import { act, fireEvent, render, screen } from '@testing-library/react'
import CustomizedPagination from '../index'

describe('CustomizedPagination', () => {
  const defaultProps = {
    current: 0,
    onChange: vi.fn(),
    total: 100,
  }

  beforeEach(() => {
    vi.clearAllMocks()
    vi.useRealTimers()
  })

  describe('Rendering', () => {
    it('should render without crashing', () => {
      const { container } = render(<CustomizedPagination {...defaultProps} />)
      expect(container).toBeInTheDocument()
    })

    it('should display current page and total pages', () => {
      render(<CustomizedPagination {...defaultProps} current={0} total={100} limit={10} />)
      // current + 1 = 1, totalPages = 10
      // The page info display shows "1 / 10" and page buttons also show numbers
      expect(screen.getByText('/')).toBeInTheDocument()
      expect(screen.getAllByText('1').length).toBeGreaterThanOrEqual(1)
    })

    it('should render prev and next buttons', () => {
      render(<CustomizedPagination {...defaultProps} />)
      const buttons = screen.getAllByRole('button')
      expect(buttons.length).toBeGreaterThanOrEqual(2)
    })

    it('should render page number buttons', () => {
      render(<CustomizedPagination {...defaultProps} total={50} limit={10} />)
      // 5 pages total, should see page numbers
      expect(screen.getByText('2')).toBeInTheDocument()
      expect(screen.getByText('3')).toBeInTheDocument()
    })

    it('should display slash separator between current page and total', () => {
      render(<CustomizedPagination {...defaultProps} />)
      expect(screen.getByText('/')).toBeInTheDocument()
    })
  })

  describe('Props', () => {
    it('should apply custom className', () => {
      const { container } = render(<CustomizedPagination {...defaultProps} className="my-custom" />)
      const wrapper = container.firstChild as HTMLElement
      expect(wrapper).toHaveClass('my-custom')
    })

    it('should default limit to 10', () => {
      render(<CustomizedPagination {...defaultProps} total={100} />)
      // totalPages = 100 / 10 = 10, displayed in the page info area
      expect(screen.getAllByText('10').length).toBeGreaterThanOrEqual(1)
    })

    it('should calculate total pages based on custom limit', () => {
      render(<CustomizedPagination {...defaultProps} total={100} limit={25} />)
      // totalPages = 100 / 25 = 4, displayed in the page info area
      expect(screen.getAllByText('4').length).toBeGreaterThanOrEqual(1)
    })

    it('should disable prev button on first page', () => {
      render(<CustomizedPagination {...defaultProps} current={0} />)
      const buttons = screen.getAllByRole('button')
      // First button is prev
      expect(buttons[0]).toBeDisabled()
    })

    it('should disable next button on last page', () => {
      render(<CustomizedPagination {...defaultProps} current={9} total={100} limit={10} />)
      const buttons = screen.getAllByRole('button')
      // Last button is next
      expect(buttons[buttons.length - 1]).toBeDisabled()
    })

    it('should not render limit selector when onLimitChange is not provided', () => {
      render(<CustomizedPagination {...defaultProps} />)
      expect(screen.queryByText(/common\.pagination\.perPage/i)).not.toBeInTheDocument()
    })

    it('should render limit selector when onLimitChange is provided', () => {
      const onLimitChange = vi.fn()
      render(<CustomizedPagination {...defaultProps} onLimitChange={onLimitChange} />)
      // Should show limit options 10, 25, 50
      expect(screen.getByText('25')).toBeInTheDocument()
      expect(screen.getByText('50')).toBeInTheDocument()
    })
  })

  describe('User Interactions', () => {
    it('should call onChange when next button is clicked', () => {
      const onChange = vi.fn()
      render(<CustomizedPagination {...defaultProps} current={0} onChange={onChange} />)
      const buttons = screen.getAllByRole('button')
      const nextButton = buttons[buttons.length - 1]
      fireEvent.click(nextButton)
      expect(onChange).toHaveBeenCalledWith(1)
    })

    it('should call onChange when prev button is clicked', () => {
      const onChange = vi.fn()
      render(<CustomizedPagination {...defaultProps} current={5} onChange={onChange} />)
      const buttons = screen.getAllByRole('button')
      fireEvent.click(buttons[0])
      expect(onChange).toHaveBeenCalledWith(4)
    })

    it('should show input when page display is clicked', () => {
      render(<CustomizedPagination {...defaultProps} />)
      // Click the current page display (the div containing "1 / 10")
      fireEvent.click(screen.getByText('/'))
      // Input should appear
      expect(screen.getByRole('textbox')).toBeInTheDocument()
    })

