#include <main.h>

#include <Core/Application/ApplicationManager.h>
#include <Core/Common/EnumUtils.h>
#include <Core/HAL/Display/Display.h>
#include <Core/HAL/Event/SystemEvent.h>
#include <Core/HAL/Filesystem/Filesystem.h>
#include <Core/JulietInit.h>
#include <Core/Logging/LogManager.h>
#include <Core/Logging/LogTypes.h>
#include <Graphics/Graphics.h>
#include <Graphics/GraphicsConfig.h>
#include <Graphics/GraphicsPipeline.h>
#include <Graphics/RenderPass.h>

#include <Core/Common/String.h>
#include <Core/Memory/Utils.h>
#include <cstdlib>

// TODO : Replace with message box from framework + call main and not winmain + subsystem
// TODO : Think how to do the draw pipeline.
// Ex: Expose a Draw method ?
// Store a graphics context ?
// For now. Put everything in Update down below.
// Should split update from draw, update should have a != timestep than graphics (60fps or more)

// TODO : Remove main.h. Useless
// May be remove that Application class, useless too.

using namespace Juliet;

namespace
{
    using GameInit_t     = void (*)(void);
    using GameShutdown_t = void (*)(void);
    using GameUpdate_t   = void (*)(float deltaTime);
    struct GameFunctionTable
    {
        GameInit_t     Init     = nullptr;
        GameShutdown_t Shutdown = nullptr;
        GameUpdate_t   Update   = nullptr;
    } Game;
    const char* GameFunctionTable[] = { "GameInit", "GameShutdown", "GameUpdate" };
} // namespace

void JulietApplication::Init()
{
    Log(LogLevel::Message, LogCategory::Tool, "Initializing Juliet Application...");

    Log(LogLevel::Message, LogCategory::Tool, "%s", CStr(GetBasePath()));

    GraphicsConfig config;
#if JULIET_DEBUG
    config.EnableDebug = true;
#endif
    GraphicsDevice = CreateGraphicsDevice(config);

    MainWindow = CreatePlatformWindow("Juliet Editor", 1280, 720);

    Running = MainWindow != nullptr && GraphicsDevice != nullptr;

    if (Running)
    {
        AttachToWindow(GraphicsDevice, MainWindow);

        {
            // Create graphics pipeline
            String           entryPoint = WrapString("main");
            ShaderCreateInfo shaderCI   = {};
            shaderCI.EntryPoint         = entryPoint;

            // TODO: Assets management that handles path to assets or something.
            String shaderPath    = WrapString("../../../Assets/compiled/Triangle.vert.dxil");
            shaderCI.Stage       = ShaderStage::Vertex;
            Shader* vertexShader = CreateShader(GraphicsDevice, shaderPath, shaderCI);

            shaderPath             = WrapString("../../../Assets/compiled/SolidColor.frag.dxil");
            shaderCI.Stage         = ShaderStage::Fragment;
            Shader* fragmentShader = CreateShader(GraphicsDevice, shaderPath, shaderCI);

            ColorTargetDescription colorTargetDescription = {};
            colorTargetDescription.Format                 = GetSwapChainTextureFormat(GraphicsDevice, MainWindow);

            GraphicsPipelineCreateInfo pipelineCI = {};
            pipelineCI.VertexShader               = vertexShader;
            pipelineCI.FragmentShader             = fragmentShader;
            pipelineCI.PrimitiveType              = PrimitiveType::TriangleList;
            pipelineCI.TargetInfo                 = { .ColorTargetDescriptions = &colorTargetDescription,
                                                      .NumColorTargets         = 1,
                                                      .DepthStencilFormat      = {},
                                                      .HasDepthStencilTarget   = false };
            pipelineCI.RasterizerState.FillMode   = FillMode::Solid;

            GraphicsPipeline = CreateGraphicsPipeline(GraphicsDevice, pipelineCI);
            if (GraphicsPipeline == nullptr)
            {
                LogError(LogCategory::Game, "Failed to create graphics pipeline!");
                Running = false;
            }

            if (vertexShader)
            {
                DestroyShader(GraphicsDevice, vertexShader);
            }
            if (fragmentShader)
            {
                DestroyShader(GraphicsDevice, fragmentShader);
            }

            if (Running == false)
            {
                return;
            }
        }

        GameCode.Functions     = reinterpret_cast<void**>(&Game);
        GameCode.FunctionCount = ArraySize(GameFunctionTable);
        GameCode.FunctionNames = GameFunctionTable;
        InitHotReloadCode(GameCode, ConstString("Game.dll"), ConstString("Game_Temp.dll"), ConstString("lock.tmp"));
        if ((Running = GameCode.IsValid))
        {
            Game.Init();
        }
    }
}

void JulietApplication::Shutdown()
{
    Log(LogLevel::Message, LogCategory::Tool, "Shutting down Juliet Application...");

    if (GameCode.IsValid)
    {
        Game.Shutdown();
        ShutdownHotReloadCode(GameCode);
    }

    if (GraphicsPipeline)
    {
        DestroyGraphicsPipeline(GraphicsDevice, GraphicsPipeline);
    }

    if (MainWindow && GraphicsDevice)
    {
        DetachFromWindow(GraphicsDevice, MainWindow);
    }

    if (MainWindow)
    {
        DestroyPlatformWindow(MainWindow);
    }

    if (GraphicsDevice)
    {
        DestroyGraphicsDevice(GraphicsDevice);
    }

    Log(LogLevel::Message, LogCategory::Tool, "Juliet App shutdown Completed");
}

void JulietApplication::Update()
{
    bool        reloadShaders         = false;
    static bool reloadShadersDebounce = false;

