import { describe, expect, it } from 'vitest'

/** WCAG 相对亮度与对比度（纯函数审计） */
function luminance(hex: string): number {
  const m = hex.replace('#', '')
  const [r, g, b] = [0, 2, 4].map((i) => parseInt(m.slice(i, i + 2), 16) / 255)
  const lin = (c: number) => (c <= 0.03928 ? c / 12.92 : Math.pow((c + 0.055) / 1.055, 2.4))
  return 0.2126 * lin(r) + 0.7152 * lin(g) + 0.0722 * lin(b)
}
function contrast(a: string, b: string): number {
  const la = luminance(a), lb = luminance(b)
  const [hi, lo] = la > lb ? [la, lb] : [lb, la]
  return (hi + 0.05) / (lo + 0.05)
}

describe('0.1.26 页面可读性（对比度审计）', () => {
  const BG = '#100d0a'
  it('次级文本 (dim/dim2/help-text) 对比度 ≥ 4.5:1', () => {
    const cases: Array<[string, string]> = [
      ['#a99c80', '.dim'],
      ['#c3b595', '.dim2'],
      ['#c9b894', '.help-text'],
      ['#efe4c9', '.feed-item'],
      ['#e2d3b4', '.tag 文字'] as never
    ]
    for (const [hex, label] of cases) {
      const c = contrast(hex, BG)
      expect(c, `${label} 对比 ${c.toFixed(2)}`).toBeGreaterThanOrEqual(4.5)
    }
  })

  it('主文本 paper 对比充足（≥8:1）', () => {
    expect(contrast('#f2e9d4', BG)).toBeGreaterThanOrEqual(8)
  })

  it('历史暗色 #6d6150 不再被引用（提亮迁移核对）', () => {
    const css = require('fs').readFileSync('src/renderer/ui/styles.css', 'utf-8')
    expect(css.includes('#6d6150')).toBe(false)
    expect(css.includes('#96896e')).toBe(false)
  })
})