index.js

var crypto = require('crypto');

/**
 * @param {[type]} securityKey
 * @param {[type]} thumborServerUrl
 */
function Thumbor(securityKey, thumborServerUrl) {
  'use strict';

  this.THUMBOR_SECURITY_KEY = securityKey;
  this.THUMBOR_URL_SERVER = thumborServerUrl;

  this.imagePath = '';
  this.width = 0;
  this.height = 0;
  this.smart = false;
  this.fitInFlag = false;
  this.withFlipHorizontally = false;
  this.withFlipVertically = false;
  this.halignValue = null;
  this.valignValue = null;
  this.cropValues = null;
  this.meta = false;
  this.filtersCalls = [];
}

Thumbor.prototype = {

  TOP: 'top',
  MIDDLE: 'middle',
  BOTTOM: 'bottom',

  RIGHT: 'right',
  CENTER: 'center',
  LEFT: 'left',

  /**
   * Set path of image
   * @param {String} imagePath [description]
   */
  setImagePath: function(imagePath) {
    this.imagePath = (imagePath.charAt(0) === '/') ?
      imagePath.substring(1, imagePath.length) : imagePath;
    return this;
  },
  /**
   * Converts operation array to string
   * @return {String}
   */
  getOperationPath: function() {
    var parts = this.urlParts();

    if (0 === parts.length) {
      return '';
    }

    return parts.join('/') + '/';
  },
  /**
   * Build operation array
   *
   * @TODO Should be refactored so that strings are generated in the
   * commands as opposed to in 1 massive function
   *
   * @return {Array}
   */
  urlParts: function() {
    if (!this.imagePath) {
      throw new Error('The image url can\'t be null or empty.');
    }

    var parts = [];

    if (this.meta) {
      parts.push('meta');
    }

    if (this.cropValues) {
      parts.push(
        this.cropValues.left +
        'x' + this.cropValues.top +
        ':' + this.cropValues.right +
        'x' + this.cropValues.bottom
      );
    }

    if (this.fitInFlag) {
      parts.push('fit-in');
    }


    if (
      this.width ||
      this.height ||
      this.withFlipHorizontally ||
      this.withFlipVertically
    ) {
      var sizeString = '';

      if (this.withFlipHorizontally) {
        sizeString += '-';
      }
      sizeString += this.width;

      sizeString += 'x';

      if (this.withFlipVertically) {
        sizeString += '-';
      }
      sizeString += this.height;

      parts.push(sizeString);
    }

    if (this.halignValue) {
      parts.push(this.halignValue);
    }

    if (this.valignValue) {
      parts.push(this.valignValue);
    }

    if (this.smart) {
      parts.push('smart');
    }

    if (this.filtersCalls.length) {
      parts.push('filters:' + this.filtersCalls.join(':'));
    }

    return parts;
  },
  /**
   * Resize the image to the specified dimensions. Overrides any previous call
   * to `fitIn` or `resize`.
   *
   * Use a value of 0 for proportional resizing. E.g. for a 640 x 480 image,
   * `.resize(320, 0)` yields a 320 x 240 thumbnail.
   *
   * Use a value of 'orig' to use an original image dimension. E.g. for a 640
   * x 480 image, `.resize(320, 'orig')` yields a 320 x 480 thumbnail.
   * @param  {String} width
   * @param  {String} height
   */
  resize: function(width, height) {
    this.width = width;
    this.height = height;
    this.fitInFlag = false;
    return this;
  },

  smartCrop: function(smartCrop) {
    this.smart = smartCrop;
    return this;
  },
  /**
   * Resize the image to fit in a box of the specified dimensions. Overrides
   * any previous call to `fitIn` or `resize`.
   *
   * @param  {String} width
   * @param  {String} height
   */
  fitIn: function(width, height) {
    this.width = width;
    this.height = height;
    this.fitInFlag = true;
    return this;
  },
  /**
   * Flip image horizontally
   */
  flipHorizontally: function() {
    this.withFlipHorizontally = true;
    return this;
  },
  /**
   * Flip image vertically
   */
  flipVertically: function() {
    this.withFlipVertically = true;
    return this;
  },
  /**
   * Specify horizontal alignment used if width is altered due to cropping
   * @param  {String} halign 'left', 'center', 'right'
   */
  halign: function(halign) {
    if (
      halign === this.LEFT ||
      halign === this.RIGHT ||
      halign === this.CENTER
    ) {
      this.halignValue = halign;
    } else {
      throw new Error('Horizontal align must be left, right or center.');
    }
    return this;
  },
  /**
   * Specify vertical alignment used if height is altered due to cropping
   * @param  {String} valign 'top', 'middle', 'bottom'
   */
  valign: function(valign) {
    if (
      valign === this.TOP ||
      valign === this.BOTTOM ||
      valign === this.MIDDLE
    ) {
      this.valignValue = valign;
    } else {
      throw new Error('Vertical align must be top, bottom or middle.');
    }
    return this;
  },
  /**
   * Specify that JSON metadata should be returned instead of the thumbnailed
   * image.
   * @param  {Boolean} metaDataOnly [description]
   */
  metaDataOnly: function(metaDataOnly) {
    this.meta = metaDataOnly;
    return this;
  },
  /**
   * Append a filter, e.g. quality(80)
   * @param  {String} filterCall
   */
  filter: function(filterCall) {
    this.filtersCalls.push(filterCall);
    return this;
  },
  /**
   * Manually specify crop window.
   * @param  {Integer} left
   * @param  {Integer} top
   * @param  {Integer} right
   * @param  {Integer} bottom
   * @return {[type]}
   */
  crop: function(left, top, right, bottom) {
    this.cropValues = {
      left: left,
      top: top,
      right: right,
      bottom: bottom
    };

    return this;
  },
  /**
   * Combine image url and operations with secure and unsecure (unsafe) paths
   * @return {String}
   */
  buildUrl: function() {
    var operation = this.getOperationPath();

    if (this.THUMBOR_SECURITY_KEY) {

      var key = crypto
        .createHmac('sha1', this.THUMBOR_SECURITY_KEY)
        .update(operation + this.imagePath)
        .digest('base64');

      key = key.replace(/\+/g, '-').replace(/\//g, '_');

      return this.THUMBOR_URL_SERVER +
        '/' + key +
        '/' + operation +
        this.imagePath;

    } else {
      return this.THUMBOR_URL_SERVER + '/unsafe/' + operation + this.imagePath;
    }
  }
};

module.exports = Thumbor;