const jwt = require("jsonwebtoken");
const fs = require("fs-extra");
const yargs = require("yargs");
const version = require("./package").version;
const asTable = require("as-table").configure({delimiter: ' | '});
const chalk = require("chalk");
const events = require("events");

const link = require("lib/link");
const errors = require("lib/errors");
const config = require("lib/config");


/**
 * Format a parsed Factorio output message with colors
 *
 * Formats a parsed Factorio output from lib/factorio into a readable
 * colorized output using terminal escape codes that can be printed.
 */
function formatOutputColored(output) {
	let time = "";
	if (output.format === 'seconds') {
		time = chalk.yellow(output.time.padStart(8)) + ' ';
	} else if (output.format === 'date') {
		time = chalk.yellow(output.time) + ' ';
	}

	let info = "";
	if (output.type === 'log') {
		let level = output.level;
		if (level === "Info") {
			level = chalk.bold.blueBright(level);
		} else if (output.level === "Warning") {
			level = chalk.bold.yellowBright(level);
		} else if (output.level === "Error") {
			level = chalk.bold.redBright(level);
		}

		info = level + ' ' + chalk.gray(output.file) + ': ';

	} else if (output.type === 'action') {
		info = '[' + chalk.yellow(output.action) + '] ';
	}

	return time + info + output.message;
}

/**
 * Represents a command that can be runned by clusterctl
 */
class Command {
	constructor({ definition, handler }) {
		this.name = definition[0];
		this._definition = definition;
		this._handler = handler;
	}

	register(yargs) {
		yargs.command(...this._definition);
	}

	async run(args, control) {
		await this._handler.call(this, args, control);
	}
}

/**
 * Resolve a string to an instance ID
 *
 * Resolves a string with either an instance name or an id into an integer
 * with the instance ID.
 *
 * @param client - link to master server to query instance on.
 * @param instanceName - string with name or id of instance.
 * @returns {number} instance ID.
 */
async function resolveInstance(client, instanceName) {
	let instanceId;
	if (/^-?\d+$/.test(instanceName)) {
		instanceId = parseInt(instanceName, 10);
	} else {
		let response = await link.messages.listInstances.send(client);
		for (let instance of response.list) {
			if (instance.name === instanceName) {
				instanceId = instance.id;
				break;
			}
		}

		if (instanceId === undefined) {
			throw new errors.CommandError(`No instance named ${instanceName}`);
		}
	}

	return instanceId;
}

/**
 * Resolve a string into a slave ID
 *
 * Resolves a string with either an slave name or an id into an integer with
 * the slave ID.
 *
 * @param client - link to master server to query slave on.
 * @param slaveName - string with name or id of slave.
 * @returns {number} slave ID.
 */
async function resolveSlave(client, slaveName) {
	let slaveId;
	if (/^-?\d+$/.test(slaveName)) {
		slaveId = parseInt(slaveName, 10);
	} else {
		let response = await link.messages.listSlaves.send(client);
		for (let slave of response.list) {
			if (slave.name === slaveName) {
				slaveId = slave.id;
				break;
			}
		}

		if (slaveId === undefined) {
			throw new errors.CommandError(`No slave named ${slaveName}`);
		}
	}

	return slaveId;
}

let commands = [];
commands.push(new Command({
	definition: ["list-slaves", "List slaves connected to the master"],
	handler: async function(args, control) {
		let response = await link.messages.listSlaves.send(control);
		console.log(asTable(response.list));
	},
}));

commands.push(new Command({
	definition: ["list-instances", "List instances known to the master"],
	handler: async function(args, control) {
		let response = await link.messages.listInstances.send(control);
		console.log(asTable(response.list));
	}
}));

commands.push(new Command({
	definition: ['create-instance', "Create an instance", (yargs) => {
		// XXX TODO: set any specific options?
		yargs.option('name', {
			type: "string",
			nargs: 1,
			describe: "Instance name",
			group: "Instance Config:",
		});
		yargs.option('id', {
			type: "number",
			nargs: 1,
			describe: "Instance ID",
			group: "Instance Config:",
		});
		yargs.option('base', {
			type: "boolean",
			nargs: 0,
			describe: "Specify this is a base config",
			group: "Instance Config:"
		});
	}],
	handler: async function(args, control) {
		let instanceConfig = new config.InstanceConfig();
		await instanceConfig.init();
		if (args.id) {
			instanceConfig.set("instance.id", args.id);
		}
		if (args.name) {
			instanceConfig.set("instance.name", args.name);
		}
		let serialized_config = instanceConfig.serialize();
		let response = await link.messages.createInstance.send(control, { serialized_config });
	},
}));

commands.push(new Command({
	definition: ["list-instance-config", "List configuration for an instance", (yargs) => {
		yargs.option({
			"instance": { describe: "Instance to list config for", nargs: 1, type: "string", demandOption: true },
		});
	}],
	handler: async function(args, control) {
		let instanceId = await resolveInstance(control, args.instance);
		let response = await link.messages.getInstanceConfig.send(control, { instance_id: instanceId });

