import { nextTick, ref, h } from 'vue'
import { mount, VueWrapper } from '@vue/test-utils'
import Pagination from '../src/index'

const assertElementsExistence = (wrapper: VueWrapper<any>, selectors: string[], existence: boolean) => {
  selectors.forEach(selector => {
    expect(wrapper.find(selector).exists()).toBe(existence)
  })
}

const assertCurrent = (wrapper, page) => {
  expect(wrapper.find('.el-pager li.active.number').text()).toBe(String(page))
}
const assertPages = (wrapper, total) => {
  expect(wrapper.find('.el-pagination .el-pager li:last-child').text()).toBe(String(total))
}

describe('Pagination', () => {
  describe('test invalid usages', () => {
    const cacheWarn = console.warn
    beforeEach(() => {
      console.warn = jest.fn()
    })
    afterEach(() => {
      console.warn = cacheWarn
    })
    test('both absence of total & pageCount is invalid', async () => {
      expect(console.warn).not.toHaveBeenCalled()
      const total = ref(undefined)
      const wrapper = mount({
        setup() {
          return () => {
            return h(Pagination, { total: total.value })
          }
        },
      })
      expect(wrapper.find('.el-pagination').exists()).toBe(false)
      expect(console.warn).toHaveBeenCalled()
      total.value = 100
      await nextTick()
      expect(wrapper.find('.el-pagination').exists()).toBe(true)
    })
    test('current-page defined while absence of current-page listener is invalid', () => {
      expect(console.warn).not.toHaveBeenCalled()
      const wrapper = mount({
        setup() {
          return () => {
            return h(Pagination, {
              total: 100,
              currentPage: 1,
            })
          }
        },
      })
      expect(wrapper.find('.el-pagination').exists()).toBe(false)
      expect(console.warn).toHaveBeenCalled()
    })
    test('layout with `sizes` restrictions(page-count)', () => {
      expect(console.warn).not.toHaveBeenCalled()
      const wrapper = mount({
        setup() {
          return () => {
            return h(Pagination, {
              layout: 'sizes, pager',
              pageCount: 10,
            })
          }
        },
      })
      expect(wrapper.find('.el-pagination').exists()).toBe(false)
      expect(console.warn).toHaveBeenCalled()
    })
    test('layout with `sizes` restrictions(page-size)', () => {
      expect(console.warn).not.toHaveBeenCalled()
      const wrapper = mount({
        setup() {
          return () => {
            return h(Pagination, {
              layout: 'sizes, pager',
              pageSize: 10,
            })
          }
        },
      })
      expect(wrapper.find('.el-pagination').exists()).toBe(false)
      expect(console.warn).toHaveBeenCalled()
    })
  })

  describe('test layout & layout reactive change', () => {
    const layoutRef = ref('')
    const wrapper = mount({
      setup() {
        return () => {
          return h(Pagination, {
            total: 100,
            layout: layoutRef.value,
          })
        }
      },
    })
    test('layout empty', async () => {
      await nextTick()
      expect(wrapper.find('.el-pagination').exists()).toBe(false)
    })
    const layoutSelectorPairs = [
      ['sizes', '.el-pagination__sizes'],
      ['prev', 'button.btn-prev'],
      ['pager', 'ul.el-pager'],
      ['next', 'button.btn-next'],
      ['jumper', '.el-pagination__jump'],
      ['total', '.el-pagination__total'],
    ]
    layoutSelectorPairs.forEach(([layout], idx) => {
      test(`layout with only '${layout}'`, async () => {
        layoutRef.value = layout
        await nextTick()
        for(let i = 0; i < layoutSelectorPairs.length; i++) {
          expect(wrapper.find(layoutSelectorPairs[i][1]).exists()).toBe(i === idx)
        }
      })
    })

    test(`layout with '->, total'`, async () => {
      layoutRef.value = '->, total'
      await nextTick()
      assertElementsExistence(wrapper, ['.el-pagination__total', '.el-pagination__rightwrapper'], true)
    })

    test('layout with default layout prop', () => {
      const wrapper = mount({
        setup() {
          return () => {
            return h(Pagination, {
              total: 100,
            })
          }
        },
      })
      assertElementsExistence(wrapper, [
        '.el-pagination__rightwrapper',
        'button.btn-prev',
        'ul.el-pager',
        'button.btn-next',
        '.el-pagination__jump',
      ], true)
    })

    test('test layout with slot', () => {
      const TestComponent = {
        template: `
          <el-pagination
            layout="slot, prev, pager, next"
            :page-size="25"
            :total="100">
            <span class="slot-test">slot test</span>
          </el-pagination>
        `,
        components: {
          'el-pagination': Pagination,
        },
      }
      const wrapper = mount(TestComponent)
      expect(wrapper.find('.slot-test').exists()).toBe(true)
    })

    test('test small layout', () => {
      const wrapper = mount({
        setup() {
          return () => {
            return h(Pagination, {
              total: 100,
              small: true,
            })
          }
        },
      })
      expect(wrapper.vm.$el.classList.contains('el-pagination--small')).toBe(true)
    })

    test('test with background', async () => {
      const withBackground = ref(true)
      const wrapper = mount({
        setup() {
          return () => {
            return h(Pagination, {
              total: 100,
              background: withBackground.value,
            })
          }
        },
      })
      expect(wrapper.find('.is-background').exists()).toBe(true)
      withBackground.value = false
      await nextTick()
      expect(wrapper.find('.is-background').exists()).toBe(false)
    })

