#include "Application.h"
#include "Core/EditorLoggingSetup.h"
#include "Core/ProjectRootResolver.h"
#include "Core/EditorWindowTitle.h"
#include "Layers/EditorLayer.h"
#include "Core/EditorContext.h"
#include "Core/EditorEvents.h"
#include "Core/EventBus.h"
#include "UI/BuiltInIcons.h"
#include "Platform/Win32Utf8.h"
#include "Platform/WindowsProcessDiagnostics.h"
#include <XCEngine/Debug/Logger.h>
#include <windows.h>

namespace XCEngine {
namespace Editor {

Application& Application::Get() {
    static Application instance;
    return instance;
}

bool Application::InitializeWindowRenderer(HWND hwnd) {
    RECT clientRect = {};
    if (!GetClientRect(hwnd, &clientRect)) {
        MessageBoxW(hwnd, L"Failed to query editor client area", L"Error", MB_OK | MB_ICONERROR);
        return false;
    }

    const int clientWidth = clientRect.right - clientRect.left;
    const int clientHeight = clientRect.bottom - clientRect.top;
    if (clientWidth <= 0 || clientHeight <= 0) {
        MessageBoxW(hwnd, L"Editor client area is invalid", L"Error", MB_OK | MB_ICONERROR);
        return false;
    }

    if (m_windowRenderer.Initialize(hwnd, clientWidth, clientHeight)) {
        return true;
    }

    MessageBoxW(hwnd, L"Failed to initialize editor window renderer", L"Error", MB_OK | MB_ICONERROR);
    return false;
}

void Application::InitializeEditorContext(const std::string& projectPath) {
    m_editorContext = std::make_shared<EditorContext>();
    m_editorContext->SetProjectPath(projectPath);
    m_exitRequestedHandlerId = m_editorContext->GetEventBus().Subscribe<EditorExitRequestedEvent>(
        [this](const EditorExitRequestedEvent&) {
            if (m_hwnd) {
                PostMessageW(m_hwnd, WM_CLOSE, 0, 0);
            }
        });
}

void Application::InitializeImGui(HWND hwnd) {
    m_imguiSession.Initialize(
        m_editorContext->GetProjectPath(),
        UI::ImGuiBackendBridge::GetDpiScaleForHwnd(hwnd));
    m_imguiBackend.Initialize(
        hwnd,
        m_windowRenderer.GetDevice(),
        m_windowRenderer.GetCommandQueue(),
        m_windowRenderer.GetSrvHeap(),
        m_windowRenderer.GetSrvDescriptorSize(),
        m_windowRenderer.GetSrvDescriptorCount());
    UI::InitializeBuiltInIcons(
        m_imguiBackend,
        m_windowRenderer.GetDevice(),
        m_windowRenderer.GetCommandQueue());

    m_viewportHostService.Initialize(m_imguiBackend, m_windowRenderer.GetRHIDevice());
    static_cast<EditorContext*>(m_editorContext.get())->SetViewportHostService(&m_viewportHostService);
}

void Application::AttachEditorLayer() {
    m_editorLayer = new EditorLayer();
    m_editorLayer->SetContext(m_editorContext);
    m_layerStack.pushLayer(std::unique_ptr<Core::Layer>(m_editorLayer));
    m_layerStack.onAttach();
}

void Application::DetachEditorLayer() {
    m_layerStack.onDetach();
    m_editorLayer = nullptr;
}

void Application::ShutdownEditorContext() {
    if (m_editorContext && m_exitRequestedHandlerId) {
        m_editorContext->GetEventBus().Unsubscribe<EditorExitRequestedEvent>(m_exitRequestedHandlerId);
        m_exitRequestedHandlerId = 0;
    }

    m_editorContext.reset();
}

void Application::RenderEditorFrame() {
    static constexpr float kClearColor[4] = { 0.22f, 0.22f, 0.22f, 1.0f };
    m_imguiBackend.BeginFrame();
    m_viewportHostService.BeginFrame();
    m_layerStack.onImGuiRender();
    UpdateWindowTitle();
    ImGui::Render();
    m_windowRenderer.Render(
        m_imguiBackend,
        kClearColor,
        [this](const Rendering::RenderContext& renderContext) {
            if (m_editorContext) {
                m_viewportHostService.RenderRequestedViewports(*m_editorContext, renderContext);
            }
        });
}

bool Application::Initialize(HWND hwnd) {
    Platform::InstallCrashExceptionFilter();
    Platform::RedirectStderrToExecutableLog();

    const std::string exeDir = Platform::GetExecutableDirectoryUtf8();
    ConfigureEditorLogging(exeDir);

    const std::string projectRoot = ResolveEditorProjectRootUtf8();
    const bool workingDirectoryChanged = SetEditorWorkingDirectory(projectRoot);

    auto& logger = Debug::Logger::Get();
    const std::string projectRootMessage = "Editor project root: " + projectRoot;
    logger.Info(Debug::LogCategory::General, projectRootMessage.c_str());

    if (!workingDirectoryChanged) {
        const std::string warningMessage = "Failed to switch editor working directory to project root: " + projectRoot;
        logger.Warning(Debug::LogCategory::General, warningMessage.c_str());
    }

    m_hwnd = hwnd;

    if (!InitializeWindowRenderer(hwnd)) {
        return false;
    }

    InitializeEditorContext(projectRoot);
    InitializeImGui(hwnd);
    AttachEditorLayer();
    m_renderReady = true;
    return true;
}

void Application::Shutdown() {
    m_renderReady = false;
    DetachEditorLayer();
    if (m_editorContext) {
        static_cast<EditorContext*>(m_editorContext.get())->SetViewportHostService(nullptr);
    }
    m_viewportHostService.Shutdown();
    UI::ShutdownBuiltInIcons();
    m_imguiBackend.Shutdown();
    m_imguiSession.Shutdown();
    ShutdownEditorContext();
    m_windowRenderer.Shutdown();
}

void Application::Render() {
    if (!m_renderReady) {
        return;
    }
    RenderEditorFrame();
}

void Application::UpdateWindowTitle() {
    if (!m_hwnd || !m_editorContext) {
        return;
    }

    const std::wstring title = Platform::Utf8ToWide(BuildEditorWindowTitle(*m_editorContext));
    if (title != m_lastWindowTitle) {
        SetWindowTextW(m_hwnd, title.c_str());
        m_lastWindowTitle = title;
    }
}

void Application::OnResize(int width, int height) {
    m_windowRenderer.Resize(width, height);
}

bool Application::SwitchProject(const std::string& projectPath) {
    if (!m_editorContext || projectPath.empty()) {
        return false;
    }

    m_imguiSession.SetProjectPath(projectPath);
    m_editorContext->SetProjectPath(projectPath);

    auto& logger = Debug::Logger::Get();
    if (!SetEditorWorkingDirectory(projectPath)) {
        const std::string warningMessage = "Failed to switch editor working directory to project root: " + projectPath;
        logger.Warning(Debug::LogCategory::General, warningMessage.c_str());
    }

    const std::string infoMessage = "Switched editor project root: " + projectPath;
    logger.Info(Debug::LogCategory::General, infoMessage.c_str());

    m_lastWindowTitle.clear();
    UpdateWindowTitle();
    return true;
}

void Application::SaveProjectState() {
    m_imguiSession.SaveSettings();
}

}
}