/*
 * Copyright (c) 2017 TOYOTA MOTOR CORPORATION
 *
 * 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.
 */

#include <stdarg.h>
#include <sys/socket.h>
#include <iostream>
#include <algorithm>
#include <thread>
#include <errno.h>
#include <libsoundmanager/libsoundmanager.hpp>

#define ELOG(args,...) _ELOG(__FUNCTION__,__LINE__,args,##__VA_ARGS__)
#define DLOG(args,...) _DLOG(__FUNCTION__,__LINE__,args,##__VA_ARGS__)

using namespace std;

static void _DLOG(const char* func, const int line, const char* log, ...);
static void _ELOG(const char* func, const int line, const char* log, ...);
static bool has_verb(const string& verb);
static const char API[] = "soundmanager";

static void _on_hangup_static(void *closure, struct afb_wsj1 *wsj)
{
	static_cast<LibSoundmanager*>(closure)->on_hangup(NULL,wsj);
}

static void _on_call_static(void *closure, const char *api, const char *verb, struct afb_wsj1_msg *msg)
{
	/* LibSoundmanager is not called from other process */
}

static void _on_event_static(void* closure, const char* event, struct afb_wsj1_msg *msg)
{
	static_cast<LibSoundmanager*>(closure)->on_event(NULL,event,msg);
}

static void _on_reply_static(void *closure, struct afb_wsj1_msg *msg)
{
	static_cast<LibSoundmanager*>(closure)->on_reply(NULL,msg);		
}


/**
 * This function is constructor
 * 
 * #### Parameters
 * - port  [in] : This argument should be specified to the port number to be used for websocket
 * - token [in] : This argument should be specified to the token to be used for websocket
 *
 * #### Rreturn
 * Nothing
 *
 * #### Note
 * Use this constructor
 *
 */
LibSoundmanager::LibSoundmanager(const int port, const string& token)
{
	int ret;
	if(port > 0 && token.size() > 0)
	{
		mport = port;
		mtoken = token;
	}
	else
	{
		ELOG("port and token should be > 0, Initial port and token uses.");
	}

	ret = initialize_websocket();
	if(ret != 0 )
	{
		ELOG("Failed to initialize websocket");
	}
	else{
		DLOG("Initialized");
	}
}

LibSoundmanager::~LibSoundmanager()
{
	if(mploop)
	{
		sd_event_unref(mploop);
	}
	if(sp_websock != NULL)
	{
		free(sp_websock);
	}
}

/**
 * This function register callback function for reply/event message from sound manager
 * 
 * #### Parameters
 * - event_cb [in] : This argument should be specified to the callback for subscribed event
 * - reply_cb [in] : This argument should be specified to the reply callback for call function
 *
 * #### Rreturn
 * - Returns 0 on success or -1 in case of error.
 *
 * #### Note
 * Event callback is invoked by sound manager for event you subscribed.
 * If you would like to get event, please call subscribe function before/after this function
 */
void LibSoundmanager::register_callback(
	void (*event_cb)(const std::string& event, struct json_object* event_contents), 
	void (*reply_cb)(struct json_object* reply_contents),
	void (*hangup_cb)(void))
{
	onEvent = event_cb;
	onReply = reply_cb;
	onHangup = hangup_cb;
}

int LibSoundmanager::initialize_websocket()
{
	mploop = NULL;
	onEvent = nullptr;
	onReply = nullptr;
	int ret = sd_event_default(&mploop);
	if(ret < 0)
	{
		ELOG("Failed to create event loop");
		goto END;
	}
	/* Initialize interface from websocket */
	
	minterface.on_hangup = _on_hangup_static;
	minterface.on_call = _on_call_static; /* Is this necessary? */
	minterface.on_event = _on_event_static;
	muri += "ws://localhost:" + to_string(mport) + "/api?token=" + mtoken; /*To be modified*/
	sp_websock = afb_ws_client_connect_wsj1(mploop, muri.c_str(), &minterface, this);
	if(sp_websock == NULL)
	{
		ELOG("Failed to create websocket connection");
		goto END;
	}

