#include <windows.h>
#include <windowsx.h>
#include <CommCtrl.h>
#include <gdiplus.h>
#include <string>

using namespace std;
using namespace Gdiplus;

namespace D3DTest1
{
    HINSTANCE hCurrentInstance;
    LPCWSTR openImageFilename;
    Image* pOpenImage;
    HWND hMainWindow;
    HWND hMainWindowStatusBar;
    int clientAreaWidth = 800;
    int clientAreaHeight = 600;
    UINT windowStyle = WS_OVERLAPPED | WS_MINIMIZEBOX | WS_SYSMENU;
    BOOL debug = TRUE;
    HANDLE hConsole;
    BOOL isDrawing = FALSE;
    Point prevMousePos;
    Point curMousePos;
    Color color = Color::Black;

    enum ToolbarItem
    {
        File_New = 0,
        File_Open = 1,
        File_Save = 2,
        File_Close = 3,

        Tool_Line = 4,
        Tool_Brush = 5,
        Tool_ColorPicker = 6
    };

    enum Tool
    {
        Brush = 0,
        Line = 1
    };

    Tool tool = Tool::Line;

    OPENFILENAME CreateOFN(HWND hOwnerWindow = hMainWindow)
    {
        OPENFILENAME ofn;
        WCHAR filename[MAX_PATH];
        ZeroMemory(&ofn, sizeof(ofn));

        ofn.lStructSize = sizeof(ofn);
        ofn.hwndOwner = hOwnerWindow;
        ofn.lpstrFile = filename;
        ofn.lpstrFile[0] = '\0';
        ofn.nMaxFile = sizeof(filename);
        ofn.lpstrFilter = L"All\0*.*\0Text\0*.TXT\0";
        ofn.nFilterIndex = 1;
        ofn.lpstrFileTitle = NULL;
        ofn.nMaxFileTitle = 0;
        ofn.lpstrInitialDir = NULL;
        ofn.Flags = OFN_PATHMUSTEXIST | OFN_FILEMUSTEXIST;

        return ofn;
    }

    CHOOSECOLOR CreateCC(HWND hOwnerWindow = hMainWindow)
    {
        CHOOSECOLOR cc;
        COLORREF cr[16];
        ZeroMemory(&cc, sizeof(CHOOSECOLOR));

        cc.lStructSize = sizeof(CHOOSECOLOR);
        cc.hwndOwner = hOwnerWindow;
        cc.rgbResult = RGB(255, 255, 255);
        cc.lpCustColors = cr;
        cc.Flags = CC_RGBINIT | CC_FULLOPEN;

        return cc;
    }

    int MessageBox(LPCWSTR text, LPCWSTR caption = L"Alert", long type = MB_OK, HWND hWnd = hMainWindow)
    {
        return MessageBox(hWnd, text, caption, type);
    }

    void SetAppState(LPCWSTR state = L"Ready")
    {
        SendMessage(hMainWindowStatusBar, SB_SETTEXT, 0, (LPARAM)state);
    }

    void OnKeyDown(WPARAM virtualKeyCode)
    {
        wstring yptfk = L"You pressed the following key: \n";
        int charCode = MapVirtualKey(virtualKeyCode, MAPVK_VK_TO_CHAR);
        wchar_t key = (wchar_t)charCode;
        wstring text = yptfk + L"Character: \"" + key + L"\"\nCharcode: " + to_wstring(charCode);
        MessageBox(text.c_str());
    }

    Size AdjustWindowSize(int width, int height)
    {
        RECT wr = { 0, 0, width, height };
        AdjustWindowRect(&wr, windowStyle, FALSE);
        return Size(wr.right - wr.left, wr.bottom - wr.top);
    }

    void SetClientAreaSize(int width, int height, HWND hWnd = hMainWindow)
    {
        clientAreaWidth = width;
        clientAreaHeight = height;
        Size size = AdjustWindowSize(width, height);
        MoveWindow(hWnd, 0, 0, size.Width, size.Height, TRUE);
    }

    // Does not work.

