#!/usr/bin/env node
/**
 * 封面生成脚本 v2 — GPT 一步出图（文字由 GPT 直接渲染）
 * 对齐 prompts/封面提示词.md 模板
 *
 * 用法: node gen-covers.js --manifest <path>
 */
const fs = require('fs')
const path = require('path')
const https = require('https')

function loadConfig() {
  const configPath = path.join(__dirname, '..', '..', 'config.json')
  return JSON.parse(fs.readFileSync(configPath, 'utf-8'))
}
const cfg = loadConfig()

// ============================================================================
// 工具
// ============================================================================

function download(url, dest) {
  return new Promise((resolve, reject) => {
    const file = fs.createWriteStream(dest)
    https.get(url, (res) => {
      if (res.statusCode >= 300 && res.statusCode < 400 && res.headers.location) {
        file.close()
        try { fs.unlinkSync(dest) } catch (_) {}
        return download(res.headers.location, dest).then(resolve, reject)
      }
      res.pipe(file)
      file.on('finish', () => { file.close(); resolve() })
    }).on('error', (err) => { try { fs.unlinkSync(dest) } catch (_) {}; reject(err) })
  })
}

function api(method, urlPath, headers, body) {
  return new Promise((resolve, reject) => {
    const u = new URL((cfg.gptImageApiBaseUrl || 'https://yunwu.ai') + urlPath)
    const opts = { hostname: u.hostname, port: 443, path: u.pathname + u.search, method, headers, timeout: 180000 }
    const req = https.request(opts, (res) => {
      const c = []; res.on('data', d => c.push(d))
      res.on('end', () => { const d = Buffer.concat(c); resolve({ status: res.statusCode, data: d, json: () => JSON.parse(d.toString()) }) })
    })
    req.on('error', reject)
    if (body) req.write(body)
    req.end()
  })
}

function sleep(ms) { return new Promise(r => setTimeout(r, ms)) }

// ============================================================================
// GPT Image edits（带重试 + b64_json 支持）
// ============================================================================

async function gptImageEdit(prompt, imagePath, size, retries = 3) {
  for (let a = 0; a <= retries; a++) {
    if (a > 0) { console.log(`  GPT 重试 ${a}/${retries}（${a * 10}s 后）...`); await sleep(a * 10000) }
    try {
      const boundary = '----FB' + Math.random().toString(36).slice(2)
      const imgBuf = fs.readFileSync(imagePath)
      const imgExt = path.extname(imagePath).toLowerCase()
      const mime = imgExt === '.jpg' || imgExt === '.jpeg' ? 'image/jpeg' : 'image/png'
      const imgName = path.basename(imagePath)

      const parts = []
      const af = (n, v) => parts.push(Buffer.from(`--${boundary}\r\nContent-Disposition: form-data; name="${n}"\r\n\r\n${v}\r\n`))
      const aff = (n, fn, buf) => { parts.push(Buffer.from(`--${boundary}\r\nContent-Disposition: form-data; name="${n}"; filename="${fn}"\r\nContent-Type: ${mime}\r\n\r\n`)); parts.push(buf); parts.push(Buffer.from('\r\n')) }

      af('model', cfg.gptImageModel || 'gpt-image-2')
      af('prompt', prompt)
      af('size', size)
      aff('image', imgName, imgBuf)
      parts.push(Buffer.from(`--${boundary}--\r\n`))
      const body = Buffer.concat(parts)

      const key = cfg.gptImageApiKey || ''
      const res = await api('POST', '/v1/images/edits', {
        'Authorization': 'Bearer ' + key,
        'Content-Type': 'multipart/form-data; boundary=' + boundary,
        'Content-Length': String(body.length),
      }, body)

      if (res.status === 200) {
        const j = res.json()
        if (j.data?.[0]?.b64_json) return { b64: Buffer.from(j.data[0].b64_json, 'base64') }
        if (j.data?.[0]?.url) return { url: j.data[0].url }
        throw new Error('GPT 未返回图片')
      }
      console.log(`  ⚠️  GPT ${res.status}: ${res.data.toString().substring(0, 100)}`)
      if (res.status >= 500 || res.status === 429) continue
    } catch (e) {
      console.log(`  ⚠️  网络: ${e.message}`)
    }
  }
  throw new Error('GPT edits 重试耗尽')
}

