/**
 * AI 批量生成知识检测题 —— 为没有 options 的知识生成 1 道四选一检测题
 * 执行: node src/scripts/generate-quiz.js [--dry] [--limit 10]
 *
 * 生成后字段: question / options[{text,isCorrect}] / answer(解析)
 * 幂等：已有 options 的知识自动跳过；单个失败不影响后续
 */
const mongoose = require('mongoose')
const path = require('path')
require('dotenv').config({ path: path.join(__dirname, '..', '..', '.env') })

const MONGODB_URI = process.env.MONGODB_URI || 'mongodb://127.0.0.1:27017/wdkj'

const args = process.argv.slice(2)
const DRY = args.includes('--dry')
const LIMIT_ARG = args.find(a => a.startsWith('--limit'))
const LIMIT = LIMIT_ARG ? parseInt(LIMIT_ARG.split('=')[1] || args[args.indexOf(LIMIT_ARG) + 1]) : 0

async function getModels() {
  const { AIModel } = require('../models')
  const active = await AIModel.getActiveModels()
  if (active && active.length) return active
  return [{
    name: 'env-model',
    apiUrl: process.env.OPENAI_API_URL || 'https://api.openai.com/v1/chat/completions',
    apiKey: process.env.OPENAI_API_KEY,
    modelId: process.env.OPENAI_MODEL || 'gpt-3.5-turbo'
  }]
}

function extractJson(text) {
  if (!text) return null
  let t = text.trim()
  const fence = t.match(/```(?:json)?\s*([\s\S]*?)```/)
  if (fence) t = fence[1].trim()
  const start = t.indexOf('{')
  const end = t.lastIndexOf('}')
  if (start === -1 || end === -1) return null
  try {
    return JSON.parse(t.slice(start, end + 1))
  } catch {
    return null
  }
}

function validate(q) {
  if (!q || typeof q.question !== 'string' || !q.question.trim()) return null
  if (!Array.isArray(q.options) || q.options.length < 3 || q.options.length > 5) return null
  const normalized = q.options.map(o => ({ text: String(o.text || '').trim(), isCorrect: !!o.isCorrect }))
  if (normalized.some(o => !o.text)) return null
  const correctCount = normalized.filter(o => o.isCorrect).length
  if (correctCount !== 1) return null
  return {
    question: q.question.trim(),
    options: normalized,
    answer: String(q.answer || '').trim()
  }
}

async function askAI(models, prompt) {
  for (const model of models) {
    try {
      const headers = { 'Content-Type': 'application/json' }
      if (model.apiKey && model.apiKey !== 'sk-dummy' && model.apiKey !== '***') {
        headers['Authorization'] = `Bearer ${model.apiKey}`
      }
      const controller = new AbortController()
      const timer = setTimeout(() => controller.abort(), 60000)
      let res
      try {
        res = await fetch(model.apiUrl, {
          method: 'POST',
          headers,
          body: JSON.stringify({
            model: model.modelId,
            messages: [
              { role: 'system', content: '你是知识测验出题官，只输出 JSON，不要输出任何其他文字。' },
              { role: 'user', content: prompt }
            ],
            temperature: 0.4,
            max_tokens: 600
          }),
          signal: controller.signal
        })
      } finally {
        clearTimeout(timer)
      }
      if (!res.ok) continue
      const data = await res.json()
      const content = data.choices?.[0]?.message?.content || ''
      return content
    } catch (e) {
      console.warn(`  模型 ${model.name} 失败: ${e.message}`)
    }
  }
  return null
}

async function main() {
  await mongoose.connect(MONGODB_URI)
  console.log('✅ 已连接 MongoDB')

  const { Knowledge } = require('../models')
  const models = await getModels()
  console.log(`🤖 出题模型: ${models.map(m => m.name).join(', ')}`)

  const query = {
    status: 'approved',
    $or: [{ options: { $exists: false } }, { options: { $size: 0 } }, { question: { $exists: false } }, { question: null }]
  }
  let items = await Knowledge.find(query).sort({ dim: 1, sortOrder: 1 }).lean()
  if (LIMIT > 0) items = items.slice(0, LIMIT)
  console.log(`📚 待出题知识: ${items.length} 条${DRY ? '（dry 模式，不写库）' : ''}\n`)

  let ok = 0
  let fail = 0
  for (const item of items) {
    const prompt = `基于以下 AI 知识内容，出一道四选一的中文检测题（考察对核心概念的理解，干扰项要有迷惑性但不歧义）。

标题：${item.title}
内容：${item.content.slice(0, 800)}

严格按此 JSON 格式输出：
{"question":"题干","options":[{"text":"选项A","isCorrect":true},{"text":"选项B","isCorrect":false},{"text":"选项C","isCorrect":false},{"text":"选项D","isCorrect":false}],"answer":"一句话解析为什么正确"}`

    console.log(`→ [dim${item.dim}] ${item.title}`)
    const raw = await askAI(models, prompt)
    const quiz = validate(extractJson(raw))

    if (!quiz) {
      console.log('  ✗ 生成或校验失败，跳过')
      fail++
    } else {
      console.log(`  ✓ ${quiz.question} (${quiz.options.length} 选项)`)
      if (!DRY) {
        await Knowledge.updateOne(
          { _id: item._id },
          { $set: { question: quiz.question, options: quiz.options, answer: quiz.answer } }
        )
      }
      ok++
    }
    await new Promise(r => setTimeout(r, 400))
  }

  console.log(`\n完成：成功 ${ok}，失败 ${fail}，共 ${items.length}`)
  await mongoose.disconnect()
}

main().catch(err => {
  console.error('执行失败:', err)
  process.exit(1)
})