//---------------------------------------------------------------------------
// Generowanie kodow kreskowych MSI
// www.algorytm.org
// (c)2007 Tomasz Lubinski
//---------------------------------------------------------------------------

#include <vcl.h>
#pragma hdrstop

#include "Unit1.h"
//---------------------------------------------------------------------------
#pragma package(smart_init)
#pragma resource "*.dfm"

char MSIsign[16] = {
      '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
      'A', 'B', 'C', 'D', 'E', 'F'};

char MSIbars[16][12] = {
        {1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0},
        {1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 1, 0},
        {1, 0, 0, 1, 0, 0, 1, 1, 0, 1, 0, 0},
        {1, 0, 0, 1, 0, 0, 1, 1, 0, 1, 1, 0},
        {1, 0, 0, 1, 1, 0, 1, 0, 0, 1, 0, 0},
        {1, 0, 0, 1, 1, 0, 1, 0, 0, 1, 1, 0},
        {1, 0, 0, 1, 1, 0, 1, 1, 0, 1, 0, 0},
        {1, 0, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0},
        {1, 1, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0},
        {1, 1, 0, 1, 0, 0, 1, 0, 0, 1, 1, 0},
        {1, 1, 0, 1, 0, 0, 1, 1, 0, 1, 0, 0},
        {1, 1, 0, 1, 0, 0, 1, 1, 0, 1, 1, 0},
        {1, 1, 0, 1, 1, 0, 1, 0, 0, 1, 0, 0},
        {1, 1, 0, 1, 1, 0, 1, 0, 0, 1, 1, 0},
        {1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 0, 0},
        {1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 1, 0}
        };

char start[3] = {
        1, 1, 0
        };

char stop[4] = {
        1, 0, 0, 1
        };

char start_length = 3;
char stop_length = 4;
char digit_length = 12;

char mod10values[16] = {0, 1, 4, 3, 8, 5, 3, 7, 7, 9, 2, 11, 6, 13, 10, 15};

TForm1 *Form1;
int curentPos;


// returns 1 if letter is correct, 0 otherwise
int checkLetter(char ch)
{
        for (int i=0; i<16; i++)
                if (MSIsign[i] == ch)
                        return 1;

        return 0;
}

// reurns 1 if txt is correct, 0 otherwise
int check(char *txt)
{
        for (unsigned int i=0; i<strlen(txt); i++)
                if (checkLetter(txt[i]) == 0)
                        return 0;

        return 1;
}

// returns letter value for check digit
int getLetterValue(char ch)
{
        for (int i=0; i<16; i++)
                if (MSIsign[i] == ch)
                        return i;

        return 0;
}

//calculate modulo 10 check digit
int mod10checkDigit (char *code, int length)
{
        int sum = 0;
        for (int i=0; i<length; i++)
        {
                sum += mod10values[getLetterValue(code[i])];
        }
        sum %= 10;
        sum = 10-sum;
        sum %= 10;

        return sum;
}

//calculate modulo 11 check digit
int mod11checkDigit (char *code, int length)
{
        int sum = 0;
        int w = 0;

        for (int i=length-1; i>=0; i--)
        {
                sum += getLetterValue(code[i]) * (w + 2);
                w++;
                w %= 6;
        }
        sum %= 11;
        sum = 11-sum;
        sum %= 11;

        return sum;
}

// reurns 1 if check digits are correct, 0 otherwise
int checkCheckDigit(char *txt)
{
        int len = strlen(txt);

        // check check digits
        if (Form1->mod10->Checked)
        {
                if (getLetterValue(txt[len-1]) != mod10checkDigit(txt, len-1))
                {
                        return 0;
                }
        }
        else if (Form1->mod10mod10->Checked)
        {
                if (getLetterValue(txt[len-2]) != mod10checkDigit(txt, len-2) ||
                    getLetterValue(txt[len-1]) != mod10checkDigit(txt, len-1))
                {
                        return 0;
                }
        }
        else if (Form1->mod11->Checked)
        {
                if (getLetterValue(txt[len-1]) != mod11checkDigit(txt, len-1))
                {
                        return 0;
                }
        }
        else if (Form1->mod11mod10->Checked)
        {
                if (getLetterValue(txt[len-2]) != mod11checkDigit(txt, len-2) ||
                    getLetterValue(txt[len-1]) != mod10checkDigit(txt, len-1))
                {
                        return 0;
                }
        }

        return 1;
}



void drawSignBars(char bars[], int length)
{
        Form1->Image1->Canvas->Brush->Color = clBlack;

        //print bars
        for (int i=0; i<length; i++)
        {
                if (bars[i] == 1)
                        Form1->Image1->Canvas->Rectangle(curentPos + 20, 10, curentPos + 22, 100);

                curentPos += 2;
        }
}

void drawBars(char *txt)
{
        char text[1000];
        char tmp[2];

        strcpy(text, txt);

        curentPos = 0;
        Form1->Image1->Canvas->Brush->Color = clWhite;
        Form1->Image1->Canvas->Rectangle(0, 0, 441, 121);

        //print start character
        drawSignBars(start, start_length);

        //print characters
        for (unsigned int i=0; i<strlen(txt); i++)
                for (int j=0; j<16; j++)
                        if (MSIsign[j] == txt[i])
                        {
                                drawSignBars(MSIbars[j], digit_length);
                                break;
                        }

        //print stop character
        drawSignBars(stop, stop_length);

        //Draw text
        Form1->Image1->Canvas->Font->Size = 10;
        Form1->Image1->Canvas->Brush->Color = clWhite;
        Form1->Image1->Canvas->Font->Color = clBlack;
        Form1->Image1->Canvas->TextOut(curentPos/2 + 20 - strlen(txt)*3, 100, text);
}

//---------------------------------------------------------------------------
__fastcall TForm1::TForm1(TComponent* Owner)
        : TForm(Owner)
{
}
//---------------------------------------------------------------------------


void __fastcall TForm1::Button1Click(TObject *Sender)
{
        if (check(Kod->Text.c_str()) == 0)
        {
                ShowMessage("Incorrect text");
                return;
        }

        if (checkCheckDigit(Kod->Text.c_str()) == 0)
        {
                ShowMessage("Incorrect check digit");
                return;
        }

        drawBars(Kod->Text.c_str());
}
//---------------------------------------------------------------------------