    it('should navigate to entered page on Enter key', () => {
      vi.useFakeTimers()
      const onChange = vi.fn()
      render(<CustomizedPagination {...defaultProps} current={0} onChange={onChange} />)
      fireEvent.click(screen.getByText('/'))
      const input = screen.getByRole('textbox')
      fireEvent.change(input, { target: { value: '5' } })
      fireEvent.keyDown(input, { key: 'Enter' })
      act(() => {
        vi.advanceTimersByTime(500)
      })
      expect(onChange).toHaveBeenCalledWith(4) // 0-indexed
    })

    it('should cancel input on Escape key', () => {
      render(<CustomizedPagination {...defaultProps} current={0} />)
      fireEvent.click(screen.getByText('/'))
      const input = screen.getByRole('textbox')
      fireEvent.keyDown(input, { key: 'Escape' })
      // Input should be hidden and page display should return
      expect(screen.queryByRole('textbox')).not.toBeInTheDocument()
      expect(screen.getByText('/')).toBeInTheDocument()
    })

    it('should confirm input on blur', () => {
      vi.useFakeTimers()
      const onChange = vi.fn()
      render(<CustomizedPagination {...defaultProps} current={0} onChange={onChange} />)
      fireEvent.click(screen.getByText('/'))
      const input = screen.getByRole('textbox')
      fireEvent.change(input, { target: { value: '3' } })
      fireEvent.blur(input)
      act(() => {
        vi.advanceTimersByTime(500)
      })
      expect(onChange).toHaveBeenCalledWith(2) // 0-indexed
    })

    it('should clamp page to max when input exceeds total pages', () => {
      vi.useFakeTimers()
      const onChange = vi.fn()
      render(<CustomizedPagination {...defaultProps} current={0} total={100} limit={10} onChange={onChange} />)
      fireEvent.click(screen.getByText('/'))
      const input = screen.getByRole('textbox')
      fireEvent.change(input, { target: { value: '999' } })
      fireEvent.keyDown(input, { key: 'Enter' })
      act(() => {
        vi.advanceTimersByTime(500)
      })
      expect(onChange).toHaveBeenCalledWith(9) // last page (0-indexed)
    })

    it('should clamp page to min when input is less than 1', () => {
      vi.useFakeTimers()
      const onChange = vi.fn()
      render(<CustomizedPagination {...defaultProps} current={5} onChange={onChange} />)
      fireEvent.click(screen.getByText('/'))
      const input = screen.getByRole('textbox')
      fireEvent.change(input, { target: { value: '0' } })
      fireEvent.keyDown(input, { key: 'Enter' })
      act(() => {
        vi.advanceTimersByTime(500)
      })
      expect(onChange).toHaveBeenCalledWith(0)
    })

    it('should ignore non-numeric input and empty input', () => {
      render(<CustomizedPagination {...defaultProps} />)
      fireEvent.click(screen.getByText('/'))
      const input = screen.getByRole('textbox')

      fireEvent.change(input, { target: { value: 'abc' } })
      expect(input).toHaveValue('')

      fireEvent.change(input, { target: { value: '' } })
      expect(input).toHaveValue('')
    })

    it('should show per page tip on hover and hide on leave', () => {
      const onLimitChange = vi.fn()
      render(<CustomizedPagination {...defaultProps} onLimitChange={onLimitChange} />)

      const container = screen.getByText('25').closest('div.flex.items-center.gap-\\[1px\\]')!

      fireEvent.mouseEnter(container)
      // I18n mock returns ns.key
      expect(screen.getByText('common.pagination.perPage')).toBeInTheDocument()

      fireEvent.mouseLeave(container)
      expect(screen.queryByText('common.pagination.perPage')).not.toBeInTheDocument()
    })

    it('should call onLimitChange when limit option is clicked', () => {
      const onLimitChange = vi.fn()
      render(<CustomizedPagination {...defaultProps} onLimitChange={onLimitChange} />)
      fireEvent.click(screen.getByText('25'))
      expect(onLimitChange).toHaveBeenCalledWith(25)
    })

    it('should call onLimitChange with 10 when 10 option is clicked', () => {
      const onLimitChange = vi.fn()
      render(<CustomizedPagination {...defaultProps} onLimitChange={onLimitChange} />)
      // The limit selector contains options 10, 25, 50.
      // Query specifically within the limit container
      const container = screen.getByText('25').closest('div.flex.items-center.gap-\\[1px\\]')!
      const option10 = Array.from(container.children).find(el => el.textContent === '10')!
      fireEvent.click(option10)
      expect(onLimitChange).toHaveBeenCalledWith(10)
    })

