export type EntityColumnMetadata = {
  groupId?: string;
  keywords?: readonly string[];
};

export type EntityColumnGroup = {
  id: string;
  label: string;
  description?: string;
};

export type EntityColumnOption = EntityColumnMetadata & {
  id: string;
  label: string;
  visible: boolean;
  hideable: boolean;
};

/** Normaliza tildes sin equiparar ñ y n, incluidas sus representaciones Unicode descompuestas. */
export function normalizeColumnSearch(value: string): string {
  return value
    .trim()
    .toLowerCase()
    .normalize("NFD")
    .replace(/n\u0303/g, "ñ")
    .replace(/\p{M}/gu, "");
}

/** Los IDs conservan identidad; la primera declaración de un grupo u opción prevalece. */
export function groupColumnOptions(
  options: readonly EntityColumnOption[],
  groups: readonly EntityColumnGroup[],
  search: string
) {
  const term = normalizeColumnSearch(search);
  const uniqueOptions = new Map<string, EntityColumnOption>();
  const uniqueGroups = new Map<string, EntityColumnGroup>();

  for (const group of groups) {
    if (!uniqueGroups.has(group.id)) {
      uniqueGroups.set(group.id, group);
    }
  }
  for (const option of options) {
    if (!uniqueOptions.has(option.id)) {
      uniqueOptions.set(option.id, option);
    }
  }
  const matches = [...uniqueOptions.values()].filter((option) =>
    [option.label, ...(option.keywords ?? [])].some((value) =>
      normalizeColumnSearch(value).includes(term)
    )
  );
  const grouped = [...uniqueGroups.values()].map((group) => ({
    group,
    options: matches.filter((option) => option.groupId === group.id),
  }));
  const ungrouped = matches.filter(
    (option) => !(option.groupId && uniqueGroups.has(option.groupId))
  );

  return [
    ...grouped.filter((group) => group.options.length > 0),
    ...(ungrouped.length ? [{ group: undefined, options: ungrouped }] : []),
  ];
}