const ImageTypeEnum = Object.freeze({ JPG: 1, JPEG: 2, PNG: 3 })
const ImageType = class {
  constructor(imageTypeEnum, suffix) {
    this.imageTypeEnum = imageTypeEnum
    this.suffix = suffix
  }
}
const ImageTypes = Object.freeze({
  JPG: new ImageType(ImageTypeEnum.JPG, 'jpg'),
  JPEG: new ImageType(ImageTypeEnum.JPEG, 'jpeg'),
  PNG: new ImageType(ImageTypeEnum.PNG, 'png')
})

export default class Base64Photo {
  constructor() {
    this.data = null
    this.imageType = null
  }

  decode(dataString) {
    let matches = dataString.match(/^data:([A-Za-z-+\/]+);base64,(.+)$/)
    if (matches.length !== 3) {
      throw new Error(`Invalid image`)
    }

    this.setTypeEnum(matches[1])
    this.data = matches[2]
  }

  readFileInput(input) {
    if (input.files && input.files[0]) {
      let reader = new FileReader()

      reader.onload = function(e) {
        this.decode(e.target.result)
      }.bind(this)

      reader.readAsDataURL(input.files[0])
    }
  }

  setTypeEnum(type) {
    switch (type) {
      case 'image/jpg':
        this.imageType = ImageTypes.JPG
        break
      case 'image/jpeg':
        this.imageType = ImageTypes.JPEG
        break
      case 'image/png':
        this.imageType = ImageTypes.PNG
        break
      default:
        throw `Invalid image type: ${type}`
    }
  }

  getSuffix() {
    return this.imageType.suffix
  }
}