    void SetWindowBackgroundImage(LPCWSTR filename, HWND hWnd = hMainWindow)
    {
        HBITMAP hImage = (HBITMAP)LoadImage(NULL, filename, IMAGE_BITMAP, 0, 0, LR_LOADFROMFILE);
        SendMessage(hWnd, STM_SETIMAGE, IMAGE_BITMAP, (LPARAM)hImage);
    }

    void RefreshWindow(HWND hWnd = hMainWindow)
    {
        if (pOpenImage != nullptr)
        {
            Graphics gc(GetDC(hWnd));
            Rect clientArea(0, 0, clientAreaWidth, clientAreaHeight);
            gc.DrawImage(pOpenImage, clientArea);
        }
    }

    void LoadFile(LPCWSTR filename)
    {
        // Disabled due to malfunction.
        // openImageFilename = filename;
        // pOpenImage = Image::FromFile(filename);

        filename = L"C:/Users/vovan/Desktop/sample.bmp";
        openImageFilename = filename;
        pOpenImage = Image::FromFile(filename);
        int width = pOpenImage->GetWidth();
        int height = pOpenImage->GetHeight();
        SetClientAreaSize(width, height);
        RefreshWindow();
        SetAppState(L"Loaded image");
    }

    LPCWSTR ChooseFile()
    {
        OPENFILENAME ofn = CreateOFN();
        GetOpenFileName(&ofn);
        return ofn.lpstrFile;
    }

    void WriteFileA(HANDLE hFile, LPCSTR data)
    {
        WriteFile(hFile, data, strlen(data), 0, NULL);
    }

    void Log(LPCSTR data)
    {
        if (debug)
        {
            WriteFileA(hConsole, data);
            WriteFileA(hConsole, "\n");
        }
    }

    void Log(int data)
    {
        Log(to_string(data).c_str());
    }

    void DrawLine(Point pt1 = prevMousePos, Point pt2 = curMousePos)
    {
        Graphics gc(pOpenImage);
        Pen pen(color, 10);
        gc.DrawLine(&pen, pt1, pt2);
        RefreshWindow();
    }

    Point GetMousePos(LPARAM lParam)
    {
        Point mousePos;
        mousePos.X = GET_X_LPARAM(lParam);
        mousePos.Y = GET_Y_LPARAM(lParam);
        return mousePos;
    }

    void FlipMousePositions(LPARAM lParam)
    {
        prevMousePos = curMousePos;
        curMousePos = GetMousePos(lParam);
    }

    void LogMousePos(Point pos)
    {
        Log("X:");
        Log(pos.X);
        Log("Y:");
        Log(pos.Y);
    }

    void PickAColor()
    {
        CHOOSECOLOR cc = CreateCC();
        ChooseColor(&cc);
        COLORREF cr = cc.rgbResult;
        BYTE R = GetRValue(cr);
        BYTE G = GetGValue(cr);
        BYTE B = GetBValue(cr);
        color = Color(R, G, B);
    }

    LRESULT CALLBACK OnWindowMessage(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
    {
        int mbResult;
        switch (message)
        {
            case WM_CLOSE:
                mbResult = MessageBox(L"Are you sure you want to exit?", L"Exit?", MB_YESNO | MB_ICONWARNING);
                if (mbResult == IDYES)
                {
                    DestroyWindow(hWnd);
                }
                return 0;
            break;

            case WM_DESTROY:
                PostQuitMessage(0);
                return 0;
            break;

            case WM_KEYDOWN:
                OnKeyDown(wParam);
            break;

            case WM_SIZE:
                SendMessage(hMainWindowStatusBar, WM_SIZE, NULL, NULL);
            break;

            case WM_PAINT:
                RefreshWindow();
            break;

            case WM_COMMAND:
                switch (LOWORD(wParam))
                {
                    case ToolbarItem::File_Open:
                        if (LPCWSTR filename = ChooseFile())
                        {
                            LoadFile(filename);
                        }
                    break;

                    case ToolbarItem::Tool_Brush:
                        tool = Tool::Brush;
                    break;

                    case ToolbarItem::Tool_Line:
                        tool = Tool::Line;
                    break;

                    case ToolbarItem::Tool_ColorPicker:
                        PickAColor();
                    break;
                }
            break;

            case WM_MOUSEMOVE:
                if (isDrawing)
                {
                    switch (tool)
                    {
                        case Tool::Brush:
                            FlipMousePositions(lParam);
                            DrawLine();
                        break;
                    }
                }
            break;

            case WM_LBUTTONDOWN:
                if (TRUE)
                {
                    switch (tool)
                    {
                        case Tool::Brush:
                            isDrawing = TRUE;
                            curMousePos = GetMousePos(lParam);
                        break;

