// 调试：验证 free_show_local_agent v2 的 CDP + 手写 WebSocket 管道
// 仅用 about:blank 等无害 URL，不访问大麦（保护服务器 IP）
// 用法：node dev_test_scripts/debug/debug_agent_cdp.js
'use strict'
const http = require('http')
const net = require('net')
const fs = require('fs')
const path = require('path')
const crypto = require('crypto')
const { spawn } = require('child_process')

const CDP_PORT = 9322 // 避开代理默认 9222
const PROFILE = path.join(__dirname, '.edge_debug_profile')
const sleep = ms => new Promise(r => setTimeout(r, ms))

function findBrowser() {
  const candidates = [
    'C:\\Program Files (x86)\\Microsoft\\Edge\\Application\\msedge.exe',
    'C:\\Program Files\\Microsoft\\Edge\\Application\\msedge.exe',
    'C:\\Program Files\\Google\\Chrome\\Application\\chrome.exe'
  ]
  for (const p of candidates) if (fs.existsSync(p)) return p
  return null
}

function cdpHttp(method, p) {
  return new Promise((resolve, reject) => {
    const req = http.request({ host: '127.0.0.1', port: CDP_PORT, path: p, method, timeout: 5000 }, res => {
      let body = ''
      res.on('data', c => { body += c })
      res.on('end', () => { try { resolve(JSON.parse(body)) } catch (e) { reject(new Error('parse fail')) } })
    })
    req.on('timeout', () => req.destroy(new Error('timeout')))
    req.on('error', reject)
    req.end()
  })
}

// ---- 与代理同款最小 WS 客户端（复制自 free_show_local_agent.js） ----
function parseWsFrame(buf) {
  if (buf.length < 2) return null
  const fin = (buf[0] & 0x80) !== 0
  const opcode = buf[0] & 0x0f
  const masked = (buf[1] & 0x80) !== 0
  let len = buf[1] & 0x7f
  let off = 2
  if (len === 126) { if (buf.length < 4) return null; len = buf.readUInt16BE(2); off = 4 }
  else if (len === 127) { if (buf.length < 10) return null; len = Number(buf.readBigUInt64BE(2)); off = 10 }
  let mask = null
  if (masked) { if (buf.length < off + 4) return null; mask = buf.slice(off, off + 4); off += 4 }
  if (buf.length < off + len) return null
  let payload = buf.slice(off, off + len)
  if (mask) { payload = Buffer.from(payload); for (let i = 0; i < payload.length; i++) payload[i] ^= mask[i % 4] }
  return { fin, opcode, payload, total: off + len }
}
function encodeWsFrame(text) {
  const payload = Buffer.from(text, 'utf8')
  const len = payload.length
  let header
  if (len < 126) header = Buffer.from([0x81, 0x80 | len])
  else if (len < 65536) { header = Buffer.from([0x81, 0x80 | 126, 0, 0]); header.writeUInt16BE(len, 2) }
  else { header = Buffer.from([0x81, 0x80 | 127, 0, 0, 0, 0, 0, 0, 0, 0]); header.writeBigUInt64BE(BigInt(len), 2) }
  const mask = crypto.randomBytes(4)
  const masked = Buffer.from(payload)
  for (let i = 0; i < masked.length; i++) masked[i] ^= mask[i % 4]
  return Buffer.concat([header, mask, masked])
}
function wsConnect(wsUrl) {
  return new Promise((resolve, reject) => {
    const u = new URL(wsUrl)
    const sock = net.connect(Number(u.port) || 80, u.hostname || '127.0.0.1')
    const key = crypto.randomBytes(16).toString('base64')
    const handshake = ['GET ' + (u.pathname || '/') + (u.search || '') + ' HTTP/1.1', 'Host: ' + u.host, 'Upgrade: websocket', 'Connection: Upgrade', 'Sec-WebSocket-Key: ' + key, 'Sec-WebSocket-Version: 13', '', ''].join('\r\n')
    let upgraded = false
    let buf = Buffer.alloc(0)
    let fragBuf = null
    const handlers = { message: null, close: null }
    const client = {
      send(t) { try { sock.write(encodeWsFrame(t)) } catch (e) {} },
      close() { try { sock.end() } catch (e) {} },
      onMessage(fn) { handlers.message = fn },
      onClose(fn) { handlers.close = fn }
    }
    sock.on('connect', () => sock.write(handshake))
    sock.on('data', chunk => {
      buf = Buffer.concat([buf, chunk])
      if (!upgraded) {
        const idx = buf.indexOf('\r\n\r\n')
        if (idx < 0) return
        if (!/^HTTP\/1\.1\s+101/.test(buf.slice(0, idx).toString())) { reject(new Error('握手失败')); sock.end(); return }
        upgraded = true
        buf = buf.slice(idx + 4)
        resolve(client)
      }
      while (true) {
        const frame = parseWsFrame(buf)
        if (!frame) break
        buf = buf.slice(frame.total)
        if (frame.opcode === 0x8) { if (handlers.close) handlers.close(); return }
        if (frame.opcode === 0x9) { sock.write(Buffer.from([0x8a, 0x80, 0, 0, 0, 0])); continue }
        if (frame.opcode === 0xA) continue
        if (frame.opcode === 0x1 || frame.opcode === 0x2) {
          if (frame.fin) { const full = fragBuf ? Buffer.concat([fragBuf, frame.payload]) : frame.payload; fragBuf = null; if (handlers.message) handlers.message(full.toString('utf8')) }
          else fragBuf = frame.payload
        } else if (frame.opcode === 0x0) {
          fragBuf = fragBuf ? Buffer.concat([fragBuf, frame.payload]) : frame.payload
          if (frame.fin) { const full = fragBuf; fragBuf = null; if (handlers.message) handlers.message(full.toString('utf8')) }
        }
      }
    })
    sock.on('error', e => { if (!upgraded) reject(e); else if (handlers.close) handlers.close() })
    sock.on('close', () => { if (handlers.close) handlers.close() })
  })
}
function makeCdp(ws) {
  let nextId = 1
  const pending = new Map()
  ws.onMessage(text => {
    let msg = null
    try { msg = JSON.parse(text) } catch (e) { return }
    if (msg && msg.id && pending.has(msg.id)) { const cb = pending.get(msg.id); pending.delete(msg.id); cb(msg) }
  })
  return {
    send(method, params) {
      return new Promise((resolve, reject) => {
        const id = nextId++
        const timer = setTimeout(() => { if (pending.has(id)) { pending.delete(id); reject(new Error('CDP 超时: ' + method)) } }, 15000)
        pending.set(id, msg => { clearTimeout(timer); resolve(msg) })
        ws.send(JSON.stringify({ id, method, params: params || {} }))
      })
    }
  }
}

