import { query, queryOne, insertReturning, execute } from '../../utils/db'
import { callOpenAI } from '../../utils/openai'
import { getCurrentUserId } from '../../utils/user'

interface GenerateBody {
  businessId: number
  reportYear: number
  reportWeek: number
  weekStartDate: string
  weekEndDate: string
}

/**
 * 사업 주간보고 취합 생성
 * POST /api/business-report/generate
 */
export default defineEventHandler(async (event) => {
  const body = await readBody<GenerateBody>(event)
  const userId = await getCurrentUserId(event)
  
  if (!body.businessId || !body.reportYear || !body.reportWeek) {
    throw createError({ statusCode: 400, message: '필수 파라미터가 누락되었습니다.' })
  }
  
  // 기존 보고서 확인
  const existing = await queryOne(`
    SELECT * FROM wr_business_weekly_report 
    WHERE business_id = $1 AND report_year = $2 AND report_week = $3
  `, [body.businessId, body.reportYear, body.reportWeek])
  
  // 사업에 속한 프로젝트 목록
  const projects = await query(`
    SELECT project_id, project_name FROM wr_project_info WHERE business_id = $1
  `, [body.businessId])
  
  if (projects.length === 0) {
    throw createError({ statusCode: 400, message: '해당 사업에 속한 프로젝트가 없습니다.' })
  }
  
  const projectIds = projects.map((p: any) => p.project_id)
  
  // 해당 주차 주간보고 실적 조회
  const tasks = await query(`
    SELECT 
      t.task_description,
      t.task_type,
      t.task_hours,
      p.project_name,
      e.employee_name
    FROM wr_weekly_report_task t
    JOIN wr_weekly_report r ON t.report_id = r.report_id
    JOIN wr_project_info p ON t.project_id = p.project_id
    JOIN wr_employee_info e ON r.author_id = e.employee_id
    WHERE t.project_id = ANY($1)
      AND r.report_year = $2
      AND r.report_week = $3
    ORDER BY p.project_name, e.employee_name
  `, [projectIds, body.reportYear, body.reportWeek])
  
  if (tasks.length === 0) {
    throw createError({ statusCode: 400, message: '해당 주차에 등록된 실적이 없습니다.' })
  }
  
  // 프로젝트별로 그룹화
  const groupedTasks: Record<string, any[]> = {}
  for (const task of tasks) {
    const key = task.project_name
    if (!groupedTasks[key]) groupedTasks[key] = []
    groupedTasks[key].push(task)
  }
  
  // OpenAI 프롬프트 생성
  let taskText = ''
  for (const [projectName, projectTasks] of Object.entries(groupedTasks)) {
    taskText += `\n[${projectName}]\n`
    for (const t of projectTasks) {
      taskText += `- ${t.employee_name}: ${t.task_description}\n`
    }
  }
  
  const prompt = `다음은 사업의 주간 실적입니다. 이를 경영진에게 보고하기 위한 간결한 요약문을 작성해주세요.

${taskText}

요약 작성 가이드:
1. 프로젝트별로 구분하여 작성
2. 핵심 성과와 진행 상황 중심
3. 한국어로 작성
4. 불릿 포인트 형식
5. 200자 이내로 간결하게

JSON 형식으로 응답해주세요:
{
  "summary": "요약 내용"
}`

  let aiSummary = ''
  try {
    const response = await callOpenAI([
      { role: 'system', content: '당신은 프로젝트 관리 전문가입니다. 주간 실적을 간결하게 요약합니다.' },
      { role: 'user', content: prompt }
    ], true)
    
    const parsed = JSON.parse(response)
    aiSummary = parsed.summary || response
  } catch (e) {
    console.error('OpenAI error:', e)
    aiSummary = '(AI 요약 생성 실패)'
  }
  
  let result
  if (existing) {
    // 업데이트
    await execute(`
      UPDATE wr_business_weekly_report SET
        ai_summary = $1,
        updated_at = NOW()
      WHERE business_report_id = $2
    `, [aiSummary, existing.business_report_id])
    result = { ...existing, ai_summary: aiSummary }
  } else {
    // 신규 생성
    result = await insertReturning(`
      INSERT INTO wr_business_weekly_report (
        business_id, report_year, report_week, week_start_date, week_end_date,
        ai_summary, status, created_by
      ) VALUES ($1, $2, $3, $4, $5, $6, 'draft', $7)
      RETURNING *
    `, [
      body.businessId,
      body.reportYear,
      body.reportWeek,
      body.weekStartDate,
      body.weekEndDate,
      aiSummary,
      userId
    ])
  }
  
  return {
    success: true,
    report: {
      businessReportId: result.business_report_id,
      aiSummary: result.ai_summary || aiSummary,
      status: result.status || 'draft'
    }
  }
})