// panda_v5.h
#pragma once

#ifdef PANDA_V5_EXPORTS
#define PANDA_API extern "C" __declspec(dllexport)
#else
#define PANDA_API extern "C" __declspec(dllimport)
#endif

// Connect to server, validate key, start heartbeat.
PANDA_API bool Validate(const char* service, const char* key);

// Returns the GetKey URL with auto-HWID appended.
PANDA_API const char* Get_Key(const char* service);

// Check if the session is still alive (heartbeat ok, not expired).
// Fails if the internal thread detects debugging or heartbeat drops.
PANDA_API bool IsValid();

// Graceful disconnect.
PANDA_API void Shutdown();

// Get the last error message string.
PANDA_API const char* PandaGetLastError();

using System;
using System.Runtime.InteropServices;

public class PandaSDK
{
    private const string DllName = "PandaLib_PUSL.dll";

    [DllImport(DllName, CallingConvention = CallingConvention.Cdecl, CharSet = CharSet.Ansi)]
    public static extern bool Validate(string service, string key);

    [DllImport(DllName, CallingConvention = CallingConvention.Cdecl, CharSet = CharSet.Ansi)]
    public static extern IntPtr Get_Key(string service);

    [DllImport(DllName, CallingConvention = CallingConvention.Cdecl)]
    public static extern bool IsValid();

    [DllImport(DllName, CallingConvention = CallingConvention.Cdecl)]
    public static extern void Shutdown();

    [DllImport(DllName, CallingConvention = CallingConvention.Cdecl, CharSet = CharSet.Ansi)]
    public static extern IntPtr PandaGetLastError();

    // Safety wraps for string pointers
    public static string GetKeyUrl(string service) {
        return Marshal.PtrToStringAnsi(Get_Key(service));
    }

    public static string GetLastError() {
        return Marshal.PtrToStringAnsi(PandaGetLastError());
    }
}

// Example C# Implementation:
class Program {
    static void Main() {
        string serviceId = "your_service_id";

        // 1. Give the user their GetKey URL
        Console.WriteLine("Get Key URL: " + PandaSDK.GetKeyUrl(serviceId));

        // 2. Prompt for key and Validate!
        Console.Write("Enter Key: ");
        string attempt = Console.ReadLine();

        if (PandaSDK.Validate(serviceId, attempt)) {
            Console.WriteLine("Authenticated!");

            // 3. Periodically ensure validation holds over time
            if (!PandaSDK.IsValid()) {
                Console.WriteLine("Session expired, heartbeat failed, or debugger detected.");
                Environment.Exit(0);
            }
        } else {
            Console.WriteLine("Failed: " + PandaSDK.GetLastError());
        }
    }
}