		for (let group of response.serialized_config.groups) {
			for (let [name, value] of Object.entries(group.fields)) {
				console.log(`${group.name}.${name} ${JSON.stringify(value)}`);
			}
		}
	},
}));

commands.push(new Command({
	definition: ["set-instance-config", "Set field in instance config", (yargs) => {
		yargs.option({
			"instance": { describe: "Instance to set config on", nargs: 1, type: "string", demandOption: true },
			"field": { describe: "Field to set", nargs: 1, type: "string", demandOption: true },
			"value": { describe: "Value to set", nargs: 1, type: "string", demandOption: true },
		});
	}],
	handler: async function(args, control) {
		let instanceId = await resolveInstance(control, args.instance);
		await link.messages.setInstanceConfigField.send(control, {
			instance_id: instanceId,
			field: args.field,
			value: args.value,
		});
	},
}));

commands.push(new Command({
	definition: ['assign-instance', "Assign instance to a slave", (yargs) => {
		yargs.options({
			'instance': { describe: "Instance to assign", nargs: 1, type: 'string', demandOption: true },
			'slave': { describe: "Slave to assign to", nargs: 1, type: 'string', demandOption: true },
		});
	}],
	handler: async function(args, control) {
		let instanceId = await resolveInstance(control, args.instance);
		let slaveId = await resolveSlave(control, args.slave);
		await link.messages.assignInstanceCommand.send(control, {
			instance_id: instanceId,
			slave_id: slaveId,
		});
	},
}));

commands.push(new Command({
	definition: ['create-save', "Create a new save on an instance", (yargs) => {
		yargs.options({
			'instance': { describe: "Instance to create on", nargs: 1, type: 'string', demandOption: true },
		});
	}],
	handler: async function(args, control) {
		let instanceId = await resolveInstance(control, args.instance);
		await link.messages.setInstanceOutputSubscriptions.send(control, { instance_ids: [instanceId] });
		let response = await link.messages.createSave.send(control, {
			instance_id: instanceId,
		});
	},
}));

commands.push(new Command({
	definition: ['start-instance', "Start instance", (yargs) => {
		yargs.options({
			'instance': { describe: "Instance to start", nargs: 1, type: 'string', demandOption: true },
		});
	}],
	handler: async function(args, control) {
		let instanceId = await resolveInstance(control, args.instance);
		await link.messages.setInstanceOutputSubscriptions.send(control, { instance_ids: [instanceId] });
		let response = await link.messages.startInstance.send(control, {
			instance_id: instanceId,
		});
	},
}));

commands.push(new Command({
	definition: ['stop-instance', "Stop instance", (yargs) => {
		yargs.options({
			'instance': { describe: "Instance to stop", nargs: 1, type: 'string', demandOption: true },
		});
	}],
	handler: async function(args, control) {
		let instanceId = await resolveInstance(control, args.instance);
		await link.messages.setInstanceOutputSubscriptions.send(control, { instance_ids: [instanceId] });
		let response = await link.messages.stopInstance.send(control, {
			instance_id: instanceId,
		});
	},
}));

commands.push(new Command({
	definition: ['delete-instance', "Delete instance", (yargs) => {
		yargs.options({
			'instance': { describe: "Instance to delete", nargs: 1, type: 'string', demandOption: true },
		});
	}],
	handler: async function(args, control) {
		let response = await link.messages.deleteInstance.send(control, {
			instance_id: await resolveInstance(control, args.instance),
		});
	},
}));

commands.push(new Command({
	definition: ['send-rcon', "Send RCON command", (yargs) => {
		yargs.options({
			'instance': { describe: "Instance to sent to", nargs: 1, type: 'string', demandOption: true },
			'command': { describe: "command to send", nargs: 1, type: 'string', demandOption: true },
		});
	}],
	handler: async function(args, control) {
		let response = await link.messages.sendRcon.send(control, {
			instance_id: await resolveInstance(control, args.instance),
			command: args.command
		})

		// Factorio includes a newline in it's response output.
		process.stdout.write(response.result);
	},
}));

// Convert to mapping from name to command instance
commands = new Map([...commands.map(command => [command.name, command])]);


/**
 * Connector for control connection to master server
 */
class ControlConnector extends link.WebSocketClientConnector {
	constructor(url, reconnectDelay, token) {
		super(url, reconnectDelay);
		this._token = token;
	}

	register() {
		console.log("SOCKET | registering control");
		this.sendHandshake("register_control", {
			token: this._token,
			agent: "clusterctl",
			version: version,
		});
	}
}

/**
 * Handles running the control
 *
 * Connects to the master server over WebSocket and sends commands to it.
 */
class Control extends link.Link {

	// I don't like God classes, but the alternative of putting all this state
	// into global variables is not much better.
	constructor(connector) {
		super('control', 'master', connector);
		link.attachAllMessages(this);
	}

	async instanceOutputEventHandler(message) {
		let { instance_id, output } = message.data;
		console.log(formatOutputColored(output));
	}

	async shutdown() {
		await link.messages.shutdownConnection.send(this);
		this.connector.close(1001, "Control Quit")
		await events.once(this.connector, "close");
	}
}

async function findCredentials(controlConfig) {
	// Try looking in the default master config location
	try {
		let masterConfig = new config.MasterConfig();
		await masterConfig.load(JSON.parse(await fs.readFile("config-master.json")));

		let token = jwt.sign({ id: "api" }, masterConfig.get("master.auth_secret"), { expiresIn: 600 });
		controlConfig.set("control.master_token", token);

		let url;
		if (masterConfig.get("master.https_port")) {
			url = `https://localhost:${masterConfig.get("master.https_port")}`;
		} else {
			url = `http://localhost:${masterConfig.get("master.http_port")}`;
		}
		controlConfig.set("control.master_url", url);

		return;

