this.S3 = this.params.S3
		this.debug( 'Thumbnail API')
		this.addListeners()
	}

	addListeners(){
		this.debug( 'Adding Listeners' )
		this.server.get({ url: '/thumbnail/:user/:sketch/:version/:artboard',
			validation: {
				resources: {
					size: {
						isRequired: false,
						min: 16,
						max: 3000
					},
					sizeh: {
						isRequired: false,
						min: 16,
						max: 3000
					},
					quality: {
						isRequired: false,
						min: 20,
						max: 100
					},
					scaleOnly: {
						isRequired: false,
						isBoolean: true
					}
				}
			}
		}, this.getStatus.bind( this ))
	}

	cropImage( img, settings ){
		return sharp( img )
			.resize( 2500, 2500 )
			.min()
			.withoutEnlargement()
			.toBuffer()
			.then(( sharpImg ) => {
				return sharp( sharpImg )
					.resize( settings.sizew, settings.size )
					.min()
					.crop(sharp.gravity.northwest)
					.jpeg({ progressive: true, quality: settings.quality })
					.toBuffer()
			})
	}

	scaleOnly( img, settings ){
		return sharp( img )
			.resize( settings.sizew, settings.size )
			.min()
			.withoutEnlargement()
			.jpeg({ progressive: true, quality: settings.quality })
			.toBuffer()
	}

	getStatus( req, res, next ){
		this.debug('got req')
		// Defaults:
		let size = 600
		if( req.params.size ) size = parseInt( req.params.size )
		let sizew = size
		if( req.params.sizew ) sizew = parseInt( req.params.sizew )
		let quality = 98
		if( req.params.quality ) quality = parseInt( req.params.quality )
		let scaleOnly = req.params.scaleOnly || false
		
		let settings = {
			size: size,
			sizew: sizew,
			quality: quality,
			scaleOnly: scaleOnly
		}

		let url = `${S3_HOST}/${req.params.user}/${req.params.sketch}/${req.params.version}/${req.params.artboard}`
		this.getImage( url )
			.then(( img ) => {
				if( scaleOnly ){
					return this.scaleOnly( img, settings )
				}
				return this.cropImage( img, settings )
			})
			.then(( buffer ) => {
				res.set('Content-Type','image/jpeg')
				res.write(buffer)
				res.end()
			})
			.catch(next)
	}


	getImage( url ){
		return request({
			uri: url,
			encoding: null
		})
	}



}