/*
 * Copyright 2011-2015 Branimir Karadzic. All rights reserved.
 * License: http://www.opensource.org/licenses/BSD-2-Clause
 */

/*
 * Based on ImWindow code from:
 * https://github.com/thennequin/ImWindow
 *
 * MIT license:
 * https://github.com/thennequin/ImWindow/blob/master/LICENSE
 */

#ifndef IMGUI_WM_H_HEADER_GUARD
#define IMGUI_WM_H_HEADER_GUARD

#include "imgui.h"

typedef unsigned int ImU32;

#ifndef ImwList
# include <list>
# define ImwList std::list
#endif // ImList

#ifndef ImwMap
# include <unordered_map>
# define ImwMap std::unordered_map
#endif // ImMap

namespace ImWindow
{
    enum EDockOrientation
    {
        E_DOCK_ORIENTATION_CENTER,
        E_DOCK_ORIENTATION_TOP,
        E_DOCK_ORIENTATION_LEFT,
        E_DOCK_ORIENTATION_RIGHT,
        E_DOCK_ORIENTATION_BOTTOM,
    };

    class ImwId
    {
    public:
        ImwId();
        ImU32 GetId() const;
        const char* GetStr() const;

    private:
        ImU32 m_iId;
        char  m_pId[11];
        static int s_iNextId;
    };

    class ImwWindow
    {
        friend class ImwWindowManager;
        friend class ImwContainer;

    public:
        virtual void OnGui() = 0;
        virtual void OnMenu() {};

        const char* GetId() const { return m_oId.GetStr(); }

        void Destroy();

        void SetTitle(const char* pTitle);
        const char* GetTitle() const;

        const ImVec2& GetLastPosition() const;
        const ImVec2& GetLastSize() const;

    protected:
        ImwWindow();
        virtual ~ImwWindow();

        char* m_pTitle;
        ImwId m_oId;

        ImVec2 m_oLastPosition;
        ImVec2 m_oLastSize;
    };

    typedef ImwList<ImwWindow*> ImwWindowList;

    class ImwPlatformWindow;

    class ImwContainer
    {
        friend class ImwPlatformWindow;

    public:
        void Dock(ImwWindow* pWindow,EDockOrientation eOrientation = E_DOCK_ORIENTATION_CENTER);
        bool UnDock(ImwWindow* pWindow);

        bool IsEmpty();
        bool IsSplit();
        bool HasWindowTabbed();
        ImwContainer* HasWindow(const ImwWindow* pWindow);
        ImwPlatformWindow* GetPlatformWindowParent() const;
        ImwContainer* GetBestDocking(const ImVec2 oCursorPosInContainer,EDockOrientation& oOutOrientation,ImVec2& oOutAreaPos,ImVec2& oOutAreaSize);

    protected:
        ImwContainer(ImwContainer* pParent);
        ImwContainer(ImwPlatformWindow* pParent);
        ~ImwContainer();

        void CreateSplits();
        void Paint();

        ImwContainer* m_pParent;
        ImwPlatformWindow* m_pParentWindow;
        ImwWindowList m_lWindows;
        ImwContainer* m_pSplits[2];

        float m_fSplitRatio;
        bool m_bVerticalSplit;
        int m_iActiveWindow;

        bool m_bIsDrag;

        ImVec2 m_oLastPosition;
        ImVec2 m_oLastSize;
    };

    class ImwPlatformWindow
    {
        friend class ImwWindowManager;

    public:
        ImwPlatformWindow(bool bMainWindow,bool bIsDragWindow);
        virtual ~ImwPlatformWindow();

        virtual bool Init(ImwPlatformWindow* pParent) = 0;

        virtual const ImVec2& GetPosition() const = 0;
        virtual const ImVec2& GetSize() const = 0;

        virtual void Show() = 0;
        virtual void Hide() = 0;
        virtual void SetSize(const ImVec2& size) = 0;
        virtual void SetPosition(const ImVec2& pos) = 0;
        virtual void SetTitle(const char* pTitle) = 0;

        bool IsMain();

        void Dock(ImwWindow* pWindow);
        bool UnDock(ImwWindow* pWindow);

        ImwContainer* GetContainer();
        ImwContainer* HasWindow(ImwWindow* pWindow);
        bool IsStateSet();

    protected:
        void SetState();
        void RestoreState();
        void OnLoseFocus();
        virtual void PreUpdate() = 0;
        virtual void Paint();
        virtual void Destroy() = 0;
        virtual void StartDrag() = 0;
        virtual void StopDrag() = 0;
        virtual bool IsDraging() = 0;

        void PaintContainer();
        void OnClose();

        ImwId m_oId;
        bool m_bMain;
        bool m_bIsDragWindow;
        ImwContainer* m_pContainer;
        void* m_pState;
        void* m_pPreviousState;
    };

    typedef ImwList<ImwPlatformWindow*> ImwPlatformWindowList;

    class ImwWindowManager
    {
        friend class ImwWindow;
        friend class ImwPlatformWindow;
        friend class ImwContainer;

        enum EPlatformWindowAction
        {
            E_PLATFORM_WINDOW_ACTION_DESTOY       =  1,
            E_PLATFORM_WINDOW_ACTION_SHOW         =  2,
            E_PLATFORM_WINDOW_ACTION_HIDE         =  4,
            E_PLATFORM_WINDOW_ACTION_SET_POSITION =  8,
            E_PLATFORM_WINDOW_ACTION_SET_SIZE     = 16,
        };

        struct PlatformWindowAction
        {
            ImwPlatformWindow* m_pPlatformWindow;
            unsigned int m_iFlags;
            ImVec2 m_oPosition;
            ImVec2 m_oSize;
        };

        struct DockAction
        {
            ImwWindow* m_pWindow;