	} catch (err) {
		if (err.code !== "ENOENT") {
			throw err;
		}
	}

	// Try looking in the default slave config location
	// In the future it's likely that tokens will be assigned more granular
	// authorizations, meaning that you cannot use a slave token to control
	// the cluster.
	try {
		let slaveConfig = new config.SlaveConfig();
		await slaveConfig.load(JSON.parse(await fs.readFile("config-slave.json")));

		controlConfig.set("control.master_token", slaveConfig.get("slave.master_token"));
		controlConfig.set("control.master_url", slaveConfig.get("slave.master_url"));
		return;

	} catch (err) {
		if (err.code !== "ENOENT") {
			throw err;
		}
	}

	throw new errors.StartupError("Couldn't find credentials to connect to the master server with");
}


class ControlGroup extends config.ConfigGroup {}
ControlGroup.groupName = "control";
ControlGroup.define({
	name: "master_url",
	description: "URL to connect to the master server at",
	type: "string",
	optional: true,
});
ControlGroup.define({
	name: "master_token",
	description: "Token to authenticate to master server with.",
	type: "string",
	optional: true,
});
ControlGroup.define({
	name: "reconnect_delay",
	title: "Reconnect Delay",
	description: "Maximum delay to wait before attempting to reconnect WebSocket",
	type: "number",
	initial_value: 2,
});
ControlGroup.finalize();

class ControlConfig extends config.Config { }
ControlConfig.registerGroup(ControlGroup);
ControlConfig.finalize();


async function startControl() {
	yargs
		.scriptName("clusterctl")
		.usage("$0 <command> [options]")
		.option('config', {
			nargs: 1,
			describe: "config file to get credentails from",
			default: "config-control.json",
			defaultDescription: "auto",
			type: 'string',
		})
		.command("control-config", "Manage Control config", config.configCommand)
		.wrap(yargs.terminalWidth())
	;

	for (let command of commands.values()) {
		command.register(yargs);
	}

	const args = yargs.demandCommand(1, "You need to specify a command to run")
		.strict()
		.argv
	;

	config.finalizeConfigs();

	console.log(`Loading config from ${args.config}`);
	let controlConfig = new ControlConfig();
	try {
		await controlConfig.load(JSON.parse(await fs.readFile(args.config)));

	} catch (err) {
		if (err.code === 'ENOENT') {
			console.log("Config not found, initializing new config");
			await controlConfig.init();

		} else {
			throw err;
		}
	}

	let commandName = args._[0];
	if (commandName === "control-config") {
		await config.handleConfigCommand(args, controlConfig, args.config);
		return;
	}

	// The remaining commands require connecting to the master server.
	if (!controlConfig.get("control.master_url") || !controlConfig.get("control.master_token")) {
		await findCredentials(controlConfig);
	}

	let controlConnector = new ControlConnector(
		controlConfig.get("control.master_url"),
		controlConfig.get("control.reconnect_delay"),
		controlConfig.get("control.master_token")
	);
	let control = new Control(controlConnector);
	try {
		await controlConnector.connect();
	} catch(err) {
		if (err instanceof errors.AuthenticationFailed) {
			throw new errors.StartupError(err.message);
		}
		throw err;
	}

	if (commands.has(commandName)) {
		command = commands.get(commandName);

		try {
			await command.run(args, control)

		} catch (err) {
			if (err instanceof errors.CommandError) {
				console.error(`Error running command: ${err.message}`);
				process.exitCode = 1;

			} else if (err instanceof errors.RequestError) {
				console.error(`Error sending request: ${err.message}`);
				process.exitCode = 1;

			} else {
				throw err;
			}

		} finally {
			await control.shutdown();
		}
	}

	//XXX control.close("done");
}

module.exports = {
	// for testing only
	_formatOutputColored: formatOutputColored,
	_resolveInstance: resolveInstance,
	_Control: Control,

	_commands: commands,
}


if (module === require.main) {
	console.warn(`
+==========================================================+
I WARNING:  This is the development branch for the 2.0     I
I           version of clusterio.  Expect things to break. I
+==========================================================+
`
	);
	startControl().catch(err => {
		if (!(err instanceof errors.StartupError)) {
			console.error(`
+----------------------------------------------------------------+
| Unexpected error occured while starting control, please report |
| it to https://github.com/clusterio/factorioClusterio/issues    |
+----------------------------------------------------------------+`
			);
		} else {
			console.error(`
+-------------------------------+
| Unable to to start clusterctl |
+-------------------------------+`
			);
		}

		console.error(err);
		process.exitCode = 1;
	});
}