'use strict';

/**
 * @ngdoc directive
 * @name angular.module.ng.$compileProvider.directive.select
 *
 * @description
 * HTML `SELECT` element with angular data-binding.
 *
 * # `ng:options`
 *
 * Optionally `ng:options` attribute can be used to dynamically generate a list of `<option>`
 * elements for a `<select>` element using an array or an object obtained by evaluating the
 * `ng:options` expression.
 *˝˝
 * When an item in the select menu is select, the value of array element or object property
 * represented by the selected option will be bound to the model identified by the `ng:model` attribute
 * of the parent select element.
 *
 * Optionally, a single hard-coded `<option>` element, with the value set to an empty string, can
 * be nested into the `<select>` element. This element will then represent `null` or "not selected"
 * option. See example below for demonstration.
 *
 * Note: `ng:options` provides iterator facility for `<option>` element which must be used instead
 * of {@link angular.module.ng.$compileProvider.directive.ng:repeat ng:repeat}. `ng:repeat` is not suitable for use with
 * `<option>` element because of the following reasons:
 *
 *   * value attribute of the option element that we need to bind to requires a string, but the
 *     source of data for the iteration might be in a form of array containing objects instead of
 *     strings
 *   * {@link angular.module.ng.$compileProvider.directive.ng:repeat ng:repeat} unrolls after the select binds causing
 *     incorect rendering on most browsers.
 *   * binding to a value not in list confuses most browsers.
 *
 * @param {string} name assignable expression to data-bind to.
 * @param {string=} required The widget is considered valid only if value is entered.
 * @param {comprehension_expression=} ng:options in one of the following forms:
 *
 *   * for array data sources:
 *     * `label` **`for`** `value` **`in`** `array`
 *     * `select` **`as`** `label` **`for`** `value` **`in`** `array`
 *     * `label`  **`group by`** `group` **`for`** `value` **`in`** `array`
 *     * `select` **`as`** `label` **`group by`** `group` **`for`** `value` **`in`** `array`
 *   * for object data sources:
 *     * `label` **`for (`**`key` **`,`** `value`**`) in`** `object`
 *     * `select` **`as`** `label` **`for (`**`key` **`,`** `value`**`) in`** `object`
 *     * `label` **`group by`** `group` **`for (`**`key`**`,`** `value`**`) in`** `object`
 *     * `select` **`as`** `label` **`group by`** `group`
 *         **`for` `(`**`key`**`,`** `value`**`) in`** `object`
 *
 * Where:
 *
 *   * `array` / `object`: an expression which evaluates to an array / object to iterate over.
 *   * `value`: local variable which will refer to each item in the `array` or each property value
 *      of `object` during iteration.
 *   * `key`: local variable which will refer to a property name in `object` during iteration.
 *   * `label`: The result of this expression will be the label for `<option>` element. The
 *     `expression` will most likely refer to the `value` variable (e.g. `value.propertyName`).
 *   * `select`: The result of this expression will be bound to the model of the parent `<select>`
 *      element. If not specified, `select` expression will default to `value`.
 *   * `group`: The result of this expression will be used to group options using the `<optgroup>`
 *      DOM element.
 *
 * @example
    <doc:example>
      <doc:source>
        <script>
        function MyCntrl($scope) {
          $scope.colors = [
            {name:'black', shade:'dark'},
            {name:'white', shade:'light'},
            {name:'red', shade:'dark'},
            {name:'blue', shade:'dark'},
            {name:'yellow', shade:'light'}
          ];
          $scope.color = $scope.colors[2]; // red
        }
        </script>
        <div ng:controller="MyCntrl">
          <ul>
            <li ng:repeat="color in colors">
              Name: <input ng:model="color.name">
              [<a href ng:click="colors.$remove(color)">X</a>]
            </li>
            <li>
              [<a href ng:click="colors.push({})">add</a>]
            </li>
          </ul>
          <hr/>
          Color (null not allowed):
          <select ng:model="color" ng:options="c.name for c in colors"></select><br>

          Color (null allowed):
          <div  class="nullable">
            <select ng:model="color" ng:options="c.name for c in colors">
              <option value="">-- chose color --</option>
            </select>
          </div><br/>

          Color grouped by shade:
          <select ng:model="color" ng:options="c.name group by c.shade for c in colors">
          </select><br/>


          Select <a href ng:click="color={name:'not in list'}">bogus</a>.<br>
          <hr/>
          Currently selected: {{ {selected_color:color}  }}
          <div style="border:solid 1px black; height:20px"
               ng:style="{'background-color':color.name}">
          </div>
        </div>
      </doc:source>
      <doc:scenario>
         it('should check ng:options', function() {
           expect(binding('{selected_color:color}')).toMatch('red');
           select('color').option('0');
           expect(binding('{selected_color:color}')).toMatch('black');
           using('.nullable').select('color').option('');
           expect(binding('{selected_color:color}')).toMatch('null');
         });
      </doc:scenario>
    </doc:example>
 */

var ngOptionsDirective = valueFn({ terminal: true });
var selectDirective = ['$compile', '$parse', function($compile,   $parse) {
                         //00001111100000000000222200000000000000000000003333000000000000044444444444444444000000000555555555555555550000000666666666666666660000000000000007777
  var NG_OPTIONS_REGEXP = /^\s*(.*?)(?:\s+as\s+(.*?))?(?:\s+group\s+by\s+(.*))?\s+for\s+(?:([\$\w][\$\w\d]*)|(?:\(\s*([\$\w][\$\w\d]*)\s*,\s*([\$\w][\$\w\d]*)\s*\)))\s+in\s+(.*)$/;

  return {
    restrict: 'E',
    require: '?ngModel',
    link: function(scope, element, attr, ctrl) {
      if (!ctrl) return;

      var multiple = attr.multiple,
          optionsExp = attr.ngOptions;

