LockManager.js.html

<script>
/**
 * LockManager.js.html — Tab-level schedule lock management
 *
 * Part of #129 Phase 1 (PR2/7): IIFE-wrapped domain separation.
 * Manages localStorage-based locks to prevent concurrent editing
 * across browser tabs. Reads App.tabId, App.activeScheduleId,
 * App.isReadOnly state properties.
 *
 * Load order: after JavaScript.html (App core), before App.init().
 */
(function(App) {

  App._getLocks = function() {
    try {
      return JSON.parse(localStorage.getItem('gemini_schedule_locks') || '{}');
    } catch (e) {
      return {};
    }
  };

  App._saveLocks = function(locks) {
    localStorage.setItem('gemini_schedule_locks', JSON.stringify(locks));
  };

  App.acquireLock = function(scheduleId) {
    const locks = App._getLocks();
    const existingLock = locks[scheduleId];
    const now = Date.now();

    if (existingLock && existingLock.tabId !== App.tabId) {
      const isStale = (now - existingLock.timestamp) > 15000; // 15 second stale threshold
      if (!isStale) {
        return false; // Lock is held by another tab
      }
      // If we are here, the lock is stale, so we break it.
    }

    // Acquire or update the lock
    locks[scheduleId] = { tabId: App.tabId, timestamp: now };
    App._saveLocks(locks);
    return true;
  };

  App.releaseLock = function(scheduleId) {
    if (!scheduleId) return;
    const locks = App._getLocks();
    if (locks[scheduleId] && locks[scheduleId].tabId === App.tabId) {
      delete locks[scheduleId];
      App._saveLocks(locks);
    }
  };

  App.releaseCurrentLock = function() {
    App.releaseLock(App.activeScheduleId);
  };

  App.refreshLockHeartbeat = function() {
    if (App.isReadOnly || !App.activeScheduleId || App.activeScheduleId === AppConfig.ALL_SCHEDULES_ID) {
      return;
    }
    const locks = App._getLocks();
    if (locks[App.activeScheduleId] && locks[App.activeScheduleId].tabId === App.tabId) {
      locks[App.activeScheduleId].timestamp = Date.now();
      App._saveLocks(locks);
    }
  };

})(App);
</script>