import type { Segment } from './types'
import { describe, expect, it } from 'vitest'
import { recolor, sliceSegments } from './segments'

const tokens: Segment[] = [
  { text: 'const', role: 'storage' },
  { text: ' ', role: 'plain' },
  { text: 'uris', role: 'variable' },
  { text: ' = ', role: 'plain' },
  { text: '42', role: 'number' },
]
const code = 'const uris = 42'

function join(segments: Segment[]): string {
  return segments.map(s => s.text).join('')
}

describe('sliceSegments', () => {
  it('跨段切出一段时每个字保留原词性', () => {
    expect(sliceSegments(tokens, 3, 8)).toEqual([
      { text: 'st', role: 'storage' },
      { text: ' ', role: 'plain' },
      { text: 'ur', role: 'variable' },
    ])
  })

  it('空区间返回空数组', () => {
    expect(sliceSegments(tokens, 4, 4)).toEqual([])
  })
})

describe('recolor', () => {
  it('文字没变时原样返回着色', () => {
    expect(recolor(tokens, code, code)).toBe(tokens)
  })

  it('中间插入的字不着色，前后沿用原词性', () => {
    const text = 'const allUris = 42'
    const result = recolor(tokens, code, text)
    expect(join(result)).toBe(text)
    expect(result).toEqual([
      { text: 'const', role: 'storage' },
      { text: ' ', role: 'plain' },
      { text: 'allU', role: 'plain' },
      { text: 'ris', role: 'variable' },
      { text: ' = ', role: 'plain' },
      { text: '42', role: 'number' },
    ])
  })

  it('删掉结尾时只剩前缀的着色', () => {
    expect(recolor(tokens, code, 'const ur')).toEqual([
      { text: 'const', role: 'storage' },
      { text: ' ', role: 'plain' },
      { text: 'ur', role: 'variable' },
    ])
  })

  it('重复字符不会让前后缀重叠', () => {
    const result = recolor([{ text: 'aa', role: 'variable' }], 'aa', 'aaa')
    expect(join(result)).toBe('aaa')
  })

  it('清空后没有任何段', () => {
    expect(recolor(tokens, code, '')).toEqual([])
  })
})