function parseStateRef(ref, current) {

var preparsed = ref.match(/^\s*({[^}]*})\s*$/), parsed;
if (preparsed) ref = current + '(' + preparsed[1] + ')';
parsed = ref.replace(/\n/g, " ").match(/^([^(]+?)\s*(\((.*)\))?$/);
if (!parsed || parsed.length !== 4) throw new Error("Invalid state ref '" + ref + "'");
return { state: parsed[1], paramExpr: parsed[3] || null };

}

function stateContext(el) {

var stateData = el.parent().inheritedData('$uiView');

if (stateData && stateData.state && stateData.state.name) {
  return stateData.state;
}

}

/**

* @ngdoc directive
* @name ui.router.state.directive:ui-sref
*
* @requires ui.router.state.$state
* @requires $timeout
*
* @restrict A
*
* @description
* A directive that binds a link (`<a>` tag) to a state. If the state has an associated 
* URL, the directive will automatically generate & update the `href` attribute via 
* the {@link ui.router.state.$state#methods_href $state.href()} method. Clicking 
* the link will trigger a state transition with optional parameters. 
*
* Also middle-clicking, right-clicking, and ctrl-clicking on the link will be 
* handled natively by the browser.
*
* You can also use relative state paths within ui-sref, just like the relative 
* paths passed to `$state.go()`. You just need to be aware that the path is relative
* to the state that the link lives in, in other words the state that loaded the 
* template containing the link.
*
* You can specify options to pass to {@link ui.router.state.$state#go $state.go()}
* using the `ui-sref-opts` attribute. Options are restricted to `location`, `inherit`,
* and `reload`.
*
* @example
* Here's an example of how you'd use ui-sref and how it would compile. If you have the 
* following template:
* <pre>
* <a ui-sref="home">Home</a> | <a ui-sref="about">About</a> | <a ui-sref="{page: 2}">Next page</a>
* 
* <ul>
*     <li ng-repeat="contact in contacts">
*         <a ui-sref="contacts.detail({ id: contact.id })">{{ contact.name }}</a>
*     </li>
* </ul>
* </pre>
* 
* Then the compiled html would be (assuming Html5Mode is off and current state is contacts):
* <pre>
* <a href="#/home" ui-sref="home">Home</a> | <a href="#/about" ui-sref="about">About</a> | <a href="#/contacts?page=2" ui-sref="{page: 2}">Next page</a>
* 
* <ul>
*     <li ng-repeat="contact in contacts">
*         <a href="#/contacts/1" ui-sref="contacts.detail({ id: contact.id })">Joe</a>
*     </li>
*     <li ng-repeat="contact in contacts">
*         <a href="#/contacts/2" ui-sref="contacts.detail({ id: contact.id })">Alice</a>
*     </li>
*     <li ng-repeat="contact in contacts">
*         <a href="#/contacts/3" ui-sref="contacts.detail({ id: contact.id })">Bob</a>
*     </li>
* </ul>
*
* <a ui-sref="home" ui-sref-opts="{reload: true}">Home</a>
* </pre>
*
* @param {string} ui-sref 'stateName' can be any valid absolute or relative state
* @param {Object} ui-sref-opts options to pass to {@link ui.router.state.$state#go $state.go()}
*/

$StateRefDirective.$inject = [‘$state’, ‘$timeout’]; function $StateRefDirective($state, $timeout) {

var allowedOptions = ['location', 'inherit', 'reload'];

return {
  restrict: 'A',
  require: ['?^uiSrefActive', '?^uiSrefActiveEq'],
  link: function(scope, element, attrs, uiSrefActive) {
    var ref = parseStateRef(attrs.uiSref, $state.current.name);
    var params = null, url = null, base = stateContext(element) || $state.$current;
    var newHref = null, isAnchor = element.prop("tagName") === "A";
    var isForm = element[0].nodeName === "FORM";
    var attr = isForm ? "action" : "href", nav = true;

    var options = { relative: base, inherit: true };
    var optionsOverride = scope.$eval(attrs.uiSrefOpts) || {};

    angular.forEach(allowedOptions, function(option) {
      if (option in optionsOverride) {
        options[option] = optionsOverride[option];
      }
    });

    var update = function(newVal) {
      if (newVal) params = angular.copy(newVal);
      if (!nav) return;

      newHref = $state.href(ref.state, params, options);

      var activeDirective = uiSrefActive[1] || uiSrefActive[0];
      if (activeDirective) {
        activeDirective.$$setStateInfo(ref.state, params);
      }
      if (newHref === null) {
        nav = false;
        return false;
      }
      attrs.$set(attr, newHref);
    };

    if (ref.paramExpr) {
      scope.$watch(ref.paramExpr, function(newVal, oldVal) {
        if (newVal !== params) update(newVal);
      }, true);
      params = angular.copy(scope.$eval(ref.paramExpr));
    }
    update();

    if (isForm) return;

    element.bind("click", function(e) {
      var button = e.which || e.button;
      if ( !(button > 1 || e.ctrlKey || e.metaKey || e.shiftKey || element.attr('target')) ) {
        // HACK: This is to allow ng-clicks to be processed before the transition is initiated:
        var transition = $timeout(function() {
          $state.go(ref.state, params, options);
        });
        e.preventDefault();

