index.js

var fs     = require('fs');
var path   = require('path');
var xml2js = require('xml2js');
var ig     = require('imagemagick');
var colors = require('colors');
var _      = require('underscore');
var Q      = require('q');
var wrench = require('wrench');

/**
 * Check which platforms are added to the project and return their icon names and sizes
 *
 * @param  {String} projectName
 * @return {Promise} resolves with an array of platforms
 */
var getPlatforms = function (projectName) {
  var deferred = Q.defer();
  var platforms = [];
  platforms.push({
    name : 'ios',
    // TODO: use async fs.exists
    isAdded : fs.existsSync('platforms/ios'),
    iconsPath : 'platforms/ios/' + projectName + '/Images.xcassets/AppIcon.appiconset/',
    icons : [
      { name : 'icon-40.png',       size : 40  },
      { name : 'icon-40@2x.png',    size : 80  },
      { name : 'icon-50.png',       size : 50  },
      { name : 'icon-50@2x.png',    size : 100 },
      { name : 'icon-60@2x.png',    size : 120 },
      { name : 'icon-60@3x.png',    size : 180 },
      { name : 'icon-72.png',       size : 72  },
      { name : 'icon-72@2x.png',    size : 144 },
      { name : 'icon-76.png',       size : 76  },
      { name : 'icon-76@2x.png',    size : 152 },
      { name : 'icon-small.png',    size : 29  },
      { name : 'icon-small@2x.png', size : 58  },
      { name : 'icon-small@3x.png', size : 87  },
      { name : 'icon.png',          size : 57  },
      { name : 'icon@2x.png',       size : 114 },
      { name : 'icon-83.5@2x.png',  size : 167 }
    ]
  });
  platforms.push({
    name : 'android',
    isAdded : fs.existsSync('platforms/android'),
    iconsPath : 'platforms/android/res/',
    icons : [
      { name : 'drawable/icon.png',       size : 96 },
      { name : 'drawable-hdpi/icon.png',  size : 72 },
      { name : 'drawable-ldpi/icon.png',  size : 36 },
      { name : 'drawable-mdpi/icon.png',  size : 48 },
      { name : 'drawable-xhdpi/icon.png', size : 96 },
      { name : 'drawable-xxhdpi/icon.png', size : 144 },
      { name : 'drawable-xxxhdpi/icon.png', size : 192 }
    ]
  });
  platforms.push({
    name : 'windows',
    isAdded : fs.existsSync('platforms/windows'),
    iconsPath : 'platforms/windows/images/',
    icons : [
      { name : 'StoreLogo.scale-100.png', size : 50  },
      { name : 'StoreLogo.scale-125.png', size : 63  },
      { name : 'StoreLogo.scale-150.png', size : 75  },
      { name : 'StoreLogo.scale-200.png', size : 100 },
      { name : 'StoreLogo.scale-400.png', size : 200 },

      { name : 'Square44x44Logo.scale-100.png', size : 44  },
      { name : 'Square44x44Logo.scale-125.png', size : 55  },
      { name : 'Square44x44Logo.scale-150.png', size : 66  },
      { name : 'Square44x44Logo.scale-200.png', size : 88  },
      { name : 'Square44x44Logo.scale-400.png', size : 176 },

      { name : 'Square71x71Logo.scale-100.png', size : 71  },
      { name : 'Square71x71Logo.scale-125.png', size : 89  },
      { name : 'Square71x71Logo.scale-150.png', size : 107 },
      { name : 'Square71x71Logo.scale-200.png', size : 142 },
      { name : 'Square71x71Logo.scale-400.png', size : 284 },

      { name : 'Square150x150Logo.scale-100.png', size : 150 },
      { name : 'Square150x150Logo.scale-125.png', size : 188 },
      { name : 'Square150x150Logo.scale-150.png', size : 225 },
      { name : 'Square150x150Logo.scale-200.png', size : 300 },
      { name : 'Square150x150Logo.scale-400.png', size : 600 },

      { name : 'Square310x310Logo.scale-100.png', size : 310  },
      { name : 'Square310x310Logo.scale-125.png', size : 388  },
      { name : 'Square310x310Logo.scale-150.png', size : 465  },
      { name : 'Square310x310Logo.scale-200.png', size : 620  },
      { name : 'Square310x310Logo.scale-400.png', size : 1240 },

      { name : 'Wide310x150Logo.scale-100.png', size : 310, height : 150  },
      { name : 'Wide310x150Logo.scale-125.png', size : 388, height : 188  },
      { name : 'Wide310x150Logo.scale-150.png', size : 465, height : 225  },
      { name : 'Wide310x150Logo.scale-200.png', size : 620, height : 300  },
      { name : 'Wide310x150Logo.scale-400.png', size : 1240, height : 600 }
    ]
  });
  // TODO: add missing platforms
  deferred.resolve(platforms);
  return deferred.promise;
};


/**
 * @var {Object} settings - names of the config file and of the icon image
 * TODO: add option to get these values as CLI params
 */
var settings = {};
settings.CONFIG_FILE = 'config.xml';
settings.ICON_FILE   = 'icon.png';

