/*!
 * Buttplug JS Source Code File - Visit https://buttplug.io for more info about
 * the project. Licensed under the BSD 3-Clause license. See LICENSE file in the
 * project root for full license information.
 *
 * @copyright Copyright (c) Nonpolynomial Labs LLC. All rights reserved.
 */

"use strict";

import { EventEmitter } from "eventemitter3";
import { ButtplugMessage } from "../core/Messages";
import { fromJSON } from "../core/MessageUtils";

export class ButtplugBrowserWebsocketConnector extends EventEmitter {
	protected _ws: WebSocket | undefined;
	protected _websocketConstructor: typeof WebSocket | null = null;

	public constructor(private _url: string) {
		super();
	}

	public get Connected(): boolean {
		return this._ws !== undefined;
	}

	public connect = async (): Promise<void> => {
		return new Promise<void>((resolve, reject) => {
			const ws = new (this._websocketConstructor ?? WebSocket)(this._url);
			const onErrorCallback = (event: Event) => {
				reject(event);
			};
			const onCloseCallback = (event: CloseEvent) => reject(event.reason);
			ws.addEventListener("open", async () => {
				this._ws = ws;
				try {
					await this.initialize();
					this._ws.addEventListener("message", (msg) => {
						this.parseIncomingMessage(msg);
					});
					this._ws.removeEventListener("close", onCloseCallback);
					this._ws.removeEventListener("error", onErrorCallback);
					this._ws.addEventListener("close", this.disconnect);
					resolve();
				} catch (e) {
					reject(e);
				}
			});
			// In websockets, our error rarely tells us much, as for security reasons
			// browsers usually only throw Error Code 1006. It's up to those using this
			// library to state what the problem might be.

			ws.addEventListener("error", onErrorCallback);
			ws.addEventListener("close", onCloseCallback);
		});
	};

	public disconnect = async (): Promise<void> => {
		if (!this.Connected) {
			return;
		}
		this._ws!.close();
		this._ws = undefined;
		this.emit("disconnect");
	};

	public sendMessage(msg: ButtplugMessage) {
		if (!this.Connected) {
			throw new Error("ButtplugBrowserWebsocketConnector not connected");
		}
		this._ws!.send("[" + msg.toJSON() + "]");
	}

	public initialize = async (): Promise<void> => {
		return Promise.resolve();
	};

	protected parseIncomingMessage(event: MessageEvent) {
		if (typeof event.data === "string") {
			const msgs = fromJSON(event.data);
			this.emit("message", msgs);
		} else if (event.data instanceof Blob) {
			// No-op, we only use text message types.
		}
	}

	protected onReaderLoad(event: Event) {
		const msgs = fromJSON((event.target as FileReader).result);
		this.emit("message", msgs);
	}
}