import { NextResponse } from 'next/server';
import supabase from '@/lib/db';

interface MahasiswaTotal {
  total_mahasiswa: number;
  mahasiswa_aktif: number;
  total_lulus: number;
  pria_lulus: number;
  wanita_lulus: number;
  total_berprestasi: number;
  prestasi_akademik: number;
  prestasi_non_akademik: number;
  ipk_rata_rata_aktif: number;
  ipk_rata_rata_lulus: number;
  total_mahasiswa_aktif_lulus: number;
}

interface IPKData {
  nim: string;
  mahasiswa: {
    ipk: number;
  };
}

// Fungsi untuk menangani preflight request (OPTIONS)
export async function OPTIONS() {
  return new NextResponse(null, {
    status: 200,
    headers: {
      'Access-Control-Allow-Origin': '*',
      'Access-Control-Allow-Methods': 'GET, OPTIONS',
      'Access-Control-Allow-Headers': 'Content-Type, Authorization',
      'Access-Control-Max-Age': '86400', // 24 jam
    },
  });
}

export async function GET() {
  try {
    // Get total mahasiswa
    const { count: totalMahasiswa } = await supabase
      .from('mahasiswa')
      .select('*', { count: 'exact', head: true });

    // Get mahasiswa aktif
    const { count: mahasiswaAktif } = await supabase
      .from('mahasiswa')
      .select('*', { count: 'exact', head: true })
      .eq('status_kuliah', 'Aktif');

    // Get total lulus
    const { count: totalLulus } = await supabase
      .from('mahasiswa')
      .select('*', { count: 'exact', head: true })
      .eq('status_kuliah', 'Lulus');

    // Get pria lulus
    const { count: priaLulus } = await supabase
      .from('mahasiswa')
      .select('*', { count: 'exact', head: true })
      .eq('status_kuliah', 'Lulus')
      .eq('jk', 'Pria');

    // Get wanita lulus
    const { count: wanitaLulus } = await supabase
      .from('mahasiswa')
      .select('*', { count: 'exact', head: true })
      .eq('status_kuliah', 'Lulus')
      .eq('jk', 'Wanita');

    // Get total berprestasi
    const { count: totalBerprestasi } = await supabase
      .from('prestasi_mahasiswa')
      .select('*', { count: 'exact', head: true });

    // Get prestasi akademik
    const { count: prestasiAkademik } = await supabase
      .from('prestasi_mahasiswa')
      .select('*', { count: 'exact', head: true })
      .eq('jenis_prestasi', 'Akademik');

    // Get prestasi non-akademik
    const { count: prestasiNonAkademik } = await supabase
      .from('prestasi_mahasiswa')
      .select('*', { count: 'exact', head: true })
      .eq('jenis_prestasi', 'Non-Akademik');

    // Get total mahasiswa aktif + lulus
    const { count: totalMahasiswaAktifLulus } = await supabase
      .from('mahasiswa')
      .select('*', { count: 'exact', head: true })
      .in('status_kuliah', ['Aktif', 'Lulus']);

    // Get IPK rata-rata aktif
    const { data: ipkAktifData } = await supabase
      .from('mahasiswa')
      .select('ipk')
      .eq('status_kuliah', 'Aktif')
      .not('ipk', 'is', null);

    const ipkRataRataAktif = ipkAktifData && ipkAktifData.length > 0
      ? Math.round((ipkAktifData.reduce((sum, item: any) => sum + (item.ipk || 0), 0) / ipkAktifData.length) * 100) / 100
      : 0;

    // Get IPK rata-rata lulus
    const { data: ipkLulusData } = await supabase
      .from('mahasiswa')
      .select('ipk')
      .eq('status_kuliah', 'Lulus')
      .not('ipk', 'is', null);

    const ipkRataRataLulus = ipkLulusData && ipkLulusData.length > 0
      ? Math.round((ipkLulusData.reduce((sum, item: any) => sum + (item.ipk || 0), 0) / ipkLulusData.length) * 100) / 100
      : 0;

    const results: MahasiswaTotal = {
      total_mahasiswa: totalMahasiswa || 0,
      mahasiswa_aktif: mahasiswaAktif || 0,
      total_lulus: totalLulus || 0,
      pria_lulus: priaLulus || 0,
      wanita_lulus: wanitaLulus || 0,
      total_berprestasi: totalBerprestasi || 0,
      prestasi_akademik: prestasiAkademik || 0,
      prestasi_non_akademik: prestasiNonAkademik || 0,
      ipk_rata_rata_aktif: ipkRataRataAktif,
      ipk_rata_rata_lulus: ipkRataRataLulus,
      total_mahasiswa_aktif_lulus: totalMahasiswaAktifLulus || 0,
    };

    // Menambahkan header cache dan CORS
    return NextResponse.json(results, {
      headers: {
        'Cache-Control': 'public, max-age=60, stale-while-revalidate=30',
        'Access-Control-Allow-Origin': '*',
        'Access-Control-Allow-Methods': 'GET, OPTIONS',
        'Access-Control-Allow-Headers': 'Content-Type, Authorization',
      },
    });
  } catch (error) {
    console.error('Error fetching total mahasiswa:', error);
    return NextResponse.json(
      { error: 'Failed to fetch total mahasiswa' },
      { 
        status: 500,
        headers: {
          'Access-Control-Allow-Origin': '*',
          'Access-Control-Allow-Methods': 'GET, OPTIONS',
          'Access-Control-Allow-Headers': 'Content-Type, Authorization',
        },
      }
    );
  }
}