	/* creates the evsrc */
	//ret = sd_event_add_io(mploop,&mevent_src, sp_websock->fd, EPOLLIN, event_callback, NULL);
	
	return 0;
END:
	if(mploop)
	{
		sd_event_unref(mploop);
	}
	return -1;
}

static void *event_loop_run(void *args)
{
	struct sd_event* loop = (struct sd_event*)(args);
	DLOG("start eventloop");
	for(;;)
		sd_event_run(loop, 30000000);
}

/**
 * This function start receiving the reply/event message from sound manager
 * 
 * #### Parameters
 *	Nothing
 * #### Rreturn
 * - Returns thread_id on success or -1 in case of error.
 *
 * #### Note
 *
 */
int LibSoundmanager::run_eventloop()
{
	if(mploop && sp_websock)
	{
		pthread_t thread_id;
	    int ret = pthread_create(&thread_id, NULL, event_loop_run, mploop);
		if(ret != 0)
		{
			ELOG("Cannot run eventloop due to error:%d", errno);
			return -1;
		}
		else
			return thread_id;
	}
	else
	{
		ELOG("Connecting is not established yet");
		return -1;
	}
}

/**
 * This function calls the API of Audio Manager via WebSocket
 * 
 * #### Parameters
 * - verb [in] : This argument should be specified to the API name (e.g. "connect")
 * - arg  [in] : This argument should be specified to the argument of API. And this argument expects JSON object
 *	
 * #### Rreturn
 * - Returns 0 on success or -1 in case of error.
 *
 * #### Note
 * To call Audio Manager's APIs, the application should set its function name, arguments to JSON format.
 *
 */
int LibSoundmanager::call(const string& verb, struct json_object* arg)
{
	int ret;
	if(!sp_websock)
	{
		return -1;
	}
	if (!has_verb(verb))
	{
		ELOG("verb doesn't exit");
		return -1;
	}
	ret = afb_wsj1_call_j(sp_websock, API, verb.c_str(), arg, _on_reply_static, this);
	if (ret < 0) {
		ELOG("Failed to call verb:%s",verb.c_str());
	}
	return ret;
}

/**
 * This function calls the API of Audio Manager via WebSocket
 * This function is overload function of "call"
 * 
 * #### Parameters
 * - verb [in] : This argument should be specified to the API name (e.g. "connect")
 * - arg  [in] : This argument should be specified to the argument of API. And this argument expects JSON object
 *	
 * #### Rreturn
 * - Returns 0 on success or -1 in case of error.
 *
 * #### Note
 * To call Audio Manager's APIs, the application should set its function name, arguments to JSON format.
 * 
 */
int LibSoundmanager::call(const char* verb, struct json_object* arg)
{
	int ret;
	if(!sp_websock)
	{
		return -1;
	}
	if (!has_verb(string(verb)))
	{
		ELOG("verb doesn't exit");
		return -1;
	}
	ret = afb_wsj1_call_j(sp_websock, API, verb, arg, _on_reply_static, this);
	if (ret < 0) {
		ELOG("Failed to call verb:%s",verb);
	}
	return ret;
}

/**
 * Register callback function for each event
 * 
 * #### Parameters
 * - event_name [in] : This argument should be specified to the event name
 *	
 * #### Rreturn
 * - Returns 0 on success or -1 in case of error.
 *
 * #### Note
 * This function enables to get an event to your callback function. 
 * Regarding the list of event name, please refer to CommandSender API and RountingSender API.
 *
 */
int LibSoundmanager::subscribe(const string& event_name)
{
	if(!sp_websock)
	{
		return -1;
	}
	struct json_object* j_obj = json_object_new_object();
	json_object_object_add(j_obj, "event", json_object_new_string(event_name.c_str()));

	int ret = afb_wsj1_call_j(sp_websock, API, "subscribe", j_obj, _on_reply_static, this);
	if (ret < 0) {
		ELOG("Failed to call verb:%s",__FUNCTION__);
	}
	return ret;
}