    it('should call onLimitChange with 50 when 50 option is clicked', () => {
      const onLimitChange = vi.fn()
      render(<CustomizedPagination {...defaultProps} onLimitChange={onLimitChange} />)
      fireEvent.click(screen.getByText('50'))
      expect(onLimitChange).toHaveBeenCalledWith(50)
    })

    it('should call onChange when a page button is clicked', () => {
      const onChange = vi.fn()
      render(<CustomizedPagination {...defaultProps} current={0} total={50} limit={10} onChange={onChange} />)
      fireEvent.click(screen.getByText('3'))
      expect(onChange).toHaveBeenCalledWith(2) // 0-indexed
    })

    it('should correctly select active limit style for 25 and 50', () => {
      // Test limit 25
      const { container: containerA } = render(<CustomizedPagination current={0} total={100} limit={25} onChange={vi.fn()} onLimitChange={vi.fn()} />)
      const wrapper25 = Array.from(containerA.querySelectorAll('div.system-sm-medium')).find(el => el.textContent === '25')!
      expect(wrapper25).toHaveClass('bg-components-segmented-control-item-active-bg')

      // Test limit 50
      const { container: containerB } = render(<CustomizedPagination current={0} total={100} limit={50} onChange={vi.fn()} onLimitChange={vi.fn()} />)
      const wrapper50 = Array.from(containerB.querySelectorAll('div.system-sm-medium')).find(el => el.textContent === '50')!
      expect(wrapper50).toHaveClass('bg-components-segmented-control-item-active-bg')
    })
  })

  describe('Edge Cases', () => {
    it('should handle total of 0', () => {
      const { container } = render(<CustomizedPagination {...defaultProps} total={0} />)
      expect(container).toBeInTheDocument()
    })

    it('should handle confirm when input value is unchanged (covers false branch of empty string check)', () => {
      vi.useFakeTimers()
      const onChange = vi.fn()
      render(<CustomizedPagination {...defaultProps} current={4} onChange={onChange} />)
      fireEvent.click(screen.getByText('/'))
      const input = screen.getByRole('textbox')

      // Blur without changing anything
      fireEvent.blur(input)

      act(() => {
        vi.advanceTimersByTime(500)
      })

      // onChange should NOT be called
      expect(onChange).not.toHaveBeenCalled()
      expect(screen.queryByRole('textbox')).not.toBeInTheDocument()
    })

    it('should ignore other keys in handleInputKeyDown (covers false branch of Escape check)', () => {
      render(<CustomizedPagination {...defaultProps} current={4} />)
      fireEvent.click(screen.getByText('/'))
      const input = screen.getByRole('textbox')

      fireEvent.keyDown(input, { key: 'a' })
      expect(screen.getByRole('textbox')).toBeInTheDocument()
    })

    it('should trigger handleInputConfirm with empty string specifically on keydown Enter', async () => {
      const { userEvent } = await import('@testing-library/user-event')
      const user = userEvent.setup()
      render(<CustomizedPagination {...defaultProps} current={4} />)
      fireEvent.click(screen.getByText('/'))
      const input = screen.getByRole('textbox')

      await user.clear(input)
      await user.type(input, '{Enter}')

      // Wait for debounce 500ms
      await new Promise(r => setTimeout(r, 600))

      // Validates `inputValue === ''` path under `handleInputConfirm` triggered by Enter
      expect(screen.queryByRole('textbox')).not.toBeInTheDocument()
    })

    it('should explicitly trigger Escape key logic in handleInputKeyDown', async () => {
      const { userEvent } = await import('@testing-library/user-event')
      const user = userEvent.setup()
      render(<CustomizedPagination {...defaultProps} current={4} />)
      fireEvent.click(screen.getByText('/'))
      const input = screen.getByRole('textbox')

      await user.type(input, '{Escape}')

      // Wait for debounce 500ms
      await new Promise(r => setTimeout(r, 600))

      expect(screen.queryByRole('textbox')).not.toBeInTheDocument()
    })

    it('should handle single page', () => {
      render(<CustomizedPagination {...defaultProps} total={5} limit={10} />)
      // totalPages = 1, both buttons should be disabled
      const buttons = screen.getAllByRole('button')
      expect(buttons[0]).toBeDisabled()
      expect(buttons[buttons.length - 1]).toBeDisabled()
    })

    it('should restore input value when blurred with empty value', () => {
      render(<CustomizedPagination {...defaultProps} current={4} />)
      fireEvent.click(screen.getByText('/'))
      const input = screen.getByRole('textbox')
      fireEvent.change(input, { target: { value: '' } })
      fireEvent.blur(input)
      // Should close input without calling onChange, restoring to current + 1
      expect(screen.queryByRole('textbox')).not.toBeInTheDocument()
    })
  })
})