const smpp = require("smpp");
const commandLineArgs = require("command-line-args");
const commandLineUsage = require("command-line-usage");
const { createLogger, format, transports } = require("winston");
const { combine, timestamp, label, printf } = format;
const NanoTimer = require("nanotimer");

const defaultFormat = printf(({ level, message, timestamp }) => {
	return `${timestamp} ${level}: ${message}`;
});
const sessionFormat = printf(({ level, message, label, timestamp }) => {
	return `${timestamp} [Session ${label}] ${level}: ${message}`;
});
const logger = createLogger({
	format: combine(format.colorize({ all: true }), timestamp(), defaultFormat),
	transports: [new transports.Console()],
});

function verifyExists(value, err) {
	if (!value) {
		logger.error(err);
		process.exit(0);
	}
}
function verifyDefaults(options) {
	for (const optionDefinition of optionDefinitions) {
		if (optionDefinition.defaultOption) {
			if (!options[optionDefinition.name]) {
				options[optionDefinition.name] = optionDefinition.defaultOption;
			}
		}
	}
}

const optionDefinitions = [
	{ name: "help", type: Boolean, description: "Display this usage guide." },
	{ name: "host", alias: "h", type: String, description: "The host (IP) to connect to." },
	{ name: "port", alias: "p", type: Number, description: "The port to connect to." },
	{ name: "systemid", alias: "s", type: String, description: "SMPP related login info." },
	{ name: "password", alias: "w", type: String, description: "SMPP related login info." },
	{ name: "sessions", type: Number, description: "Number of sessions to start, defaults to 1.", defaultOption: 1 },
	{
		name: "messagecount",
		type: Number,
		description: "Number of messages to send; Optional, defaults to 1.",
		defaultOption: 1,
	},
	{
		name: "window",
		type: Number,
		description:
			"Defines the amount of messages that are allowed to be 'in flight'. The client no longer waits for a response before sending the next message for up to <window> messages. Defaults to 100.",
		defaultOption: 100,
	},
	{
		name: "windowsleep",
		type: Number,
		description:
			"Defines the amount time (in ms) waited between retrying in the case of full window. Defaults to 100.",
		defaultOption: 100,
	},
	{
		name: "mps",
		type: Number,
		description: "Number of messages to send per second",
		defaultOption: 999999,
	},
	{
		name: "source",
		type: String,
		description: "Source field of the sent messages.",
		defaultOption: "smppDebugClient",
	},
	{
		name: "destination",
		type: String,
		description: "Destination field of the sent messages.",
		defaultOption: "smpp",
	},
	{
		name: "message",
		type: String,
		description: "Text content of the sent messages.",
		defaultOption: "smpp debug message",
	},
	{ name: "debug", type: Boolean, description: "Display all traffic to and from the client; Debug mode." },
];

const options = commandLineArgs(optionDefinitions);

if (options.help) {
	const usage = commandLineUsage([
		{
			header: "CLI SMPP (Client)",
		},
		{
			header: "Options",
			optionList: optionDefinitions,
		},
		{
			content: "Project home: {underline https://github.com/PhatDave/SMPP_CLI}",
		},
	]);
	console.log(usage);
	process.exit(0);
}

verifyDefaults(options);
verifyExists(options.host, "Host can not be undefined or empty! (--host)");
verifyExists(options.port, "Port can not be undefined or empty! (--port)");
verifyExists(options.systemid, "SystemID can not be undefined or empty! (--systemid)");
verifyExists(options.password, "Password can not be undefined or empty! (--password)");

let inFlight = 0;
let sent = 0;
let success = 0;
let failed = 0;
const sendTimer = new NanoTimer();

function startInterval(session, sessionLogger) {
	sendTimer.setInterval(
		async () => {
			if (sent >= options.messagecount) {
				sessionLogger.info("Finished sending messages, idling...");
				sendTimer.clearInterval();
			} else if (inFlight < options.window) {
				sessionLogger.info(`Sending message ${sent + 1}/${options.messagecount}`);
				session.submit_sm(
					{
						source_addr: options.source,
						destination_addr: options.destination,
						short_message: options.message,
					},
					function (pdu) {
						inFlight--;
						if (pdu.command_status === 0) {
							sessionLogger.info(`Received response with id ${pdu.message_id}`);
							success++;
						} else {
							sessionLogger.warn(`Message failed with id ${pdu.message_id}`);
							failed++;
						}
					}
				);
				sent++;
				inFlight++;
			} else {
				sessionLogger.warn(
					`${inFlight}/${options.window} messages pending, waiting for a reply before sending more`
				);
				sendTimer.clearInterval();
				setTimeout(() => startInterval(session, sessionLogger), options.windowsleep);
			}
		},
		"",
		`${1 / options.mps} s`
	);
}

for (let i = 0; i < options.sessions; i++) {
	const sessionLogger = createLogger({
		format: combine(label({ label: i }), format.colorize({ all: true }), timestamp(), sessionFormat),
		transports: [new transports.Console()],
	});

	sessionLogger.info(`Connecting to ${options.host}:${options.port}...`);
	const session = smpp.connect(
		{
			url: `smpp://${options.host}:${options.port}`,
			auto_enquire_link_period: 10000,
			debug: options.debug,
		},
		function () {
			sessionLogger.info(
				`Connected, sending bind_transciever with systemId '${options.systemid}' and password '${options.password}'...`
			);
			session.bind_transceiver(
				{
					system_id: options.systemid,
					password: options.password,
				},
				function (pdu) {
					if (pdu.command_status === 0) {
						sessionLogger.info(
							`Successfully bound, sending ${options.messagecount} messages '${options.source}'->'${options.destination}' ('${options.message}')`
						);
						startInterval(session, sessionLogger);

						session.on("deliver_sm", function (pdu) {
							sessionLogger.info("Got deliver_sm, replying...");
							session.send(pdu.response());
						});
						session.on("close", function () {
							sessionLogger.error(`Session closed`);
							process.exit(1);
						});
						session.on("error", function (err) {
							sessionLogger.error(`Fatal error ${err}`);
							process.exit(1);
						});
					}
				}
			);
		}
	);
}