// 仿射密碼Dlg.cpp : implementation file
//
#include "stdafx.h"
#include "仿射密碼.h"
#include "仿射密碼Dlg.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()

/////////////////////////////////////////////////////////////////////////////
// CMyDlg dialog

CMyDlg::CMyDlg(CWnd* pParent /*=NULL*/)
	: CDialog(CMyDlg::IDD, pParent)
{
	//{{AFX_DATA_INIT(CMyDlg)
	m_InFile = _T("");
	m_OutFile = _T("");
	m_A = 0;
	m_B = 0;
	//}}AFX_DATA_INIT
	// Note that LoadIcon does not require a subsequent DestroyIcon in Win32
	m_hIcon = AfxGetApp()->LoadIcon(IDR_MAINFRAME);

}

void CMyDlg::DoDataExchange(CDataExchange* pDX)
{
	CDialog::DoDataExchange(pDX);
	//{{AFX_DATA_MAP(CMyDlg)
	DDX_Control(pDX, IDC_EDIT_B, m_InputB);
	DDX_Control(pDX, IDC_EDIT_A, m_InputA);
	DDX_Control(pDX, IDC_BUTTON_SaveFile, m_SaveFile);
	DDX_Control(pDX, IDC_BUTTON_OpenFile, m_OpenFile);
	DDX_Control(pDX, IDC_BUTTON_EnCode, m_EnCode);
	DDX_Control(pDX, IDC_BUTTON_Code, m_Code);
	DDX_Text(pDX, IDC_EDIT_InFile, m_InFile);
	DDX_Text(pDX, IDC_EDIT_OutFile, m_OutFile);
	DDX_Text(pDX, IDC_EDIT_A, m_A);
	DDV_MinMaxInt(pDX, m_A, 0, 65536);
	DDX_Text(pDX, IDC_EDIT_B, m_B);
	DDV_MinMaxInt(pDX, m_B, 0, 65536);
	//}}AFX_DATA_MAP
}

BEGIN_MESSAGE_MAP(CMyDlg, CDialog)
	//{{AFX_MSG_MAP(CMyDlg)
	ON_WM_SYSCOMMAND()
	ON_WM_PAINT()
	ON_WM_QUERYDRAGICON()
	ON_BN_CLICKED(IDC_BUTTON_Code, OnBUTTONCode)
	ON_BN_CLICKED(IDC_BUTTON_EnCode, OnBUTTONEnCode)
	ON_BN_CLICKED(IDC_BUTTON_OpenFile, OnBUTTONOpenFile)
	ON_BN_CLICKED(IDC_BUTTON_SaveFile, OnBUTTONSaveFile)
	//}}AFX_MSG_MAP
END_MESSAGE_MAP()

/////////////////////////////////////////////////////////////////////////////
// CMyDlg message handlers

BOOL CMyDlg::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	
	m_OpenFile.SetFocus();
	return TRUE;  // return TRUE  unless you set the focus to a control
}

void CMyDlg::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 CMyDlg::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();
	}
	m_OpenFile.SetFocus();
}

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

void CMyDlg::OnBUTTONCode() 
{
	// TODO: Add your control notification handler code here
    FILE *f_in,*f_out;	
	if((f_in=fopen(m_InFile,"rb"))==NULL)
	{
      MessageBox("源文件打不開！","錯誤！");
	  return;
	}  
	 if((f_out=fopen(m_OutFile,"wb"))==NULL)
	{
       MessageBox("目標地址有誤！","錯誤！");
	   return;
	}
	
	UpdateData(true);

    if(Gcd(m_A,65536)!=1)
	{
        MessageBox("輸入的KEY不對，請重新輸入！","錯誤！");
		return;
	}
		
	unsigned int *buf=(unsigned int*)malloc(5);
    *buf=0;
    bool flag= true ; 
	while((*buf=fgetc(f_in))!=EOF)
	{
        if(flag)
		{
			buf+=1;
			flag=false;
		}
		else
		{
            flag=true;
			buf--;;
            *buf = ((*buf) * m_A + m_B) % 65536;
			fputc(*buf,f_out);
            fputc(*(buf+1),f_out); 
		}
	}
	if(!flag)
	{
     	buf--;
	    *buf = ((*buf) * m_A + m_B) % 65536;
        fputc(*(buf),f_out);  
	}
	fclose(f_in);
	fclose(f_out);
	MessageBox("加密結束！","恭喜");
}

void CMyDlg::OnBUTTONEnCode() 
{
	// TODO: Add your control notification handler code here
	FILE *f_in,*f_out;
	if((f_in=fopen(m_InFile,"rb"))==NULL)
	{
      MessageBox("源文件打不開！","錯誤！");
	  m_OpenFile.SetFocus();
	  return;
	}  
	 if((f_out=fopen(m_OutFile,"wb"))==NULL)
	{
       MessageBox("目標地址有誤！","錯誤！");
	   m_SaveFile.SetFocus();
	   return;
	}
	UpdateData(true); 
    CString   str; 	
	int niyuan = Ni(m_A,65536);
	str.Format("%d",niyuan);
	MessageBox("逆元算出為："+str,"提示");
	unsigned int *buf=(unsigned int*)malloc(5);
    *buf=0;
    bool flag= true ; 
	while((*buf=fgetc(f_in))!=EOF)
	{
        if(flag)
		{
			buf+=1;
			flag=false;
		}
		else
		{
            flag=true;
			buf--;
            *buf = (niyuan*((*buf)-m_B)) % 65536;
			fputc(*buf,f_out);
            fputc(*(buf+1),f_out); 
		}
	}
	if(!flag)
	{
		buf--;
        *buf = (niyuan*((*buf)-m_B)) % 65536;
        fputc(*(buf),f_out);  
	}
	fclose(f_in);
	fclose(f_out);
	MessageBox("解密結束！","恭喜");
}

void CMyDlg::OnBUTTONOpenFile() 
{
	// TODO: Add your control notification handler code here
	UpdateData(true);
    CFileDialog m_OpenDialog(TRUE,"txt","*.*");
	m_OpenDialog.DoModal();
	m_InFile=m_OpenDialog.GetPathName();
    UpdateData(false);
	m_SaveFile.SetFocus();
}

void CMyDlg::OnBUTTONSaveFile() 
{
	// TODO: Add your control notification handler code here
	UpdateData(true);
    CFileDialog m_OpenDialog(FALSE,"txt","*.*");
	m_OpenDialog.DoModal();
	m_OutFile=m_OpenDialog.GetPathName();
    UpdateData(false);
	m_InputA.SetFocus();
}

int CMyDlg::Gcd(int a, int b)
{
	int k = 0; 
    do 
    { 
       k = a%b; 
       a = b; 
       b = k; 
    }
	while(k!=0); 
    return a; 
}

int CMyDlg::Ni(int a, int b)
{
	int i = 0; 
    while(a*(++i)%b!=1); 
    return i; 
}