/*=================================================================================
# Filename: gserver.cpp
# Author: Bookug Lobert
# Mail: 1181955272@qq.com
# Last Modified: 2016-02-26 19:15
# Description: first written by hanshuo, modified by zengli, improved by Wang Libo
=================================================================================*/

#include "../Server/Server.h"
#include "../Util/Util.h"

using namespace std;

//#define GSERVER_PORT_FILE "bin/.gserver_port"
//#define GSERVER_PORT_SWAP "bin/.gserver_port.swap"
//#define GSERVER_LOG "logs/gserver.log"

bool isOnlyProcess(const char* argv0);
void checkSwap();
bool startServer(bool _debug);
bool stopServer();

int main(int argc, char* argv[])
{
//#ifdef DEBUG
	Util util;
//#endif

	string mode;
	if (argc == 1) {
		mode = "-h";
	}
	else {
		mode = argv[1];
	}

	if (argc > 3 || (argc == 3 && mode != "-p" && mode != "--port")) {
		cout << "Invalid arguments! Input \"bin/gserver -h\" for help." << endl;
		return -1;
	}

	else if (mode == "-h" || mode == "--help") {
		cout << endl;
		cout << "gStore Server (gServer)" << endl;
		cout << endl;
		cout << "Usage:\tbin/gserver [option]" << endl;
		cout << endl;
		cout << "Options:" << endl;
		cout << "\t-h,--help\t\tDisplay this message." << endl;
		cout << "\t-s,--start\t\tStart gServer." << endl;
		cout << "\t-t,--stop\t\tStop gServer." << endl;
		cout << "\t-r,--restart\t\tRestart gServer." << endl;
		cout << "\t-p,--port [PORT=" << Socket::DEFAULT_CONNECT_PORT << "]\tChange connection port configuration, takes effect after restart if gServer running." << endl;
		cout << "\t-P,--printport\t\tDisplay current connection port configuration." << endl;
		cout << "\t-d,--debug\t\tStart gServer in debug mode (keep gServer in the foreground)." << endl;
		cout << "\t-k,--kill\t\tKill existing gServer process(es), ONLY use when out of normal procedures." << endl;
		cout << endl;
		return 0;
	}

	if (mode == "-p" || mode == "--port") {
		unsigned short port = Socket::DEFAULT_CONNECT_PORT;
		if (argc == 3) {
			if (!Util::isValidPort(string(argv[2]))) {
				cerr << "Invalid port: " << argv[2] << endl;
				return -1;
			}
			else {
				stringstream ss(argv[2]);
				ss >> port;
			}
		}
		if (!isOnlyProcess(argv[0])) {
			//ofstream out(GSERVER_PORT_SWAP, ios::out);
			ofstream out(Util::gserver_port_swap.c_str());
			if (!out) {
				cerr << "Failed to change port!" << endl;
				return -1;
			}
			out << port;
			out.close();
			cout << "Port will be changed to " << port << " after the current server stops or restarts." << endl;
			return 0;
		}
		//ofstream out(GSERVER_PORT_FILE, ios::out);
		ofstream out(Util::gserver_port_file.c_str());
		if (!out) {
			cerr << "Failed to change port!" << endl;
			return -1;
		}
		out << port;
		out.close();
		cout << "Port changed to " << port << '.' << endl;
		return 0;
	}

	else if (mode == "-s" || mode == "--start") {
		if (!isOnlyProcess(argv[0])) {
			cerr << "gServer already running!" << endl;
			return -1;
		}
		if (startServer(false)) {
			sleep(1);
			if (isOnlyProcess(argv[0])) {
				cerr << "Server stopped unexpectedly. Check for port conflicts!" << endl;
				return -1;
			}
			return 0;
		}
		else {
			return -1;
		}
	}

	else if (mode == "-t" || mode == "--stop") {
		if (isOnlyProcess(argv[0])) {
			cerr << "gServer not running!" << endl;
			return -1;
		}
		if (stopServer()) {
			return 0;
		}
		else {
			return -1;
		}
	}

	else if (mode == "-r" || mode == "--restart") {
		if (isOnlyProcess(argv[0])) {
			cerr << "gServer not running!" << endl;
			return -1;
		}
		if (!stopServer()) {
			return -1;
		}
		if (startServer(false)) {
			sleep(1);
			if (isOnlyProcess(argv[0])) {
				cerr << "Server stopped unexpectedly. Check for port conflicts!" << endl;
				return -1;
			}
			return 0;
		}
		else {
			return -1;
		}
		return 0;
	}

	else if (mode == "-P" || mode == "--printport") {
		unsigned short port = Socket::DEFAULT_CONNECT_PORT;
		//ifstream in(GSERVER_PORT_FILE);
		ifstream in(Util::gserver_port_file.c_str());
		if (in) {
			in >> port;
			in.close();
		}
		cout << "Current connection port is " << port << '.' << endl;
		unsigned short portSwap = 0;
		//ifstream inSwap(GSERVER_PORT_SWAP);
		ifstream inSwap(Util::gserver_port_swap.c_str());
		if (inSwap) {
			inSwap >> portSwap;
			inSwap.close();
		}
		if (portSwap != 0) {
			cout << "Connection port to be changed to " << portSwap << '.' << endl;
		}
		return 0;
	}

