"use strict";

class Client {
	constructor(wsUri) {
		this.wsUri = wsUri;

		// Create WebSocket and set internal callbacks
		console.log("Initialize Client...")
		this.webSocket = new WebSocket(wsUri);
		this.webSocket.onopen = this._onSocketOpen.bind(this);
		this.webSocket.onclose = this._onSocketClose.bind(this);
		this.webSocket.onerror = this._onSocketError.bind(this);
		this.webSocket.onmessage = this._onSocketMessage.bind(this);
	}

	// Internal WebSocket event handlers
	_onSocketOpen(evt) {
		console.log("Connected to " + this.wsUri);

		// Send init command containing chat ID and nickname
		this.sendInit();
	}

	_onSocketClose(evt) {
		console.log("Connection closed (code " + evt.code + ").");
	}

	_onSocketError(evt) {
		console.error("Connection error: ", evt);
	}

	_onSocketMessage(evt) {
		console.log("Received: " + evt.data);
		this._parseMessage(evt.data);
	}

	/**
	 * Sends an arbitrary command as JSON.
	 *
	 * commandObj: The command as an object ('action' specifies type of command).
	 */
	sendCommand(commandObj) {
		const commandJson = JSON.stringify(commandObj);
		console.log("Sending command: " + commandJson);
		this.webSocket.send(commandJson);
	}

	/**
	 * Sends the 'init' command which sets up the session. Also sets the chat ID and nickname.
	 */
	sendInit() {
		this.sendCommand({
			action: "init",
			chat_id: "42",
			nickname: "binaryDiv",
		});
	}

	/**
	 * Sends the 'message' command which sends a chat message to the chat.
	 *
	 * msgText: The text of the chat message.
	 */
	sendChatMessage(msgText) {
		this.sendCommand({
			action: "message",
			text: msgText,
		});
	}

	/**
	 * Parses an incoming JSON message and dispatches specific events.
	 */
	_parseMessage(msgString) {
		try {
			const msg = JSON.parse(msgString);

			switch (msg.type) {
				// Response to "init" command
				case "init":
					// TODO
					console.log("Got init response: ", msg);
					break;

				// Incoming chat message
				case "message":
					// TODO
					console.log("Got message event: from '" + msg.from + "', text '" + msg.text + "'");
					break;

				// TODO Topic change, user join/leave, error, ...

				default:
					console.error("Unknown message type '" + msg.type + "'");
			}
		}
		catch (e) {
			console.error("Error parsing message JSON: " + e.message);
		}
	}
}

// Run script after page is loaded
$(function() {
	const wsUri = AppSettings.serverWsUri;
	let client = new Client(wsUri);
});