/*
 * Copyright 2025 Commonwealth Scientific and Industrial Research
 * Organisation (CSIRO) ABN 41 687 119 230.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import type { GroupTableRowModel } from '../interfaces/groupTable.interface';

export function reorderRows(
  rows: GroupTableRowModel[],
  sourceIndex: number,
  destinationIndex: number
) {
  // Handle empty array case
  if (rows.length === 0) {
    return [];
  }

  const result = Array.from(rows);
  const [removed] = result.splice(sourceIndex, 1);
  result.splice(destinationIndex, 0, removed);

  return result;
}

export function getGroupTableItemsToUpdate(tableRows: GroupTableRowModel[], selectedIds: string[]) {
  return tableRows
    .filter((row) => selectedIds.includes(row.id))
    .flatMap((singleRow) => (singleRow.qrItem ? [structuredClone(singleRow.qrItem)] : []));
}

/**
 * Get the QuestionnaireResponse index of every rendered gtable row, in rendered order. A row with no
 * QuestionnaireResponse counterpart gets `null`.
 *
 * Rows that are unselected or still empty are dropped by {@link getGroupTableItemsToUpdate}, so a
 * row's rendered index is not its index in the QuestionnaireResponse. Validation walks the
 * QuestionnaireResponse, so instance-scoped error keys must use these indices instead.
 *
 * Computed for the whole table in a single pass over a Set of selected ids, so callers rendering n
 * rows stay linear rather than re-scanning the preceding rows once per row.
 *
 * Keep the selection/emptiness test here in sync with {@link getGroupTableItemsToUpdate}.
 *
 * @author Clinton Gillespie
 */
export function getQrGroupTableRowIndexes(
  tableRows: GroupTableRowModel[],
  selectedIds: string[]
): (number | null)[] {
  const selectedIdSet = new Set(selectedIds);
  let qrIndex = 0;

  return tableRows.map((row) => (selectedIdSet.has(row.id) && row.qrItem ? qrIndex++ : null));
}