/**
 * Frontend modal performance marks.
 *
 * Records only bounded domain/event names and timing data. Never include
 * payment credentials, order contents, identity evidence, or user payloads.
 *
 * @package AKSRT
 */
(function (window) {
  'use strict';

  var allowedKinds = {
    identity: true,
    badges: true,
    orders: true,
    vip: true,
  };
  var allowedEvents = {
    click: true,
    shell: true,
    'first-content': true,
    ready: true,
    'action-start': true,
    'action-end': true,
    unauthorized: true,
    error: true,
  };
  var sessions = Object.create(null);
  var sequence = 0;
  var maxSessions = 100;

  function normalize(value, fallback) {
    var normalized = String(value || fallback || '').toLowerCase().replace(/[^a-z0-9-]/g, '');
    return normalized || fallback;
  }

  function now() {
    return window.performance && typeof window.performance.now === 'function'
      ? window.performance.now()
      : 0;
  }

  function markName(session, event) {
    return 'aksrt-modal-' + session.kind + '-' + session.id + '-' + event;
  }

  function emit(session, event) {
    if (!window.performance || typeof window.performance.mark !== 'function') return;

    var name = markName(session, event);
    window.performance.mark(name);
    session.marks[event] = name;

    if (typeof window.performance.measure === 'function' && session.marks.click && event !== 'click') {
      try {
        window.performance.measure(
          'aksrt-modal-' + session.kind + '-' + session.id + '-click-to-' + event,
          session.marks.click,
          name
        );
      } catch (error) {
        // A missing mark must never affect the modal interaction.
      }
    }
  }

  function start(kind) {
    var safeKind = normalize(kind, 'unknown');
    if (!allowedKinds[safeKind]) safeKind = 'unknown';

    sequence += 1;
    var id = String(sequence);
    var session = {
      id: id,
      kind: safeKind,
      startedAt: now(),
      marks: Object.create(null),
    };

    sessions[id] = session;
    emit(session, 'click');

    var ids = Object.keys(sessions);
    while (ids.length > maxSessions) {
      delete sessions[ids.shift()];
    }

    return id;
  }

  function mark(id, event) {
    var session = sessions[String(id || '')];
    var safeEvent = normalize(event, 'error');
    if (!session || !allowedEvents[safeEvent]) return;
    emit(session, safeEvent);
  }

  function finish(id) {
    mark(id, 'ready');
  }

  function fail(id) {
    mark(id, 'error');
  }

  window.AksrtModalTelemetry = {
    start: start,
    mark: mark,
    finish: finish,
    error: fail,
  };
})(window);