// @vitest-environment jsdom
import { describe, it, expect, vi, beforeEach, afterEach } from 'vitest'
import { render, screen, fireEvent } from '@testing-library/react'
import { SplitPane } from '@/components/split-pane/split-pane'

// Helper to set a cookie
function setCookie(key: string, value: string) {
  Object.defineProperty(document, 'cookie', {
    writable: true,
    configurable: true,
    value: `sp:${key}=${encodeURIComponent(value)}`,
  })
}

function clearCookies() {
  Object.defineProperty(document, 'cookie', {
    writable: true,
    configurable: true,
    value: '',
  })
}

describe('SplitPane', () => {
  beforeEach(() => {
    clearCookies()
    // Default: desktop viewport
    Object.defineProperty(window, 'innerWidth', { writable: true, configurable: true, value: 1440 })
    window.dispatchEvent(new Event('resize'))
  })

  afterEach(() => {
    vi.restoreAllMocks()
  })

  it('renders 2 panes', () => {
    render(
      <SplitPane
        panes={[<div key="a">Pane A</div>, <div key="b">Pane B</div>]}
        defaultSplit={[30, 70]}
        cookieKey="test-2pane"
      />
    )
    expect(screen.getByText('Pane A')).toBeTruthy()
    expect(screen.getByText('Pane B')).toBeTruthy()
  })

  it('renders 3 panes with 2 dividers', () => {
    const { container } = render(
      <SplitPane
        panes={[
          <div key="a">Left</div>,
          <div key="b">Middle</div>,
          <div key="c">Right</div>,
        ]}
        defaultSplit={[28, 35, 37]}
        cookieKey="test-3pane"
      />
    )
    expect(screen.getByText('Left')).toBeTruthy()
    expect(screen.getByText('Middle')).toBeTruthy()
    expect(screen.getByText('Right')).toBeTruthy()
    // 2 dividers: cursor-col-resize elements
    const dividers = container.querySelectorAll('.cursor-col-resize')
    expect(dividers).toHaveLength(2)
  })

  it('restores splits from cookie on mount', () => {
    const stored = JSON.stringify([40, 60])
    setCookie('test-restore', stored)

    const { container } = render(
      <SplitPane
        panes={[<div key="a">A</div>, <div key="b">B</div>]}
        defaultSplit={[20, 80]}
        cookieKey="test-restore"
      />
    )

    // Left pane should have width 40%, not the default 20%
    const paneDiv = container.querySelector<HTMLElement>('[style*="40%"]')
    expect(paneDiv).toBeTruthy()
  })

  it('falls back to defaultSplit when cookie is invalid', () => {
    setCookie('test-invalid', 'not-valid-json')

    const { container } = render(
      <SplitPane
        panes={[<div key="a">A</div>, <div key="b">B</div>]}
        defaultSplit={[25, 75]}
        cookieKey="test-invalid"
      />
    )

    const paneDiv = container.querySelector<HTMLElement>('[style*="25%"]')
    expect(paneDiv).toBeTruthy()
  })

  it('renders tabs on mobile viewport', () => {
    Object.defineProperty(window, 'innerWidth', { writable: true, configurable: true, value: 768 })
    window.dispatchEvent(new Event('resize'))

    render(
      <SplitPane
        panes={[<div key="a">Content A</div>, <div key="b">Content B</div>]}
        defaultSplit={[50, 50]}
        cookieKey="test-mobile"
        tabLabels={['Tab A', 'Tab B']}
      />
    )

    expect(screen.getByText('Tab A')).toBeTruthy()
    expect(screen.getByText('Tab B')).toBeTruthy()
    // Only first tab content visible by default
    expect(screen.getByText('Content A')).toBeTruthy()
    expect(screen.queryByText('Content B')).toBeNull()
  })

  it('switches tab content on mobile', () => {
    Object.defineProperty(window, 'innerWidth', { writable: true, configurable: true, value: 600 })
    window.dispatchEvent(new Event('resize'))

    render(
      <SplitPane
        panes={[<div key="a">Content A</div>, <div key="b">Content B</div>]}
        defaultSplit={[50, 50]}
        cookieKey="test-mobile-switch"
        tabLabels={['Tab A', 'Tab B']}
      />
    )

    // Click second tab
    fireEvent.click(screen.getByText('Tab B'))
    expect(screen.queryByText('Content A')).toBeNull()
    expect(screen.getByText('Content B')).toBeTruthy()
  })

  it('back button not visible on tab 0 in mobile', () => {
    Object.defineProperty(window, 'innerWidth', { writable: true, configurable: true, value: 600 })
    window.dispatchEvent(new Event('resize'))

    render(
      <SplitPane
        panes={[<div key="a">A</div>, <div key="b">B</div>, <div key="c">C</div>]}
        defaultSplit={[33, 33, 34]}
        cookieKey="test-back-hidden"
        tabLabels={['T1', 'T2', 'T3']}
      />
    )

    // On tab 0, no back button
    expect(screen.queryByLabelText('Terug')).toBeNull()
  })

  it('back button visible on tab > 0 and navigates back', () => {
    Object.defineProperty(window, 'innerWidth', { writable: true, configurable: true, value: 600 })
    window.dispatchEvent(new Event('resize'))

    render(
      <SplitPane
        panes={[<div key="a">A</div>, <div key="b">B</div>, <div key="c">C</div>]}
        defaultSplit={[33, 33, 34]}
        cookieKey="test-back-nav"
        tabLabels={['T1', 'T2', 'T3']}
      />
    )

    // Switch to tab 2
    fireEvent.click(screen.getByText('T3'))
    expect(screen.getByText('C')).toBeTruthy()
    expect(screen.getByLabelText('Terug')).toBeTruthy()

    // Click back → tab 1
    fireEvent.click(screen.getByLabelText('Terug'))
    expect(screen.getByText('B')).toBeTruthy()

    // Click back again → tab 0, no back button
    fireEvent.click(screen.getByLabelText('Terug'))
    expect(screen.getByText('A')).toBeTruthy()
    expect(screen.queryByLabelText('Terug')).toBeNull()
  })

  it('controlled activeTab prop switches the active pane', () => {
    Object.defineProperty(window, 'innerWidth', { writable: true, configurable: true, value: 600 })
    window.dispatchEvent(new Event('resize'))

    const { rerender } = render(
      <SplitPane
        panes={[<div key="a">A</div>, <div key="b">B</div>, <div key="c">C</div>]}
        defaultSplit={[33, 33, 34]}
        cookieKey="test-controlled"
        tabLabels={['T1', 'T2', 'T3']}
        activeTab={0}
        onActiveTabChange={vi.fn()}
      />
    )
    expect(screen.getByText('A')).toBeTruthy()

    rerender(
      <SplitPane
        panes={[<div key="a">A</div>, <div key="b">B</div>, <div key="c">C</div>]}
        defaultSplit={[33, 33, 34]}
        cookieKey="test-controlled"
        tabLabels={['T1', 'T2', 'T3']}
        activeTab={2}
        onActiveTabChange={vi.fn()}
      />
    )
    expect(screen.getByText('C')).toBeTruthy()
  })

  it('does not render dividers on mobile', () => {
    Object.defineProperty(window, 'innerWidth', { writable: true, configurable: true, value: 600 })
    window.dispatchEvent(new Event('resize'))

    const { container } = render(
      <SplitPane
        panes={[<div key="a">A</div>, <div key="b">B</div>]}
        defaultSplit={[50, 50]}
        cookieKey="test-no-dividers"
      />
    )

    const dividers = container.querySelectorAll('.cursor-col-resize')
    expect(dividers).toHaveLength(0)
  })
})