FilterEngine.js.html

<script>
/**
 * FilterEngine.js.html — Filter logic methods extracted from JavaScript.html
 *
 * Part of #129 Phase 1 (PR4/7): IIFE-wrapped domain separation.
 * These methods handle tag/course/teacher filtering, persisted filter
 * restoration, and schedule data filtering by predicates.
 *
 * Load order: after JavaScript.html + DataCollection.js (which provides
 * App.getAllTags), before App.init() trigger.
 *
 * Dependencies: DataCollection.js (App.getAllTags), AppElements (filter* DOM),
 * localStorage (persisted filters)
 */
(function(App) {

  // --- Filter UI methods ---

  App.loadAndApplyPersistedFilters = function() {
    const persistedTagsJSON = localStorage.getItem('activeTagFilters');
    if (persistedTagsJSON) {
      try {
        const persistedTags = JSON.parse(persistedTagsJSON);
        const allCurrentTags = new Set(App.getAllTags());

        const validPersistedTags = persistedTags.filter(tag => allCurrentTags.has(tag));

        App.activeFilters = validPersistedTags.map(tag => ({ type: 'tag', value: tag }));

        if (App.tagFilterTagify) {
          App.tagFilterTagify.loadOriginalValues(validPersistedTags);
        }

        if (persistedTags.length !== validPersistedTags.length) {
          localStorage.setItem('activeTagFilters', JSON.stringify(validPersistedTags));
        }
      } catch (e) {
        console.error("Failed to parse persisted tag filters:", e);
        localStorage.removeItem('activeTagFilters');
        App.activeFilters = [];
      }
    } else {
      App.activeFilters = [];
    }
    App.ui.updateClearFilterButtonVisibility();
    App.ui.updateAdvancedFilterButtonState();
    App.ui.updateClearAllFiltersButtonVisibility();
  };

  App.toggleAllFilterCheckboxes = function(shouldBeChecked) {
    AppElements.filterCourseList.querySelectorAll('input[type="checkbox"]').forEach(cb => {
      cb.checked = shouldBeChecked;
    });
  };

  App.applyFilters = function() {
    const filterType = AppElements.filterTypeSelector.querySelector('input[name="filterType"]:checked').value;
    const selectedItems = Array.from(AppElements.filterCourseList.querySelectorAll('input[type="checkbox"]:checked')).map(cb => cb.value);

    const tagFilters = App.activeFilters.filter(f => f.type === 'tag');
    const newAdvancedFilters = selectedItems.map(item => ({ type: filterType, value: item }));
    App.activeFilters = [...tagFilters, ...newAdvancedFilters];

    App.ui.renderScheduleTable();
    App.ui.updateAdvancedFilterButtonState();
    App.ui.updateClearAllFiltersButtonVisibility();
    AppElements.filterModal.style.display = 'none';
  };

  App.clearAdvancedFilters = function() {
    App.activeFilters = App.activeFilters.filter(f => f.type === 'tag');
    App.modals.populateFilterModal();
    App.ui.renderScheduleTable();
    App.ui.updateAdvancedFilterButtonState();
    App.ui.updateClearAllFiltersButtonVisibility();
  };

  App.clearAllFilters = function() {
    App.activeFilters = [];
    localStorage.removeItem('activeTagFilters');
    if (App.tagFilterTagify) {
      App.tagFilterTagify.removeAllTags();
    }
    App.modals.populateFilterModal();
    App.ui.renderScheduleTable();
    App.ui.updateAdvancedFilterButtonState();
    App.ui.updateClearFilterButtonVisibility();
    App.ui.updateClearAllFiltersButtonVisibility();
  };

  // --- Data filtering methods ---

  App._filterScheduleData = function(data, filterPredicate) {
    const filteredData = {};
    for (const classroom in data) {
      const dayData = data[classroom];
      const newDayData = {};
      let classroomHasCourses = false;
      for (const day in dayData) {
        const filteredCourses = dayData[day].filter(filterPredicate);
        if (filteredCourses.length > 0) {
          newDayData[day] = filteredCourses;
          classroomHasCourses = true;
        }
      }
      if (classroomHasCourses) {
        filteredData[classroom] = newDayData;
      }
    }
    return filteredData;
  };

  App.filterDataByTags = function(data) {
    const tagFilters = new Set(App.activeFilters.filter(f => f.type === 'tag').map(f => f.value));
    if (tagFilters.size === 0) {
      return data;
    }
    return App._filterScheduleData(data, course =>
      course.tags && course.tags.some(d => tagFilters.has(d))
    );
  };

  App.filterDataByActiveFilters = function(data) {
    const nameFilters = new Set(App.activeFilters.filter(f => f.type === 'name').map(f => f.value));
    const tagFilters = new Set(App.activeFilters.filter(f => f.type === 'tag').map(f => f.value));
    const teacherFilters = new Set(App.activeFilters.filter(f => f.type === 'teacher').map(f => f.value));

    if (nameFilters.size === 0 && tagFilters.size === 0 && teacherFilters.size === 0) {
      return data;
    }

    return App._filterScheduleData(data, course => {
      const nameMatch = nameFilters.size === 0 || nameFilters.has(course.name);
      const tagMatch = tagFilters.size === 0 || (course.tags && course.tags.some(d => tagFilters.has(d)));
      const teacherMatch = teacherFilters.size === 0 || teacherFilters.has(course.teacher);
      return nameMatch && tagMatch && teacherMatch;
    });
  };

})(App);
</script>