      // required validator
      if (multiple && (attr.required || attr.ngRequired)) {
        var requiredValidator = function(value) {
          ctrl.setValidity('REQUIRED', !attr.required || (value && value.length));
          return value;
        };

        ctrl.parsers.push(requiredValidator);
        ctrl.formatters.unshift(requiredValidator);

        attr.$observe('required', function() {
          requiredValidator(ctrl.viewValue);
        });
      }

      if (optionsExp) Options(scope, element, ctrl);
      else if (multiple) Multiple(scope, element, ctrl);
      else Single(scope, element, ctrl);


      ////////////////////////////



      function Single(scope, selectElement, ctrl) {
        ctrl.render = function() {
          selectElement.val(ctrl.viewValue);
        };

        selectElement.bind('change', function() {
          scope.$apply(function() {
            ctrl.touch();
            ctrl.read(selectElement.val());
          });
        });
      }

      function Multiple(scope, selectElement, ctrl) {
        ctrl.render = function() {
          var items = new HashMap(ctrl.viewValue);
          forEach(selectElement.children(), function(option) {
            option.selected = isDefined(items.get(option.value));
          });
        };

        selectElement.bind('change', function() {
          scope.$apply(function() {
            var array = [];
            forEach(selectElement.children(), function(option) {
              if (option.selected) {
                array.push(option.value);
              }
            });
            ctrl.touch();
            ctrl.read(array);
          });
        });
      }

      function Options(scope, selectElement, ctrl) {
        var match;

        if (! (match = optionsExp.match(NG_OPTIONS_REGEXP))) {
          throw Error(
            "Expected ng:options in form of '_select_ (as _label_)? for (_key_,)?_value_ in _collection_'" +
            " but got '" + optionsExp + "'.");
        }

        var displayFn = $parse(match[2] || match[1]),
            valueName = match[4] || match[6],
            keyName = match[5],
            groupByFn = $parse(match[3] || ''),
            valueFn = $parse(match[2] ? match[1] : valueName),
            valuesFn = $parse(match[7]),
            // we can't just jqLite('<option>') since jqLite is not smart enough
            // to create it in <select> and IE barfs otherwise.
            optionTemplate = jqLite(document.createElement('option')),
            optGroupTemplate = jqLite(document.createElement('optgroup')),
            nullOption = false, // if false then user will not be able to select it
            // This is an array of array of existing option groups in DOM. We try to reuse these if possible
            // optionGroupsCache[0] is the options with no option group
            // optionGroupsCache[?][0] is the parent: either the SELECT or OPTGROUP element
            optionGroupsCache = [[{element: selectElement, label:''}]];

        // find existing special options
        forEach(selectElement.children(), function(option) {
          if (option.value == '') {
            // developer declared null option, so user should be able to select it
            nullOption = jqLite(option).remove();
            // compile the element since there might be bindings in it
            $compile(nullOption)(scope);
          }
        });
        selectElement.html(''); // clear contents

        selectElement.bind('change', function() {
          scope.$apply(function() {
            var optionGroup,
                collection = valuesFn(scope) || [],
                locals = {},
                key, value, optionElement, index, groupIndex, length, groupLength;

            if (multiple) {
              value = [];
              for (groupIndex = 0, groupLength = optionGroupsCache.length;
              groupIndex < groupLength;
              groupIndex++) {
                // list of options for that group. (first item has the parent)
                optionGroup = optionGroupsCache[groupIndex];

                for(index = 1, length = optionGroup.length; index < length; index++) {
                  if ((optionElement = optionGroup[index].element)[0].selected) {
                    key = optionElement.val();
                    if (keyName) locals[keyName] = key;
                    locals[valueName] = collection[key];
                    value.push(valueFn(scope, locals));
                  }
                }
              }
            } else {
              key = selectElement.val();
              if (key == '?') {
                value = undefined;
              } else if (key == ''){
                value = null;
              } else {
                locals[valueName] = collection[key];
                if (keyName) locals[keyName] = key;
                value = valueFn(scope, locals);
              }
            }
            ctrl.touch();

            if (ctrl.viewValue !== value) {
              ctrl.read(value);
            }
          });
        });

        ctrl.render = render;

