/** 店铺列表筛选与分页（任务 89）：店铺 FilterBar 的分组/店铺名筛选与列表查询、分页信息，纯逻辑。 */
import {
  normalizeShopListParams,
  SHOP_PAGE_DEFAULT_SIZE,
  SHOP_PAGE_MAX_SIZE,
  SHOP_PAGE_MIN_PAGE,
  toShopManagePageQuery,
  type ShopManageListParams,
  type ShopManagePageQuery,
} from './shop-dto.ts'

/** 店铺列表筛选状态（页面局部）。 */
export interface ShopManageFilter {
  groupId: number | null
  shopName: string
}

export function createShopManageFilter(): ShopManageFilter {
  return { groupId: null, shopName: '' }
}

function positiveGroupOrNull(value: unknown): number | null {
  if (typeof value === 'number') return Number.isFinite(value) && value >= 1 ? Math.floor(value) : null
  if (typeof value === 'string') {
    const text = value.trim()
    if (/^\d+$/.test(text)) {
      const parsed = Number(text)
      return parsed >= 1 ? Math.floor(parsed) : null
    }
  }
  return null
}

function shopNameText(value: unknown): string {
  return typeof value === 'string' ? value.trim() : ''
}

/** 由界面输入(分组下拉文本/店铺名输入)归一筛选状态。 */
export function shopManageFilterFromInput(input: { groupId?: string | number | null; shopName?: string }): ShopManageFilter {
  const shopName = shopNameText(input.shopName)
  return { groupId: positiveGroupOrNull(input.groupId), shopName: shopName ? shopName : '' }
}

export function shopManageFilterActive(filter: ShopManageFilter): boolean {
  return filter.groupId !== null || Boolean(filter.shopName && filter.shopName.trim())
}

/** 筛选 + 页码 → 归一化列表参数（供 fetch 与查询序列化复用）。 */
export function toShopManageListParams(page: number, pageSize: number, filter: ShopManageFilter): ShopManageListParams {
  return normalizeShopListParams({
    page,
    pageSize,
    groupId: filter.groupId,
    shopName: filter.shopName.trim() || undefined,
  })
}

/** 筛选 + 页码 → Java 查询参数（camelCase，仅下发非空）。 */
export function toShopManageQuery(page: number, pageSize: number, filter: ShopManageFilter): ShopManagePageQuery {
  return toShopManagePageQuery(toShopManageListParams(page, pageSize, filter))
}

export interface ShopManagePageInfo {
  page: number
  pageSize: number
  total: number
  totalPages: number
  from: number
  to: number
  hasPrev: boolean
  hasNext: boolean
}

function finiteInt(value: unknown): number | null {
  return typeof value === 'number' && Number.isFinite(value) ? Math.floor(value) : null
}

/** 由总数与目标分页派生页码信息：页码钳制到 [1, totalPages]，空数据视为第 1 页。 */
export function shopManagePageInfo(page: unknown, pageSize: unknown, total: unknown): ShopManagePageInfo {
  const rawSize = Math.max(finiteInt(pageSize) ?? SHOP_PAGE_DEFAULT_SIZE, SHOP_PAGE_MIN_PAGE)
  const size = Math.min(rawSize, SHOP_PAGE_MAX_SIZE)
  const safeTotal = Math.max(finiteInt(total) ?? 0, 0)
  const totalPages = safeTotal === 0 ? 1 : Math.max(1, Math.ceil(safeTotal / size))
  const requested = Math.max(finiteInt(page) ?? SHOP_PAGE_MIN_PAGE, SHOP_PAGE_MIN_PAGE)
  const safePage = Math.min(requested, totalPages)
  const from = safeTotal === 0 ? 0 : (safePage - 1) * size + 1
  const to = Math.min(safeTotal, safePage * size)
  return {
    page: safePage,
    pageSize: size,
    total: safeTotal,
    totalPages,
    from,
    to,
    hasPrev: safePage > 1,
    hasNext: safePage < totalPages && safeTotal > 0,
  }
}