//Kod kreskowy UPC-E
//(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.UPC_E
{
    public partial class Form1 : Form
    {
        private readonly int[,,] parityTable = 
        {
            {
                {1, 1, 1, 0, 0, 0},
                {1, 1, 0, 1, 0, 0},
                {1, 1, 0, 0, 1, 0},
                {1, 1, 0, 0, 0, 1},
                {1, 0, 1, 1, 0, 0},
                {1, 0, 0, 1, 1, 0},
                {1, 0, 0, 0, 1, 1},
                {1, 0, 1, 0, 1, 0},
                {1, 0, 1, 0, 0, 1},
                {1, 0, 0, 1, 0, 1}
            },
            {
                {0, 0, 0, 1, 1, 1},
                {0, 0, 1, 0, 1, 1},
                {0, 0, 1, 1, 0, 1},
                {0, 0, 1, 1, 1, 0},
                {0, 1, 0, 0, 1, 1},
                {0, 1, 1, 0, 0, 1},
                {0, 1, 1, 1, 0, 0},
                {0, 1, 0, 1, 0, 1},
                {0, 1, 0, 1, 1, 0},
                {0, 1, 1, 0, 1, 0}
            }
        };


        private readonly int[, ,] left = 
        {
            {
                {0, 0, 0, 1, 1, 0, 1},
                {0, 0, 1, 1, 0, 0, 1},
                {0, 0, 1, 0, 0, 1, 1},
                {0, 1, 1, 1, 1, 0, 1},
                {0, 1, 0, 0, 0, 1, 1},
                {0, 1, 1, 0, 0, 0, 1},
                {0, 1, 0, 1, 1, 1, 1},
                {0, 1, 1, 1, 0, 1, 1},
                {0, 1, 1, 0, 1, 1, 1},
                {0, 0, 0, 1, 0, 1, 1}
            },
            {
                {0, 1, 0, 0, 1, 1, 1},
                {0, 1, 1, 0, 0, 1, 1},
                {0, 0, 1, 1, 0, 1, 1},
                {0, 1, 0, 0, 0, 0, 1},
                {0, 0, 1, 1, 1, 0, 1},
                {0, 1, 1, 1, 0, 0 ,1},
                {0, 0, 0, 0, 1, 0, 1},
                {0, 0, 1, 0, 0, 0 ,1},
                {0, 0, 0, 1, 0, 0, 1},
                {0, 0, 1, 0, 1, 1, 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>
        /// Generuj kod kreskowy UPC-E
        /// </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 (checkCode(code) == false)
            {
                MessageBox.Show("Nieprawidłowy kod UPC-E!", "Bład", MessageBoxButtons.OK, MessageBoxIcon.Error);
                return;
            }

            //Wygeneruj i narysuj kod
            int[] bars = generateBars(code);
            int length;
            for (int i = 0; i < bars.Length; i++)
            {
                if ((i >= 0 && i <= 2) ||
                (i >= 45 && i <= 50))
                {
                    //Paski ochronne sa dluzsze
                    length = 100;
                }
                else
                {
                    //Paski kodujace cyfry sa krotsze
                    length = 90;
                }
                if (bars[i] == 1)
                {
                    graphics.FillRectangle(blackBrush, i * 2 + 70, 10, 2, length);
                }
            }

            //Wypisz cyfry pod kodem
            graphics.DrawString(code.Substring(0, 1), drawFont, blackBrush, 57, 95);
            for (int i = 1; i < 7; i++)
            {
                graphics.DrawString(code.Substring(i, 1), drawFont, blackBrush, i * 14 + 66, 100);
            }
            graphics.DrawString(code.Substring(7, 1), drawFont, blackBrush, 173, 95);

            //Odswiez
            pictureBox.Refresh();

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

        /// <summary>
        /// Sprawdz UPC-E
        /// </summary>
        /// <param name="code"></param>
        /// <returns>true jezeli prawidlowy, false w przeciwnym razie</returns>
        private bool checkCode(string code)
        {
            int[] upca = new int[12];

            //Sprawdz dlugosc
            if (code.Length != 8)
            {
                return false;
            }

            //Sprawdz czy podano tylko cyfry
            int[] upce = new int[8];
            for (int i = 0; i < 8; i++)
            {
                if (int.TryParse(code.Substring(i, 1), out upce[i]) == false)
                    return false;
            }

            //Sprawdz numer systemu
            if ((upce[0] != 0) && (upce[0] != 1))
            {
                return false;

            }

            //konwertuj UPC-E do UPC-A
            if ((upce[6] >= 0) && (upce[6] <= 2))
            {
                upca[3] = upce[6];     
                upca[4] = 0;
                upca[5] = 0;
                upca[6] = 0;
                upca[7] = 0;
                upca[8] = upce[3];
                upca[9] = upce[4];
                upca[10] = upce[5];
            }
            else if ((upce[6] == 3) && (upce[3] >= 3) && (upce[3] <= 9))
            {
                upca[3] = upce[3];     
                upca[4] = 0;
                upca[5] = 0;
                upca[6] = 0;
                upca[7] = 0;
                upca[8] = 0;
                upca[9] = upce[4];
                upca[10] = upce[5];
            }
            else if (upce[6] == 4)
            {
                upca[3] = upce[3];     
                upca[4] = upce[4];
                upca[5] = 0;
                upca[6] = 0;
                upca[7] = 0;                 
                upca[8] = 0;
                upca[9] = 0;
                upca[10] = upce[5];
            }
            else if ((upce[6] >= 5) && (upce[6] <= 9))
            {
                upca[3] = upce[3];     
                upca[4] = upce[4];
                upca[5] = upce[5];
                upca[6] = 0;
                upca[7] = 0;                 
                upca[8] = 0;
                upca[9] = 0;
                upca[10] = upce[6];
            }   
            else
            {
                return false;    
            }
 
            //Kopiuj dwie pierwsze cyfyr (kod producenta)
            upca[1] = upce[1];
            upca[2] = upce[2];
 
            //Kopiuj numer systemu i cyfre kontrolna
            upca[0] = upce[0];
            upca[11] = upce[7];  
 
            //Oblicz cyfre kontrolna
            int sum = 3 * upca[0] +
                      1 * upca[1] +
                      3 * upca[2] +
                      1 * upca[3] +
                      3 * upca[4] +
                      1 * upca[5] +
                      3 * upca[6] +
                      1 * upca[7] +
                      3 * upca[8] +
                      1 * upca[9] +
                      3 * upca[10];
            sum %= 10;
            sum = 10 - sum;
            sum %= 10;
            if (sum != upca[11])
            {
                return false;
            }

            return true;
        }

        /// <summary>
        /// Generuje kod kreskowy
        /// </summary>
        /// <param name="code">kod UPC-E</param>
        /// <returns>kod kreskowy - 1 pasek czarny, 0 - pasek bialy</returns>
        private int[] generateBars(string code)
        {
            int[] bars = new int[51];

            int[] UPCE = new int[8];
            for (int i = 0; i < 8; i++)
            {
                int.TryParse(code.Substring(i, 1), out UPCE[i]);
            }

            bars[0] = 1;
            bars[1] = 0;
            bars[2] = 1;

            for (int i = 1; i < 7; i++)
            {
                for (int j = 0; j < 7; j++)
                {
                    bars[(i - 1) * 7 + 3 + j] = left[parityTable[UPCE[0], UPCE[7], i - 1], UPCE[i], j];
                }
            }

            bars[45] = 0;
            bars[46] = 1;
            bars[47] = 0;
            bars[48] = 1;
            bars[49] = 0;
            bars[50] = 1;

            return bars;
        }
    }
}