/** 店铺数据任务列表分页与选择派生（任务 111/112）：分页信息 + 可批量选择的结果行，纯逻辑。 */
import { SHOP_DATA_DEFAULT_PAGE_SIZE, SHOP_DATA_MAX_PAGE_SIZE, SHOP_DATA_PAGE_MIN } from './shop-data-filter.ts'
import type { ShopDataTaskGroup } from './shop-data-model.ts'

export interface ShopDataPageInfo {
  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；空数据视为第 1 页。 */
export function shopDataPageInfo(page: unknown, pageSize: unknown, total: unknown): ShopDataPageInfo {
  const rawSize = finiteInt(pageSize)
  const size =
    rawSize === null || rawSize < 1
      ? SHOP_DATA_DEFAULT_PAGE_SIZE
      : Math.min(Math.max(rawSize, 10), SHOP_DATA_MAX_PAGE_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_DATA_PAGE_MIN, SHOP_DATA_PAGE_MIN)
  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,
  }
}

/** 展平本页所有可选中的结果行(result_id)，供批量下载/勾选；缺行忽略。 */
export function selectableResultRows(groups: readonly ShopDataTaskGroup[]): string[] {
  const ids: string[] = []
  for (const group of groups) {
    for (const row of group.results) {
      if (row.resultId) ids.push(row.resultId)
    }
  }
  return ids
}