            // Is Dock or Float
            bool m_bFloat;

            //For Docking
            ImwWindow* m_pWith;
            EDockOrientation m_eOrientation;
            ImwPlatformWindow* m_pToPlatformWindow;
            ImwContainer* m_pToContainer;

            //For Floating
            ImVec2 m_oPosition;
            ImVec2 m_oSize;
        };

        struct DrawWindowAreaAction
        {
            DrawWindowAreaAction(ImwPlatformWindow* pWindow,const ImVec2& oRectPos,const ImVec2& oRectSize,const ImColor& oColor);
            ImwPlatformWindow* m_pWindow;
            ImVec2 m_oRectPos;
            ImVec2 m_oRectSize;
            ImColor m_oColor;
        };

    public:
        struct Config
        {
            Config();
            float m_fDragMarginRatio;
            float m_fDragMarginSizeRatio;
            ImColor m_oHightlightAreaColor;
        };

        ImwWindowManager();
        virtual ~ImwWindowManager();

        bool Init();
        bool Run();
        void Exit();

        ImwPlatformWindow* GetMainPlatformWindow();
        Config& GetConfig();

        void SetMainTitle(const char* pTitle);

        void Dock(ImwWindow* pWindow,EDockOrientation eOrientation = E_DOCK_ORIENTATION_CENTER,ImwPlatformWindow* pToPlatformWindow = NULL);
        void DockTo(ImwWindow* pWindow,EDockOrientation eOrientation = E_DOCK_ORIENTATION_CENTER,ImwContainer* pContainer = NULL);
        void DockWith(ImwWindow* pWindow,ImwWindow* pWithWindow,EDockOrientation eOrientation = E_DOCK_ORIENTATION_CENTER);
        void Float(ImwWindow* pWindow,const ImVec2& oPosition = ImVec2(-1,-1),const ImVec2& oSize = ImVec2(-1,-1));

        const ImwWindowList& GetWindowList() const;
        ImwPlatformWindow* GetCurrentPlatformWindow();
        ImwPlatformWindow* GetWindowParent(ImwWindow* pWindow);

        void  Log(const char* pFormat, ...);
        virtual void LogFormatted(const char* pStr) = 0;;

        static ImwWindowManager* GetInstance();

    protected:
        virtual ImwPlatformWindow*  CreatePlatformWindow(bool bMain,ImwPlatformWindow* pParent,bool bDragWindow) = 0;
        virtual void InternalRun() = 0;
        virtual ImVec2 GetCursorPos() = 0;
        virtual bool IsLeftClickDown() = 0;

        void AddWindow(ImwWindow* pWindow);
        void RemoveWindow(ImwWindow* pWindow);
        void DestroyWindow(ImwWindow* pWindow);

        void InternalDock(ImwWindow* pWindow,EDockOrientation eOrientation,ImwPlatformWindow* pToPlatformWindow);
        void InternalDockTo(ImwWindow* pWindow,EDockOrientation eOrientation,ImwContainer* pToContainer);
        void InternalDockWith(ImwWindow* pWindow,ImwWindow* pWithWindow,EDockOrientation eOrientation);
        void InternalFloat(ImwWindow* pWindow,ImVec2 oPosition,ImVec2 oSize);
        void InternalUnDock(ImwWindow* pWindow);
        void InternalDrag(ImwWindow* pWindow);

        void OnClosePlatformWindow(ImwPlatformWindow* pWindow);

        void DrawWindowArea(ImwPlatformWindow* pWindow,const ImVec2& oPos,const ImVec2& oSize,const ImColor& oColor);

        void PreUpdate();
        void Update();
        void UpdatePlatformwWindowActions();
        void UpdateDockActions();
        void UpdateOrphans();

        void Paint(ImwPlatformWindow* pWindow);

        void StartDragWindow(ImwWindow* pWindow);
        void StopDragWindow();
        void UpdateDragWindow();
        ImwContainer*  GetBestDocking(ImwPlatformWindow* pPlatformWindow,const ImVec2 oCursorPos,EDockOrientation& oOutOrientation,ImVec2& oOutAreaPos,ImVec2& oOutAreaSize);

        Config m_oConfig;
        ImwPlatformWindow* m_pMainPlatformWindow;
        ImwPlatformWindowList m_lPlatformWindows;
        ImwPlatformWindow* m_pDragPlatformWindow;
        ImwWindowList m_lWindows;
        ImwWindowList m_lOrphanWindows;
        ImwWindowList m_lToDestroyWindows;
        ImwPlatformWindowList m_lToDestroyPlatformWindows;
        ImwList<PlatformWindowAction*> m_lPlatformWindowActions;
        ImwList<DockAction*> m_lDockActions;
        ImwList<DrawWindowAreaAction> m_lDrawWindowAreas;

        ImwPlatformWindow* m_pCurrentPlatformWindow;
        ImwWindow* m_pDraggedWindow;

        ImVec2 m_oDragPreviewOffset;

        static ImwWindowManager* s_pInstance;
    };
}

#endif // IMGUI_WM_H_HEADER_GUARD