async function main() {
  const browser = findBrowser()
  if (!browser) { console.log('FAIL: 未找到浏览器'); return }
  console.log('浏览器:', browser)
  const child = spawn(browser, [
    '--headless=new', '--disable-gpu',
    '--remote-debugging-port=' + CDP_PORT,
    '--user-data-dir=' + PROFILE,
    '--disable-blink-features=AutomationControlled',
    '--exclude-switches=enable-automation',
    '--no-first-run', '--no-default-browser-check',
    'about:blank'
  ], { detached: true, stdio: 'ignore' })
  child.unref()

  let ver = null
  for (let i = 0; i < 30; i++) {
    await sleep(500)
    ver = await cdpHttp('GET', '/json/version').catch(() => null)
    if (ver) break
  }
  if (!ver) { console.log('FAIL: CDP 未就绪'); try { child.kill() } catch (e) {}; return }
  console.log('PASS: /json/version =>', ver.Browser || ver['User-Agent'] || 'ok')

  let tab = null
  try { tab = await cdpHttp('PUT', '/json/new?' + encodeURIComponent('about:blank')) }
  catch (e) { tab = await cdpHttp('GET', '/json/new?' + encodeURIComponent('about:blank')).catch(() => null) }
  if (!tab || !tab.webSocketDebuggerUrl) { console.log('FAIL: 开标签失败'); try { child.kill() } catch (e) {}; return }
  console.log('PASS: /json/new =>', tab.id)

  const ws = await wsConnect(tab.webSocketDebuggerUrl)
  const cdp = makeCdp(ws)
  const r1 = await cdp.send('Runtime.evaluate', { expression: '1+1', returnByValue: true })
  console.log('PASS: evaluate 1+1 =>', r1 && r1.result && r1.result.result ? r1.result.result.value : 'null')
  const r2 = await cdp.send('Runtime.evaluate', { expression: 'navigator.webdriver', returnByValue: true })
  console.log('INFO: navigator.webdriver =>', r2 && r2.result && r2.result.result ? r2.result.result.value : 'null')
  ws.close()
  await cdpHttp('GET', '/json/close/' + tab.id).catch(() => null)
  console.log('PASS: 标签已关闭')

  try { child.kill() } catch (e) {}
  console.log('DONE')
  process.exit(0)
}

main().catch(e => { console.log('FAIL:', e.message || e); process.exit(1) })