import { isInteger } from 'lodash-es'
import { Component, Vue } from 'vue-property-decorator'

interface IPaginationQuery {
  page?: number
  pageSize?: number
}

interface IPaginationMixin {
  pagination: IPagination
}

// HTTP 请求返回的翻页信息
interface ResponsePagination {
  page: number
  totalCount: number
  pageSize: number
}

export interface IPagination {
  current: number // 当前页
  pageSize: number // 每页数量
  total: number // 数据总数
  hasMore: boolean // 是否还有更多数据 (是否有下一页)
  defaults: typeof defaults // 默认的翻页

  reset(): void // 重置翻页
  update(params: ResponsePagination): void // 更新
  updateDefaults(params: typeof defaults): void // 更新默认的翻页

  // 用以发送 HTTP 请求，例如 ?page=1&pageSize=10
  query: IPaginationQuery
  // 用于 Vue Ant Design Pagination 翻页组件
  JSON: {
    current: number
    pageSize: number
    total: number
    showQuickJumper: boolean
    showSizeChanger: boolean
    showTotal(total: number, range: number): string
  }
}

const defaults = { current: 1, pageSize: 10 }

function definedPagination(current: number, pageSize: number): IPagination {
  let defaultPagination = { ...defaults }
  const target = {
    current,
    pageSize,
    total: 0,
  } as IPagination

  Object.defineProperty(target, 'defaults', {
    get() {
      return { ...defaultPagination }
    },
  })

  Object.defineProperty(target, 'hasMore', {
    get() {
      return target.current * target.pageSize < target.total
    },
  })

  Object.defineProperty(target, 'query', {
    get() {
      return {
        page: target.current,
        pageSize: target.pageSize,
      }
    },
  })

  Object.defineProperty(target, 'reset', {
    get() {
      return function () {
        target.current = defaultPagination.current
        target.pageSize = defaultPagination.pageSize
        target.total = 0
      }
    },
  })

  Object.defineProperty(target, 'update', {
    get() {
      return function (params: ResponsePagination) {
        target.current = params.page
        target.pageSize = params.pageSize
        target.total = params.totalCount
      }
    },
  })

  Object.defineProperty(target, 'updateDefaults', {
    get() {
      return function (params: typeof defaults) {
        defaultPagination = { ...params }
      }
    },
  })

  Object.defineProperty(target, 'JSON', {
    get() {
      return {
        current: target.current,
        pageSize: target.pageSize,
        total: target.total,
        showQuickJumper: true,
        showSizeChanger: true,
        showTotal(total: number) {
          const _totalPage = total / this.pageSize

          let totalPage = _totalPage

          if (!isInteger(_totalPage)) {
            totalPage = parseInt(_totalPage + '', 10) + 1
          }

          const isLastPage = target.current === totalPage

          const currentSize =
            total < pageSize ? total : isLastPage ? total - (target.current - 1) * target.pageSize : target.pageSize

          return `当前页${currentSize}条 共${total}条 共${totalPage}页`
        },
      }
    },
  })

  return target
}

/**
 * 动态表单项组件的混入
 */
@Component({})
export default class PaginationMixin extends Vue implements IPaginationMixin {
  public pagination = definedPagination(defaults.current, defaults.pageSize) as IPagination
}