/**
 * Canonical notification alert registry.
 *
 * Single source of truth for the 30 standard-threshold-driven alert keys used
 * across surgeChecker, patternChecker, and staffNotifications. Consumed by:
 *   - the three checker services (startup drift-check)
 *   - routes/internalApi.js GET /notifications/alerts
 *   - settings-site UI (via proxied /api/notifications/alerts, with fallback)
 *
 * Not covered here (intentionally fallback-only in the UI):
 *   - rapid_t2_t3        — uses count-milestone firing, not shouldFire()
 *   - chat_messages/time — owned by chatAlertChecker.js, out of Phase 5 scope
 *
 * `windowType` is the reset window used by shouldFire() for pattern keys
 * (today/week/month). For surge and unclaimed, firing is cooldown-escalating
 * rather than window-based, so windowType is null.
 */

const REGISTRY = Object.freeze({
  surge: Object.freeze([
    Object.freeze({
      key: 'surge_tickets',
      description: 'Fires when total active ticket volume exceeds configured surge thresholds, signaling broad queue pressure that needs staffing attention.',
      windowType: null
    }),
    Object.freeze({
      key: 'surge_game',
      description: 'Fires when one game accumulates tickets unusually fast within the configured window, indicating a localized incident that should be triaged.',
      windowType: null
    }),
    Object.freeze({
      key: 'surge_stale',
      description: 'Fires when too many tickets stay unresolved past the stale-time threshold, prompting staff to clear aging backlog.',
      windowType: null
    }),
    Object.freeze({
      key: 'surge_needs_response',
      description: 'Fires when tickets needing a staff reply exceed count and age limits, indicating response latency is building.',
      windowType: null
    }),
    Object.freeze({
      key: 'surge_unclaimed',
      description: 'Fires when the unclaimed queue crosses configured count/age thresholds, signaling ownership gaps that need pickup.',
      windowType: null
    }),
    Object.freeze({
      key: 'surge_tier3_unclaimed',
      description: "Fires when Tier 3 tickets have been sitting unclaimed past each threshold. Escalating intervals prevent spam while ensuring critical tickets don't go unnoticed.",
      windowType: null
    }),
    Object.freeze({
      key: 'surge_no_staff',
      description: 'Fires when open-ticket load is high while no staff are detected as available, prompting immediate coverage.',
      windowType: null
    })
  ]),