    test('test hide-on-single-page prop', async () => {
      const hideOnSinglePage = ref(false)
      const wrapper = mount({
        setup() {
          return () => {
            return h(Pagination, {
              total: 10, // deivded by default page-size(10), there will be only one page
              hideOnSinglePage: hideOnSinglePage.value,
            })
          }
        },
      })
      expect(wrapper.find('.el-pagination').exists()).toBe(true)
      hideOnSinglePage.value = true
      await nextTick()
      expect(wrapper.find('.el-pagination').exists()).toBe(false)
    })
  })

  describe('test pageSize & currentPage reactive change', () => {
    test(`test pageSize change`, async () => {
      const pageSize = ref(10)
      const wrapper = mount({
        setup() {
          return () => {
            return h(Pagination, {
              layout: 'pager',
              total: 100,
              pageSize: pageSize.value,
            })
          }
        },
      })
      // total pages = Math.ceil(total / pageSize)
      assertPages(wrapper, 10)
      pageSize.value = 20
      await nextTick()
      assertPages(wrapper, 5)
      pageSize.value = 55
      await nextTick()
      assertPages(wrapper, 2)
    })
    test('test currentPage change', async () => {
      const pageSize = ref(10)
      const defaultCurrentPage = ref(2)
      const wrapper = mount({
        setup() {
          return () => {
            return h(Pagination, {
              layout: 'prev, pager, next',
              total: 100,
              pageSize: pageSize.value,
              defaultCurrentPage: defaultCurrentPage.value,
            })
          }
        },
      })
      assertCurrent(wrapper, 2)
      defaultCurrentPage.value = 1
      assertCurrent(wrapper, 2) // still 2
      await wrapper.find('.el-pager li:last-child').trigger('click')
      assertCurrent(wrapper, 10)
      await wrapper.find('button.btn-prev').trigger('click')
      assertCurrent(wrapper, 9)
      await wrapper.find('button.btn-next').trigger('click')
      assertCurrent(wrapper, 10)
      pageSize.value = 50
      await nextTick()
      assertCurrent(wrapper, 2)
    })

    test('test pageCount change and side effect', async () => {
      const pageCount = ref(10)
      const wrapper = mount({
        setup() {
          return () => {
            return h(Pagination, {
              layout: 'prev, pager, next',
              pageCount: pageCount.value,
            })
          }
        },
      })
      assertPages(wrapper, 10)
      pageCount.value = 20
      await nextTick()
      assertPages(wrapper, 20)
      await wrapper.find('.el-pager li:last-child').trigger('click')
      assertCurrent(wrapper, 20)
      pageCount.value = 5
      await nextTick()
      // side effect, if currentPage is greater than pageCount
      // currentPage should change accordingly
      assertPages(wrapper, 5)
      assertCurrent(wrapper, 5)
    })

    test('test listener work', async () => {
      const pageSizeWatcher = jest.fn()
      const currentPageWatcher = jest.fn()
      const wrapper = mount({
        setup() {
          return () => {
            return h(Pagination, {
              total: 100,
              layout: 'prev, pager, next, sizes',
              ['onUpdate:currentPage']: currentPageWatcher,
              ['onUpdate:pageSize']: pageSizeWatcher,
            })
          }
        },
      })
      await wrapper.find('.el-pager li:last-child').trigger('click')
      assertCurrent(wrapper, 10 /* Math.ceil(100/10) */)
      expect(currentPageWatcher).toHaveBeenCalled()
      await wrapper.find('.el-select').trigger('click')
      await wrapper.getComponent('.el-select-dropdown').find('li:nth-child(2)').trigger('click')
      expect(pageSizeWatcher).toHaveBeenCalled()
      assertCurrent(wrapper, 5/* Math.ceil(100/20) */)
    })
  })

  describe('test a11y supports', () => {
    test('test a11y attributes', async () => {
      const wrapper = mount({
        setup() {
          return () => {
            return h(Pagination, {
              total: 100,
            })
          }
        },
      })
      expect(wrapper.find('.el-pagination').attributes('aria-label')).toBe('pagination')
      expect(wrapper.find('.el-pagination').attributes('role')).toBe('pagination')
      expect(wrapper.find('.el-pagination .btn-prev').attributes('aria-disabled')).toBe('true')
      expect(wrapper.find('.el-pagination .btn-next').attributes('aria-disabled')).toBe('false')
      expect(wrapper.find('.el-pager li:first-child').attributes('aria-current')).toBe('true')
      expect(wrapper.find('.el-pager li:last-child').attributes('aria-current')).toBe('false')
      await wrapper.find('.el-pager li:last-child').trigger('click')
      expect(wrapper.find('.el-pagination .btn-prev').attributes('aria-disabled')).toBe('false')
      expect(wrapper.find('.el-pagination .btn-next').attributes('aria-disabled')).toBe('true')
      expect(wrapper.find('.el-pager li:first-child').attributes('aria-current')).toBe('false')
      expect(wrapper.find('.el-pager li:last-child').attributes('aria-current')).toBe('true')
    })

    test('test tabindex interactive', async () => {
      const wrapper = mount({
        setup() {
          return () => {
            return h(Pagination, {
              total: 100,
            })
          }
        },
      })
      await wrapper.find('.el-pager li:nth-child(2)').trigger('click')
      assertCurrent(wrapper, 2)
      await wrapper.find('.el-pager li:nth-child(3)').trigger('click', {
        key: 'Enter',
      })
      assertCurrent(wrapper, 3)
      // TODO getComputedStyle is not implemented in jsdom, so I duno how to assert style of psuedo-class
      /*
       * await wrapper.find('.el-pager li:nth-child(3)').trigger('keyup', {
       *   key: 'Tab',
       * })
       * const style = window.getComputedStyle(wrapper.find('.el-pager li:nth-child(4)').element, ':focus-visible')
       * expect(style.outline).toBeTruthy()
       */
    })
  })
})