// affineDlg.cpp : implementation file
//

#include "stdafx.h"
#include "affine.h"
#include "affineDlg.h"
#include "Euclid.h"

#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif

/////////////////////////////////////////////////////////////////////////////
// CAboutDlg dialog used for App About

class CAboutDlg : public CDialog
{
public:
	CAboutDlg();

// Dialog Data
	//{{AFX_DATA(CAboutDlg)
	enum { IDD = IDD_ABOUTBOX };
	//}}AFX_DATA

	// ClassWizard generated virtual function overrides
	//{{AFX_VIRTUAL(CAboutDlg)
	protected:
	virtual void DoDataExchange(CDataExchange* pDX);    // DDX/DDV support
	//}}AFX_VIRTUAL

// Implementation
protected:
	//{{AFX_MSG(CAboutDlg)
	//}}AFX_MSG
	DECLARE_MESSAGE_MAP()
};

CAboutDlg::CAboutDlg() : CDialog(CAboutDlg::IDD)
{
	//{{AFX_DATA_INIT(CAboutDlg)
	//}}AFX_DATA_INIT
}

void CAboutDlg::DoDataExchange(CDataExchange* pDX)
{
	CDialog::DoDataExchange(pDX);
	//{{AFX_DATA_MAP(CAboutDlg)
	//}}AFX_DATA_MAP
}

BEGIN_MESSAGE_MAP(CAboutDlg, CDialog)
	//{{AFX_MSG_MAP(CAboutDlg)
		// No message handlers
	//}}AFX_MSG_MAP
END_MESSAGE_MAP()

/////////////////////////////////////////////////////////////////////////////
// CAffineDlg dialog

CAffineDlg::CAffineDlg(CWnd* pParent /*=NULL*/)
	: CDialog(CAffineDlg::IDD, pParent)
{
	//{{AFX_DATA_INIT(CAffineDlg)
	m_message1 = _T("");
	m_message2 = _T("");
	m_keya = _T("");
	m_keyb = _T("");
	//}}AFX_DATA_INIT
	// Note that LoadIcon does not require a subsequent DestroyIcon in Win32
	m_hIcon = AfxGetApp()->LoadIcon(IDR_MAINFRAME);
}

void CAffineDlg::DoDataExchange(CDataExchange* pDX)
{
	CDialog::DoDataExchange(pDX);
	//{{AFX_DATA_MAP(CAffineDlg)
	DDX_Text(pDX, IDC_EDIT3, m_message1);
	DDX_Text(pDX, IDC_EDIT4, m_message2);
	DDX_Text(pDX, IDC_EDIT1, m_keya);
	DDX_Text(pDX, IDC_EDIT2, m_keyb);
	//}}AFX_DATA_MAP
}

BEGIN_MESSAGE_MAP(CAffineDlg, CDialog)
	//{{AFX_MSG_MAP(CAffineDlg)
	ON_WM_SYSCOMMAND()
	ON_WM_PAINT()
	ON_WM_QUERYDRAGICON()
	ON_BN_CLICKED(IDOK, Encrypt)
	ON_BN_CLICKED(IDC_BUTTON1, Open)
	//}}AFX_MSG_MAP
END_MESSAGE_MAP()

/////////////////////////////////////////////////////////////////////////////
// CAffineDlg message handlers

BOOL CAffineDlg::OnInitDialog()
{
	CDialog::OnInitDialog();

	// Add "About..." menu item to system menu.

	// IDM_ABOUTBOX must be in the system command range.
	ASSERT((IDM_ABOUTBOX & 0xFFF0) == IDM_ABOUTBOX);
	ASSERT(IDM_ABOUTBOX < 0xF000);

	CMenu* pSysMenu = GetSystemMenu(FALSE);
	if (pSysMenu != NULL)
	{
		CString strAboutMenu;
		strAboutMenu.LoadString(IDS_ABOUTBOX);
		if (!strAboutMenu.IsEmpty())
		{
			pSysMenu->AppendMenu(MF_SEPARATOR);
			pSysMenu->AppendMenu(MF_STRING, IDM_ABOUTBOX, strAboutMenu);
		}
	}

