#!/usr/bin/env node
/* C-2 视觉变更验证（旧蓝→品牌橙/信息蓝分流批次专用）
 * 用法：node scripts/tmp_c2_verify.js <页面路径> <替换规则.json>
 * 替换规则.json 支持两种规则形态（按序施加）：
 *   1. 全局规则：["#5B9BD5", "#F97316"] 字面替换；["/^color: #5B9BD5/m", "color: #0EA5E9"] 正则（flags 直通，缺省补 g）
 *   2. 块级规则：{"block": ".channel-tip-text", "pairs": [["color: #5B9BD5", "color: #0EA5E9"]]}
 *      —— 仅在该选择器规则块（至第一个 } 行）内应用 pairs；块内未命中即报错
 * 原理：before(HEAD) 与 after(工作区) 分别拼接 uni.scss 编译并归一；
 * 对 before 产物按序施加预期替换后，必须与 after 产物逐字节相同
 * → 证明除预期颜色替换外零其他变化。
 */
const { execSync } = require('child_process')
const fs = require('fs')
const path = require('path')

const PAGE = process.argv[2]
const SUBST_FILE = process.argv[3]
if (!PAGE || !SUBST_FILE) {
  console.error('用法: node scripts/tmp_c2_verify.js <页面路径> <替换规则.json>')
  process.exit(2)
}

const ROOT = path.resolve(__dirname, '..')
const REPO = path.resolve(ROOT, '..')
const REL = path.relative(REPO, path.join(ROOT, PAGE)).split(path.sep).join('/')
const TMP = path.join(ROOT, '.tmp_equiv')
fs.mkdirSync(TMP, { recursive: true })

function extractStyle(src) {
  const m = src.match(/^[ \t]*<style[^>]*>[\s\S]*?<\/style>/m)
  if (!m) throw new Error('未找到 style 块: ' + PAGE)
  return m[0].replace(/^[ \t]*<style[^>]*>/, '').replace(/<\/style>$/, '')
}

const uniScss = fs.readFileSync(path.join(ROOT, 'uni.scss'), 'utf8')
const afterVue = fs.readFileSync(path.join(ROOT, PAGE), 'utf8')
const beforeVue = execSync(`git -C "${REPO}" show HEAD:${REL}`, { encoding: 'utf8', maxBuffer: 1e8 })

fs.writeFileSync(path.join(TMP, 'after.scss'), uniScss + '\n' + extractStyle(afterVue))
fs.writeFileSync(path.join(TMP, 'before.scss'), uniScss + '\n' + extractStyle(beforeVue))

const sass = path.join(ROOT, 'node_modules/.bin/sass.cmd')
execSync(`"${sass}" --no-source-map "${TMP}/after.scss" "${TMP}/after.out.css"`, { stdio: 'pipe' })
execSync(`"${sass}" --no-source-map "${TMP}/before.scss" "${TMP}/before.out.css"`, { stdio: 'pipe' })

function norm(s) {
  return s
    .replace(/rgba\(([^)]+)\)/g, (m, inner) => 'rgba(' + inner.split(',').map((x) => x.trim()).join(',') + ')') // canonical rgba spacing
    .replace(/\/\*[\s\S]*?\*\//g, '') // strip block comments
    .replace(/#([0-9a-fA-F]{3,8})\b/g, (m) => {
      let h = m.slice(1).toUpperCase()
      if (h.length === 3) h = h.split('').map((c) => c + c).join('')
      return '#' + h
    })
    .split('\n').map((l) => l.trim()).filter(Boolean).join('\n')
}

function toRegExp(pat) {
  const last = pat.lastIndexOf('/')
  const flags = pat.slice(last + 1)
  return new RegExp(pat.slice(1, last), flags.includes('g') ? flags : flags + 'g')
}

function applyBlockRules(text, sel, pairs) {
  const lines = text.split('\n')
  let idx = -1
  for (let i = 0; i < lines.length; i++) {
    if (lines[i].trim() === sel + ' {') { idx = i; break }
  }
  if (idx === -1) throw new Error('块选择器未找到: ' + sel)
  let end = -1
  for (let j = idx + 1; j < lines.length; j++) {
    if (lines[j].trim() === '}') { end = j; break }
  }
  if (end === -1) throw new Error('块未闭合: ' + sel)
  const body = lines.slice(idx + 1, end)
  for (const [pat, rep] of pairs) {
    const before = body.join('\n')
    const after = pat.startsWith('/') && pat.lastIndexOf('/') > 0
      ? before.replace(toRegExp(pat), rep)
      : before.split(pat).join(rep)
    if (after === before) throw new Error('块内替换未生效: ' + sel + ' :: ' + pat)
    body.length = 0
    body.push(...after.split('\n'))
  }
  lines.splice(idx + 1, end - idx - 1, ...body)
  return lines.join('\n')
}

const substs = JSON.parse(fs.readFileSync(SUBST_FILE, 'utf8'))
let expected = norm(fs.readFileSync(path.join(TMP, 'before.out.css'), 'utf8'))
for (const rule of substs) {
  if (Array.isArray(rule)) {
    const [pat, rep] = rule
    expected = pat.startsWith('/') && pat.lastIndexOf('/') > 0
      ? expected.replace(toRegExp(pat), rep)
      : expected.split(pat).join(rep)
  } else if (rule && rule.block && Array.isArray(rule.pairs)) {
    expected = applyBlockRules(expected, rule.block, rule.pairs)
  } else {
    throw new Error('未知规则形态: ' + JSON.stringify(rule))
  }
}

const after = norm(fs.readFileSync(path.join(TMP, 'after.out.css'), 'utf8'))

if (expected === after) {
  console.log(`C-2 验证 PASS（${PAGE}）：before 施加预期替换后与 after 逐字节相同，仅含预期颜色变更`)
} else {
  const el = expected.split('\n'), al = after.split('\n')
  console.log(`C-2 验证 DIFF（${PAGE}）：expected ${el.length} 行 / after ${al.length} 行`)
  let shown = 0
  for (let i = 0; i < Math.max(el.length, al.length) && shown < 40; i++) {
    if (el[i] !== al[i]) {
      console.log(`L${i + 1}\n  expected: ${el[i]}\n  after:    ${al[i]}`)
      shown++
    }
  }
  if (shown >= 40) console.log('...（仅显示前 40 处差异）')
  process.exit(1)
}