//Kod kreskowy EAN-5
//(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.EAN5
{
    public partial class Form1 : Form
    {
        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}
            }
        };

        private readonly int [,] checksumTable = 
        {
            {1, 1, 0, 0, 0},
            {1, 0, 1, 0, 0},
            {1, 0, 0, 1, 0},
            {1, 0, 0, 0, 1},
            {0, 1, 1, 0, 0},
            {0, 0, 1, 1, 0},
            {0, 0, 0, 1, 1},
            {0, 1, 0, 1, 0},
            {0, 1, 0, 0, 1},
            {0, 0, 1, 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>
        /// Generuj kod kreskowy EAN-5
        /// </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 EAN-5!", "Bład", MessageBoxButtons.OK, MessageBoxIcon.Error);
                return;
            }

            //Wygeneruj i narysuj kod
            int[] bars = generateBars(code);
            for (int i = 0; i < bars.Length; i++)
            {
                if (bars[i] == 1)
                {
                    graphics.FillRectangle(blackBrush, i * 2 + 70, 40, 2, 60);
                }
            }

            //Wypisz cyfry nad kodem
            for (int i = 0; i < 5; i++)
            {
                graphics.DrawString(code.Substring(i, 1), drawFont, blackBrush, i * 17 + 80, 20);
            }

            //Odswiez
            pictureBox.Refresh();

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

        /// <summary>
        /// Sprawdz EAN-5
        /// </summary>
        /// <param name="code"></param>
        /// <returns>true jezeli prawidlowy, false w przeciwnym razie</returns>
        private bool checkCode(string code)
        {
            //Sprawdz dlugosc
            if (code.Length != 5)
            {
                return false;
            }

            //Sprawdz czy podano tylko cyfry
            int[] values = new int[5];
            for (int i = 0; i < 5; i++)
            {
                if (int.TryParse(code.Substring(i, 1), out values[i]) == false)
                    return false;
            }

            return true;
        }

        /// <summary>
        /// Generuje kod kreskowy
        /// </summary>
        /// <param name="code">kod EAN-5</param>
        /// <returns>kod kreskowy - 1 pasek czarny, 0 - pasek bialy</returns>
        private int[] generateBars(string code)
        {
            int[] bars = new int[47];

            int[] EAN5 = new int[5];
            for (int i = 0; i < 5; i++)
            {
                int.TryParse(code.Substring(i, 1), out EAN5[i]);
            }

            //oblicz sume kontrolna
            int checkSum = 3 * EAN5[0] + 9 * EAN5[1] + 3 * EAN5[2] + 9 * EAN5[3] + 3 * EAN5[4];
            checkSum %= 10;

            bars[0] = 1;
            bars[1] = 0;
            bars[2] = 1;
            bars[3] = 1;

            for (int i = 0; i < 5; i++)
            {
                for (int j = 0; j < 7; j++)
                {
                    bars[i * 9 + 4 + j] = left[checksumTable[checkSum, i], EAN5[i], j];
                }
                if (i < 4)
                {
                    bars[i * 9 + 11] = 0;
                    bars[i * 9 + 12] = 1;
                }
            }

            return bars;
        }
    }
}