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.IO;

namespace m13
{
    public partial class MainForm : Form
    {
        public MainForm()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            if (openFileDialog.ShowDialog() == DialogResult.OK)
            {
                textBox1.Text = openFileDialog.FileName;
            }
        }

        private void run_Click(object sender, EventArgs e)
        {
            if (!File.Exists(textBox1.Text))
            {
                MessageBox.Show("Soubor neexistuje!", "Chyba", MessageBoxButtons.OK, MessageBoxIcon.Error);
                return;
            }
            //try
            {
                commands = ParseCommands(textBox1.Text);

                Bitmap bmp = new Bitmap(700, 700);
                Graphics g = Graphics.FromImage(bmp);
                g.Clear(Color.White);
                foreach (ZLine ln in commands)
                    g.DrawLine(Pens.Black, 350 + ln.p1.X, 350 - ln.p1.Y, 350 + ln.p2.X, 350 - ln.p2.Y);
                g.Flush();
                render.Image = bmp;
            }
            /*catch 
            {
                MessageBox.Show("Neznámá chyba!", "Chyba", MessageBoxButtons.OK, MessageBoxIcon.Error);
            }/*/
        }

        private struct ZLine
        {
            public Point p1;
            public Point p2;
        }

        private List<ZLine> commands = new List<ZLine>();

        private List<ZLine> ParseCommands(string filename)
        {
            List<ZLine> ret = new List<ZLine>();
            int angle = 90;
            int posx = 0;
            int posy = 0;
            int pen = 0;

            string func = "";
            string numb = "";
            bool justNumbers = false;

            StreamReader sr = new StreamReader(filename);
            try
            {
                while (!sr.EndOfStream)
                {
                    char c = (char)(sr.Read());
                    if (justNumbers)
                    {
                        if (c == ')')
                        {
                            justNumbers = false;
                            int n = int.Parse(numb);
                            switch (func)
                            {
                                case "left":
                                    angle += n;
                                    if (angle >= 360)
                                        angle -= 360;
                                    break;

                                case "right":
                                    angle -= n;
                                    if (angle < 0)
                                        angle += 360;
                                    break;

                                case "pen":
                                    pen = n;
                                    break;

                                case "forward":
                                    int nposx = posx;
                                    int nposy = posy;
                                    switch (angle)
                                    {
                                        case 0:
                                            nposx += n;
                                            break;
                                        case 180:
                                            nposx -= n;
                                            break;
                                        case 90:
                                            nposy += n;
                                            break;
                                        case 270:
                                            nposy -= n;
                                            break;
                                    }
                                    if (pen > 0)
                                    {
                                        ZLine ln = new ZLine();
                                        ln.p1 = new Point(posx, posy);
                                        ln.p2 = new Point(nposx, nposy);
                                        ret.Add(ln);
                                    }
                                    posx = nposx;
                                    posy = nposy;
                                    break;
                            }
                            func = "";
                            numb = "";
                        }
                        else
                            if (((c >= '0') && (c <= '9')) || (c == '-'))
                                numb += c;
                    }
                    else
                    {
                        if ((c >= 'a') && (c <= 'z'))
                            func += c;
                        else
                            if (c == '(')
                                justNumbers = true;
                    }
                }
            }
            finally
            {
                sr.Close();
            }
            return ret;
        }
    }
}