/**
 * @var {Object} console utils
 */
var display = {};
display.success = function (str) {
  str = '✓  '.green + str;
  console.log('  ' + str);
};
display.error = function (str) {
  str = '✗  '.red + str;
  console.log('  ' + str);
};
display.header = function (str) {
  console.log('');
  console.log(' ' + str.cyan.underline);
  console.log('');
};

/**
 * read the config file and get the project name
 *
 * @return {Promise} resolves to a string - the project's name
 */
var getProjectName = function () {
  var deferred = Q.defer();
  var parser = new xml2js.Parser();
  data = fs.readFile(settings.CONFIG_FILE, function (err, data) {
    if (err) {
      deferred.reject(err);
    }
    parser.parseString(data, function (err, result) {
      if (err) {
        deferred.reject(err);
      }
      var projectName = result.widget.name[0];
      deferred.resolve(projectName);
    });
  });
  return deferred.promise;
};

/**
 * Resizes, crops (if needed) and creates a new icon in the platform's folder.
 *
 * @param  {Object} platform
 * @param  {Object} icon
 * @return {Promise}
 */
var generateIcon = function (platform, icon) {
  var deferred = Q.defer();
  var srcPath = settings.ICON_FILE;
  var platformPath = srcPath.replace(/\.png$/, '-' + platform.name + '.png');
  if (fs.existsSync(platformPath)) {
    srcPath = platformPath;
  }
  var dstPath = platform.iconsPath + icon.name;
  var dst = path.dirname(dstPath);
  if (!fs.existsSync(dst)) {
    wrench.mkdirSyncRecursive(dst);
  }
  ig.resize({
    srcPath: srcPath,
    dstPath: dstPath,
    quality: 1,
    format: 'png',
    width: icon.size,
    height: icon.size
  } , function(err, stdout, stderr){
    if (err) {
      deferred.reject(err);
    } else {
      deferred.resolve();
      display.success(icon.name + ' created');
    }
  });
  if (icon.height) {
    ig.crop({
      srcPath: srcPath,
      dstPath: dstPath,
      quality: 1,
      format: 'png',
      width: icon.size,
      height: icon.height
    } , function(err, stdout, stderr){
      if (err) {
        deferred.reject(err);
      } else {
        deferred.resolve();
        display.success(icon.name + ' cropped');
      }
    });
  }
  return deferred.promise;
};

/**
 * Generates icons based on the platform object
 *
 * @param  {Object} platform
 * @return {Promise}
 */
var generateIconsForPlatform = function (platform) {
  display.header('Generating Icons for ' + platform.name);
  var all = [];
  var icons = platform.icons;
  icons.forEach(function (icon) {
    all.push(generateIcon(platform, icon));
  });
  return Promise.all(all);
};

/**
 * Goes over all the platforms and triggers icon generation
 *
 * @param  {Array} platforms
 * @return {Promise}
 */
var generateIcons = function (platforms) {
  var deferred = Q.defer();
  var sequence = Q();
  var all = [];
  _(platforms).where({ isAdded : true }).forEach(function (platform) {
    sequence = sequence.then(function () {
      return generateIconsForPlatform(platform);
    });
    all.push(sequence);
  });
  Q.all(all).then(function () {
    deferred.resolve();
  });
  return deferred.promise;
};

/**
 * Checks if at least one platform was added to the project
 *
 * @return {Promise} resolves if at least one platform was found, rejects otherwise
 */
var atLeastOnePlatformFound = function () {
  var deferred = Q.defer();
  getPlatforms().then(function (platforms) {
    var activePlatforms = _(platforms).where({ isAdded : true });
    if (activePlatforms.length > 0) {
      display.success('platforms found: ' + _(activePlatforms).pluck('name').join(', '));
      deferred.resolve();
    } else {
      display.error('No cordova platforms found.' +
                    'Make sure you are in the root folder of your Cordova project' +
                      'and add platforms with \'cordova platform add\'');
                      deferred.reject();
    }
  });
  return deferred.promise;
};

/**
 * Checks if a valid icon file exists
 *
 * @return {Promise} resolves if exists, rejects otherwise
 */
var validIconExists = function () {
  var deferred = Q.defer();
  fs.exists(settings.ICON_FILE, function (exists) {
    if (exists) {
      display.success(settings.ICON_FILE + ' exists');
      deferred.resolve();
    } else {
      display.error(settings.ICON_FILE + ' does not exist in the root folder');
      deferred.reject();
    }
  });
  return deferred.promise;
};

/**
 * Checks if a config.xml file exists
 *
 * @return {Promise} resolves if exists, rejects otherwise
 */
var configFileExists = function () {
  var deferred = Q.defer();
  fs.exists(settings.CONFIG_FILE, function (exists) {
    if (exists) {
      display.success(settings.CONFIG_FILE + ' exists');
      deferred.resolve();
    } else {
      display.error('cordova\'s ' + settings.CONFIG_FILE + ' does not exist in the root folder');
      deferred.reject();
    }
  });
  return deferred.promise;
};

display.header('Checking Project & Icon');

atLeastOnePlatformFound()
  .then(validIconExists)
  .then(configFileExists)
  .then(getProjectName)
  .then(getPlatforms)
  .then(generateIcons)
  .catch(function (err) {
    if (err) {
      console.log(err);
    }
  }).then(function () {
    console.log('');
  });