/*global angular */
/*jshint unused:false */
'use strict';
/**
 * The main TodoMVC app module
 *
 * @type {angular.Module}
 */
var todomvc = angular.module('todomvc', []);

/*global todomvc */
'use strict';
/**
 * Services that persists and retrieves TODOs from localStorage
 */
todomvc.factory('todoStorage', function () {
    // todos JSON字符串存儲的唯一標識
    var STORAGE_ID = 'todos-angularjs';
    return {
        // 從localStorage中取出todos，并解析成JSON對象
        get: function () {
            return JSON.parse(localStorage.getItem(STORAGE_ID) || '[]');
        },
        // 將todos對象轉化成JSON字符串，并存入localStorage
        put: function (todos) {
            localStorage.setItem(STORAGE_ID, JSON.stringify(todos));
        }
    };
});

/*global todomvc */
'use strict';
/**
 * Directive that places focus on the element it is applied to when the expression it binds to evaluates to true
 */
todomvc.directive('todoFocus', function todoFocus($timeout) {
    return function (scope, elem, attrs) {
        // 為todoFocus屬性的值添加監(jiān)聽
        scope.$watch(attrs.todoFocus, function (newVal) {
            if (newVal) {
                $timeout(function () {
                    elem[0].focus();
                }, 0, false);
            }
        });
    };
});

/*global todomvc */
'use strict';
/**
 * Directive that executes an expression when the element it is applied to gets
 * an `escape` keydown event.
 */
todomvc.directive('todoEscape', function () {
    var ESCAPE_KEY = 27;
    return function (scope, elem, attrs) {
        elem.bind('keydown', function (event) {
            if (event.keyCode === ESCAPE_KEY) {
                scope.$apply(attrs.todoEscape);
            }
        });
    };
});

/*global todomvc, angular */
'use strict';
/**
 * The main controller for the app. The controller:
 * - retrieves and persists the model via the todoStorage service
 * - exposes the model to the template and provides event handlers
 */
todomvc.controller('TodoCtrl', function TodoCtrl($scope, $location, todoStorage, filterFilter) {
    // 從localStorage中獲取todos
    var todos = $scope.todos = todoStorage.get();

    // 記錄新的todo
    $scope.newTodo = '';
    // 記錄編輯過的todo
    $scope.editedTodo = null;
    // 當todos的值改變時執(zhí)行其中的方法
    $scope.$watch('todos', function (newValue, oldValue) {
        // 獲取未完成的todos的數目
        $scope.remainingCount = filterFilter(todos, { completed: false }).length;
        // 獲取已完成的todos的數目
        $scope.completedCount = todos.length - $scope.remainingCount;
        // 當且僅當$scope.remainingCount為0時，$scope.allChecked為true
        $scope.allChecked = !$scope.remainingCount;
        // 當todos的新值和舊值不相等時，向localStorage中存入todos
        if (newValue !== oldValue) { // This prevents unneeded calls to the local storage
            todoStorage.put(todos);
        }
    }, true);
    if ($location.path() === '') {
        // 如果$location.path()為空，就設置為/
        $location.path('/');
    }
    $scope.location = $location;
    // 當location.path()的值改變時執(zhí)行其中的方法
    $scope.$watch('location.path()', function (path) {
        // 獲取狀態(tài)的過濾器
        // 如果path為'/active'，過濾器為{ completed: false }
        // 如果path為'/completed'，過濾器為{ completed: true }
        // 否則，過濾器為null
        $scope.statusFilter = (path === '/active') ?
            { completed: false } : (path === '/completed') ?
            { completed: true } : null;
    });
    // 添加一個新的todo
    $scope.addTodo = function () {
        var newTodo = $scope.newTodo.trim();
        if (!newTodo.length) {
            return;
        }
        // 向todos里添加一個todo，completed屬性默認為false
        todos.push({
            title: newTodo,
            completed: false
        });
        // 置空
        $scope.newTodo = '';
    };
    // 編輯一個todo
    $scope.editTodo = function (todo) {
        $scope.editedTodo = todo;
        // Clone the original todo to restore it on demand.
        // 保存編輯前的todo，為恢復編輯前做準備
        $scope.originalTodo = angular.extend({}, todo);
    };
    // 編輯todo完成
    $scope.doneEditing = function (todo) {
        // 置空
        $scope.editedTodo = null;
        todo.title = todo.title.trim();
        if (!todo.title) {
            // 如果todo的title為空，則移除該todo
            $scope.removeTodo(todo);
        }
    };
    // 恢復編輯前的todo
    $scope.revertEditing = function (todo) {
        todos[todos.indexOf(todo)] = $scope.originalTodo;
        $scope.doneEditing($scope.originalTodo);
    };
    // 移除todo
    $scope.removeTodo = function (todo) {
        todos.splice(todos.indexOf(todo), 1);
    };
    // 清除已完成的todos
    $scope.clearCompletedTodos = function () {
        $scope.todos = todos = todos.filter(function (val) {
            return !val.completed;
        });
    };
    // 標記所有的todo的狀態(tài)（true或false）
    $scope.markAll = function (completed) {
        todos.forEach(function (todo) {
            todo.completed = completed;
        });
    };
});

