//Kod kreskowy MSI
//(c) 2019 by Tomasz Lubinski
//www.algorytm.org

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Drawing.Imaging;

namespace Barcodes.MSI
{
    public partial class Form1 : Form
    {
        private readonly static int[] mod10values = 
            {0, 1, 4, 3, 8, 5, 3, 7, 7, 9, 2, 11, 6, 13, 10, 15};

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

        private readonly static int[,] MSIbars = 
        {
            {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}
        };

        private readonly static int[] start = { 1, 1, 0 };
        private readonly static int[] stop = { 1, 0, 0, 1 };

        /// <summary>
        /// Zainicjuj
        /// </summary>
        public Form1()
        {
            InitializeComponent();
            pictureBox.Image = new Bitmap(pictureBox.Width, pictureBox.Height, PixelFormat.Format24bppRgb);
            System.Drawing.SolidBrush whiteBrush = new System.Drawing.SolidBrush(System.Drawing.Color.White);
            System.Drawing.Graphics graphics = Graphics.FromImage(pictureBox.Image);
            graphics.FillRectangle(whiteBrush, new Rectangle(0, 0, pictureBox.Width, pictureBox.Height));
            pictureBox.Refresh();
            whiteBrush.Dispose();
            graphics.Dispose();
        }

        /// <summary>
        /// Sprawdza czy podany txt mozna zakodowac MSI
        /// </summary>
        /// <param name="txt">tekst do zakodowania</param>
        /// <returns>true jezeli mozna zakodowac, false w przeciwnym razie</returns>
        public bool check(string txt)
        {
            for (int i = 0; i < txt.Length; i++)
            {
                if (checkLetter(txt[i]) == false)
                    return false;
            }
            return true;
        }

        /// <summary>
        /// Sprawdza czy podany znak mozna zakodowac MSI
        /// </summary>
        /// <param name="ch">znak do zakodowania</param>
        /// <returns>true jezeli mozna zakodowac, false w przeciwnym razie</returns>
        private bool checkLetter(char ch)
        {
            for (int i = 0; i < MSIsigns.Length; i++)
            {
                if (MSIsigns[i] == ch)
                    return true;
            }
            return false;
        }

        /// <summary>
        /// Zwraca wartosc danego znaku
        /// </summary>
        /// <param name="ch">znak</param>
        /// <returns>wartosc danego znaku</returns>
        private int getLetterValue(char ch)
        {
            for (int i = 0; i < MSIsigns.Length; i++)
                if (MSIsigns[i] == ch)
                    return i;

            return 0;
        }

        /// <summary>
        /// Zwraca sume kontrolna modulo 10
        /// </summary>
        /// <param name="txt">kodowany ciag</param>
        /// <returns>suma kontrolna C</returns>
        private int mod10checkDigit(string code)
        {
            int sum = 0;
            for (int i = 0; i < code.Length; i++)
            {
                sum += mod10values[getLetterValue(code[i])];
            }
            sum %= 10;
            sum = 10 - sum;
            sum %= 10;

            return sum;
        }

        /// <summary>
        /// Zwraca sume kontrolna modulo 11
        /// </summary>
        /// <param name="txt">kodowany ciag</param>
        /// <returns>suma kontrolna C</returns>
        private int mod11checkDigit(string code)
        {
            int sum = 0;
            int w = 0;

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

            return sum;
        }

        /// <summary>
        /// Generuj MSI
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void Generate_Click(object sender, EventArgs e)
        {
            //Zainicjuj narzedzia do rysowania
            System.Drawing.SolidBrush whiteBrush = new System.Drawing.SolidBrush(System.Drawing.Color.White);
            System.Drawing.SolidBrush blackBrush = new System.Drawing.SolidBrush(System.Drawing.Color.Black);
            System.Drawing.Graphics graphics = Graphics.FromImage(pictureBox.Image);
            Font drawFont = new Font("Arial", 10);

            //Wyczysc obszar rysowania
            graphics.FillRectangle(whiteBrush, new Rectangle(0, 0, pictureBox.Width, pictureBox.Height));

            string code = Code.Text.Trim();
            if (check(code) == false)
            {
                MessageBox.Show("Nieprawidłowe znaki!", "Bład", MessageBoxButtons.OK, MessageBoxIcon.Error);
                return;
            }

            //Wygeneruj i narysuj kod
            int[] bars = generateBars(ref code, checksumMethod.SelectedIndex);
            for (int i = 0; i < bars.Length; i++)
            {
                if (bars[i] == 1)
                {
                    graphics.FillRectangle(blackBrush, i * 2 + 20, 10, 2, 90);
                }
            }

            //Wypisz cyfry pod kodem
            for (int i = 0; i < code.Length; i++)
            {
                graphics.DrawString(code.Substring(i, 1), drawFont, blackBrush, i * 24 + 30, 102);
            }


            //Odswiez
            pictureBox.Refresh();

            //Zwolinij zasoby
            whiteBrush.Dispose();
            blackBrush.Dispose();
            graphics.Dispose();
        }

        /// <summary>
        /// Generuje kod kreskowy
        /// </summary>
        /// <param name="code">string do zakodowania kodem kreskowym</param>
        /// <returns>kod kreskowy - 1 pasek czarny, 0 - pasek bialy</returns>
        private int[] generateBars(ref string code, int checksumMethod)
        {
            //Sprawdz jaka cyfre kontrolna wybral uzytkownik
            if (checksumMethod == 0)
            {
                //Modulo 10
                code += MSIsigns[mod10checkDigit(code)];
            }
            else if (checksumMethod == 1)
            {
                //2 Modulo 10
                code += MSIsigns[mod10checkDigit(code)];
                code += MSIsigns[mod10checkDigit(code)];
            }
            else if (checksumMethod == 2)
            {
                //Modulo 11
                code += MSIsigns[mod11checkDigit(code)];
            }
            else
            {
                //Modulo 11/10
                code += MSIsigns[mod11checkDigit(code)];
                code += MSIsigns[mod10checkDigit(code)];
            }

            int[] bars = new int[code.Length * 12 + 7];

            //Dodaj znak start
            for (int i = 0; i < 3; i++)
            {
                bars[i] = start[i];
            }                          

            //Koduj kolejne znaki (lacznie z dodanymi sumami kontrolnymi)
            for (int i = 0; i < code.Length; i++)
            {
                int letterValue = getLetterValue(code[i]);
                for (int j = 0; j < 12; j++)
                {
                    bars[i*12 + 3 + j] = MSIbars[letterValue, j];
                }
            }

            //Dodaj znak stop
            for (int i = 0; i < 4; i++)
            {
                bars[code.Length * 12 + 3 + i] = stop[i];
            } 
            
            return bars;
        }
    }
}