AdminService.java

import java.io.BufferedReader;
import java.sql.*;

public class AdminService {
    
    public static void menuAdmin(Connection conn, BufferedReader input) {
        try {
            boolean isAdmin = true;
            while (isAdmin) {
                System.out.println("\n=== PANEL ADMIN GAMECENTRE ===");
                System.out.println("1. Lihat Peminjaman Aktif (Semua User)");
                System.out.println("2. Proses Pengembalian (Return & Restock)");
                System.out.println("3. Batalkan Peminjaman (Force Cancel & Restock)");
                System.out.println("4. Kirim Reminder ke User (Log Notifikasi)");
                System.out.println("0. Logout");
                System.out.print("Pilihan: ");
                
                String choice = input.readLine();
                switch (choice) {
                    case "1": showActiveLoans(conn); break;
                    case "2": updateStatusTrx(conn, input, "returned"); break;
                    case "3": updateStatusTrx(conn, input, "cancelled"); break;
                    case "4": sendReminder(conn, input); break;
                    case "0": isAdmin = false; break;
                    default: System.out.println("Menu tidak tersedia.");
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    // Menampilkan semua peminjaman aktif
    private static void showActiveLoans(Connection conn) throws SQLException {
        String sql = "SELECT t.trx_id, u.username, g.title, t.borrow_date " +
                     "FROM transactions t " +
                     "JOIN users u ON t.user_id = u.user_id " +
                     "JOIN games g ON t.game_id = g.game_id " +
                     "WHERE t.status = 'active'";
        PreparedStatement ps = conn.prepareStatement(sql);
        ResultSet rs = ps.executeQuery();

        System.out.println("\n--- LIST SEMUA PEMINJAMAN AKTIF ---");
        boolean adaData = false;
        while (rs.next()) {
            System.out.printf("ID Trx: %d | User: %s | Game: %s | Tgl: %s\n",
                    rs.getInt("trx_id"), rs.getString("username"),
                    rs.getString("title"), rs.getDate("borrow_date"));
            adaData = true;
        }
        if (!adaData) System.out.println("Tidak ada peminjaman aktif.");
    }

    private static void updateStatusTrx(Connection conn, BufferedReader input, String newStatus) throws Exception {
        System.out.print("Masukkan ID Transaksi: ");
        int trxId = Integer.parseInt(input.readLine());

        String checkSql = "SELECT game_id, status FROM transactions WHERE trx_id = ?";
        PreparedStatement ps = conn.prepareStatement(checkSql);
        ps.setInt(1, trxId);
        ResultSet rs = ps.executeQuery();

        if (rs.next()) {
            int gameId = rs.getInt("game_id");
            String currentStatus = rs.getString("status");

            if (currentStatus.equals("active")) {
                String updateTrx = "UPDATE transactions SET status = ? WHERE trx_id = ?";
                ps = conn.prepareStatement(updateTrx);
                ps.setString(1, newStatus);
                ps.setInt(2, trxId);
                ps.executeUpdate();

                String updateStock = "UPDATE games SET stock = stock + 1 WHERE game_id = ?";
                ps = conn.prepareStatement(updateStock);
                ps.setInt(1, gameId);
                ps.executeUpdate();

                System.out.println("SUKSES: Status '" + newStatus + "' & Stok dikembalikan.");
            } else {
                System.out.println("GAGAL: Transaksi sudah tidak aktif.");
            }
        } else {
            System.out.println("ID Transaksi tidak ditemukan.");
        }
    }

    private static void sendReminder(Connection conn, BufferedReader input) throws Exception {
        System.out.print("Masukkan ID Peminjaman target: ");
        int trxId = Integer.parseInt(input.readLine());
        
        // 1. Cari tahu siapa pemilik transaksi ini dan apa gamenya
        String sql = "SELECT t.user_id, u.username, g.title FROM transactions t " +
                     "JOIN users u ON t.user_id = u.user_id " +
                     "JOIN games g ON t.game_id = g.game_id " +
                     "WHERE t.trx_id = ? AND t.status = 'active'";
        
        PreparedStatement ps = conn.prepareStatement(sql);
        ps.setInt(1, trxId);
        ResultSet rs = ps.executeQuery();

        if (rs.next()) {
            int targetUserId = rs.getInt("user_id");
            String username = rs.getString("username");
            String gameTitle = rs.getString("title");
            
            // 2. Buat Pesan Notifikasi
            String message = "Halo " + username + ", Peminjaman anda akan segera berakhir, mohon kembalikan: " + gameTitle;
            
            // 3. Masukkan ke tabel notifications
            String insertNotif = "INSERT INTO notifications (user_id, message) VALUES (?, ?)";
            ps = conn.prepareStatement(insertNotif);
            ps.setInt(1, targetUserId);
            ps.setString(2, message);
            ps.executeUpdate();

            System.out.println("SUKSES: Notifikasi telah dikirim ke Inbox User " + username);
        } else {
            System.out.println("Gagal: Transaksi tidak ditemukan atau sudah selesai.");
        }
    }
}