simple sprites

const PLUGIN_NAME = 'gulp-sprites';
var gutil = require('gulp-util');
var log = gutil.log;
//var PluginError = gutil.PluginError;
var path = require('path');
var sprite = require('node-sprite');
var vow = require('vow');
var exec = require('child_process').exec;
var fs = require('fs');

var defaultStyles = [
  '.{I}',
  '  display: inline-block;',
  '  background: url("/images/{I}.png?{HASH}") no-repeat 0 0;',
  ''
].join('\n');

var defaultStylesTmpl = [
  '.i--{F}',
  '  width: {W}px;',
  '  height: {H}px;',
  '  background-position: -{PX}px -{PY}px;',
  ''
].join('\n');
module.exports = function (options) {
  sprite.sprites({
    path: path.resolve(options.src)
  }, function (err, result) {
    if (err) {
      log(gutil.colors.red(err));
    } else {
      var spriteStr = '';
      var promises = [];
      log('folders:', gutil.colors.green(Object.keys(result).join(',')));
      Object.keys(result).forEach(function (e) {
        var defer = vow.defer();
        var pack = result[e];
        var currentStyles = defaultStyles
          .replace(/\{I\}/g, e)
          .replace(/\{HASH\}/g, pack.shortsum())
          .replace('{S}', Math.round(pack.mapper.width));
        var spritePath = pack.path + '/' + pack.filename();
        var lnPath = ['build/', e, '.png'].join('');

        pack.images.forEach(function (file) {
          currentStyles += defaultStylesTmpl
            .replace('{F}', file.name)
            .replace('{W}', Math.ceil(file.width))
            .replace('{H}', Math.ceil(file.height))
            .replace('{PX}', Math.round(file.positionX))
            .replace('{PY}', Math.round(file.positionY))
        });
        spriteStr += currentStyles;
        promises.push(defer.promise());
        exec('ln -sf ' + [spritePath, lnPath].join(' '), {}, function (error, stdout, stderr) {
          if (error) {
            log(gutil.colors.red(error));
          } else {
            log('ln -sf ', [spritePath, lnPath].join(' '), gutil.colors.green('successed!'));
            defer.resolve();
          }
          if (stderr) {
            log(gutil.colors.red(stderr));
          }
          if (stdout) {
            log(stdout);
          }
        });
      });

      vow.all(promises).then(function () {
        log(gutil.colors.green('all promises resolved!'));
        fs.writeFile(path.resolve(options.dest), spriteStr, function (error, result) {
          if (result) {
            log(result);
          }
          if (error) {
            log(gutil.colors.red(error));
          } else {
            options.done();
          }
        });
      });
    }
  });
}