        // if the state has no URL, ignore one preventDefault from the <a> directive.
        var ignorePreventDefaultCount = isAnchor && !newHref ? 1: 0;
        e.preventDefault = function() {
          if (ignorePreventDefaultCount-- <= 0)
            $timeout.cancel(transition);
        };
      }
    });
  }
};

}

/**

* @ngdoc directive
* @name ui.router.state.directive:ui-sref-active
*
* @requires ui.router.state.$state
* @requires ui.router.state.$stateParams
* @requires $interpolate
*
* @restrict A
*
* @description
* A directive working alongside ui-sref to add classes to an element when the
* related ui-sref directive's state is active, and removing them when it is inactive.
* The primary use-case is to simplify the special appearance of navigation menus
* relying on `ui-sref`, by having the "active" state's menu button appear different,
* distinguishing it from the inactive menu items.
*
* ui-sref-active can live on the same element as ui-sref or on a parent element. The first
* ui-sref-active found at the same level or above the ui-sref will be used.
*
* Will activate when the ui-sref's target state or any child state is active. If you
* need to activate only when the ui-sref target state is active and *not* any of
* it's children, then you will use
* {@link ui.router.state.directive:ui-sref-active-eq ui-sref-active-eq}
*
* @example
* Given the following template:
* <pre>
* <ul>
*   <li ui-sref-active="active" class="item">
*     <a href ui-sref="app.user({user: 'bilbobaggins'})">@bilbobaggins</a>
*   </li>
* </ul>
* </pre>
*
*
* When the app state is "app.user" (or any children states), and contains the state parameter "user" with value "bilbobaggins",
* the resulting HTML will appear as (note the 'active' class):
* <pre>
* <ul>
*   <li ui-sref-active="active" class="item active">
*     <a ui-sref="app.user({user: 'bilbobaggins'})" href="/users/bilbobaggins">@bilbobaggins</a>
*   </li>
* </ul>
* </pre>
*
* The class name is interpolated **once** during the directives link time (any further changes to the
* interpolated value are ignored).
*
* Multiple classes may be specified in a space-separated format:
* <pre>
* <ul>
*   <li ui-sref-active='class1 class2 class3'>
*     <a ui-sref="app.user">link</a>
*   </li>
* </ul>
* </pre>
*/

/**

* @ngdoc directive
* @name ui.router.state.directive:ui-sref-active-eq
*
* @requires ui.router.state.$state
* @requires ui.router.state.$stateParams
* @requires $interpolate
*
* @restrict A
*
* @description
* The same as {@link ui.router.state.directive:ui-sref-active ui-sref-active} but will only activate
* when the exact target state used in the `ui-sref` is active; no child states.
*
*/

$StateRefActiveDirective.$inject = [‘$state’, ‘$stateParams’, ‘$interpolate’]; function $StateRefActiveDirective($state, $stateParams, $interpolate) {

return  {
  restrict: "A",
  controller: ['$scope', '$element', '$attrs', function ($scope, $element, $attrs) {
    var state, params, activeClass;

    // There probably isn't much point in $observing this
    // uiSrefActive and uiSrefActiveEq share the same directive object with some
    // slight difference in logic routing
    activeClass = $interpolate($attrs.uiSrefActiveEq || $attrs.uiSrefActive || '', false)($scope);

    // Allow uiSref to communicate with uiSrefActive[Equals]
    this.$$setStateInfo = function (newState, newParams) {
      state = $state.get(newState, stateContext($element));
      params = newParams;
      update();
    };

    $scope.$on('$stateChangeSuccess', update);

    // Update route state
    function update() {
      if (isMatch()) {
        $element.addClass(activeClass);
      } else {
        $element.removeClass(activeClass);
      }
    }

    function isMatch() {
      if (typeof $attrs.uiSrefActiveEq !== 'undefined') {
        return state && $state.is(state.name, params);
      } else {
        return state && $state.includes(state.name, params);
      }
    }
  }]
};

}

angular.module(‘ui.router.state’)

.directive('uiSref', $StateRefDirective)
.directive('uiSrefActive', $StateRefActiveDirective)
.directive('uiSrefActiveEq', $StateRefActiveDirective);