import { computed, ref, type ComputedRef, type Ref } from 'vue'

import { DEFAULT_LIST_PAGE_SIZE } from '@/utils/table/tableConfig'

type Source<T> = Ref<T[]> | ComputedRef<T[]> | (() => T[])

interface UsePagedTableOptions {
  initialPage?: number
  initialPageSize?: number
}

export function usePagedTable<T>(source: Source<T>, options: UsePagedTableOptions = {}) {
  const currentPage = ref(options.initialPage ?? 1)
  const pageSize = ref(options.initialPageSize ?? DEFAULT_LIST_PAGE_SIZE)

  const sourceRows = computed(() => {
    if (typeof source === 'function') return source()
    return source.value
  })

  const total = computed(() => sourceRows.value.length)

  const pagedRows = computed(() => {
    const start = (currentPage.value - 1) * pageSize.value
    const end = start + pageSize.value
    return sourceRows.value.slice(start, end)
  })

  const rangeText = computed(() => {
    const count = total.value
    const start = count === 0 ? 0 : (currentPage.value - 1) * pageSize.value + 1
    const end = Math.min(currentPage.value * pageSize.value, count)
    return `显示 ${start}-${end} / ${count}`
  })

  function onSizeChange() {
    currentPage.value = 1
  }

  return {
    currentPage,
    pageSize,
    total,
    pagedRows,
    rangeText,
    onSizeChange
  }
}