        // TODO(vojta): can't we optimize this ?
        scope.$watch(render);

        function render() {
          var optionGroups = {'':[]}, // Temporary location for the option groups before we render them
              optionGroupNames = [''],
              optionGroupName,
              optionGroup,
              option,
              existingParent, existingOptions, existingOption,
              modelValue = ctrl.modelValue,
              values = valuesFn(scope) || [],
              keys = keyName ? sortedKeys(values) : values,
              groupLength, length,
              groupIndex, index,
              locals = {},
              selected,
              selectedSet = false, // nothing is selected yet
              lastElement,
              element;

          if (multiple) {
            selectedSet = new HashMap(modelValue);
          } else if (modelValue === null || nullOption) {
            // if we are not multiselect, and we are null then we have to add the nullOption
            optionGroups[''].push({selected:modelValue === null, id:'', label:''});
            selectedSet = true;
          }

          // We now build up the list of options we need (we merge later)
          for (index = 0; length = keys.length, index < length; index++) {
               locals[valueName] = values[keyName ? locals[keyName]=keys[index]:index];
               optionGroupName = groupByFn(scope, locals) || '';
            if (!(optionGroup = optionGroups[optionGroupName])) {
              optionGroup = optionGroups[optionGroupName] = [];
              optionGroupNames.push(optionGroupName);
            }
            if (multiple) {
              selected = selectedSet.remove(valueFn(scope, locals)) != undefined;
            } else {
              selected = modelValue === valueFn(scope, locals);
              selectedSet = selectedSet || selected; // see if at least one item is selected
            }
            optionGroup.push({
              id: keyName ? keys[index] : index,   // either the index into array or key from object
              label: displayFn(scope, locals) || '', // what will be seen by the user
              selected: selected                   // determine if we should be selected
            });
          }
          if (!multiple && !selectedSet) {
            // nothing was selected, we have to insert the undefined item
            optionGroups[''].unshift({id:'?', label:'', selected:true});
          }

          // Now we need to update the list of DOM nodes to match the optionGroups we computed above
          for (groupIndex = 0, groupLength = optionGroupNames.length;
               groupIndex < groupLength;
               groupIndex++) {
            // current option group name or '' if no group
            optionGroupName = optionGroupNames[groupIndex];

            // list of options for that group. (first item has the parent)
            optionGroup = optionGroups[optionGroupName];

            if (optionGroupsCache.length <= groupIndex) {
              // we need to grow the optionGroups
              existingParent = {
                element: optGroupTemplate.clone().attr('label', optionGroupName),
                label: optionGroup.label
              };
              existingOptions = [existingParent];
              optionGroupsCache.push(existingOptions);
              selectElement.append(existingParent.element);
            } else {
              existingOptions = optionGroupsCache[groupIndex];
              existingParent = existingOptions[0];  // either SELECT (no group) or OPTGROUP element

              // update the OPTGROUP label if not the same.
              if (existingParent.label != optionGroupName) {
                existingParent.element.attr('label', existingParent.label = optionGroupName);
              }
            }

            lastElement = null;  // start at the begining
            for(index = 0, length = optionGroup.length; index < length; index++) {
              option = optionGroup[index];
              if ((existingOption = existingOptions[index+1])) {
                // reuse elements
                lastElement = existingOption.element;
                if (existingOption.label !== option.label) {
                  lastElement.text(existingOption.label = option.label);
                }
                if (existingOption.id !== option.id) {
                  lastElement.val(existingOption.id = option.id);
                }
                if (existingOption.element.selected !== option.selected) {
                  lastElement.prop('selected', (existingOption.selected = option.selected));
                }
              } else {
                // grow elements

                // if it's a null option
                if (option.id === '' && nullOption) {
                  // put back the pre-compiled element
                  element = nullOption;
                } else {
                  // jQuery(v1.4.2) Bug: We should be able to chain the method calls, but
                  // in this version of jQuery on some browser the .text() returns a string
                  // rather then the element.
                  (element = optionTemplate.clone())
                      .val(option.id)
                      .attr('selected', option.selected)
                      .text(option.label);
                }

                existingOptions.push(existingOption = {
                    element: element,
                    label: option.label,
                    id: option.id,
                    selected: option.selected
                });
                if (lastElement) {
                  lastElement.after(element);
                } else {
                  existingParent.element.append(element);
                }
                lastElement = element;
              }
            }
            // remove any excessive OPTIONs in a group
            index++; // increment since the existingOptions[0] is parent element not OPTION
            while(existingOptions.length > index) {
              existingOptions.pop().element.remove();
            }
          }
          // remove any excessive OPTGROUPs from select
          while(optionGroupsCache.length > groupIndex) {
            optionGroupsCache.pop()[0].element.remove();
          }
        };
      }
    }
  }
}];

var optionDirective = ['$interpolate', function($interpolate) {
  return {
    restrict: 'E',
    priority: 100,
    compile: function(element, attr) {
      if (isUndefined(attr.value)) {
        var interpolateFn = $interpolate(element.text(), true);
        if (interpolateFn) {
          return function (scope, element, attr) {
            scope.$watch(interpolateFn, function(value) {
              attr.$set('value', value);
            });
          }
        } else {
          attr.$set('value', element.text());
        }
      }
    }
  }
}];