import { NextResponse } from 'next/server';
import pool from '@/lib/db';
import { RowDataPacket } from 'mysql2';

interface StatusKuliah extends RowDataPacket {
  tahun_angkatan: number;
  status_kuliah: string;
  jumlah: number;
}

export async function GET(request: Request) {
  const { searchParams } = new URL(request.url);
  const tahunAngkatan = searchParams.get('tahun_angkatan');
  
  const connection = await pool.getConnection();
  
  try {
    let query = `
      SELECT m.tahun_angkatan, s.status_kuliah, COUNT(*) AS jumlah
      FROM mahasiswa m
      JOIN status_mahasiswa s ON m.nim = s.nim
      WHERE s.status_kuliah IN ('Lulus', 'Cuti', 'Aktif', 'DO')
    `;

    const params: any[] = [];

    if (tahunAngkatan && tahunAngkatan !== 'all') {
      query += ` AND m.tahun_angkatan = ?`;
      params.push(tahunAngkatan);
    }

    query += `
      GROUP BY m.tahun_angkatan, s.status_kuliah
      ORDER BY m.tahun_angkatan, s.status_kuliah
    `;

    const [results] = await connection.query<StatusKuliah[]>(query, params);

    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 status kuliah:', error);
    return NextResponse.json(
      { error: 'Failed to fetch status kuliah data' },
      { 
        status: 500,
        headers: {
          'Access-Control-Allow-Origin': '*',
          'Access-Control-Allow-Methods': 'GET, OPTIONS',
          'Access-Control-Allow-Headers': 'Content-Type, Authorization',
        },
      }
    );
  } finally {
    connection.release();
  }
}