// =====================================================
// 競賽統計 API
// =====================================================

import { NextRequest, NextResponse } from 'next/server';
import { CompetitionService } from '@/lib/services/database-service';

// 獲取競賽統計數據
export async function GET(request: NextRequest) {
  try {
    const competitions = await CompetitionService.getAllCompetitions();
    
    // 動態計算每個競賽的狀態
    const now = new Date();
    const competitionsWithCalculatedStatus = competitions.map(competition => {
      const startDate = new Date(competition.start_date);
      const endDate = new Date(competition.end_date);
      
      let calculatedStatus = competition.status;
      
      // 確保日期比較的準確性，使用 UTC 時間避免時區問題
      const nowUTC = new Date(now.getTime() + now.getTimezoneOffset() * 60000);
      const startDateUTC = new Date(startDate.getTime() + startDate.getTimezoneOffset() * 60000);
      const endDateUTC = new Date(endDate.getTime() + endDate.getTimezoneOffset() * 60000);
      
      // 根據實際日期計算狀態
      if (nowUTC < startDateUTC) {
        calculatedStatus = 'upcoming'; // 即將開始
      } else if (nowUTC >= startDateUTC && nowUTC <= endDateUTC) {
        calculatedStatus = 'active'; // 進行中
      } else if (nowUTC > endDateUTC) {
        calculatedStatus = 'completed'; // 已完成
      }
      
      return {
        ...competition,
        status: calculatedStatus
      };
    });
    
    // 計算統計數據
    const stats = {
      total: competitionsWithCalculatedStatus.length,
      upcoming: competitionsWithCalculatedStatus.filter(c => c.status === 'upcoming').length,
      active: competitionsWithCalculatedStatus.filter(c => c.status === 'active' || c.status === 'ongoing').length,
      ongoing: competitionsWithCalculatedStatus.filter(c => c.status === 'ongoing').length,
      judging: competitionsWithCalculatedStatus.filter(c => c.status === 'judging').length,
      completed: competitionsWithCalculatedStatus.filter(c => c.status === 'completed').length,
      individual: competitionsWithCalculatedStatus.filter(c => c.type === 'individual').length,
      team: competitionsWithCalculatedStatus.filter(c => c.type === 'team').length,
      mixed: competitionsWithCalculatedStatus.filter(c => c.type === 'mixed').length,
      proposal: competitionsWithCalculatedStatus.filter(c => c.type === 'proposal').length,
      currentYear: competitionsWithCalculatedStatus.filter(c => c.year === new Date().getFullYear()).length,
      thisMonth: competitionsWithCalculatedStatus.filter(c => 
        c.year === new Date().getFullYear() && 
        c.month === new Date().getMonth() + 1
      ).length
    };

    return NextResponse.json({
      success: true,
      message: '競賽統計獲取成功',
      data: stats
    });

  } catch (error) {
    console.error('獲取競賽統計失敗:', error);
    return NextResponse.json({
      success: false,
      message: '獲取競賽統計失敗',
      error: error instanceof Error ? error.message : '未知錯誤'
    }, { status: 500 });
  }
}