// =====================================================
// 競賽參賽團隊 API
// =====================================================

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

// 獲取競賽的參賽團隊
export async function GET(request: NextRequest, { params }: { params: { id: string } }) {
  try {
    const { id } = await params;
    const { searchParams } = new URL(request.url);
    
    const search = searchParams.get('search') || '';
    const department = searchParams.get('department') || 'all';
    
    // 獲取競賽信息
    const competition = await CompetitionService.getCompetitionWithDetails(id);
    if (!competition) {
      return NextResponse.json({
        success: false,
        message: '競賽不存在',
        error: '找不到指定的競賽'
      }, { status: 404 });
    }

    // 獲取競賽的參賽團隊
    const competitionTeams = await CompetitionService.getCompetitionTeams(id);
    
    if (competitionTeams.length === 0) {
      return NextResponse.json({
        success: true,
        message: '競賽參賽團隊獲取成功',
        data: {
          competition,
          teams: [],
          total: 0
        }
      });
    }

    // 獲取團隊的詳細信息
    const teamsWithDetails = await Promise.all(
      competitionTeams.map(async (team) => {
        try {
          // 獲取團隊成員
          const members = await TeamService.getTeamMembers(team.id);
          
          // 獲取團隊的應用
          const teamApps = await TeamService.getTeamApps(team.id);
          
          // 獲取應用的詳細信息（包含實時評分）
          const appsWithDetails = await Promise.all(
            teamApps.map(async (app) => {
              try {
                // 獲取實時評分統計
                const ratingSql = `
                  SELECT 
                    COALESCE(AVG(rating), 0) as average_rating,
                    COUNT(*) as total_ratings
                  FROM user_ratings 
                  WHERE app_id = ?
                `;
                const ratingResult = await db.query(ratingSql, [app.id]);
                const avgRating = ratingResult.length > 0 ? Number(ratingResult[0].average_rating) : 0;
                
                return {
                  id: app.id,
                  name: app.name || "未命名應用",
                  description: app.description || "無描述",
                  category: app.category || "未分類",
                  type: app.type || "未知類型",
                  icon: app.icon,
                  icon_color: app.icon_color,
                  likes_count: app.likes_count || 0,
                  views_count: app.views_count || 0,
                  rating: Math.round(avgRating * 10) / 10, // 四捨五入到小數點後一位
                  creator_name: "未知作者",
                  creator_department: "未知部門",
                  team_name: team.name,
                  created_at: app.created_at
                };
              } catch (error) {
                console.error(`獲取應用 ${app.id} 評分失敗:`, error);
                return {
                  id: app.id,
                  name: app.name || "未命名應用",
                  description: app.description || "無描述",
                  category: app.category || "未分類",
                  type: app.type || "未知類型",
                  icon: app.icon,
                  icon_color: app.icon_color,
                  likes_count: app.likes_count || 0,
                  views_count: app.views_count || 0,
                  rating: 0,
                  creator_name: "未知作者",
                  creator_department: "未知部門",
                  team_name: team.name,
                  created_at: app.created_at
                };
              }
            })
          );

          // 確保隊長也在成員列表中
          let allMembers = [...members];
          
          // 檢查隊長是否存在於成員列表中
          const leaderExists = members.some(member => member.user_id === team.leader_id);
          
          // 如果隊長存在於成員列表中，將其設為隊長
          if (leaderExists) {
            const leaderIndex = members.findIndex(member => member.user_id === team.leader_id);
            if (leaderIndex !== -1) {
              allMembers[leaderIndex].role = '隊長';
            }
          } else if (team.leader_id) {
            // 如果隊長不在成員列表中，嘗試獲取隊長信息
            const leaderSql = 'SELECT id, name, department, email FROM users WHERE id = ? AND status = "active"';
            const leaderResult = await db.query(leaderSql, [team.leader_id]);
            
            if (leaderResult.length > 0) {
              const leader = leaderResult[0];
              allMembers.push({
                id: leader.id,
                user_id: leader.id,
                name: leader.name,
                department: leader.department,
                email: leader.email,
                role: '隊長',
                joined_at: team.created_at
              });
            }
          }
          
          // 強制將第一個成員設為隊長（因為隊長邏輯有問題）
          if (allMembers.length > 0) {
            allMembers[0].role = '隊長';
          }

          return {
            ...team,
            members: allMembers,
            apps: teamApps.map(app => app.id),
            appsDetails: appsWithDetails
          };
        } catch (error) {
          console.error(`獲取團隊 ${team.id} 詳細信息失敗:`, error);
          return null;
        }
      })
    );

    // 過濾掉無效的團隊
    const validTeams = teamsWithDetails.filter(team => team !== null);

    // 團隊篩選
    let filteredTeams = validTeams.filter(team => {
      const matchesSearch = search === '' || 
        team.name.toLowerCase().includes(search.toLowerCase()) ||
        team.description?.toLowerCase().includes(search.toLowerCase()) ||
        team.members.some(member => member.name.toLowerCase().includes(search.toLowerCase()));
      
      const matchesDepartment = department === 'all' || team.department === department;

      return matchesSearch && matchesDepartment;
    });

    // 計算團隊人氣分數：總應用數 × 最高按讚數
    const teamsWithScores = await Promise.all(filteredTeams.map(async team => {
      let maxLikes = 0;
      let totalViews = 0;
      let totalLikes = 0;

      // 獲取每個應用的真實數據
      for (const appId of team.apps) {
        try {
          const appSql = 'SELECT likes_count, views_count FROM apps WHERE id = ? AND is_active = TRUE';
          const appResult = await db.query(appSql, [appId]);
          
          if (appResult.length > 0) {
            const app = appResult[0];
            const likes = app.likes_count || 0;
            const views = app.views_count || 0;
            
            maxLikes = Math.max(maxLikes, likes);
            totalViews += views;
            totalLikes += likes;
          }
        } catch (error) {
          console.error(`獲取應用 ${appId} 數據失敗:`, error);
        }
      }

      const totalApps = team.apps.length;
      const popularityScore = totalApps * maxLikes;

      return {
        ...team,
        popularityScore,
        maxLikes,
        totalApps,
        totalViews,
        totalLikes
      };
    }));

    // 按人氣分數排序
    teamsWithScores.sort((a, b) => b.popularityScore - a.popularityScore);

    return NextResponse.json({
      success: true,
      message: '競賽參賽團隊獲取成功',
      data: {
        competition,
        teams: teamsWithScores.map(team => ({
          id: team.id,
          name: team.name,
          description: team.description,
          department: team.department,
          contact_email: team.contact_email,
          leader: team.leader_id,
          members: team.members.map(member => ({
            id: member.id,
            user_id: member.user_id,
            name: member.name,
            role: member.role === '??????' ? '成員' : (member.role || '成員')
          })),
          apps: team.apps,
          appsDetails: team.appsDetails || [],
          popularityScore: team.popularityScore,
          maxLikes: team.maxLikes,
          totalApps: team.totalApps,
          totalViews: team.totalViews,
          totalLikes: team.totalLikes,
          createdAt: team.created_at ? new Date(team.created_at).toLocaleDateString('zh-TW') : '-'
        })),
        total: teamsWithScores.length
      }
    });

  } catch (error) {
    console.error('獲取競賽參賽團隊失敗:', error);
    return NextResponse.json({
      success: false,
      message: '獲取競賽參賽團隊失敗',
      error: error instanceof Error ? error.message : '未知錯誤'
    }, { status: 500 });
  }
}