<!doctype html>
<html lang="en" ng-app="todomvc" data-framework="angularjs">
    <head>
        <meta charset="utf-8">
        <meta http-equiv="X-UA-Compatible" content="IE=edge">
        <title>AngularJS • TodoMVC</title>
        <link rel="stylesheet" href="bower_components/todomvc-common/base.css">
        <style>[ng-cloak] { display: none; }</style>
    </head>
    <body>
        <section id="todoapp" ng-controller="TodoCtrl">
            <header id="header">
                <h1>todos</h1>
                <form id="todo-form" ng-submit="addTodo()">
                    <input id="new-todo" placeholder="What needs to be done?" ng-model="newTodo" autofocus>
                </form>
            </header>
            <section id="main" ng-show="todos.length" ng-cloak>
                <input id="toggle-all" type="checkbox" ng-model="allChecked" ng-click="markAll(allChecked)">
                <label for="toggle-all">Mark all as complete</label>
                <ul id="todo-list">
                    <li ng-repeat="todo in todos | filter:statusFilter track by $index" ng-class="{completed: todo.completed, editing: todo == editedTodo}">
                        <div class="view">
                            <input class="toggle" type="checkbox" ng-model="todo.completed">
                            <label ng-dblclick="editTodo(todo)">{{todo.title}}</label>
                            <button class="destroy" ng-click="removeTodo(todo)"></button>
                        </div>
                        <form ng-submit="doneEditing(todo)">
                            <input class="edit" ng-trim="false" ng-model="todo.title" todo-escape="revertEditing(todo)" ng-blur="doneEditing(todo)" todo-focus="todo == editedTodo">
                        </form>
                    </li>
                </ul>
            </section>
            <footer id="footer" ng-show="todos.length" ng-cloak>
                <span id="todo-count"><strong>{{remainingCount}}</strong>
                    <ng-pluralize count="remainingCount" when="{ one: 'item left', other: 'items left' }"></ng-pluralize>
                </span>
                <ul id="filters">
                    <li>
                        <a ng-class="{selected: location.path() == '/'} " href="#/">All</a>
                    </li>
                    <li>
                        <a ng-class="{selected: location.path() == '/active'}" href="#/active">Active</a>
                    </li>
                    <li>
                        <a ng-class="{selected: location.path() == '/completed'}" href="#/completed">Completed</a>
                    </li>
                </ul>
                <button id="clear-completed" ng-click="clearCompletedTodos()" ng-show="completedCount">Clear completed ({{completedCount}})</button>
            </footer>
        </section>
        <footer id="info">
            <p>Double-click to edit a todo</p>
            <p>Credits:
                <a href=" Burgdorf</a>,
                <a href=" Bidelman</a>,
                <a href=" Mumm</a> and
                <a href=" Minar</a>
            </p>
            <p>Part of <a href=">
        </footer>
        <script src="bower_components/todomvc-common/base.js"></script>
        <script src="bower_components/angular/angular.js"></script>
        <script src="js/app.js"></script>
        <script src="js/controllers/todoCtrl.js"></script>
        <script src="js/services/todoStorage.js"></script>
        <script src="js/directives/todoFocus.js"></script>
        <script src="js/directives/todoEscape.js"></script>
    </body>
</html>

<script src="bower_components/todomvc-common/base.js"></script>
<script src="bower_components/angular/angular.js"></script>
<script src="js/app.js"></script>
<script src="js/controllers/todoCtrl.js"></script>
<script src="js/services/todoStorage.js"></script>
<script src="js/directives/todoFocus.js"></script>
<script src="js/directives/todoEscape.js"></script>

<style>[ng-cloak] { display: none; }</style>

<form id="todo-form" ng-submit="addTodo()">
    <input id="new-todo" placeholder="What needs to be done?" ng-model="newTodo" autofocus>
</form>

<section id="main" ng-show="todos.length" ng-cloak>
    <input id="toggle-all" type="checkbox" ng-model="allChecked" ng-click="markAll(allChecked)">
    <label for="toggle-all">Mark all as complete</label>
    <ul id="todo-list">
        <li ng-repeat="todo in todos | filter:statusFilter track by $index" ng-class="{completed: todo.completed, editing: todo == editedTodo}">
            <div class="view">
                <input class="toggle" type="checkbox" ng-model="todo.completed">
                <label ng-dblclick="editTodo(todo)">{{todo.title}}</label>
                <button class="destroy" ng-click="removeTodo(todo)"></button>
            </div>
            <form ng-submit="doneEditing(todo)">
                <input class="edit" ng-trim="false" ng-model="todo.title" todo-escape="revertEditing(todo)" ng-blur="doneEditing(todo)" todo-focus="todo == editedTodo">
            </form>
        </li>
    </ul>
</section>

<footer id="footer" ng-show="todos.length" ng-cloak>
    <span id="todo-count"><strong>{{remainingCount}}</strong>
        <ng-pluralize count="remainingCount" when="{ one: 'item left', other: 'items left' }"></ng-pluralize>
    </span>
    <ul id="filters">
        <li>
            <a ng-class="{selected: location.path() == '/'} " href="#/">All</a>
        </li>
        <li>
            <a ng-class="{selected: location.path() == '/active'}" href="#/active">Active</a>
        </li>
        <li>
            <a ng-class="{selected: location.path() == '/completed'}" href="#/completed">Completed</a>
        </li>
    </ul>
    <button id="clear-completed" ng-click="clearCompletedTodos()" ng-show="completedCount">Clear completed ({{completedCount}})</button>
</footer>