	else if (mode == "-k" || mode == "--kill") {
		if (isOnlyProcess(argv[0])) {
			cerr << "No process to kill!" << endl;
			return -1;
		}
		execl("/usr/bin/killall", "killall", Util::getExactPath(argv[0]).c_str(), NULL);
		return 0;
	}

	else {
		cerr << "Invalid arguments! Type \"bin/gserver -h\" for help." << endl;
		return -1;
	}
}

bool isOnlyProcess(const char* argv0) {
	return Util::getSystemOutput("pidof " + Util::getExactPath(argv0)) == Util::int2string(getpid());
}

void checkSwap() {
	//if (access(GSERVER_PORT_SWAP, 00) != 0) {
	if (access(Util::gserver_port_swap.c_str(), 00) != 0) {
		return;
	}
	//ifstream in(GSERVER_PORT_SWAP, ios::in);
	ifstream in(Util::gserver_port_swap.c_str());
	if (!in) {
		cerr << "Failed in checkSwap(), port may not be changed." << endl;
		return;
	}
	unsigned short port;
	in >> port;
	in.close();
	//ofstream out(GSERVER_PORT_FILE, ios::out);
	ofstream out(Util::gserver_port_file.c_str());
	if (!out) {
		cerr << "Failed in checkSwap(), port may not be changed." << endl;
		return;
	}
	out << port;
	out.close();
	//chmod(GSERVER_PORT_FILE, 0644);
	chmod(Util::gserver_port_file.c_str(), 0644);
	//string cmd = string("rm ") + GSERVER_PORT_SWAP;
	string cmd = string("rm ") + Util::gserver_port_swap;
	system(cmd.c_str());
}

bool startServer(bool _debug) {
	unsigned short port = Socket::DEFAULT_CONNECT_PORT;
	//ifstream in(GSERVER_PORT_FILE, ios::in);
	ifstream in(Util::gserver_port_file.c_str());
	if (!in) {
		//ofstream out(GSERVER_PORT_FILE, ios::out);
		ofstream out(Util::gserver_port_file.c_str());
		if (out) {
			out << port;
			out.close();
			//chmod(GSERVER_PORT_FILE, 0644);
			chmod(Util::gserver_port_file.c_str(), 0644);
		}
	}
	else {
		in >> port;
		in.close();
	}

	if (_debug) {
		Server server(port);
		if (!server.createConnection()) {
			cerr << Util::getTimeString() << "Failed to create connection at port " << port << '.' << endl;
			return false;
		}
		cout << Util::getTimeString() << "Server started at port " << port << '.' << endl;
		server.listen();
		return true;
	}

	pid_t fpid = fork();

	// child
	if (fpid == 0) {
		if (!Util::dir_exist("logs")) {
			Util::create_dir("logs");
		}
		freopen(Util::gserver_log.c_str(), "a", stdout);
		freopen(Util::gserver_log.c_str(), "a", stderr);

		int status;

		while (true) {
			fpid = fork();

			// child, main process
			if (fpid == 0) {
				Server server(port);
				if (!server.createConnection()) {
					cerr << Util::getTimeString() << "Failed to create connection at port " << port << '.' << endl;
					return false;
				}
				cout << Util::getTimeString() << "Server started at port " << port << '.' << endl;
				server.listen();
				exit(0);
				return true;
			}

			// parent, deamon process
			else if (fpid > 0) {
				waitpid(fpid, &status, 0);
				if (WIFEXITED(status)) {
					exit(0);
					return true;
				}
				cerr << Util::getTimeString() << "Server stopped abnormally, restarting server..." << endl;
			}

			// fork failure
			else {
				cerr << Util::getTimeString() << "Failed to start server: deamon fork failure." << endl;
				return false;
			}
		}
	}

	// parent
	else if (fpid > 0) {
		cout << "Server started at port " << port << '.' << endl;
		return true;
	}

	// fork failure
	else {
		cerr << "Failed to start server at port " << port << '.' << endl;
		return false;
	}
}

bool stopServer() {
	unsigned short port = Socket::DEFAULT_CONNECT_PORT;
	//ifstream in(GSERVER_PORT_FILE, ios::in);
	ifstream in(Util::gserver_port_file.c_str());
	if (in) {
		in >> port;
		in.close();
	}
	Socket socket;
	if (!socket.create() || !socket.connect("127.0.0.1", port) || !socket.send("stop")) {
		cerr << "Failed to stop server at port " << port << '.' << endl;
		return false;
	}
	string recv_msg;
	socket.recv(recv_msg);
	socket.close();
	if (recv_msg != "server stopped.") {
		cerr << "Failed to stop server at port " << port << '.' << endl;
		return false;
	}
	cout << "Server stopped at port " << port << '.' << endl;
	checkSwap();
	return true;
}