let hostConnection;
let displayConnection;

function initHostConnection() {
    console.log("Initialize Host connection...");

    hostConnection.on('message', (data) => {
        console.log("[HOST] " + data);
        if (displayConnection) {
            displayConnection.send("" + data);
        }
    });

    hostConnection.on('error', (data) => {
        console.error("[HOST] " + data);
        hostConnection = undefined;
        if (displayConnection) {
            displayConnection.send("HOST-DISCONNECTED");
        }
    });

    hostConnection.on('close', (code, reason) => {
        console.error("[HOST] " + code + " " + reason);
        hostConnection = undefined;
        if (displayConnection) {
            displayConnection.send("HOST-DISCONNECTED");
        }
    });

    hostConnection.send("HOST");
    if (displayConnection) {
        displayConnection.send("HOST-CONNECTED");
        hostConnection.send("DISPLAY-CONNECTED");
    }
}

function initDisplayConnection() {
    console.log("Initialize Display connection...");

    displayConnection.on('message', (data) => {
        console.log("[DISPLAY] " + data);
    });

    displayConnection.on('error', (data) => {
        console.error("[DISPLAY] " + data);
        displayConnection = undefined;
        if (hostConnection) {
            hostConnection.send("DISPLAY-DISCONNECTED");
        }
    });

    displayConnection.on('close', (code, reason) => {
        console.error("[DISPLAY] " + code + " " + reason);
        displayConnection = undefined;
        if (hostConnection) {
            hostConnection.send("DISPLAY-DISCONNECTED");
        }
    });

    displayConnection.send("DISPLAY");
    if (hostConnection) {
        hostConnection.send("DISPLAY-CONNECTED");
        displayConnection.send("HOST-CONNECTED");
    }
}

export function initWebsocket(app) {
    app.ws("/websocket", (ws, req) => {
        console.log("Trying to connect");
        ws.on('error', console.error);

        ws.on('message', (data) => {
            if (ws == hostConnection || ws == displayConnection) return;
            console.log('received: %s', data);
            if (data == "HOST") {
                if (hostConnection === undefined) {
                    hostConnection = ws;
                    initHostConnection();
                }
                else
                {
                    ws.send("ERROR HOST");
                    ws.close();
                }
            } else if (data == "DISPLAY") {
                if (displayConnection === undefined) {
                    displayConnection = ws;
                    initDisplayConnection();
                }
                else
                {
                    ws.send("ERROR DISPLAY");
                    ws.close();
                }
            }
            else
            {
                ws.send("ERROR MESSAGE");
                ws.close();
            }
        })
    });
}