    SystemEvent evt;
    while (GetEvent(evt))
    {
        if (evt.Type == EventType::Window_Close_Request)
        {
            if (evt.Data.Window.AssociatedWindowID == GetWindowID(MainWindow))
            {
                Running = false;
            }
        }

        if (evt.Type == EventType::Key_Down)
        {
        }

        // Shader hot reload using keyboard.
        // TODO: Add Input debounce in the library. (Just pressed vs pressed)
        if (!reloadShadersDebounce && ((GetKeyModState() & KeyMod::Alt) != KeyMod::None) && IsKeyDown(ScanCode::R))
        {
            reloadShaders         = true;
            reloadShadersDebounce = true;
        }

        if (reloadShadersDebounce && !IsKeyDown(ScanCode::R))
        {
            reloadShadersDebounce = false;
        }
    }

    Game.Update(0.0f);

    if (ShouldReloadCode(GameCode))
    {
        ReloadCode(GameCode);
    }

    if (reloadShaders)
    {
        // We need to wait for the gpu to be idle to recreate our graphics pipelines
        WaitUntilGPUIsIdle(GraphicsDevice);

#if ALLOW_SHADER_HOT_RELOAD
        String           entryPoint = WrapString("main");
        ShaderCreateInfo shaderCI   = {};
        shaderCI.EntryPoint         = entryPoint;
        String shaderPath    = WrapString("../../../Assets/compiled/Triangle.vert.dxil");
        shaderCI.Stage       = ShaderStage::Vertex;
        Shader* vertexShader = CreateShader(GraphicsDevice, shaderPath, shaderCI);

        shaderPath             = WrapString("../../../Assets/compiled/SolidColor.frag.dxil");
        shaderCI.Stage         = ShaderStage::Fragment;
        Shader* fragmentShader = CreateShader(GraphicsDevice, shaderPath, shaderCI);

        UpdateGraphicsPipelineShaders(GraphicsDevice, GraphicsPipeline, vertexShader, fragmentShader);

        if (vertexShader)
        {
            DestroyShader(GraphicsDevice, vertexShader);
        }
        if (fragmentShader)
        {
            DestroyShader(GraphicsDevice, fragmentShader);
        }
#endif
    }

    // Draw here for now
    // 1) Acquire a Command Buffer
    CommandList* cmdList = AcquireCommandList(GraphicsDevice, QueueType::Graphics);
    if (cmdList == nullptr)
    {
        Log(LogLevel::Error, LogCategory::Tool, "Failed to acquire command list.");
        Running = false;
        return;
    }

    Texture* swapChainTexture = nullptr;
    if (!WaitAndAcquireSwapChainTexture(cmdList, MainWindow, &swapChainTexture))
    {
        Log(LogLevel::Error, LogCategory::Tool, "Failed to acquire swapchain texture.");
        Running = false;
        return;
    }

    if (swapChainTexture)
    {
        ColorTargetInfo colorTargetInfo = {};
        colorTargetInfo.TargetTexture   = swapChainTexture;
        colorTargetInfo.ClearColor      = { .R = .5f, .G = .8f, .B = .0f, .A = 1.f };
        colorTargetInfo.LoadOperation   = LoadOperation::Clear;
        colorTargetInfo.StoreOperation  = StoreOperation::Store;

        RenderPass* renderPass = BeginRenderPass(cmdList, colorTargetInfo);
        BindGraphicsPipeline(renderPass, GraphicsPipeline);
        DrawPrimitives(renderPass, 3, 1, 0, 0);
        EndRenderPass(renderPass);
    }

    // Submit Commands
    SubmitCommandLists(cmdList);
}

bool JulietApplication::IsRunning()
{
    return Running;
}

namespace
{
    JulietApplication EditorApplication;
}

JulietApplication& GetEditorApplication()
{
    return EditorApplication;
}

int main(int argc, char** argv)
{
    // Allow only one instance to be launched.
    // Need to create Mutex code in the lib because i dont want to include windows.h in this file anymore
    // CreateMutex(0, false, L"Local\\Juliet.App");
    // if (GetLastError() == ERROR_ALREADY_EXISTS)
    // {
    //     MessageBox(nullptr, L"An instance of Juliet is already running.", L"Juliet", MB_OK | MB_ICONEXCLAMATION);
    //     return EXIT_FAILURE;
    // }

    StartApplication(EditorApplication, JulietInit_Flags::Display);

    // Pause here to not close the console window immediatly on stop
    system("PAUSE");

    return EXIT_SUCCESS;
}