/*
This file is part of Ext JS 3.4

Copyright (c) 2011-2013 Sencha Inc

Contact:  http://www.sencha.com/contact

GNU General Public License Usage
This file may be used under the terms of the GNU General Public License version 3.0 as
published by the Free Software Foundation and appearing in the file LICENSE included in the
packaging of this file.

Please review the following information to ensure the GNU General Public License version 3.0
requirements will be met: http://www.gnu.org/copyleft/gpl.html.

If you are unsure which license is appropriate for your use, please contact the sales department
at http://www.sencha.com/contact.

Build date: 2013-04-03 15:07:25
*/

/**
 * @class Ext.data.Api
 * @extends Object
 * Ext.data.Api is a singleton designed to manage the data API including methods
 * for validating a developer's DataProxy API.  Defines variables for CRUD actions
 * create, read, update and destroy in addition to a mapping of RESTful HTTP methods
 * GET, POST, PUT and DELETE to CRUD actions.
 * @singleton
 */
Ext.data.Api = (function() {

    // private validActions.  validActions is essentially an inverted hash of Ext.data.Api.actions, where value becomes the key.
    // Some methods in this singleton (e.g.: getActions, getVerb) will loop through actions with the code <code>for (var verb in this.actions)</code>
    // For efficiency, some methods will first check this hash for a match.  Those methods which do acces validActions will cache their result here.
    // We cannot pre-define this hash since the developer may over-ride the actions at runtime.
    var validActions = {};

    return {
        /**
         * Defined actions corresponding to remote actions:
         * <pre><code>
actions: {
    create  : 'create',  // Text representing the remote-action to create records on server.
    read    : 'read',    // Text representing the remote-action to read/load data from server.
    update  : 'update',  // Text representing the remote-action to update records on server.
    destroy : 'destroy'  // Text representing the remote-action to destroy records on server.
}
         * </code></pre>
         * @property actions
         * @type Object
         */
        actions : {
            create  : 'create',
            read    : 'read',
            update  : 'update',
            destroy : 'destroy'
        },

        /**
         * Defined {CRUD action}:{HTTP method} pairs to associate HTTP methods with the
         * corresponding actions for {@link Ext.data.DataProxy#restful RESTful proxies}.
         * Defaults to:
         * <pre><code>
restActions : {
    create  : 'POST',
    read    : 'GET',
    update  : 'PUT',
    destroy : 'DELETE'
},
         * </code></pre>
         */
        restActions : {
            create  : 'POST',
            read    : 'GET',
            update  : 'PUT',
            destroy : 'DELETE'
        },

        /**
         * Returns true if supplied action-name is a valid API action defined in <code>{@link #actions}</code> constants
         * @param {String} action Action to test for availability.
         * @return {Boolean}
         */
        isAction : function(action) {
            return (Ext.data.Api.actions[action]) ? true : false;
        },

        /**
         * Returns the actual CRUD action KEY "create", "read", "update" or "destroy" from the supplied action-name.  This method is used internally and shouldn't generally
         * need to be used directly.  The key/value pair of Ext.data.Api.actions will often be identical but this is not necessarily true.  A developer can override this naming
         * convention if desired.  However, the framework internally calls methods based upon the KEY so a way of retreiving the the words "create", "read", "update" and "destroy" is
         * required.  This method will cache discovered KEYS into the private validActions hash.
         * @param {String} name The runtime name of the action.
         * @return {String/null} returns the action-key, or verb of the user-action or null if invalid.
         * @nodoc
         */
        getVerb : function(name) {
            if (validActions[name]) {
                return validActions[name];  // <-- found in cache.  return immediately.
            }
            for (var verb in this.actions) {
                if (this.actions[verb] === name) {
                    validActions[name] = verb;
                    break;
                }
            }
            return (validActions[name] !== undefined) ? validActions[name] : null;
        },

        /**
         * Returns true if the supplied API is valid; that is, check that all keys match defined actions
         * otherwise returns an array of mistakes.
         * @return {String[]|true}
         */
        isValid : function(api){
            var invalid = [];
            var crud = this.actions; // <-- cache a copy of the actions.
            for (var action in api) {
                if (!(action in crud)) {
                    invalid.push(action);
                }
            }
            return (!invalid.length) ? true : invalid;
        },

        /**
         * Returns true if the supplied verb upon the supplied proxy points to a unique url in that none of the other api-actions
         * point to the same url.  The question is important for deciding whether to insert the "xaction" HTTP parameter within an
         * Ajax request.  This method is used internally and shouldn't generally need to be called directly.
         * @param {Ext.data.DataProxy} proxy
         * @param {String} verb
         * @return {Boolean}
         */
        hasUniqueUrl : function(proxy, verb) {
            var url = (proxy.api[verb]) ? proxy.api[verb].url : null;
            var unique = true;
            for (var action in proxy.api) {
                if ((unique = (action === verb) ? true : (proxy.api[action].url != url) ? true : false) === false) {
                    break;
                }
            }
            return unique;
        },

