export const ADMIN_MEMBERS_PATH = '/admins';

export const ADMIN_MEMBERS_EXCEL_PATH = `${ADMIN_MEMBERS_PATH}/excel`;

export type AdminMemberSearchField = 'name' | 'loginId' | 'phoneNumber';

export const ADMIN_MEMBER_SEARCH_FIELD_OPTIONS: ReadonlyArray<{
  value: AdminMemberSearchField;
  label: string;
}> = [
  { value: 'name', label: '회원명' },
  { value: 'loginId', label: 'ID' },
  { value: 'phoneNumber', label: '휴대전화번호' },
];

export type AdminMemberSortOption = 'createdAt' | 'name';

export const ADMIN_MEMBER_SORT_OPTIONS: ReadonlyArray<{
  value: AdminMemberSortOption;
  label: string;
}> = [
  { value: 'createdAt', label: '생성일순' },
  { value: 'name', label: '이름순' },
];

export const ADMIN_MEMBER_PAGE_SIZE_OPTIONS = [10, 30, 50] as const;
export type AdminMemberPageSize =
  (typeof ADMIN_MEMBER_PAGE_SIZE_OPTIONS)[number];

export const DEFAULT_ADMIN_MEMBER_SEARCH_FIELD: AdminMemberSearchField = 'name';
export const DEFAULT_ADMIN_MEMBER_SORT: AdminMemberSortOption = 'createdAt';
export const DEFAULT_ADMIN_MEMBER_PAGE_SIZE: AdminMemberPageSize = 10;
const DEFAULT_PAGE = 1;
const MAX_KEYWORD_LENGTH = 100;

export type AdminMemberQuery = {
  searchField: AdminMemberSearchField;
  keyword: string;
  sort: AdminMemberSortOption;
  page: number;
  pageSize: AdminMemberPageSize;
};

type RawSearchParams = Record<string, string | string[] | undefined>;

function readParam(params: RawSearchParams, key: string): string | undefined {
  const value = params[key];
  return Array.isArray(value) ? value[0] : value;
}

function isAdminMemberSearchField(
  value: string | undefined
): value is AdminMemberSearchField {
  return (
    value !== undefined &&
    ADMIN_MEMBER_SEARCH_FIELD_OPTIONS.some((option) => option.value === value)
  );
}

function isAdminMemberSortOption(
  value: string | undefined
): value is AdminMemberSortOption {
  return (
    value !== undefined &&
    ADMIN_MEMBER_SORT_OPTIONS.some((option) => option.value === value)
  );
}

function isAdminMemberPageSize(value: number): value is AdminMemberPageSize {
  return (ADMIN_MEMBER_PAGE_SIZE_OPTIONS as readonly number[]).includes(value);
}

export function parseAdminMemberQuery(
  searchParams: RawSearchParams
): AdminMemberQuery {
  const searchFieldRaw = readParam(searchParams, 'searchField');
  const sortRaw = readParam(searchParams, 'sort');
  const keywordRaw = readParam(searchParams, 'keyword');
  const pageRaw = Number(readParam(searchParams, 'page'));
  const pageSizeRaw = Number(readParam(searchParams, 'pageSize'));

  return {
    searchField: isAdminMemberSearchField(searchFieldRaw)
      ? searchFieldRaw
      : DEFAULT_ADMIN_MEMBER_SEARCH_FIELD,
    keyword: (keywordRaw ?? '').trim().slice(0, MAX_KEYWORD_LENGTH),
    sort: isAdminMemberSortOption(sortRaw)
      ? sortRaw
      : DEFAULT_ADMIN_MEMBER_SORT,
    page: Number.isInteger(pageRaw) && pageRaw > 0 ? pageRaw : DEFAULT_PAGE,
    pageSize: isAdminMemberPageSize(pageSizeRaw)
      ? pageSizeRaw
      : DEFAULT_ADMIN_MEMBER_PAGE_SIZE,
  };
}

export function buildAdminMemberHref(
  query: AdminMemberQuery,
  overrides: Partial<AdminMemberQuery> = {}
): string {
  const merged = { ...query, ...overrides };
  const params = new URLSearchParams();

  if (merged.searchField !== DEFAULT_ADMIN_MEMBER_SEARCH_FIELD) {
    params.set('searchField', merged.searchField);
  }
  if (merged.keyword) {
    params.set('keyword', merged.keyword);
  }
  if (merged.sort !== DEFAULT_ADMIN_MEMBER_SORT) {
    params.set('sort', merged.sort);
  }
  if (merged.pageSize !== DEFAULT_ADMIN_MEMBER_PAGE_SIZE) {
    params.set('pageSize', String(merged.pageSize));
  }
  if (merged.page !== DEFAULT_PAGE) {
    params.set('page', String(merged.page));
  }

  const queryString = params.toString();
  return queryString
    ? `${ADMIN_MEMBERS_PATH}?${queryString}`
    : ADMIN_MEMBERS_PATH;
}