/******************************************************************************
*	File		-	panel_manager.cpp
*	Author		-	Joey Pollack
*	Date		-	2022/02/07 (y/m/d)
*	Mod Date	-	2022/02/07 (y/m/d)
*	Description	-	Manage the editor panels
******************************************************************************/

#include "panel_manager.h"
#include "editor.h"
#include <utils/logger.h>
#include <gui/dearimgui/imgui_internal.h>   // To use the DockWindowXXX methods
#include <filesystem>

// Panels
#include "panels/about.h"
#include "panels/assetBrowser.h"
#include "panels/worldTree.h"
#include "panels/worldView.h"
#include "panels/propertiesView.h"

using namespace lunarium::gui;

namespace lunarium { namespace editor
{
    PanelManager::PanelManager()
        : mpEditor(nullptr), mResetDockSpace(false), mDockSpaceID(0)
    {

    }

    OpRes PanelManager::Initialize(Editor* editor, std::string name)
    {
        mpEditor = editor;
        mName = name;

        memset(&mWindowClass, 0, sizeof(ImGuiWindowClass));
        mWindowClass.ClassId = mpEditor->GetNextWindowID();
        
        if (!std::filesystem::exists("imgui.ini"))
        {
            mResetDockSpace = true;
        }

        return OpRes::OK();
    }

    void PanelManager::Shutdown()
    {
        DestoryPanels();
    }

    
    OpRes PanelManager::AddPanel(gui::PanelType type, gui::Panel* panel)
    {
        if (GetPanel(type))
        {
            return OpRes::Fail("Cannot add panel - panel already exists. Panel Name: %s", panel->GetName());
        }

        mPanels[type] = panel;

        return OpRes::OK();
    }

    void PanelManager::OpenPanel(PanelType type)
    {
        Panel* p = GetPanel(type);
        if (!p || p->IsOpen())
        {
            return;
        }

        p->SetOpen(true);
    }

    void PanelManager::ClosePanel(PanelType type)
    {
        Panel* p = GetPanel(type);
        if (!p || !p->IsOpen())
        {
            return;
        }

        p->SetOpen(false);
    }

    bool PanelManager::IsOpen(PanelType type)
    {
        Panel* p = GetPanel(type);
        if (!p)
        {
            return false;
        }

        return p->IsOpen();
    }

    Panel* PanelManager::GetPanel(PanelType type)
    {
        auto iter = mPanels.find(type);
        if (iter != mPanels.end())
        {
            return iter->second;
        }

        Logger::Log(mpEditor->GetLogCat(), LogLevel::WARNING, "Requested panel not found: %d", type);
        return nullptr;
    }

    const ImGuiWindowClass* PanelManager::GetWindowClass() const
    {
        return &mWindowClass;
    }

    void PanelManager::ResetDocking()
    {
        mResetDockSpace = true;
    }
    
    void PanelManager::OnTick(double delta)
    {
        for (auto iter = mPanels.begin(); iter != mPanels.end(); iter++)
        {
            if (iter->second->IsOpen())
            {
                iter->second->Update(delta);
            }
        }
    }
    
    void PanelManager::OnRender(lunarium::IGraphics* g)
    {
        // mpMainPanel->DoFrame();
            
        //ImGuiViewport* Viewport = ImGui::GetMainViewport();
        ImGuiViewport* Viewport = ImGui::GetWindowViewport();
        ImGui::SetNextWindowPos( Viewport->WorkPos );
        ImGui::SetNextWindowSize( Viewport->WorkSize );
        ImGui::SetNextWindowViewport( Viewport->ID );
        ImGuiWindowFlags WindowFlags = 0;
        WindowFlags |= ImGuiWindowFlags_NoTitleBar | ImGuiWindowFlags_NoCollapse | ImGuiWindowFlags_NoResize | ImGuiWindowFlags_NoMove | ImGuiWindowFlags_NoDocking;
        WindowFlags |= ImGuiWindowFlags_NoBringToFrontOnFocus | ImGuiWindowFlags_NoNavFocus;

        ImGui::PushStyleVar( ImGuiStyleVar_WindowRounding, 0.0f );
        ImGui::PushStyleVar( ImGuiStyleVar_WindowBorderSize, 0.0f );
        ImGui::PushStyleVar( ImGuiStyleVar_WindowPadding, ImVec2( 0.0f, 0.0f ) );

        ImGui::Begin(mName.c_str(), nullptr, WindowFlags);
        ImGui::PopStyleVar(3);

        MakeDockSpaces();
        
        ImGui::End();

        for (auto iter = mPanels.begin(); iter != mPanels.end(); iter++)
        {
            if (iter->second->IsOpen())
            {
                ImGui::SetNextWindowClass(&mWindowClass);
                iter->second->DoFrame();
            }
        }
    }

    ////////////////////////////////////////////////////////////
    //				HELPER METHODS
    ////////////////////////////////////////////////////////////
    void PanelManager::DestoryPanels()
    {
        for (auto iter = mPanels.begin(); iter != mPanels.end(); iter++)
        {
            delete iter->second;
        }

        mPanels.clear();
    }

    void PanelManager::MakeDockSpaces()
    {
        //ImGuiViewport* Viewport = ImGui::GetMainViewport();
        ImGuiViewport* Viewport = ImGui::GetWindowViewport();
        ImGuiID windowID = mpEditor->GetNextWindowID();
        std::string dock_name = mName;
        dock_name += " DockSpace";
        mDockSpaceID = ImGui::DockSpace(ImGui::GetID(dock_name.c_str()), ImVec2(0, 0), 0, &mWindowClass);
        if (!ImGui::DockBuilderGetNode(mDockSpaceID) || mResetDockSpace) 
        {
            Logger::Log(mpEditor->GetLogCat(), LogLevel::INFO_VERBOSE, "Resetting Dockspace: %s", dock_name.c_str());

            mResetDockSpace = false;
            ImGui::DockBuilderRemoveNode(mDockSpaceID);
            ImGui::DockBuilderAddNode(mDockSpaceID, ImGuiDockNodeFlags_DockSpace);
            ImGui::DockBuilderSetNodeSize(mDockSpaceID, Viewport->Size);
            //ImGui::DockBuilderSetNodePos(mDockSpaces.Main, Viewport->WorkPos);

            ImGui::DockBuilderSplitNode(mDockSpaceID, ImGuiDir_Down, 0.25f, &mDockZoneIDs[PanelDockZone::DDZ_BOTTOM], &mDockZoneIDs[PanelDockZone::DDZ_CENTER]);
            ImGui::DockBuilderSplitNode(mDockZoneIDs[PanelDockZone::DDZ_CENTER], ImGuiDir_Right, 0.2f, &mDockZoneIDs[PanelDockZone::DDZ_RIGHT], &mDockZoneIDs[PanelDockZone::DDZ_CENTER]);
            ImGui::DockBuilderSplitNode(mDockZoneIDs[PanelDockZone::DDZ_CENTER], ImGuiDir_Left, 0.2f, &mDockZoneIDs[PanelDockZone::DDZ_LEFT], &mDockZoneIDs[PanelDockZone::DDZ_CENTER]);
            ImGui::DockBuilderFinish(mDockSpaceID);

            // Dock Panels
            for (auto iter = mPanels.begin(); iter != mPanels.end(); iter++)
            {
                PanelDockZone dz = iter->second->GetDockZone();
                if (dz != PanelDockZone::DDZ_NONE)
                {
                    ImGui::DockBuilderDockWindow(iter->second->GetName(), mDockZoneIDs[dz]);
                }
            }
        }

    }
}}