/* 倒计时与 JS 链并行（秒数与 config.js countdownSeconds 一致 = 8）。
 * ?e=0 整页刷新不重置截止时间；到点必定跳 index，不受 ?e=0 影响。 */
(function () {
  var TOTAL_SEC = 8;
  var KEY = "__er_countdown_deadline_ms";
  var LANDED = "__er_landed";
  var INDEX_URL = "/index.html?landed=1";
  var CIRC = 2 * Math.PI * 54;

  try {
    if (sessionStorage.getItem(LANDED) === "1") {
      // 已进过 index：链后续若再导航到 /qqtime/?e=0，立刻回落地页
      location.replace(INDEX_URL);
      return;
    }
  } catch (e0) {}

  var now = Date.now();
  var deadline = 0;
  try {
    deadline = parseInt(sessionStorage.getItem(KEY) || "0", 10) || 0;
  } catch (e) {}
  // 仅首次写入截止时间；?e=0 刷新沿用原 deadline，倒计时不归零
  if (!deadline || deadline < now - 5000) {
    deadline = now + TOTAL_SEC * 1000;
    try {
      sessionStorage.setItem(KEY, String(deadline));
    } catch (e2) {}
  }

  var countEl = document.getElementById("count");
  var fg = document.getElementById("fg");
  if (fg) fg.style.strokeDasharray = String(CIRC);

  var jumped = false;
  function goIndex() {
    if (jumped) return;
    jumped = true;
    try {
      sessionStorage.setItem(LANDED, "1");
      sessionStorage.removeItem(KEY);
    } catch (e3) {}
    location.replace(INDEX_URL);
  }

  function tick() {
    var leftMs = deadline - Date.now();
    var left = Math.max(0, Math.ceil(leftMs / 1000));
    if (countEl) countEl.textContent = String(left);
    if (fg) {
      var progressed = Math.min(
        1,
        Math.max(0, 1 - leftMs / (TOTAL_SEC * 1000))
      );
      fg.style.strokeDashoffset = String(CIRC * (1 - progressed));
    }
    if (leftMs <= 0) {
      goIndex();
      return;
    }
    setTimeout(tick, 200);
  }

  tick();
})();