	// Set the icon for this dialog.  The framework does this automatically
	//  when the application's main window is not a dialog
	SetIcon(m_hIcon, TRUE);			// Set big icon
	SetIcon(m_hIcon, FALSE);		// Set small icon
	
	// TODO: Add extra initialization here
	
	return TRUE;  // return TRUE  unless you set the focus to a control
}

void CAffineDlg::OnSysCommand(UINT nID, LPARAM lParam)
{
	if ((nID & 0xFFF0) == IDM_ABOUTBOX)
	{
		CAboutDlg dlgAbout;
		dlgAbout.DoModal();
	}
	else
	{
		CDialog::OnSysCommand(nID, lParam);
	}
}

// If you add a minimize button to your dialog, you will need the code below
//  to draw the icon.  For MFC applications using the document/view model,
//  this is automatically done for you by the framework.

void CAffineDlg::OnPaint() 
{
	if (IsIconic())
	{
		CPaintDC dc(this); // device context for painting

		SendMessage(WM_ICONERASEBKGND, (WPARAM) dc.GetSafeHdc(), 0);

		// Center icon in client rectangle
		int cxIcon = GetSystemMetrics(SM_CXICON);
		int cyIcon = GetSystemMetrics(SM_CYICON);
		CRect rect;
		GetClientRect(&rect);
		int x = (rect.Width() - cxIcon + 1) / 2;
		int y = (rect.Height() - cyIcon + 1) / 2;

		// Draw the icon
		dc.DrawIcon(x, y, m_hIcon);
	}
	else
	{
		CDialog::OnPaint();
	}
}

// The system calls this to obtain the cursor to display while the user drags
//  the minimized window.
HCURSOR CAffineDlg::OnQueryDragIcon()
{
	return (HCURSOR) m_hIcon;
}

void CAffineDlg::Encrypt() 
{
	// TODO: Add your control notification handler code here
	UpdateData(true);
	int a,b;
	a=atoi(m_keya);
	b=atoi(m_keyb);
    if (m_keya==""||m_keyb=="") {
		MessageBox("請輸入密鑰！");
    }
    else
	{
		Euclid euc;
		euc.Backspin(a);
		if (euc.Backspin(a)==0) {
		MessageBox("該數沒有乘法逆元。");
		}
        else{
			if (m_message1=="") {MessageBox("請輸入明文！");}
				
		    else
			{
				int i,j,x,length;
				CString miwen,str;
				length=m_message1.GetLength();
				for (i=0;i<length;i++) {
					x=int(m_message1[i]);
					if (x>96&&x<123) {
						j=(a*(x-97)+b)%26;
						str.Format("%c",j+97);
						miwen=miwen+str;
					}
					else
						if(x>64&&x<91){
						j=(a*(x-65)+b)%26;
						str.Format("%c",j+65);
						miwen=miwen+str;
					}
						else {MessageBox("明文必須為字母！");break;};
				}
				m_message2=miwen;
			}
		}
	}	
	UpdateData(false);
}

void CAffineDlg::Open() 
{
	// TODO: Add your control notification handler code here
	UpdateData(true);
	int a,b;
	a=atoi(m_keya);
	b=atoi(m_keyb);
    if (m_keya==""||m_keyb=="") {
		MessageBox("請輸入密鑰！");
    }
    else
	{
		Euclid euc;
		euc.Backspin(a);
		if (euc.Backspin(a)==0) {
		MessageBox("該數沒有乘法逆元。");
		}
        else{
			if (m_message2=="") {MessageBox("請輸入密文！");}
				
		    else
			{
				int i,j,x,length;
				CString mingwen,str;
				length=m_message2.GetLength();
				for (i=0;i<length;i++) {
					x=int(m_message2[i]);
					if (x>96&&x<123) {
						j=euc.Backspin(a)*(x-97-b);
						j=j%26;
                        if (j<0) {j=j+26;}
						str.Format("%c",j+97);
						mingwen=mingwen+str;
					}
					else
						if (x>64&&x<91) {
							j=euc.Backspin(a)*(x-65-b);
							j=j%26;
							if (j<0) {j=j+26;}
							str.Format("%c",j+65);
							mingwen=mingwen+str;
						}
						else {MessageBox("密文必須為字母！");break;};
				}
				m_message1=mingwen;
			}
		}
	}	
	UpdateData(false);
}