import { NextResponse } from 'next/server';
import pool from '@/lib/db';
import bcrypt from 'bcryptjs';

export async function POST(request: Request) {
  let connection;
  try {
    const { username, nim, password } = await request.json();

    // Validate input
    if (!username || !nim || !password) {
      return NextResponse.json(
        { error: 'Semua field harus diisi' },
        { status: 400 }
      );
    }

    // Validate NIM format (11 characters)
    if (nim.length !== 11) {
      return NextResponse.json(
        { error: 'NIM harus 11 karakter' },
        { status: 400 }
      );
    }

    // Get connection from pool
    connection = await pool.getConnection();

    // Check if NIM exists in mahasiswa table
    const [mahasiswa]: any = await connection.execute(
      'SELECT * FROM mahasiswa WHERE nim = ?',
      [nim]
    );

    if (mahasiswa.length === 0) {
      connection.release();
      return NextResponse.json(
        { error: 'NIM tidak terdaftar sebagai mahasiswa' },
        { status: 400 }
      );
    }

    // Check if NIM already exists in user table
    const [existingUsers]: any = await connection.execute(
      'SELECT * FROM user WHERE nim = ?',
      [nim]
    );

    if (existingUsers.length > 0) {
      connection.release();
      return NextResponse.json(
        { error: 'NIM sudah terdaftar sebagai pengguna' },
        { status: 400 }
      );
    }

    // Hash password
    const hashedPassword = await bcrypt.hash(password, 10);

    // Insert new user
    await connection.execute(
      'INSERT INTO user (nim, username, password, role, created_at, updated_at) VALUES (?, ?, ?, ?, NOW(), NOW())',
      [nim, username, hashedPassword, 'mahasiswa']
    );

    connection.release();

    return NextResponse.json(
      { message: 'Registrasi berhasil' },
      { status: 201 }
    );
  } catch (error) {
    if (connection) {
      connection.release();
    }
    
    console.error('Registration error:', error);
    return NextResponse.json(
      { error: 'Terjadi kesalahan saat registrasi' },
      { status: 500 }
    );
  }
}