/**
 * @author Ed Spencer
 *
 * The Rest proxy is a specialization of the {@link Ext.data.proxy.Ajax AjaxProxy} which simply maps the four actions
 * (create, read, update and destroy) to RESTful HTTP verbs. For example, let's set up a {@link Ext.data.Model Model}
 * with an inline Rest proxy
 *
 *     Ext.define('User', {
 *         extend: 'Ext.data.Model',
 *         fields: ['id', 'name', 'email'],
 *
 *         proxy: {
 *             type: 'rest',
 *             url : '/users'
 *         }
 *     });
 *
 * Now we can create a new User instance and save it via the Rest proxy. Doing this will cause the Proxy to send a POST
 * request to '/users':
 *
 *     var user = Ext.create('User', {name: 'Ed Spencer', email: '[email protected]'});
 *
 *     user.save(); //POST /users
 *
 * Let's expand this a little and provide a callback for the {@link Ext.data.Model#save} call to update the Model once
 * it has been created. We'll assume the creation went successfully and that the server gave this user an ID of 123:
 *
 *     user.save({
 *         success: function(user) {
 *             user.set('name', 'Khan Noonien Singh');
 *
 *             user.save(); //PUT /users/123
 *         }
 *     });
 *
 * Now that we're no longer creating a new Model instance, the request method is changed to an HTTP PUT, targeting the
 * relevant url for that user. Now let's delete this user, which will use the DELETE method:
 *
 *         user.destroy(); //DELETE /users/123
 *
 * Finally, when we perform a load of a Model or Store, Rest proxy will use the GET method:
 *
 *     //1. Load via Store
 *
 *     //the Store automatically picks up the Proxy from the User model
 *     var store = Ext.create('Ext.data.Store', {
 *         model: 'User'
 *     });
 *
 *     store.load(); //GET /users
 *
 *     //2. Load directly from the Model
 *
 *     //GET /users/123
 *     Ext.ModelManager.getModel('User').load(123, {
 *         success: function(user) {
 *             console.log(user.getId()); //outputs 123
 *         }
 *     });
 *
 * # Url generation
 *
 * The Rest proxy is able to automatically generate the urls above based on two configuration options - {@link #appendId} and
 * {@link #format}. If appendId is true (it is by default) then Rest proxy will automatically append the ID of the Model
 * instance in question to the configured url, resulting in the '/users/123' that we saw above.
 *
 * If the request is not for a specific Model instance (e.g. loading a Store), the url is not appended with an id.
 * The Rest proxy will automatically insert a '/' before the ID if one is not already present.
 *
 *     new Ext.data.proxy.Rest({
 *         url: '/users',
 *         appendId: true //default
 *     });
 *
 *     // Collection url: /users
 *     // Instance url  : /users/123
 *
 * The Rest proxy can also optionally append a format string to the end of any generated url:
 *
 *     new Ext.data.proxy.Rest({
 *         url: '/users',
 *         format: 'json'
 *     });
 *
 *     // Collection url: /users.json
 *     // Instance url  : /users/123.json
 *
 * If further customization is needed, simply implement the {@link #buildUrl} method and add your custom generated url
 * onto the {@link Ext.data.Request Request} object that is passed to buildUrl. See [Rest proxy's implementation][1] for
 * an example of how to achieve this.
 *
 * Note that Rest proxy inherits from {@link Ext.data.proxy.Ajax AjaxProxy}, which already injects all of the sorter,
 * filter, group and paging options into the generated url. See the {@link Ext.data.proxy.Ajax AjaxProxy docs} for more
 * details.
 *
 * [1]: source/Rest.html#Ext-data-proxy-Rest-method-buildUrl
 */
Ext.define('Ext.data.proxy.Rest', {
    extend: 'Ext.data.proxy.Ajax',
    alternateClassName: 'Ext.data.RestProxy',
    alias : 'proxy.rest',

    /**
     * @property {Object} actionMethods
     * Mapping of action name to HTTP request method. These default to RESTful conventions for the 'create', 'read',
     * 'update' and 'destroy' actions (which map to 'POST', 'GET', 'PUT' and 'DELETE' respectively). This object
     * should not be changed except globally via {@link Ext#override Ext.override} - the {@link #getMethod} function
     * can be overridden instead.
     */
    actionMethods: {
        create : 'POST',
        read   : 'GET',
        update : 'PUT',
        destroy: 'DELETE'
    },
    
    defaultActionMethods: {
        create : 'POST',
        read   : 'GET',
        update : 'PUT',
        destroy: 'DELETE' 
    },

    /**
     * @cfg {Boolean} appendId
     * True to automatically append the ID of a Model instance when performing a request based on that single instance.
     * See Rest proxy intro docs for more details. Defaults to true.
     */
    appendId: true,

    /**
     * @cfg {String} format
     * Optional data format to send to the server when making any request (e.g. 'json'). See the Rest proxy intro docs
     * for full details. Defaults to undefined.
     */

    /**
     * @cfg {Boolean} batchActions
     * True to batch actions of a particular type when synchronizing the store. Defaults to false.
     */
    batchActions: false,

    /**
     * Specialized version of buildUrl that incorporates the {@link #appendId} and {@link #format} options into the
     * generated url. Override this to provide further customizations, but remember to call the superclass buildUrl so
     * that additional parameters like the cache buster string are appended.
     * @param {Object} request
     */
    buildUrl: function(request) {
        var me        = this,
            operation = request.operation,
            records   = operation.records || [],
            record    = records[0],
            format    = me.format,
            url       = me.getUrl(request),
            id        = record ? record.getId() : operation.id;

        if (me.appendId && me.isValidId(id)) {
            if (!url.match(/\/$/)) {
                url += '/';
            }

            url += id;
        }

        if (format) {
            if (!url.match(/\.$/)) {
                url += '.';
            }

            url += format;
        }

        request.url = url;

        return me.callParent(arguments);
    },
    
    isValidId: function(id) {
        return id || id === 0;
    }
});