        /**
         * This method is used internally by <tt>{@link Ext.data.DataProxy DataProxy}</tt> and should not generally need to be used directly.
         * Each action of a DataProxy api can be initially defined as either a String or an Object.  When specified as an object,
         * one can explicitly define the HTTP method (GET|POST) to use for each CRUD action.  This method will prepare the supplied API, setting
         * each action to the Object form.  If your API-actions do not explicitly define the HTTP method, the "method" configuration-parameter will
         * be used.  If the method configuration parameter is not specified, POST will be used.
         <pre><code>
new Ext.data.HttpProxy({
    method: "POST",     // <-- default HTTP method when not specified.
    api: {
        create: 'create.php',
        load: 'read.php',
        save: 'save.php',
        destroy: 'destroy.php'
    }
});

// Alternatively, one can use the object-form to specify the API
new Ext.data.HttpProxy({
    api: {
        load: {url: 'read.php', method: 'GET'},
        create: 'create.php',
        destroy: 'destroy.php',
        save: 'update.php'
    }
});
        </code></pre>
         *
         * @param {Ext.data.DataProxy} proxy
         */
        prepare : function(proxy) {
            if (!proxy.api) {
                proxy.api = {}; // <-- No api?  create a blank one.
            }
            for (var verb in this.actions) {
                var action = this.actions[verb];
                proxy.api[action] = proxy.api[action] || proxy.url || proxy.directFn;
                if (typeof(proxy.api[action]) == 'string') {
                    proxy.api[action] = {
                        url: proxy.api[action],
                        method: (proxy.restful === true) ? Ext.data.Api.restActions[action] : undefined
                    };
                }
            }
        },

        /**
         * Prepares a supplied Proxy to be RESTful.  Sets the HTTP method for each api-action to be one of
         * GET, POST, PUT, DELETE according to the defined {@link #restActions}.
         * @param {Ext.data.DataProxy} proxy
         */
        restify : function(proxy) {
            proxy.restful = true;
            for (var verb in this.restActions) {
                proxy.api[this.actions[verb]].method ||
                    (proxy.api[this.actions[verb]].method = this.restActions[verb]);
            }
            // TODO: perhaps move this interceptor elsewhere?  like into DataProxy, perhaps?  Placed here
            // to satisfy initial 3.0 final release of REST features.
            proxy.onWrite = proxy.onWrite.createInterceptor(function(action, o, response, rs) {
                var reader = o.reader;
                var res = new Ext.data.Response({
                    action: action,
                    raw: response
                });

                switch (response.status) {
                    case 200:   // standard 200 response, send control back to HttpProxy#onWrite by returning true from this intercepted #onWrite
                        return true;
                        break;
                    case 201:   // entity created but no response returned
                        if (Ext.isEmpty(res.raw.responseText)) {
                          res.success = true;
                        } else {
                          //if the response contains data, treat it like a 200
                          return true;
                        }
                        break;
                    case 204:  // no-content.  Create a fake response.
                        res.success = true;
                        res.data = null;
                        break;
                    default:
                        return true;
                        break;
                }
                if (res.success === true) {
                    this.fireEvent("write", this, action, res.data, res, rs, o.request.arg);
                } else {
                    this.fireEvent('exception', this, 'remote', action, o, res, rs);
                }
                o.request.callback.call(o.request.scope, res.data, res, res.success);

                return false;   // <-- false to prevent intercepted function from running.
            }, proxy);
        }
    };
})();

/**
 * Ext.data.Response
 * Experimental.  Do not use directly.
 */
Ext.data.Response = function(params, response) {
    Ext.apply(this, params, {
        raw: response
    });
};
Ext.data.Response.prototype = {
    message : null,
    success : false,
    status : null,
    root : null,
    raw : null,

    getMessage : function() {
        return this.message;
    },
    getSuccess : function() {
        return this.success;
    },
    getStatus : function() {
        return this.status;
    },
    getRoot : function() {
        return this.root;
    },
    getRawResponse : function() {
        return this.raw;
    }
};

/**
 * @class Ext.data.Api.Error
 * @extends Ext.Error
 * Error class for Ext.data.Api errors
 */
Ext.data.Api.Error = Ext.extend(Ext.Error, {
    constructor : function(message, arg) {
        this.arg = arg;
        Ext.Error.call(this, message);
    },
    name: 'Ext.data.Api'
});
Ext.apply(Ext.data.Api.Error.prototype, {
    lang: {
        'action-url-undefined': 'No fallback url defined for this action.  When defining a DataProxy api, please be sure to define an url for each CRUD action in Ext.data.Api.actions or define a default url in addition to your api-configuration.',
        'invalid': 'received an invalid API-configuration.  Please ensure your proxy API-configuration contains only the actions defined in Ext.data.Api.actions',
        'invalid-url': 'Invalid url.  Please review your proxy configuration.',
        'execute': 'Attempted to execute an unknown action.  Valid API actions are defined in Ext.data.Api.actions"'
    }
});


