/* HR Candidate Matcher — Storage Layer */
/* global window */
(function () {
  'use strict';

  var APP = window.HRMatcher = window.HRMatcher || {};

  var NAMESPACE = 'hr_matcher';
  var SCHEMA_VERSION = 1;
  var STORAGE_KEY = NAMESPACE + '_v' + SCHEMA_VERSION;

  var storageAvailable = false;
  var memoryFallback = {};

  function testStorage() {
    try {
      var test = '__storage_test__';
      localStorage.setItem(test, test);
      localStorage.removeItem(test);
      return true;
    } catch (e) {
      return false;
    }
  }

  storageAvailable = testStorage();

  APP.storage = {
    isAvailable: function () { return storageAvailable; },

    save: function (data) {
      var payload = {
        version: SCHEMA_VERSION,
        timestamp: Date.now(),
        data: data
      };
      if (storageAvailable) {
        try {
          localStorage.setItem(STORAGE_KEY, JSON.stringify(payload));
          return true;
        } catch (e) {
          if (e.name === 'QuotaExceededError' || e.code === 22) {
            APP.ui && APP.ui.showToast && APP.ui.showToast('Хранилище переполнено. Изменения не сохраняются.', 'error');
          }
          memoryFallback = payload;
          return false;
        }
      } else {
        memoryFallback = payload;
        return false;
      }
    },

    load: function () {
      if (storageAvailable) {
        try {
          var raw = localStorage.getItem(STORAGE_KEY);
          if (!raw) return null;
          var parsed = JSON.parse(raw);
          if (parsed && parsed.version === SCHEMA_VERSION && parsed.data) {
            return parsed.data;
          }
          return null;
        } catch (e) {
          return null;
        }
      }
      return memoryFallback && memoryFallback.data ? memoryFallback.data : null;
    },

    clear: function () {
      if (storageAvailable) {
        try {
          localStorage.removeItem(STORAGE_KEY);
        } catch (e) { /* ignore */ }
      }
      memoryFallback = {};
    },

    savePartial: function (key, value) {
      var current = this.load() || {};
      current[key] = value;
      return this.save(current);
    },

    removePartial: function (key) {
      var current = this.load() || {};
      delete current[key];
      return this.save(current);
    }
  };
})();