                        case Tool::Line:
                            isDrawing = TRUE;
                            curMousePos = GetMousePos(lParam);
                        break;
                    }
                }
            break;

            case WM_LBUTTONUP:
                switch (tool)
                {
                    case Tool::Brush:
                        isDrawing = FALSE;
                    break;

                    case Tool::Line:
                        isDrawing = FALSE;
                        FlipMousePositions(lParam);
                        DrawLine();
                    break;
                }
            break;
        }
        return DefWindowProc(hWnd, message, wParam, lParam);
    }

    HWND CreateStatusBar(HWND hParentWindow, int id, LPCWSTR text = L"Ready")
    {
        return CreateStatusWindow(WS_CHILD | WS_VISIBLE, text, hParentWindow, id);
    }

    HMENU CreateMainWindowToolbar()
    {
        HMENU hToolbar = CreateMenu();

        HMENU hFileMenu = CreatePopupMenu();
        AppendMenu(hFileMenu, MF_STRING, ToolbarItem::File_Open, L"Open");
        AppendMenu(hFileMenu, MF_STRING, ToolbarItem::File_New, L"New");
        AppendMenu(hFileMenu, MF_STRING, ToolbarItem::File_Save, L"Save");
        AppendMenu(hFileMenu, MF_STRING, ToolbarItem::File_Close, L"Close");

        HMENU hToolMenu = CreatePopupMenu();
        AppendMenu(hToolMenu, MF_STRING, ToolbarItem::Tool_Line, L"Line");
        AppendMenu(hToolMenu, MF_STRING, ToolbarItem::Tool_Brush, L"Brush");
        AppendMenu(hToolMenu, MF_STRING, ToolbarItem::Tool_ColorPicker, L"Color Picker");

        AppendMenu(hToolbar, MF_POPUP, (UINT_PTR)hFileMenu, L"File");
        AppendMenu(hToolbar, MF_POPUP, (UINT_PTR)hToolMenu, L"Tool");

        return hToolbar;
    }

    void LoadConsole()
    {
        AllocConsole();
        hConsole = GetStdHandle(STD_OUTPUT_HANDLE);
    }

    int WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nShowCmd)
    {
        if (debug)
        {
            LoadConsole();
        }

        WNDCLASSEX wc;
        ZeroMemory(&wc, sizeof(wc));

        wc.cbSize = sizeof(WNDCLASSEX);
        wc.style = CS_HREDRAW | CS_VREDRAW;
        wc.lpfnWndProc = OnWindowMessage;
        wc.hInstance = hInstance;
        wc.hCursor = LoadCursor(NULL, IDC_ARROW);
        wc.hbrBackground = (HBRUSH)COLOR_WINDOW;
        wc.lpszClassName = L"WC_Default";

        RegisterClassEx(&wc);

        Size sz = AdjustWindowSize(clientAreaWidth, clientAreaHeight);
        HMENU hMainWindowMenu = CreateMainWindowToolbar();

        GdiplusStartupInput gdipsi;
        ULONG_PTR gdipToken;
        GdiplusStartup(&gdipToken, &gdipsi, NULL);

        hMainWindow = CreateWindowEx
        (
            NULL,
            L"WC_Default",
            L"D3DTest1 Main Window",
            windowStyle,
            300,
            300,
            sz.Width,
            sz.Height,
            NULL,
            hMainWindowMenu,
            hInstance,
            NULL
        );

        hMainWindowStatusBar = CreateStatusBar(hMainWindow, 0);
        ShowWindow(hMainWindow, nShowCmd);

        MSG message;
        while (GetMessage(&message, NULL, 0, 0))
        {
            TranslateMessage(&message);
            DispatchMessage(&message);
        }

        GdiplusShutdown(gdipToken);

        return 0;
    }
}

int WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nShowCmd)
{
    D3DTest1::WinMain(hInstance, hPrevInstance, lpCmdLine, nShowCmd);
};