// ============================================================================
// 封面提示词构建
// ============================================================================

function buildEditPrompt(topicA, styleDesc, ratio) {
  const parts = topicA.split('·')
  const line1 = parts[0]
  const line2 = parts.length === 2 ? parts[1] : ''

  const textPart = line2
    ? `At the center of the image, prominently display the Chinese text "${line1}" on the first line and "${line2}" on the second line, in very large bold white characters with a thick golden metallic outline, like a movie poster title. The text should be the dominant visual element, taking up most of the frame.`
    : `At the center of the image, prominently display the Chinese text "${line1}" in very large bold white characters with a thick golden metallic outline, like a movie poster title. The text should be the dominant visual element, taking up most of the frame.`

  return `Create a vertical ${ratio} social media cover poster. Keep the EXACT same art style, color palette, lighting, atmosphere and aesthetic as the reference image: ${styleDesc} The composition should be tighter and more poster-like with a strong focal point. ${textPart}`
}

// ============================================================================
// OSS 上传
// ============================================================================

async function uploadToOSS(filePath, ossName) {
  const ossUpload = require(path.join(__dirname, 'oss-upload'))
  const { url } = await ossUpload.uploadFile(filePath, { name: ossName })
  return url
}

// ============================================================================
// 主流程
// ============================================================================

async function main() {
  const args = process.argv.slice(2)
  const mi = args.indexOf('--manifest')
  if (mi === -1 || !args[mi + 1]) {
    console.error('用法: node gen-covers.js --manifest <path>')
    process.exit(1)
  }
  const manifestPath = args[mi + 1]
  const manifest = JSON.parse(fs.readFileSync(manifestPath, 'utf-8'))
  const inputDir = path.dirname(manifestPath)
  const coversDir = path.join(inputDir, 'covers')
  fs.mkdirSync(coversDir, { recursive: true })

  const topicA = manifest.topicA
  if (!topicA) { console.error('manifest 缺少 topicA'); process.exit(1) }

  const firstItem = manifest.items[0]
  if (!firstItem || !firstItem.url) { console.error('没有可用的图片 URL'); process.exit(1) }

  // 风格描述 = imagePrompt 第一句
  const imagePrompt = firstItem.imagePrompt
  const styleDesc = imagePrompt.split('。')[0] + '。'

  console.log(`封面: ${topicA}`)
  console.log(`风格: ${styleDesc.substring(0, 80)}...`)

  // 下载参考图
  const refPath = path.join(coversDir, '_ref.png')
  console.log('下载参考图...')
  await download(firstItem.url, refPath)

  const dirName = path.basename(inputDir)
  const seqNum = dirName.split('_').pop()

  const sizes = [
    { label: '抖音', ratio: '9:16', size: '1088x1920', suffix: `cover_${String(seqNum).padStart(3, '0')}_抖音` },
    { label: '小红书', ratio: '3:4', size: '1152x1536', suffix: `cover_${String(seqNum).padStart(3, '0')}_小红书` },
  ]

  for (const { label, ratio, size, suffix } of sizes) {
    console.log(`\n生成 ${label} 封面 (${size})...`)

    // 按模板构建封面提示词（含文字）
    const editPrompt = buildEditPrompt(topicA, styleDesc, ratio)

    // GPT 一步出图
    const result = await gptImageEdit(editPrompt, refPath, size)

    const coverFinalPath = path.join(coversDir, `${suffix}.png`)
    if (result.b64) {
      fs.writeFileSync(coverFinalPath, result.b64)
    } else if (result.url) {
      console.log('下载生成图...')
      await download(result.url, coverFinalPath)
    }

    // OSS 上传
    const ossName = `covers/${dirName}/${suffix}.png`
    console.log('上传 OSS...')
    const url = await uploadToOSS(coverFinalPath, ossName)

    if (label === '抖音') manifest.coverUrl_抖音 = url
    else manifest.coverUrl_小红书 = url

    console.log(`  ✅ ${label}`)
  }

  // 回写 manifest
  manifest.pipeline = manifest.pipeline || {}
  manifest.pipeline.phases = manifest.pipeline.phases || {}
  manifest.pipeline.phases.cover = 'done'
  fs.writeFileSync(manifestPath, JSON.stringify(manifest, null, 2), 'utf-8')
  console.log('\n封面已写入 manifest')

  try { fs.unlinkSync(refPath) } catch (_) {}
}

main().catch(err => {
  console.error('封面生成失败:', err.message)
  process.exit(1)
})