index.js

// index.js
const WebSocket = require("ws");
const { spawn } = require("child_process");

// this is for tetris.com 
const moveToKey = {
  "R": "up",      // rotate
  "R'": "space",     // piece down
  "L": "space",      // piece down
  "L'": "up",     // rotate
  "U": "left",  // move left
  "U'": "right", // move right
  "D": "z",  // whatever z does
  "D'": "c", // hold
};

function pressKey(key) {
  let script;

  switch (key) {
    // normal character keys
    case "z":
    case "c":
      script = `tell application "System Events" to keystroke "${key}"`;
      break;

    // spacebar (key code 49)
    case "space":
      script = `tell application "System Events" to key code 49`;
      break;

    // left shift (key code 56)
    case "shift":
      script = `tell application "System Events" to key code 56`;
      break;
    case "up":
      script = `tell application "System Events" to key code 126`;
      break;
    case "down":
      script = `tell application "System Events" to key code 125`;
      break;
    case "left":
      script = `tell application "System Events" to key code 123`;
      break;
    case "right":
      script = `tell application "System Events" to key code 124`;
      break;

    default:
      console.log("[pressKey] No script for key", key);
      return;
  }

  console.log("[pressKey] Running:", script);
  const child = spawn("osascript", ["-e", script]);

  child.stdout.on("data", (data) => {
    console.log("[osascript stdout]", data.toString());
  });

  child.stderr.on("data", (data) => {
    console.error("[osascript stderr]", data.toString());
  });

  child.on("close", (code) => {
    console.log("[osascript] exited with code", code);
  });

  child.on("error", (err) => {
    console.error("[osascript error]", err);
  });
}

const wss = new WebSocket.Server({ port: 8081 });
console.log("WebSocket server listening on ws://localhost:8081");

wss.on("connection", (ws) => {
  console.log("[ws] Browser connected");

  ws.on("message", (msg) => {
    const raw = msg.toString();
    console.log("[ws] got message:", JSON.stringify(raw));

    const trimmed = raw.trim();
    let key = moveToKey[trimmed];

    if (!key && trimmed.startsWith("MOVE:")) {
      const move = trimmed.slice("MOVE:".length);
      key = moveToKey[move];
    }

    if (!key) {
      console.log("[ws] no key mapped for", trimmed);
      return;
    }

    pressKey(key);
  });

  ws.on("close", () => {
    console.log("[ws] Browser disconnected");
  });

  ws.on("error", (err) => {
    console.error("[ws] error:", err);
  });
});