import * as React from "react";

export type CheckedState = boolean | "indeterminate";

/**
 * Hook para manejar selección múltiple con estado "seleccionar todo".
 */
export function useRowSelection(totalRows: number) {
  const [selectedRows, setSelection] = React.useState<Set<number>>(new Set());

  // Deriva array de índices seleccionados
  const selectedIndexes = React.useMemo(
    () => [...selectedRows].sort((a, b) => a - b),
    [selectedRows]
  );

  // Estado visual del checkbox maestro
  const selectAllState: CheckedState = React.useMemo(() => {
    if (totalRows === 0 || selectedRows.size === 0) return false;
    if (selectedRows.size === totalRows) return true;
    return "indeterminate";
  }, [selectedRows, totalRows]);

  // Seleccionar/deseleccionar una fila
  const toggleRow = React.useCallback((index: number) => {
    setSelection((prev) => {
      const next = new Set(prev);
      next.has(index) ? next.delete(index) : next.add(index);
      return next;
    });
  }, []);

  // Seleccionar todas o limpiar
  const setSelectAll = React.useCallback(
    (checked: CheckedState) => {
      if (checked === false) {
        setSelection(new Set());
      } else {
        setSelection(new Set(Array.from({ length: totalRows }, (_, i) => i)));
      }
    },
    [totalRows]
  );

  const clearSelection = React.useCallback(() => setSelection(new Set()), []);

  return {
    selectedRows,
    selectedIndexes,
    selectAllState,
    toggleRow,
    setSelectAll,
    clearSelection,
  };
}