  patterns: Object.freeze([
    Object.freeze({
      key: 'user_tickets',
      description: 'Detects users opening unusually high ticket counts in the active window, suggesting repeat-issue or abuse patterns.',
      windowType: 'today'
    }),
    Object.freeze({
      key: 'user_reopen',
      description: 'Detects users who repeatedly reopen or recreate issues after closure, signaling unresolved root-cause patterns.',
      windowType: 'week'
    }),
    Object.freeze({
      key: 'user_crossgame',
      description: 'Detects users reporting similar issues across multiple games in a short period, indicating broader account-level impact.',
      windowType: 'week'
    }),
    Object.freeze({
      key: 'game_surge',
      description: 'Detects game-specific ticket spikes crossing thresholds in the pattern window, signaling service instability for that title.',
      windowType: 'today'
    }),
    Object.freeze({
      key: 'game_backlog',
      description: 'Detects games accumulating unresolved backlog above threshold, implying triage capacity is lagging for that queue.',
      windowType: 'today'
    }),
    Object.freeze({
      key: 'game_resolution',
      description: 'Detects unusual drops in resolution rate for a game, indicating tickets are staying open longer than expected.',
      windowType: 'week'
    }),
    Object.freeze({
      key: 'game_spike',
      description: 'Detects abrupt short-window jumps in ticket volume for a game, flagging incidents that may need escalation.',
      windowType: 'today'
    }),
    Object.freeze({
      key: 'tag_top',
      description: 'Detects tag frequency leaders above threshold so recurring issue types can be prioritized for fixes or macros.',
      windowType: 'today'
    }),
    Object.freeze({
      key: 'tag_escalation',
      description: 'Detects tags with unusually high escalation rates, indicating categories that routinely require higher-tier handling.',
      windowType: 'week'
    }),
    Object.freeze({
      key: 'untagged_closes',
      description: 'Detects elevated counts of closed tickets without tags, prompting cleanup to preserve reporting quality.',
      windowType: 'today'
    }),
    Object.freeze({
      key: 'tag_game_corr',
      description: 'Detects strong tag-to-game concentration patterns, highlighting issue types tightly linked to specific games.',
      windowType: 'week'
    }),
    Object.freeze({
      key: 'user_esc',
      description: 'Detects users whose tickets escalate unusually often, implying complex cases that may need proactive follow-up.',
      windowType: 'week'
    }),
    Object.freeze({
      key: 'game_esc_rate',
      description: 'Detects games with escalating ticket-rate thresholds exceeded, signaling deeper technical issues for that title.',
      windowType: 'week'
    }),
    Object.freeze({
      key: 'staff_no_close',
      description: 'Detects staff with prolonged periods of claims but few closes, suggesting overloaded ownership or stuck work.',
      windowType: 'today'
    }),
    Object.freeze({
      key: 'staff_overloaded',
      description: 'Detects staff carrying ticket loads beyond threshold, indicating balancing or reassignment may be needed.',
      windowType: 'today'
    }),
    Object.freeze({
      key: 'staff_stale',
      description: 'Detects staff-owned tickets aging beyond stale limits, prompting review and unblock actions.',
      windowType: 'today'
    }),
    Object.freeze({
      key: 'staff_transfer_rate',
      description: 'Detects unusually high transfer/reassignment rates by staff, signaling ownership churn that may hurt throughput.',
      windowType: 'today'
    }),
    Object.freeze({
      key: 'staff_esc',
      description: 'Detects staff escalation counts above threshold, highlighting where extra support or training may be needed.',
      windowType: 'week'
    }),
    Object.freeze({
      key: 'staff_game_esc',
      description: 'Detects high escalation concentration for specific staff/game combinations, indicating targeted expertise gaps.',
      windowType: 'week'
    }),
    Object.freeze({
      key: 'game_tag_spike',
      description: 'Detects sudden spikes of specific tags within a game, flagging focused incident signatures.',
      windowType: 'today'
    }),
    Object.freeze({
      key: 'overnight_gap',
      description: 'Detects recurring unattended overnight windows with active demand, suggesting staffing coverage gaps.',
      windowType: 'week'
    }),
    Object.freeze({
      key: 'staff_always_esc',
      description: 'Detects staff whose handled tickets escalate at consistently high rates, implying sustained tier-fit issues.',
      windowType: 'month'
    })
  ]),

  unclaimed: Object.freeze([
    Object.freeze({
      key: 'unclaimed_reminder',
      description: 'Reminds all staff notification channels about unclaimed tickets. Thresholds are per-ticket age — each threshold fires once per ticket and resets on escalation.',
      windowType: null
    })
  ])
});

const ALL_KEYS = Object.freeze([
  ...REGISTRY.surge.map(e => e.key),
  ...REGISTRY.patterns.map(e => e.key),
  ...REGISTRY.unclaimed.map(e => e.key)
]);

const ALL_KEYS_SET = new Set(ALL_KEYS);

/**
 * Throws if any of `keys` is not in the registry. Call at module load from
 * each checker that references registry keys so drift fails fast.
 */
function assertKeysRegistered(moduleName, keys) {
  const missing = keys.filter(k => !ALL_KEYS_SET.has(k));
  if (missing.length > 0) {
    throw new Error(
      `[notificationRegistry] ${moduleName} references keys not in REGISTRY: ${missing.join(', ')}`
    );
  }
}

module.exports = { REGISTRY, ALL_KEYS, assertKeysRegistered };