api/libs/resize.js

const fs = require('fs')
const resizeImg = require('resize-img')

class Resize {
  constructor (width, heigth) {
    this.size = {
      width: 128,
      heigth: 128
    }

    if (width && heigth) {
      this.setSize(width, heigth)
    }
  }

  _createOutputFilename (input) {
    return `${input}_${this.size.width}x${this.size.heigth}`
  }

  _resize (input, output, callback) {
    fs.readFile(input, (err, data) => {
      if (err) {
        callback(err, null)
        return false
      }

      resizeImg(data, this.size).then(buf => {
        fs.writeFile(output, buf, (err) => {
          if (err) {
            callback(err, null)
            return false
          }
          callback(null, { input: input, output: output, size: this.size })
        })
      })
    })
  }

  setSize (width, heigth) {
    this.size = {
      width: width,
      heigth: heigth
    }
  }

  createThumbnail (file, callback) {
    this.setSize(128, 128)
    this._resize(file, this._createOutputFilename(file), callback)
  }

  createLargeImage (file, callback) {
    this.setSize(1200, 900)
    this._resize(file, this._createOutputFilename(file), callback)
  }

  resize (file, width, heigth, callback) {
    this.setSize(width, heigth)
    this._resize(file, this._createOutputFilename(file), callback)
  }
}

module.exports = Resize