'use strict';

/**
 * @ngdoc filter
 * @name linky
 * @kind function
 *
 * @description
 * Finds links in text input and turns them into html links. Supports `http/https/ftp/sftp/mailto` and
 * plain email address links.
 *
 * Requires the {@link ngSanitize `ngSanitize`} module to be installed.
 *
 * @param {string} text Input text.
 * @param {string} [target] Window (`_blank|_self|_parent|_top`) or named frame to open links in.
 * @param {object|function(url)} [attributes] Add custom attributes to the link element.
 *
 *    Can be one of:
 *
 *    - `object`: A map of attributes
 *    - `function`: Takes the url as a parameter and returns a map of attributes
 *
 *    If the map of attributes contains a value for `target`, it overrides the value of
 *    the target parameter.
 *
 *
 * @returns {string} Html-linkified and {@link $sanitize sanitized} text.
 *
 * @usage
   <span ng-bind-html="linky_expression | linky"></span>
 *
 * @example
   <example module="linkyExample" deps="angular-sanitize.js" name="linky-filter">
     <file name="index.html">
       <div ng-controller="ExampleController">
       Snippet: <textarea ng-model="snippet" cols="60" rows="3"></textarea>
       <table>
         <tr>
           <th>Filter</th>
           <th>Source</th>
           <th>Rendered</th>
         </tr>
         <tr id="linky-filter">
           <td>linky filter</td>
           <td>
             <pre>&lt;div ng-bind-html="snippet | linky"&gt;<br>&lt;/div&gt;</pre>
           </td>
           <td>
             <div ng-bind-html="snippet | linky"></div>
           </td>
         </tr>
         <tr id="linky-target">
          <td>linky target</td>
          <td>
            <pre>&lt;div ng-bind-html="snippetWithSingleURL | linky:'_blank'"&gt;<br>&lt;/div&gt;</pre>
          </td>
          <td>
            <div ng-bind-html="snippetWithSingleURL | linky:'_blank'"></div>
          </td>
         </tr>
         <tr id="linky-custom-attributes">
          <td>linky custom attributes</td>
          <td>
            <pre>&lt;div ng-bind-html="snippetWithSingleURL | linky:'_self':{rel: 'nofollow'}"&gt;<br>&lt;/div&gt;</pre>
          </td>
          <td>
            <div ng-bind-html="snippetWithSingleURL | linky:'_self':{rel: 'nofollow'}"></div>
          </td>
         </tr>
         <tr id="escaped-html">
           <td>no filter</td>
           <td><pre>&lt;div ng-bind="snippet"&gt;<br>&lt;/div&gt;</pre></td>
           <td><div ng-bind="snippet"></div></td>
         </tr>
       </table>
     </file>
     <file name="script.js">
       angular.module('linkyExample', ['ngSanitize'])
         .controller('ExampleController', ['$scope', function($scope) {
           $scope.snippet =
             'Pretty text with some links:\n' +
             'http://angularjs.org/,\n' +
             'mailto:us@somewhere.org,\n' +
             'another@somewhere.org,\n' +
             'and one more: ftp://127.0.0.1/.';
           $scope.snippetWithSingleURL = 'http://angularjs.org/';
         }]);
     </file>
     <file name="protractor.js" type="protractor">
       it('should linkify the snippet with urls', function() {
         expect(element(by.id('linky-filter')).element(by.binding('snippet | linky')).getText()).
             toBe('Pretty text with some links: http://angularjs.org/, us@somewhere.org, ' +
                  'another@somewhere.org, and one more: ftp://127.0.0.1/.');
         expect(element.all(by.css('#linky-filter a')).count()).toEqual(4);
       });

       it('should not linkify snippet without the linky filter', function() {
         expect(element(by.id('escaped-html')).element(by.binding('snippet')).getText()).
             toBe('Pretty text with some links: http://angularjs.org/, mailto:us@somewhere.org, ' +
                  'another@somewhere.org, and one more: ftp://127.0.0.1/.');
         expect(element.all(by.css('#escaped-html a')).count()).toEqual(0);
       });

       it('should update', function() {
         element(by.model('snippet')).clear();
         element(by.model('snippet')).sendKeys('new http://link.');
         expect(element(by.id('linky-filter')).element(by.binding('snippet | linky')).getText()).
             toBe('new http://link.');
         expect(element.all(by.css('#linky-filter a')).count()).toEqual(1);
         expect(element(by.id('escaped-html')).element(by.binding('snippet')).getText())
             .toBe('new http://link.');
       });

       it('should work with the target property', function() {
        expect(element(by.id('linky-target')).
            element(by.binding("snippetWithSingleURL | linky:'_blank'")).getText()).
            toBe('http://angularjs.org/');
        expect(element(by.css('#linky-target a')).getAttribute('target')).toEqual('_blank');
       });

       it('should optionally add custom attributes', function() {
        expect(element(by.id('linky-custom-attributes')).
            element(by.binding("snippetWithSingleURL | linky:'_self':{rel: 'nofollow'}")).getText()).
            toBe('http://angularjs.org/');
        expect(element(by.css('#linky-custom-attributes a')).getAttribute('rel')).toEqual('nofollow');
       });
     </file>
   </example>
 */
angular.module('ngSanitize').filter('linky', ['$sanitize', function($sanitize) {
  var LINKY_URL_REGEXP =
        /((s?ftp|https?):\/\/|(www\.)|(mailto:)?[A-Za-z0-9._%+-]+@)\S*[^\s.;,(){}<>"\u201d\u2019]/i,
      MAILTO_REGEXP = /^mailto:/i;

  var linkyMinErr = angular.$$minErr('linky');
  var isDefined = angular.isDefined;
  var isFunction = angular.isFunction;
  var isObject = angular.isObject;
  var isString = angular.isString;

  return function(text, target, attributes) {
    if (text == null || text === '') return text;
    if (!isString(text)) throw linkyMinErr('notstring', 'Expected string but received: {0}', text);

    var attributesFn =
      isFunction(attributes) ? attributes :
      isObject(attributes) ? function getAttributesObject() {return attributes;} :
      function getEmptyAttributesObject() {return {};};

    var match;
    var raw = text;
    var html = [];
    var url;
    var i;
    while ((match = raw.match(LINKY_URL_REGEXP))) {
      // We can not end in these as they are sometimes found at the end of the sentence
      url = match[0];
      // if we did not match ftp/http/www/mailto then assume mailto
      if (!match[2] && !match[4]) {
        url = (match[3] ? 'http://' : 'mailto:') + url;
      }
      i = match.index;
      addText(raw.substr(0, i));
      addLink(url, match[0].replace(MAILTO_REGEXP, ''));
      raw = raw.substring(i + match[0].length);
    }
    addText(raw);
    return $sanitize(html.join(''));

    function addText(text) {
      if (!text) {
        return;
      }
      html.push(sanitizeText(text));
    }

    function addLink(url, text) {
      var key, linkAttributes = attributesFn(url);
      html.push('<a ');

      for (key in linkAttributes) {
        html.push(key + '="' + linkAttributes[key] + '" ');
      }

      if (isDefined(target) && !('target' in linkAttributes)) {
        html.push('target="',
                  target,
                  '" ');
      }
      html.push('href="',
                url.replace(/"/g, '&quot;'),
                '">');
      addText(text);
      html.push('</a>');
    }
  };
}]);
