(() => {
  function initialize() {
    const table = document.getElementById('asset-table');
    const openButton = document.getElementById('duplicate-search-button');
    const dialog = document.getElementById('duplicate-search-dialog');
    const select = document.getElementById('duplicate-field-select');
    const applyButton = document.getElementById('duplicate-apply-button');
    const clearButton = document.getElementById('duplicate-clear-button');
    const ignoreEmpty = document.getElementById('duplicate-ignore-empty');
    const caseInsensitive = document.getElementById('duplicate-case-insensitive');
    const summary = document.getElementById('duplicate-search-summary');
    if (!table || !openButton || !dialog || table.dataset.duplicateSearchReady === '1') return;
    table.dataset.duplicateSearchReady = '1';

    const dataRows = () => [...table.tBodies[0].rows].filter(row => !row.querySelector('.empty-state'));
    const normallyVisible = row => {
      if (row.classList.contains('duplicate-hidden')) return false;
      if (row.hidden || row.classList.contains('hidden')) return false;
      const style = getComputedStyle(row);
      return style.display !== 'none' && style.visibility !== 'hidden';
    };
    const availableFields = () => [...table.querySelectorAll('thead tr:first-child th[data-field]')]
      .filter(th => th.style.display !== 'none')
      .map(th => ({
        field: th.dataset.field,
        label: th.dataset.label || th.textContent.trim()
      }));

    function fillSelect() {
      const previous = select.value;
      select.innerHTML = '';
      availableFields().forEach(item => {
        const option = document.createElement('option');
        option.value = item.field;
        option.textContent = item.label;
        select.appendChild(option);
      });
      if ([...select.options].some(option => option.value === previous)) {
        select.value = previous;
      }
    }

    function clearDuplicateFilter() {
      dataRows().forEach(row => row.classList.remove('duplicate-hidden', 'duplicate-match'));
      summary.hidden = true;
      window.dispatchEvent(new Event('asset-table-filter-changed'));
    }

    function normalize(value) {
      let result = value.trim().replace(/\s+/g, ' ');
      if (caseInsensitive.checked) result = result.toLocaleLowerCase();
      return result;
    }

    function applyDuplicateFilter() {
      // Remove only our previous result first. Normal column filters stay intact.
      dataRows().forEach(row => row.classList.remove('duplicate-hidden', 'duplicate-match'));
      const field = select.value;
      if (!field) return;

      const candidates = dataRows().filter(normallyVisible);
      const groups = new Map();
      candidates.forEach(row => {
        const cell = row.querySelector(`td[data-field="${CSS.escape(field)}"]`);
        const value = normalize(cell?.textContent || '');
        if (ignoreEmpty.checked && !value) return;
        const rows = groups.get(value) || [];
        rows.push(row);
        groups.set(value, rows);
      });

      const duplicateRows = new Set();
      let duplicateGroups = 0;
      groups.forEach(rows => {
        if (rows.length > 1) {
          duplicateGroups += 1;
          rows.forEach(row => duplicateRows.add(row));
        }
      });

      candidates.forEach(row => {
        if (duplicateRows.has(row)) {
          row.classList.add('duplicate-match');
        } else {
          row.classList.add('duplicate-hidden');
        }
      });

      summary.textContent = `${duplicateRows.size} Datensätze in ${duplicateGroups} Dublettengruppen gefunden.`;
      summary.hidden = false;
      window.dispatchEvent(new Event('asset-table-filter-changed'));
      dialog.close();
    }

    openButton.addEventListener('click', () => {
      // Search always starts from the current normal filter result, not from
      // a previous duplicate result.
      clearDuplicateFilter();
      fillSelect();
      dialog.showModal();
    });
    applyButton.addEventListener('click', applyDuplicateFilter);
    clearButton.addEventListener('click', clearDuplicateFilter);
  }

  if (document.readyState === 'loading') {
    document.addEventListener('DOMContentLoaded', initialize);
  } else {
    initialize();
  }
  window.addEventListener('asset-table-content-reloaded', initialize);
})();