// 输入：IWBT 经典键位（Shift 跳 / Z 跳 / X 射击 / R 重来）
export const BIND = {
  left:    ['ArrowLeft', 'KeyA'],
  right:   ['ArrowRight', 'KeyD'],
  up:      ['ArrowUp', 'KeyW'],
  down:    ['ArrowDown', 'KeyS'],
  jump:    ['ShiftLeft', 'ShiftRight', 'Space', 'KeyZ', 'KeyN'],
  shoot:   ['KeyX', 'KeyJ', 'KeyC', 'KeyM'],
  suicide: ['KeyR'],          // IWBT 标准：自杀并回到最近存档点
  restart: ['Backspace'],     // 整关从头再来（放弃所有存档点）
  pause:   ['Escape', 'KeyP'],
  menu:    ['KeyQ'],
};

// 出厂键位快照（供设置里的「恢复默认」使用）
const DEFAULT_BIND = JSON.parse(JSON.stringify(BIND));

const down = new Set();      // 当前按住的原始 code
const now = {};              // action 是否按下
const prev = {};             // 上一帧
const touch = {};            // action -> bool（来自触屏虚拟按键）
const blocked = new Set(['Space', 'ArrowUp', 'ArrowDown', 'ArrowLeft', 'ArrowRight', 'Tab']);

export const Input = {
  enabled: true,
  /** 是否按下 */
  is(action) { return !!now[action]; },
  /** 本帧刚按下 */
  hit(action) { return !!now[action] && !prev[action]; },
  /** 本帧刚松开 */
  released(action) { return !now[action] && !!prev[action]; },
  raw(code) { return down.has(code); },
  anyHit() { for (const k in now) if (now[k] && !prev[k]) return true; return false; },

  clear() {
    down.clear();
    for (const k in now) now[k] = false;
    for (const k in prev) prev[k] = false;
  },

  /** 每逻辑帧末尾调用 */
  endFrame() {
    for (const k in now) prev[k] = now[k];
  },
};

function refresh() {
  for (const act in BIND) {
    let v = false;
    for (const c of BIND[act]) if (down.has(c)) { v = true; break; }
    if (touch[act]) v = true;          // 触屏虚拟按键
    now[act] = Input.enabled ? v : false;
  }
}

// ---------------- 触屏虚拟按键接口 ----------------
export function setTouch(action, on) {
  if (!(action in touch)) touch[action] = false;
  if (touch[action] === on) return;
  touch[action] = on;
  refresh();
}
export function clearTouch() {
  let any = false;
  for (const k in touch) if (touch[k]) { touch[k] = false; any = true; }
  if (any) refresh();
}

addEventListener('keydown', e => {
  if (blocked.has(e.code)) e.preventDefault();
  if (e.repeat) return;
  down.add(e.code);
  refresh();
});
addEventListener('keyup', e => {
  down.delete(e.code);
  refresh();
});
addEventListener('blur', () => { down.clear(); refresh(); });

// ---------------- 键位自定义（设置界面调用） ----------------
/** 返回一份出厂键位的深拷贝 */
export function defaultBindings() { return JSON.parse(JSON.stringify(DEFAULT_BIND)); }
/** 用一份 {action: [code,...]} 映射覆盖当前生效键位（设置确定后调用） */
export function applyBindings(map) {
  if (!map) return;
  for (const act in map) if (act in BIND) BIND[act] = map[act].slice();
}

// 初始化
for (const act in BIND) { now[act] = false; prev[act] = false; }
export const ACTIONS = Object.keys(BIND);