import { query } from '../../utils/db'

/**
 * 대시보드 통계 API
 * GET /api/dashboard/stats
 * 
 * - 인원별 이번 주 실적/차주 계획 시간
 * - 프로젝트별 투입 인원/시간
 * - 제출 현황
 */
export default defineEventHandler(async (event) => {
  const userId = getCookie(event, 'user_id')
  if (!userId) {
    throw createError({ statusCode: 401, message: '로그인이 필요합니다.' })
  }
  
  const q = getQuery(event)
  const year = parseInt(q.year as string) || new Date().getFullYear()
  const week = parseInt(q.week as string) || getISOWeek(new Date())
  
  // 1. 인원별 실적/계획 현황
  const employeeStats = await query<any>(`
    SELECT 
      e.employee_id,
      e.employee_name,
      e.company,
      r.report_id,
      r.report_status,
      COALESCE(SUM(CASE WHEN t.task_type = 'WORK' THEN t.task_hours ELSE 0 END), 0) as work_hours,
      COALESCE(SUM(CASE WHEN t.task_type = 'PLAN' THEN t.task_hours ELSE 0 END), 0) as plan_hours,
      COUNT(DISTINCT CASE WHEN t.task_type = 'WORK' THEN t.project_id END) as work_project_count,
      COUNT(DISTINCT CASE WHEN t.task_type = 'PLAN' THEN t.project_id END) as plan_project_count
    FROM wr_employee_info e
    LEFT JOIN wr_weekly_report r ON e.employee_id = r.author_id 
      AND r.report_year = $1 AND r.report_week = $2
    LEFT JOIN wr_weekly_report_task t ON r.report_id = t.report_id
    WHERE e.is_active = true
    GROUP BY e.employee_id, e.employee_name, e.company, r.report_id, r.report_status
    ORDER BY work_hours DESC, e.employee_name
  `, [year, week])
  
  // 2. 프로젝트별 투입 현황
  const projectStats = await query<any>(`
    SELECT 
      p.project_id,
      p.project_code,
      p.project_name,
      COUNT(DISTINCT r.author_id) as member_count,
      COALESCE(SUM(CASE WHEN t.task_type = 'WORK' THEN t.task_hours ELSE 0 END), 0) as work_hours,
      COALESCE(SUM(CASE WHEN t.task_type = 'PLAN' THEN t.task_hours ELSE 0 END), 0) as plan_hours,
      ARRAY_AGG(DISTINCT e.employee_name) as members
    FROM wr_project_info p
    JOIN wr_weekly_report_task t ON p.project_id = t.project_id
    JOIN wr_weekly_report r ON t.report_id = r.report_id
      AND r.report_year = $1 AND r.report_week = $2
    JOIN wr_employee_info e ON r.author_id = e.employee_id
    WHERE p.project_status = 'IN_PROGRESS'
    GROUP BY p.project_id, p.project_code, p.project_name
    ORDER BY work_hours DESC
  `, [year, week])
  
  // 3. 전체 요약
  const activeEmployees = employeeStats.length
  const submittedCount = employeeStats.filter((e: any) => e.report_id).length
  const totalWorkHours = employeeStats.reduce((sum: number, e: any) => sum + parseFloat(e.work_hours || 0), 0)
  const totalPlanHours = employeeStats.reduce((sum: number, e: any) => sum + parseFloat(e.plan_hours || 0), 0)
  
  return {
    year,
    week,
    summary: {
      activeEmployees,
      submittedCount,
      notSubmittedCount: activeEmployees - submittedCount,
      totalWorkHours,
      totalPlanHours,
      projectCount: projectStats.length
    },
    employees: employeeStats.map((e: any) => ({
      employeeId: e.employee_id,
      employeeName: e.employee_name,
      company: e.company,
      reportId: e.report_id,
      reportStatus: e.report_status,
      workHours: parseFloat(e.work_hours) || 0,
      planHours: parseFloat(e.plan_hours) || 0,
      workProjectCount: parseInt(e.work_project_count) || 0,
      planProjectCount: parseInt(e.plan_project_count) || 0,
      isSubmitted: !!e.report_id
    })),
    projects: projectStats.map((p: any) => ({
      projectId: p.project_id,
      projectCode: p.project_code,
      projectName: p.project_name,
      memberCount: parseInt(p.member_count) || 0,
      workHours: parseFloat(p.work_hours) || 0,
      planHours: parseFloat(p.plan_hours) || 0,
      members: p.members || []
    }))
  }
})

function getISOWeek(date: Date): number {
  const target = new Date(date)
  target.setHours(0, 0, 0, 0)
  const thursday = new Date(target)
  thursday.setDate(target.getDate() - ((target.getDay() + 6) % 7) + 3)
  const year = thursday.getFullYear()
  const firstThursday = new Date(year, 0, 4)
  firstThursday.setDate(firstThursday.getDate() - ((firstThursday.getDay() + 6) % 7) + 3)
  return Math.ceil((thursday.getTime() - firstThursday.getTime()) / (7 * 24 * 60 * 60 * 1000)) + 1
}