import { describe, it, expect } from 'vitest'
import { openPreviewTab, closePreviewTab } from '../src/previewtabs'

describe('preview tabs', () => {
  it('opens a new tab and re-activates an existing one without duplicating it', () => {
    const first = openPreviewTab([], { id: 'a', name: '甲.docx' })
    const second = openPreviewTab(first.tabs, { id: 'b', name: '乙.pptx' })
    expect(second.tabs.map(t => t.id)).toEqual(['a', 'b'])
    expect(second.activeId).toBe('b')
    const again = openPreviewTab(second.tabs, { id: 'a', name: '甲.docx' })
    expect(again.tabs).toHaveLength(2)
    expect(again.activeId).toBe('a')
  })

  it('closing the active tab selects the neighbor, and closing another keeps the active tab', () => {
    const tabs = [{ id: 'a', name: '甲' }, { id: 'b', name: '乙' }, { id: 'c', name: '丙' }]
    const closedB = closePreviewTab(tabs, 'b', 'b')
    expect(closedB.tabs.map(t => t.id)).toEqual(['a', 'c'])
    expect(closedB.activeId).toBe('c')
    const closedA = closePreviewTab(closedB.tabs, 'c', 'a')
    expect(closedA.activeId).toBe('c')
    expect(closePreviewTab([{ id: 'a', name: '甲' }], 'a', 'a')).toEqual({ tabs: [], activeId: null })
  })
})