import { describe, it, expect, vi } from 'vitest'
import { render, screen } from '@testing-library/react'
import userEvent from '@testing-library/user-event'
import { BrowserRouter, MemoryRouter } from 'react-router-dom'
import { Header } from './Header'

const renderWithRouter = (element: React.ReactElement) => {
  return render(
    <BrowserRouter>
      {element}
    </BrowserRouter>,
  )
}

const renderAtPath = (element: React.ReactElement, path: string) => {
  return render(
    <MemoryRouter initialEntries={[path]}>
      {element}
    </MemoryRouter>,
  )
}

describe('Header', () => {
  it('renders header with default title', () => {
    renderWithRouter(<Header />)
    expect(screen.getByTestId('header-title')).toHaveTextContent('Föräldraledigplannerare')
  })

  it('renders parent name when provided', () => {
    renderWithRouter(<Header parentName="Elin" />)
    expect(screen.getByTestId('parent-name')).toHaveTextContent('Elin')
  })

  it('renders child select when children provided', () => {
    const childrenList = [
      { id: '1', name: 'Emma' },
      { id: '2', name: 'Oscar' },
    ]
    renderWithRouter(<Header childrenList={childrenList} selectedChildId="1" />)
    expect(screen.getByTestId('child-select')).toBeInTheDocument()
    expect(screen.getByDisplayValue('Emma')).toBeInTheDocument()
  })

  it('calls onChildSelect when child selection changes', async () => {
    const onChildSelect = vi.fn()
    const childrenList = [
      { id: '1', name: 'Emma' },
      { id: '2', name: 'Oscar' },
    ]
    renderWithRouter(
      <Header childrenList={childrenList} selectedChildId="1" onChildSelect={onChildSelect} />,
    )
    const select = screen.getByTestId('child-select') as HTMLSelectElement
    await userEvent.selectOptions(select, '2')
    expect(onChildSelect).toHaveBeenCalledWith('2')
  })

  it('renders navigation links', () => {
    renderWithRouter(<Header />)
    expect(screen.getByText('Översikt')).toBeInTheDocument()
    expect(screen.getByText('Kalender')).toBeInTheDocument()
    expect(screen.getByText('Inställningar')).toBeInTheDocument()
  })

  it('does not render the retired Plan/Tips nav entries', () => {
    renderWithRouter(<Header />)
    expect(screen.queryByText('Planering')).not.toBeInTheDocument()
    expect(screen.queryByText('Tips')).not.toBeInTheDocument()
  })

  it('sets an aria-label on the child select for accessibility', () => {
    const childrenList = [
      { id: '1', name: 'Emma' },
      { id: '2', name: 'Oscar' },
    ]
    renderWithRouter(<Header childrenList={childrenList} selectedChildId="1" />)
    expect(screen.getByTestId('child-select')).toHaveAttribute('aria-label', 'Välj barn')
  })

  it('sets an aria-label on the logout button for accessibility', () => {
    renderWithRouter(<Header onLogout={vi.fn()} />)
    expect(screen.getByTestId('logout-button')).toHaveAttribute('aria-label', 'Logga ut')
  })

  it('renders logout button when onLogout provided', () => {
    const onLogout = vi.fn()
    renderWithRouter(<Header onLogout={onLogout} />)
    const button = screen.getByTestId('logout-button')
    expect(button).toBeInTheDocument()
  })

  it('calls onLogout when logout button clicked', async () => {
    const onLogout = vi.fn()
    renderWithRouter(<Header onLogout={onLogout} />)
    const button = screen.getByTestId('logout-button')
    await userEvent.click(button)
    expect(onLogout).toHaveBeenCalled()
  })

  it('does not render logout button when not provided', () => {
    renderWithRouter(<Header />)
    expect(screen.queryByTestId('logout-button')).not.toBeInTheDocument()
  })

  it('does not crash and renders the select when selectedChildId is not provided (falls back to "")', () => {
    const childrenList = [
      { id: '1', name: 'Emma' },
      { id: '2', name: 'Oscar' },
    ]
    renderWithRouter(<Header childrenList={childrenList} />)
    const select = screen.getByTestId('child-select') as HTMLSelectElement
    // selectedChildId ?? '' binds the select to a value ('') that matches no
    // <option>, so the browser falls back to the first option — it must not
    // be coerced to something else (e.g. "undefined" or a stale selection).
    expect(select.value).toBe('1')
  })

  it('marks the calendar link active on the calendar route', () => {
    renderAtPath(<Header />, '/calendar')
    expect(screen.getByText('Kalender')).toHaveAttribute('aria-current', 'page')
    expect(screen.getByText('Översikt')).not.toHaveAttribute('aria-current', 'page')
  })

  it('marks the settings link active on the settings route, and the overview link inactive', () => {
    renderAtPath(<Header />, '/settings')
    expect(screen.getByText('Inställningar')).toHaveAttribute('aria-current', 'page')
    expect(screen.getByText('Översikt')).not.toHaveAttribute('aria-current', 'page')
  })
})