AriaNg/src/scripts/services/aria2WebSocketRpcService.js

(function () {
    'use strict';

    angular.module('ariaNg').factory('aria2WebSocketRpcService', ['$q', '$websocket', 'ariaNgSettingService', 'ariaNgLogService', function ($q, $websocket, ariaNgSettingService, ariaNgLogService) {
        var rpcUrl = ariaNgSettingService.getCurrentRpcUrl();
        var socketClient = null;

        var sendIdStates = {};
        var eventCallbacks = {};

        var processMethodCallback = function (content) {
            var uniqueId = content.id;

            if (!uniqueId) {
                return;
            }

            var state = sendIdStates[uniqueId];

            if (!state) {
                return;
            }

            var context = state.context;

            state.deferred.resolve({
                success: true,
                context: context
            });

            if (content.result && context.successCallback) {
                ariaNgLogService.debug('[aria2WebSocketRpcService.request] response success', content);

                context.successCallback(context.id, content.result);
            }

            if (content.error && context.errorCallback) {
                ariaNgLogService.debug('[aria2WebSocketRpcService.request] response error', content);

                context.errorCallback(context.id, content.error);
            }

            delete sendIdStates[uniqueId];
        };

        var processEventCallback = function (content) {
            var method = content.method;

            if (!method) {
                return;
            }

            var callbacks = eventCallbacks[method];

            if (!angular.isArray(callbacks) || callbacks.length < 1) {
                return;
            }

            for (var i = 0; i < callbacks.length; i++) {
                var callback = callbacks[i];
                var context = (angular.isArray(content.params) && content.params.length > 0 ? content.params[0] : null);
                callback(context);
            }
        };

        var getSocketClient = function () {
            if (socketClient === null) {
                try {
                    socketClient = $websocket(rpcUrl);

                    socketClient.onMessage(function (message) {
                        if (!message || !message.data) {
                            return;
                        }

                        var content = angular.fromJson(message.data);

                        if (!content) {
                            return;
                        }

                        if (content.id) {
                            processMethodCallback(content);
                        } else if (content.method) {
                            processEventCallback(content);
                        }
                    });
                } catch (ex) {
                    return {
                        success: false,
                        error: 'Cannot initialize WebSocket!',
                        exception: ex
                    }
                }
            }

            return {
                success: true,
                instance: socketClient
            };
        };

        return {
            request: function (context) {
                if (!context) {
                    return;
                }

                var client = getSocketClient();
                var uniqueId = context.uniqueId;
                var requestBody = angular.toJson(context.requestBody);

                ariaNgLogService.debug('[aria2WebSocketRpcService.request] request start', context);

                var deferred = $q.defer();

                sendIdStates[uniqueId] = {
                    context: context,
                    deferred: deferred
                };

                if (client.instance) {
                    client.instance.send(requestBody);
                } else {
                    deferred.reject({
                        success: false,
                        context: context
                    });

                    ariaNgLogService.debug('[aria2WebSocketRpcService.request] client error', client);
                    context.errorCallback(context.id, { message: client.error });
                }

                return deferred.promise;
            },
            on: function (eventName, callback) {
                var callbacks = eventCallbacks[eventName];

                if (!angular.isArray(callbacks)) {
                    callbacks = eventCallbacks[eventName] = [];
                }

                callbacks.push(callback);
            }
        };
    }]);
}());