import { describe, it, expect } from 'vitest'
import { testRegex, explainRegex } from '../src/utils/regex-tester.js'

describe('regex-tester', () => {
  it('finds simple matches', () => {
    const result = testRegex({ pattern: '\\d+', flags: 'g', text: 'abc 123 def 456' })
    expect(result.valid).toBe(true)
    expect(result.matches.length).toBe(2)
    expect(result.matches[0].full).toBe('123')
    expect(result.matches[1].full).toBe('456')
  })

  it('captures groups', () => {
    const result = testRegex({ pattern: '(\\w+)=(\\d+)', flags: 'g', text: 'a=1,b=2' })
    expect(result.valid).toBe(true)
    expect(result.matches[0].groups).toEqual(['a', '1'])
  })

  it('reports invalid regex', () => {
    const result = testRegex({ pattern: '[', flags: '', text: 'test' })
    expect(result.valid).toBe(false)
    expect(result.error).toBeDefined()
  })

  it('shows replace preview', () => {
    const result = testRegex({
      pattern: '\\d+',
      flags: 'g',
      text: 'abc 123',
      replacement: 'XXX',
    })
    expect(result.replacePreview).toBe('abc XXX')
  })

  it('explains patterns', () => {
    const exp = explainRegex('\\d+')
    expect(exp).toContain('\\d')
  })
})