/**
 * User-scoped in-memory modal cache with short TTLs and request deduplication.
 * Private modal payloads are never persisted to browser storage.
 *
 * @package AKSRT
 */
(function (window, document) {
  "use strict";

  var DEFAULT_TTL = 15000;
  var entries = Object.create(null);
  var flights = Object.create(null);

  function scope() {
    var config = window.aksrtData || window.aksrt || {};
    var userId = parseInt(config.userId || 0, 10) || 0;
    return (config.isLoggedIn && userId > 0 ? "user:" + userId : "guest") + ":v1";
  }

  function token(key) {
    return scope() + "::" + String(key || "");
  }

  function read(key) {
    var id = token(key);
    var entry = entries[id];
    if (!entry) return { hit: false, value: undefined };
    if (entry.expiresAt <= Date.now()) {
      delete entries[id];
      return { hit: false, value: undefined };
    }
    return { hit: true, value: entry.value };
  }

  function tagsOf(value) {
    return Array.isArray(value) ? value.slice() : (value ? [value] : []);
  }

  function set(key, value, options) {
    options = options || {};
    var ttl = Number(options.ttl || DEFAULT_TTL);
    entries[token(key)] = {
      value: value,
      expiresAt: Date.now() + Math.max(0, ttl),
      tags: tagsOf(options.tags),
    };
    return value;
  }

  function matchesTags(entry, wanted) {
    if (!wanted.length) return true;
    return wanted.some(function (tag) { return entry.tags.indexOf(tag) >= 0; });
  }

  function invalidate(tags) {
    var wanted = Array.isArray(tags) ? tags : (tags ? [tags] : []);
    var removed = 0;
    Object.keys(entries).forEach(function (id) {
      if (!wanted.length || matchesTags(entries[id], wanted)) {
        delete entries[id];
        removed += 1;
      }
    });
    Object.keys(flights).forEach(function (id) {
      var flight = flights[id];
      if (!wanted.length || matchesTags(flight, wanted)) {
        flight.cancelled = true;
        delete flights[id];
        if (typeof flight.cancel === "function") flight.cancel();
      }
    });
    return removed;
  }

  function clear() {
    entries = Object.create(null);
    Object.keys(flights).forEach(function (id) {
      var flight = flights[id];
      flight.cancelled = true;
      if (typeof flight.cancel === "function") flight.cancel();
    });
    flights = Object.create(null);
  }

  function acquire(key, loader, options) {
    options = options || {};
    var id = token(key);
    var cached = options.skipCache ? { hit: false } : read(key);

    if (cached.hit) {
      return {
        cached: true,
        promise: Promise.resolve(cached.value),
        release: function () {},
      };
    }

    var flight = flights[id];
    if (!flight) {
      flight = {
        refs: 0,
        settled: false,
        cancelled: false,
        tags: tagsOf(options.tags),
        cancel: options.cancel,
      };
      flight.promise = Promise.resolve().then(loader).then(function (value) {
        flight.settled = true;
        if (!flight.cancelled && options.store !== false) set(key, value, options);
        if (flights[id] === flight) delete flights[id];
        return value;
      }, function (error) {
        flight.settled = true;
        if (flights[id] === flight) delete flights[id];
        throw error;
      });
      flights[id] = flight;
    }

    flight.refs += 1;
    var released = false;
    return {
      cached: false,
      promise: flight.promise,
      release: function () {
        if (released) return;
        released = true;
        flight.refs = Math.max(0, flight.refs - 1);
        if (flight.refs === 0 && !flight.settled) {
          flight.cancelled = true;
          if (flights[id] === flight) delete flights[id];
          if (typeof flight.cancel === "function") flight.cancel();
        }
      },
    };
  }

  ["aksrt:auth:logout", "aksrt:account-switch", "aksrt:logout", "aksrt:user:logout", "aksrt:auth:changed", "wp_logout"].forEach(function (eventName) {
    document.addEventListener(eventName, clear);
  });

  window.AksrtModalCache = {
    get: function (key) { return read(key); },
    set: set,
    acquire: acquire,
    invalidate: invalidate,
    clear: clear,
    scope: scope,
  };
})(window, document);