/**
 * Unregister callback function for each event
 * 
 * #### Parameters
 * - event_name [in] : This argument should be specified to the event name
 *	
 * #### Rreturn
 * - Returns 0 on success or -1 in case of error.
 *
 * #### Note
 * This function disables to get an event to your callback function. 
 *
 */
int LibSoundmanager::unsubscribe(const string& event_name)
{
	if(!sp_websock)
	{
		return -1;
	}
	struct json_object* j_obj = json_object_new_object();
	json_object_object_add(j_obj, "event", json_object_new_string(event_name.c_str()));

	int ret = afb_wsj1_call_j(sp_websock, API, "unsubscribe", j_obj, _on_reply_static, this);
	if (ret < 0) {
		ELOG("Failed to call verb:%s",__FUNCTION__);
	}
	return ret;
}

am_Error_e LibSoundmanager::connect(const am_sourceID_t sourceID, const am_sinkID_t sinkID, am_mainConnectionID_t& mainConnectionID)
{
	/*int ret;
	char *key;
	rc = asprintf(&key, "%d:%s/%s", ++num, api, "connect"); 
	ret = afb_wsj1_call_s(wsj1, api, verb, object, on_reply, key);
	if(ret < 0)
	{
		fprintf(stderr, "calling %s/%s(%s) failed: %m\n", api, verb, object);
		
	}*/
	/* open the json scripts */
	// get mainconnedction ID */
	//mainConnectionID = xx; 
	return E_OK;	
}

am_Error_e LibSoundmanager::disconnect(const am_mainConnectionID_t mainConnectionID)
{
	return E_OK;
}

/*const struct afb_wsj1* LibSoundmanager::get_websocket_handler()
{
	if(sp_websock)
	{
		return sp_websock;
	}
	return nullptr;
}

const struct sd_event* LibSoundmanager::get_sd_event()
{
	if(mploop)
	{
		return mploop;
	}
	return nullptr;
}*/

/************* Callback Function *************/

void LibSoundmanager::on_hangup(void *closure, struct afb_wsj1 *wsj)
{
	DLOG("%s called", __FUNCTION__);
	if(onHangup != nullptr)
	{
		onHangup();
	}
}

void LibSoundmanager::on_call(void *closure, const char *api, const char *verb, struct afb_wsj1_msg *msg)
{
}

/*
* event is like "soundmanager/newMainConnection"
* msg is like {"event":"soundmanager\/newMainConnection","data":{"mainConnectionID":3,"sourceID":101,"sinkID":100,"delay":0,"connectionState":4},"jtype":"afb-event"})}
*               ^key^   ^^^^^^^^^^^^ value ^^^^^^^^^^^^
* so you can get 
	event name : struct json_object obj = json_object_object_get(msg,"event")
*/ 
void LibSoundmanager::on_event(void *closure, const char *event, struct afb_wsj1_msg *msg)
{
	cout << "ON-EVENT:" << event << "(" << afb_wsj1_msg_object_s(msg) << ")" << endl;	
	if(onEvent != nullptr)
	{
		const string ev(event);
		struct json_object* ev_contents = afb_wsj1_msg_object_j(msg);
		onEvent(ev, ev_contents);
	}
}

void LibSoundmanager::on_reply(void *closure, struct afb_wsj1_msg *msg)
{
	cout << "ON-REPLY:" <<  "(" << afb_wsj1_msg_object_s(msg) << ")" << endl;
	if(onReply != nullptr)
	{
		struct json_object* reply = afb_wsj1_msg_object_j(msg);
		onReply(reply);
	}
}

/* Internal Function in libsoundmanager */

static void _ELOG(const char* func, const int line, const char* log, ...)
{
	char *message;
	va_list args;
	va_start(args, log);
	if (log == NULL || vasprintf(&message, log, args) < 0)
		message = NULL;
	cout << "[ERROR]" << func << "(" << line << "):" << message << endl; 
	va_end(args);
	free(message);
}

static void _DLOG(const char* func, const int line, const char* log, ...)
{
	char *message;
	va_list args;
	va_start(args, log);
	if (log == NULL || vasprintf(&message, log, args) < 0)
		message = NULL;
	cout << "[DEBUG]" << func << "(" << line << "):" << message << endl; 
	va_end(args);
	free(message);
}

static bool has_verb(const string& verb)
{
	DLOG("verb is %s", verb.c_str());
	if(find(api_list.begin(), api_list.end(), verb) != api_list.end())
		return true;
	else
		return false;
}