// Conditional load for NodeJS
if (typeof require !== 'undefined') {
  var angular = require('angular'),
      showdown = require('showdown');
}

//Check if AngularJs and Showdown is defined and only load ng-Showdown if both are present
if (typeof angular !== 'undefined' && typeof showdown !== 'undefined') {

  (function (module, showdown) {
    'use strict';

    module
      .provider('$showdown', provider)
      .directive('sdModelToHtml', ['$showdown', '$sanitize', markdownToHtmlDirective])
      .filter('sdStripHtml', stripHtmlFilter);

    /**
     * Angular Provider
     * Enables configuration of showdown via angular.config and Dependency Injection into controllers, views
     * directives, etc... This assures the directives and filters provided by the library itself stay consistent
     * with the user configurations.
     * If the user wants to use a different configuration in a determined context, he can use the "classic" Showdown
     * object instead.
     */
    function provider() {

      // Configuration parameters for Showdown
      var config = {
        extensions: [],
        stripHtml:  true
      };

      /**
       * Sets a configuration option
       *
       * @param {string} key Config parameter key
       * @param {string} value Config parameter value
       */
      /* jshint validthis: true */
      this.setOption = function (key, value) {
        config[key] = value;

        return this;
      };

      /**
       * Gets the value of the configuration parameter specified by key
       *
       * @param {string} key The config parameter key
       * @returns {string|null} Returns the value of the config parameter. (or null if the config parameter is not set)
       */
      this.getOption = function (key) {
        if (config.hasOwnProperty(key)) {
          return config.key;
        } else {
          return null;
        }
      };

      /**
       * Loads a Showdown Extension
       *
       * @param {string} extensionName The name of the extension to load
       */
      this.loadExtension = function (extensionName) {
        config.extensions.push(extensionName);

        return this;
      };

      function SDObject() {
        var converter = new showdown.Converter(config);

        /**
         * Converts a markdown text into HTML
         *
         * @param {string} markdown The markdown string to be converted to HTML
         * @returns {string} The converted HTML
         */
        this.makeHtml = function (markdown) {
          return converter.makeHtml(markdown);
        };

        /**
         * Strips a text of it's HTML tags
         *
         * @param {string} text
         * @returns {string}
         */
        this.stripHtml = function (text) {
          return String(text).replace(/<[^>]+>/gm, '');
        };
      }

      // The object returned by service provider
      this.$get = function () {
        return new SDObject();
      };
    }

    /**
     * AngularJS Directive to Md to HTML transformation
     *
     * Usage example:
     * <div sd-model-to-html="markdownText" ></div>
     *
     * @param {showdown.Converter} $showdown
     * @param $sanitize
     * @returns {*}
     */
    function markdownToHtmlDirective($showdown, $sanitize) {

      var link = function (scope, element) {
        scope.$watch('model', function (newValue) {
          var val;
          if (typeof newValue === 'string') {
            val = $sanitize($showdown.makeHtml(newValue));
          } else {
            val = typeof newValue;
          }
          element.html(val);
        });
      };

      return {
        restrict: 'A',
        link:     link,
        scope:    {
          model: '=sdModelToHtml'
        }
      };
    }

    /**
     * AngularJS Filter to Strip HTML tags from text
     *
     * @returns {Function}
     */
    function stripHtmlFilter() {
      return function (text) {
        return String(text).replace(/<[^>]+>/gm, '');
      };
    }

  })(angular.module('showdown', ['ngSanitize']), showdown);

} else {
  throw new Error('ng-showdown was not loaded because one of its dependencies (AngularJS or Showdown) was not met');
}