/**
 * 通过 CDP 截图，用于无人值守环境下的界面功能验证。
 *
 * 用法：
 *   node scripts/shot.mjs <port> <outfile>
 */

import { writeFile } from 'node:fs/promises'

const port = Number(process.argv[2] ?? 9335)
const outFile = process.argv[3] ?? 'shot.png'

async function main() {
  const listRes = await fetch(`http://127.0.0.1:${port}/json/list`)
  const targets = await listRes.json()
  const page = targets.find((t) => t.type === 'page')
  if (!page) {
    console.error('未找到 page 目标。当前目标：', targets.map((t) => `${t.type}:${t.url}`).join(', '))
    process.exit(1)
  }
  console.log('目标页面:', page.url)

  const ws = new WebSocket(page.webSocketDebuggerUrl)
  let id = 0
  const pending = new Map()

  const send = (method, params = {}) =>
    new Promise((resolve, reject) => {
      const msgId = ++id
      const timer = setTimeout(() => {
        pending.delete(msgId)
        reject(new Error(`CDP 调用超时: ${method}`))
      }, 8000)
      pending.set(msgId, (value) => {
        clearTimeout(timer)
        resolve(value)
      })
      ws.send(JSON.stringify({ id: msgId, method, params }))
    })

  await new Promise((resolve, reject) => {
    const timer = setTimeout(() => reject(new Error('WebSocket 连接超时（8s）')), 8000)
    ws.addEventListener('open', () => {
      clearTimeout(timer)
      resolve()
    })
    ws.addEventListener('error', (e) => {
      clearTimeout(timer)
      reject(new Error(`WebSocket 错误: ${e?.message ?? 'unknown'}`))
    })
  })
  console.log('CDP 已连接')

  ws.addEventListener('message', (ev) => {
    const msg = JSON.parse(ev.data)
    if (msg.id && pending.has(msg.id)) {
      pending.get(msg.id)(msg.result)
      pending.delete(msg.id)
    }
  })

  await send('Page.enable')
  // 等首屏与字体稳定
  await new Promise((r) => setTimeout(r, 2500))

  const metrics = await send('Runtime.evaluate', {
    expression: `(() => {
      const c = document.createElement('canvas')
      const gl = c.getContext('webgl2') || c.getContext('webgl')
      const dbg = gl && gl.getExtension('WEBGL_debug_renderer_info')
      return JSON.stringify({
        title: document.title,
        theme: document.documentElement.dataset.theme,
        hasApi: typeof window.ycode === 'object',
        gpuRenderer: dbg ? gl.getParameter(dbg.UNMASKED_RENDERER_WEBGL) : (gl ? 'webgl(no-debug-ext)' : 'NO WEBGL'),
        bodyText: (document.body.innerText || '').slice(0, 400),
        shell: !!document.querySelector('.app-shell'),
        columns: document.querySelector('.app-shell')
          ? getComputedStyle(document.querySelector('.app-shell')).gridTemplateColumns : null,
        composer: !!document.querySelector('.composer__input'),
        sessionItems: document.querySelectorAll('.sidebar__item-title').length,
        panels: document.querySelectorAll('.panel').length
      })
    })()`,
    returnByValue: true
  })
  console.log('DOM 状态:', metrics?.result?.value)

  const shot = await send('Page.captureScreenshot', { format: 'png' })
  if (!shot?.data) {
    console.error('截图失败')
    process.exit(1)
  }
  await writeFile(outFile, Buffer.from(shot.data, 'base64'))
  console.log('已保存:', outFile)
  ws.close()
}

main().catch((err) => {
  console.error('异常:', err.message)
  process.exit(1)
})