preload.js

const { ipcRenderer } = require('electron');

// Gamepad polling and input state
const DEADZONE = 0.45;
const INITIAL_REPEAT_DELAY = 350; // ms before repeat starts
const REPEAT_INTERVAL = 120; // ms between repeated inputs

// Button index mappings (Standard Gamepad specification)
const BUTTON_MAP = {
  0: 'Return', // A / Cross -> Select / OK
  1: 'Escape', // B / Circle -> Back
  2: 'Space',  // X / Square -> Play/Pause
  3: '/',      // Y / Triangle -> Search
  4: 'j',      // LB / L1 -> Rewind
  5: 'l',      // RB / R1 -> Fast forward
  8: 'Escape', // Select / View / Share -> Back
  9: 'Return'  // Start / Menu -> Enter
};

// State trackers across frames
const buttonStates = new Map();
const directionalStates = {
  Up: { active: false, nextTime: 0 },
  Down: { active: false, nextTime: 0 },
  Left: { active: false, nextTime: 0 },
  Right: { active: false, nextTime: 0 }
};

function triggerKey(key) {
  ipcRenderer.send('controller-key', key);
}

function handleDirection(dir, isPressed, now) {
  const state = directionalStates[dir];
  if (isPressed) {
    if (!state.active) {
      // First press
      state.active = true;
      state.nextTime = now + INITIAL_REPEAT_DELAY;
      triggerKey(dir);
    } else if (now >= state.nextTime) {
      // Repeat while held
      state.nextTime = now + REPEAT_INTERVAL;
      triggerKey(dir);
    }
  } else {
    state.active = false;
    state.nextTime = 0;
  }
}

function pollGamepads() {
  const gamepads = navigator.getGamepads ? navigator.getGamepads() : [];
  const now = Date.now();

  for (const gp of gamepads) {
    if (!gp) continue;

    // 1. Directional controls (combine D-pad buttons and Left Analog Stick)
    const stickX = gp.axes && gp.axes.length > 0 ? gp.axes[0] : 0;
    const stickY = gp.axes && gp.axes.length > 1 ? gp.axes[1] : 0;

    const dpadUp = gp.buttons[12] && gp.buttons[12].pressed;
    const dpadDown = gp.buttons[13] && gp.buttons[13].pressed;
    const dpadLeft = gp.buttons[14] && gp.buttons[14].pressed;
    const dpadRight = gp.buttons[15] && gp.buttons[15].pressed;

    const isUp = dpadUp || stickY < -DEADZONE;
    const isDown = dpadDown || stickY > DEADZONE;
    const isLeft = dpadLeft || stickX < -DEADZONE;
    const isRight = dpadRight || stickX > DEADZONE;

    handleDirection('Up', isUp, now);
    handleDirection('Down', isDown, now);
    handleDirection('Left', isLeft, now);
    handleDirection('Right', isRight, now);

    // 2. Action buttons (single-press triggers)
    for (const [btnIndexStr, keyCode] of Object.entries(BUTTON_MAP)) {
      const btnIndex = parseInt(btnIndexStr, 10);
      const btn = gp.buttons[btnIndex];
      const isPressed = btn ? btn.pressed || btn.value > 0.5 : false;
      const wasPressed = buttonStates.get(btnIndex) || false;

      if (isPressed && !wasPressed) {
        triggerKey(keyCode);
      }

      buttonStates.set(btnIndex, isPressed);
    }

    // Only process the first active gamepad
    break;
  }
}

window.addEventListener('gamepadconnected', (e) => {
  console.log(`Gamepad connected at index ${e.gamepad.index}: ${e.gamepad.id}. Controller navigation enabled.`);
});

window.addEventListener('gamepaddisconnected', (e) => {
  console.log(`Gamepad disconnected at index ${e.gamepad.index}: ${e.gamepad.id}`);
});

// Run gamepad polling loop continuously
setInterval(pollGamepads, 16);