// Version (see package.json)
// AngularJS simple file upload directive
// this directive uses an iframe as a target
// to enable the uploading of files without
// losing focus in the ng-app.
//
// <div ng-app="app">
//   <div ng-controller="mainCtrl">
//    <form ng-attr-action="/uploads" 
//      ng-upload="completed(content)"> 
//      ng-upload-loading="loading()"
//      <input type="file" name="avatar"></input>
//      <input type="submit" value="Upload" 
//         ng-disabled="$isUploading"></input>
//    </form>
//  </div>
// </div>
//
//  angular.module('app', ['ngUpload'])
//    .controller('mainCtrl', function($scope) {
//      $scope.loading = function() {
//        console.log('loading...');
//      }
//      $scope.completed = function(content) {
//        console.log(content);
//      };
//  });
//
angular.module('ngUpload', [])
  .directive('uploadSubmit', ["$parse", function($parse) {
    // Utility function to get the closest parent element with a given tag
    function getParentNodeByTagName(element, tagName) {
      element = angular.element(element);
      var parent = element.parent();
      tagName = tagName.toLowerCase();

      if ( parent && parent[0].tagName.toLowerCase() === tagName ) {
          return parent;
      } else {
          return !parent ? null : getParentNodeByTagName(parent, tagName);
      }
    }
    return {
      restrict: 'AC',
      link: function(scope, element, attrs) {
        element.bind('click', function($event) {
          // prevent default behavior of click
          if ($event) {
            $event.preventDefault();
            $event.stopPropagation();
          }

          if (element.attr('disabled')) { return; }
          var form = getParentNodeByTagName(element, 'form');
          form.triggerHandler('submit');
          form[0].submit();
        });
      }
    };
  }])
  .directive('ngUpload', ["$log", "$parse", "$document",
    function ($log, $parse, $document) {
    var iframeID = 1;
    // Utility function to get meta tag with a given name attribute
    function getMetaTagWithName(name) {
      var head = $document.find('head');
      var match;

      angular.forEach(head.find('meta'), function(element) {
        if ( element.getAttribute('name') === name ) {
            match = element;
        }
      });

      return angular.element(match);
    }

    return {
      restrict: 'AC',
      link: function (scope, element, attrs) {
        // Give each directive instance a new id
        iframeID++;

        function setLoadingState(state) {
          scope.$isUploading = state;
        }

        var options = {};
        // Options (just 1 for now)
        // Each option should be prefixed with 'upload-options-' or 'uploadOptions'
        // {
        //    // add the Rails CSRF hidden input to form
        //    enableRailsCsrf: bool
        // }
        var fn = attrs.ngUpload ? $parse(attrs.ngUpload) : null;
        var errorCatcher = attrs.errorCatcher ? $parse(attrs.errorCatcher) : null;
        var loading = attrs.ngUploadLoading ? $parse(attrs.ngUploadLoading) : null;

        if ( attrs.hasOwnProperty( "uploadOptionsConvertHidden" ) ) {
            // Allow blank or true
            options.convertHidden = attrs.uploadOptionsConvertHidden != "false";
        }

        if ( attrs.hasOwnProperty( "uploadOptionsEnableRailsCsrf" ) ) {
            // allow for blank or true
            options.enableRailsCsrf = attrs.uploadOptionsEnableRailsCsrf != "false";
        }

        if ( attrs.hasOwnProperty( "uploadOptionsBeforeSubmit" ) ) {
            options.beforeSubmit = $parse(attrs.uploadOptionsBeforeSubmit);
        }

        element.attr({
          'target': 'upload-iframe-' + iframeID,
          'method': 'post',
          'enctype': 'multipart/form-data',
          'encoding': 'multipart/form-data'
        });

        var iframe = angular.element(
          '<iframe name="upload-iframe-' + iframeID + '" ' +
          'border="0" width="0" height="0" ' +
          'style="width:0px;height:0px;border:none;display:none">'
        );

        // If enabled, add csrf hidden input to form
        if ( options.enableRailsCsrf ) {
          var input = angular.element("<input />");
            input.attr("class", "upload-csrf-token");
            input.attr("type", "hidden");
            input.attr("name", getMetaTagWithName('csrf-param').attr('content'));
            input.val(getMetaTagWithName('csrf-token').attr('content'));

          element.append(input);
        }
        element.after(iframe);

        setLoadingState(false);
        // Start upload
        element.bind('submit', function uploadStart($event) {
          var formController = scope[attrs.name];
          // if form is invalid don't submit (e.g. keypress 13)
          if(formController && formController.$invalid) {
            $event.preventDefault();
            return false;
          }
          // perform check before submit file
          if (options.beforeSubmit && options.beforeSubmit(scope, {}) === false) {
            if(!scope.$$phase){
              scope.$apply();
            }
            $event.preventDefault();
            return false;
          }

          // bind load after submit to prevent initial load triggering uploadEnd
          iframe.bind('load', uploadEnd);

          // If convertHidden option is enabled, set the value of hidden fields to the eval of the ng-model
          if (options.convertHidden) {
            angular.forEach(element.find('input'), function(el) {
              var _el = angular.element(el);
              if (_el.attr('ng-model') &&
                _el.attr('type') &&
                _el.attr('type') == 'hidden') {
                _el.attr('value', scope.$eval(_el.attr('ng-model')));
              }
            });
          }

          if (!scope.$$phase) {
            scope.$apply(function() {
              if (loading) loading(scope);
              setLoadingState(true);
            });
          } else {
            if (loading) loading(scope);
            setLoadingState(true);
          }
        });

        // Finish upload
       function uploadEnd() {
          // unbind load after uploadEnd to prevent another load triggering uploadEnd
          iframe.unbind('load');
          if (!scope.$$phase) {
            scope.$apply(function() {
              setLoadingState(false);
            });
          } else {
            setLoadingState(false);
          }
          // Get iframe body contents
          try {
              var bodyContent = (iframe[0].contentDocument ||
                iframe[0].contentWindow.document).body;

              var content;
              try {
                content = angular.fromJson(bodyContent.innerText || bodyContent.textContent);
                if (!scope.$$phase) {
                   scope.$apply(function () {
                       fn(scope, { content: content});
                   });
                } else {
                  fn(scope, { content: content});
                }
              } catch (e) {
                // Fall back to html if json parse failed
                content = bodyContent.innerHTML;
                var error = 'ng-upload: Response is not valid JSON';
                $log.warn(error);

                if ( errorCatcher ){
                   if (!scope.$$phase) {
                      scope.$apply(function () {
                          errorCatcher(scope, { error: error});
                      });
                   } else {
                     errorCatcher(scope, { error: error});
                   }
                }

              }
              // if outside a digest cycle, execute the upload response function in the active scope
              // else execute the upload response function in the current digest

          } catch (error) {
            $log.warn('ng-upload: Server error');

            if ( errorCatcher ){
               if (!scope.$$phase) {
                  scope.$apply(function () {
                      errorCatcher(scope, { error: error});
                  });
               } else {
                 errorCatcher(scope, { error: error});
               }
            }

          }
        }
      }
    };
  }]);