#include <windows.h>
#include <math.h>
#include <cmath>
#include <tchar.h>
#include <strsafe.h>
#include <errno.h>

#define ID_STTL		577
#define ID_SWDT		587
#define ID_SHGT		597
#define ID_SADD		549
#define ID_SINFO	519
#define ID_SNEW		1000
#define MAX_CHARS	16

HWND hMain;
HINSTANCE cur;

TCHAR buf[MAX_CHARS], title[MAX_CHARS];
int width, height, tmp;
int maxWidth = 170, maxHeight = 170;
int btnCount = ID_SNEW, hCur = 160;

LONG WINAPI WndProc(HWND, UINT, WPARAM,LPARAM);

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow)
{
    MSG msg;
    WNDCLASS w;
    memset(&w, 0, sizeof(WNDCLASS));
    w.style = CS_HREDRAW | CS_VREDRAW;
    w.lpfnWndProc = WndProc;
    w.hInstance = hInstance;
	cur = hInstance;
	w.hbrBackground = (HBRUSH)GetStockObject(WHITE_BRUSH);
    w.lpszClassName = L"Lab3";
	w.hIcon = LoadIcon(NULL, IDI_EXCLAMATION);
	w.hCursor = LoadCursor(NULL, IDC_ARROW);
    RegisterClass(&w);
    hMain = CreateWindow(L"Lab3", L"Nepryakhin 3121", WS_CAPTION | WS_POPUPWINDOW, 200, 200, 200, 800, NULL, NULL, hInstance, NULL);

	// create 3 textboxes (btn title, width, height)
	HWND hTitle = CreateWindow(L"Edit", NULL, WS_BORDER | WS_CHILD | WS_VISIBLE | ES_LEFT, 120, 8, 60, 20, hMain, (HMENU)ID_STTL, hInstance, 0);
	HWND hWidth = CreateWindow(L"Edit", NULL, WS_BORDER | WS_CHILD | WS_VISIBLE | ES_LEFT | ES_NUMBER, 120, 38, 60, 20, hMain, (HMENU)ID_SWDT, hInstance, 0);
	HWND hHeight = CreateWindow(L"Edit", NULL, WS_BORDER | WS_CHILD | WS_VISIBLE | ES_LEFT | ES_NUMBER, 120, 68, 60, 20, hMain, (HMENU)ID_SHGT, hInstance, 0);
	HWND hInfo = CreateWindow(L"Edit", NULL, WS_BORDER | WS_CHILD | WS_VISIBLE | ES_LEFT | ES_READONLY, 10, 128, 170, 20, hMain, (HMENU)ID_SINFO, hInstance, 0);
	SetWindowText(hTitle, L"Btn");		// def title
	SetWindowText(hWidth, L"50");		// def width
	SetWindowText(hHeight, L"20");		// def height
	// create button to create new btns
	HWND hAddBtn = CreateWindow(L"Button", NULL, WS_CHILD | WS_VISIBLE | BS_PUSHBUTTON, 10, 98, 170, 20, hMain, (HMENU)ID_SADD, hInstance, 0);
	SetWindowText(hAddBtn, L"Add Button");

    ShowWindow(hMain, nCmdShow);
    UpdateWindow(hMain);
	
	while(GetMessage(&msg, NULL, 0, 0))
    {
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }
    
	return msg.wParam;
}

void SetText(int CID, int data)
{
	StringCbPrintf(buf, sizeof(buf), L"%d", data);
	SetDlgItemText(hMain, CID, buf);
}

void TextBoxHandle(WPARAM param)
{
	// get text, set btn title
	if (LOWORD(param) == ID_STTL)
		GetDlgItemText(hMain, ID_STTL, title, MAX_CHARS);
	
	// get width
	if (LOWORD(param) == ID_SWDT)
	{
		// get text, convert to int
		GetDlgItemText(hMain, ID_SWDT, buf, MAX_CHARS);
		tmp = _tstoi(buf);
		
		// check max, set value
		if (tmp <= maxWidth)
			width = tmp;
		else
			SetText(ID_SWDT, maxWidth);
	}

	if (LOWORD(param) == ID_SHGT)
	{
		// get text, convert to int
		GetDlgItemText(hMain, ID_SHGT, buf, MAX_CHARS);
		tmp = _tstoi(buf);
		
		// check max, set value
		if (tmp <= maxHeight)
			height = tmp;
		else
			SetText(ID_SHGT, maxHeight);
	}
}

class Button {
public:	// w/ params
	Button(LPCWSTR ttl, int w, int h)
	{
		HWND hNewBtn = CreateWindow(L"Button", NULL, WS_CHILD | WS_VISIBLE | BS_PUSHBUTTON, 10, hCur, w, h, hMain, (HMENU)btnCount++, cur, 0);
		SetWindowText(hNewBtn, ttl);
		addHeight(h);
	}

public: // default
	Button()
	{
		HWND hNewBtn = CreateWindow(L"Button", NULL, WS_CHILD | WS_VISIBLE | BS_PUSHBUTTON, 10, hCur, 50, 20, hMain, (HMENU)btnCount++, cur, 0);
		SetWindowText(hNewBtn, L"Default");
		addHeight(20);
	}

private: // add btn h and gap to total h
	void addHeight(int val)
	{
		hCur = hCur + val + 10;
	}
};

LONG WINAPI WndProc(HWND hwnd, UINT Message, WPARAM wparam, LPARAM lparam)
{
	HDC hdc;
	PAINTSTRUCT ps;
	
    switch (Message){
    case WM_DESTROY: 
        PostQuitMessage(0);
        break;
	case WM_COMMAND:
		if (HIWORD(wparam) == EN_UPDATE)
			TextBoxHandle(wparam);	// goto tbox handle
		
		if (HIWORD(wparam) == BN_CLICKED)
			if (LOWORD(wparam) == ID_SADD)	// 'new btn add' clicked
				if (width == 0 || height == 0 || wcslen(title) == 0)
					Button *btn = new Button();	// some value is null, use def
				else	// or use params
					Button *btn = new Button(title, width, height);
			else
			{
				// other btn cliked, set to tb its title
				GetDlgItemText(hMain, LOWORD(wparam), buf, MAX_CHARS);
				StringCbPrintf(buf, sizeof(buf), L"%s clicked", buf);
				SetDlgItemText(hMain, ID_SINFO, buf);
			}
		
		break;
	case WM_PAINT:
		hdc = BeginPaint(hwnd, &ps);
		
		TextOut(hdc, 10, 10, L"button title:", 13);
		TextOut(hdc, 10, 40, L"button width:", 13);
		TextOut(hdc, 10, 70, L"button height:", 14);

		EndPaint(hwnd, &ps);
		break;
    default:
        return DefWindowProc(hwnd, Message, wparam, lparam);
    }

    return 0;
}