using System;
using System.Runtime.InteropServices;
using UnityEngine;

public class UniQuake: MonoBehaviour
{
    private const string DllName = "uniquake.dll";
    private const int MemSize = 0x4000000;  // 64 MB of heap space

    private QuakeParms quakeParms;
    private SysCalls sysCalls;
    private ModCalls modCalls;

    private bool initialized = false;

    void Start()
    {
        string[] arguments = 
        {
            "",
            "-window",
            "-width", "1440",
            "-height", "1080",
            "+developer", "1",
        };

        quakeParms = new QuakeParms
        {
            baseDir = Application.persistentDataPath,
            cacheDir = null,
        };
        quakeParms.SetArguments(arguments);
        quakeParms.AllocateMemory(MemSize);

        sysCalls = new SysCalls(this);
        modCalls = new ModCalls(this);

        try
        {
            UniQuake_Init(quakeParms, sysCalls.ToIntPtr, modCalls.ToIntPtr);
            initialized = true;
        }
        catch (QuakeException ex)
        {
            if (ex.ExitCode == 0)
                Debug.Log(ex.Message);
            else
                Debug.LogException(ex);

            Shutdown();
        }
        catch (Exception ex)
        {
            Debug.LogException(ex);
            Shutdown();
        }
    }

    void Update()
    {
        if (!initialized)
            return;

        try
        {
            UniQuake_Update(Time.deltaTime);
        }
        catch (QuakeException ex)
        {
            if (ex.ExitCode == 0)
                Debug.Log(ex.Message);
            else
                Debug.LogException(ex);

            Shutdown();
        }
        catch (Exception ex)
        {
            Debug.LogException(ex);
            Shutdown();
        }
    }

    private void Shutdown()
    {
        initialized = false;
        UniQuake_Shutdown();
        Destroy(this);
    }

    private void OnDestroy()
    {
        modCalls.Destroy();
        sysCalls.Destroy();

        if (quakeParms != null)
        {
            quakeParms.Destroy();
            quakeParms = null;
        }
    }

    [DllImport(DllName, CallingConvention = CallingConvention.Cdecl)]
    private static extern void UniQuake_Init(QuakeParms parms, IntPtr sysCalls, IntPtr modCalls);

    [DllImport(DllName, CallingConvention = CallingConvention.Cdecl)]
    private static extern void UniQuake_Update(float deltaTime);

    [DllImport(DllName, CallingConvention = CallingConvention.Cdecl)]
    private static extern void UniQuake_Shutdown();
}

public class QuakeException: Exception
{
    public int ExitCode { get; }

    public QuakeException(string message, int exitCode = 0)
        : base(message)
    {
        ExitCode = exitCode;
    }
}