// Copyright 2015 rain1017.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
// implied. See the License for the specific language governing
// permissions and limitations under the License. See the AUTHORS file
// for names of contributors.

'use strict';

var _ = require('lodash');
var path = require('path');
var logger = require('memdb-client').logger.getLogger('route', __filename);
var util = require('util');
var requireChildren = require('../../utils/require-children');
var dispatcher = require('../../utils/dispatcher');

var DEFAULT_BASE_PATH = 'app/routes';

var Routes = function(app, opts){
    opts = app.get('routesConfig') || opts || {};

    this.app = app;
    this.basePath = opts.basePath || DEFAULT_BASE_PATH;
};

var proto = Routes.prototype;

proto.name = 'routes';

proto.start = function(cb){
    var basePath = path.join(this.app.getBase(), this.basePath);
    this.loadRoutes(basePath);
    cb();
};

proto.stop = function(force, cb){
    cb();
};

proto.loadRoutes = function(basePath){
    var modules = requireChildren(module, basePath);

    var self = this;
    Object.keys(modules).forEach(function(serverType){
        var route = modules[serverType];

        self.app.route(serverType, function(sessionOrParam, msg, app, cb){
            var servers = app.getServersByType(serverType);
            if(servers.length === 0){
                cb(new Error('No server for type ' + serverType));
            }

            var key = null, method = null;
            if(msg.namespace === 'sys' && msg.service === 'msgRemote' && msg.method === 'forwardMessage'){
                // handler message
                method = msg.args[0].route;
                var body = msg.args[0].body;
                if(typeof(route.handler) === 'function'){
                    key = route.handler(sessionOrParam, method, body);
                }
            }
            else{
                // remote message
                if(typeof(route.remote) === 'function'){
                    method = msg.serverType + '.' + msg.service + '.' + msg.method;
                    key = route.remote(sessionOrParam, method, msg.args);
                }
                else{
                    key = sessionOrParam;
                }
            }

            var server = null;
            if(!key){
                server = _.sample(servers);
            }
            else{
                server = dispatcher.hashDispatch(key, servers);
            }

            logger.debug('%s %j => %s => %j', sessionOrParam, msg, key, server.id);

            cb(null, server.id);
        });
    });

    // Connector router is exception
    this.app.route('connector', function(routeParam, msg, app, cb){
        cb(null, routeParam.frontendId);
    });
};

module.exports = function(app, opts){
    var routes = new Routes(app, opts);
    return routes;
};