window.modules.register("GatewayClient", () => {
    const messageSchema = { t: "number", d: "object" };
    const messageTypes = {
        HELLO: 0,
        YOO: 1,
        READY: 2,
        EVENT: 3
    };

    class GatewayClient {
        constructor(gatewayPath) {
            this.gatewayPath = gatewayPath;
            this.ws = null;
            this.token = null;
            this.user = null;
            this.onEvent = (e) => {};
            this.onConnected = () => {};
            this.onDisconnected = () => {};
        }
    
        connect(token) {
            if (!token)
                token = this.token;
    
            console.log("gateway: connecting");
    
            this.ws = new WebSocket(this.gatewayPath);
    
            this.ws.addEventListener("message", ({ data }) => {
                if (typeof data !== "string") {
                    console.warn("gateway: got non-string data from server, ignoring...");
                    return;
                }
    
                let message;
                try {
                    message = JSON.parse(data);
                } catch(e) {
                    console.warn("gateway: got invalid JSON from server (failed to parse), ignoring...");
                    return;
                }
    
                if (!this._checkMessageSchema(message)) {
                    console.warn("gateway: got invalid JSON from server (does not match schema), ignoring...");
                    return;
                }
    
                switch (message.t) {
                    case messageTypes.HELLO: {
                        console.log("gateway: HELLO");
                        this.ws.send(JSON.stringify({
                            t: messageTypes.YOO,
                            d: {
                                token
                            }
                        }));
                        break;
                    }
                    case messageTypes.READY: {
                        console.log("gateway: READY");
                        this.user = message.d.user;
                        this.onConnected();
                        break;
                    }
                    case messageTypes.EVENT: {
                        this.onEvent(message.d);
                        break;
                    }
                    default: {
                        console.warn("gateway: got invalid JSON from server (invalid type), ignoring...");
                        return;
                    }
                }
            });
            this.ws.addEventListener("open", () => {
                console.log("gateway: open");
            });
            this.ws.addEventListener("close", ({ code }) => {
                console.log("gateway: closed");
                this.onDisconnected(code);
                if (code === 4001) {
                    console.log(`gateway: disconnect code is ${code} (bad auth), will not attempt reconnect`);
                    return;
                }
                setTimeout(() => {
                    console.log("gateway: reconnecting");
                    this.connect(token);
                }, 4000);
            });
        }
    
        _checkMessageSchema(message) {
            for (const [key, value] of Object.entries(message)) {
                if (!messageSchema[key])
                    return false;
    
                if (typeof value !== messageSchema[key])
                    return false;
            }
            return true;
        }
    }

    return GatewayClient;
});