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 Zelvaci {
    public enum prikaz
    {
        FORWARD, PEN, LEFT, RIGHT, COLOR, REPEAT, IF, DEFINE
    };

    public struct pair
    {
        public prikaz typ;
        public List<int> parameters;
    };

    public partial class Zelvaci : Form
    {
        Image result;
        InteractiveViewForm iv;
        Dictionary<string, string> functions = new Dictionary<string,string>();

        public Zelvaci()
        {
            DocumentationForm d = new DocumentationForm();
            d.ShowDialog();
            InitializeComponent();
        }

        /// <summary>
        /// Naparsuje vstup do seznamu příkazů které poté vykreslí pomocí další metody draw
        /// </summary>
        /// <param name="input"></param>
        private List<pair> parse(string input)
        {
            int readed = 0; // počet přečtených znaků ze vstupu
            int start = 0; // index prvního znaku nového příkazu
            
            List<pair> prog = new List<pair>();
            while (readed < input.Length)
            {
				if (input[readed] == '}')
					readed++;
                start = readed;
                while (readed < input.Length && input[readed] != ')')
                {
                    readed++;
                }
                if (readed == input.Length)
                    break;
                int end = readed; // konec příkazu bez parametrů
                while(input[end] != '(')
                    end--;
                
                pair next = new pair();
                string name = input.Substring(start, end-start);
                string funcname = "";
                if(name.Length > 6 && name.Substring(0, 6) == "define")
                {
					funcname = name.Substring(6);
					StringBuilder sb = new StringBuilder(input);
					sb[start+6] = 'ř';
					input = sb.ToString();
					name = "define";
                }
                next.typ = (prikaz)Enum.Parse(typeof(prikaz), name.ToUpper());
                next.parameters = new List<int>();
                // načteme parametry do seznamu
                int i = end + 1;                
                while(i < input.Length && input[i] != ')')
                {
                    int lastEnd = i;
                    while (i < input.Length && input[i] != ')' && input[i] != ',')
                    {
                        i++;
                    }
                    next.parameters.Add(int.Parse(input.Substring(lastEnd, i-(lastEnd))));
                    if (input[i] == ',')
                        i++;
                }
                if (next.typ == prikaz.IF || next.typ == prikaz.REPEAT || next.typ == prikaz.DEFINE) // blokové příkazy
                {
                    int startBlock = i + 1; // index znaku se složenou závorkou (otevírací)
                    i = startBlock;
                    int slozene = 0;
                    while (i < input.Length)
                    {
						if(input[i] == '{')
							slozene++;
						else if(input[i] == '}')
							slozene--;
						if(slozene == 0)
							break;
                        i++;
                    }
                    int endBlock = i-1;
                    if (next.typ == prikaz.IF)
                    {
                        if (next.parameters[0] > 0) {
                            List<pair> subprog = parse(input.Substring(startBlock+1, endBlock - startBlock));
                            foreach (pair p in subprog)
                                prog.Add(p);
                            readed = endBlock;
                        }
                        else
                        {
                            readed = endBlock;
                        }
                        readed++;
                    }
					else if (next.typ == prikaz.REPEAT)
					{
						if (next.parameters[0] > 0) {
							List<pair> subprog = parse(input.Substring(startBlock + 1, endBlock - startBlock));
							for (int j = 0; j < next.parameters[0]; j++) {
								foreach (pair p in subprog)
								{
									prog.Add(p);
								}
							}
						}
						readed = endBlock+1;
					}
					else if(next.typ == prikaz.DEFINE)
					{
						functions.Add(funcname + "()", input.Substring(startBlock + 1, endBlock - startBlock));
						readed = endBlock - 1;
					}
                }
                else
                {
                    prog.Add(next);
                }
                readed++;
                foreach(KeyValuePair<string, string> kv in functions)
                {
					input = input.Replace(kv.Key, kv.Value);
                }
            }
            
            
            return prog;
        }

        /// <summary>
        /// Vykreslí program do obrázku
        /// </summary>
        /// <param name="prog"></param>
        public void draw(List<pair> prog)
        {
            result = (Image)new Bitmap(700, 700);
            Graphics g = Graphics.FromImage(result);
            g.FillRectangle(Brushes.White, 0, 0, 700, 700);

            // výchozí parametry
            Color c = Color.Black;
            float x = 350, y = 350; // pozice želvy
            int rotation = -90;
            int pen = 0;

            int stepsDone = 0;
            int maxSteps = 0;
            if (tbSteps.Text.Length == 0 || int.Parse(tbSteps.Text) == 0) {
                int pppp = 0;
                foreach (pair p in prog) {
                    switch (p.typ) {
                        case prikaz.FORWARD:
                            if (pppp > 0) {
                                maxSteps++;
                            }
                            break;
                        case prikaz.PEN:
                            pppp = p.parameters[0];
                            break;
                    }
                }
            }
            else {
                maxSteps = int.Parse(tbSteps.Text);
            }
            foreach(pair p in prog)
            {
                switch (p.typ)
                {
                    case prikaz.FORWARD:
                        
                        float endX = x + p.parameters[0] * (float)Math.Cos(rotation * (Math.PI / 180));
                        float endY = y + p.parameters[0] * (float)Math.Sin(rotation * (Math.PI / 180));
                        if (pen > 0)
                        {
                            float startX = x;
                            float startY = y;
                            stepsDone++;
                            g.DrawLine(new Pen(c, pen), new PointF(startX, startY), new PointF(endX, endY));
                        }
                        x = endX;
                        y = endY;
                        break;
                    case prikaz.LEFT:
                        rotation -= p.parameters[0];
                        break;
                    case prikaz.RIGHT:
                        rotation += p.parameters[0];
                        break;
                    case prikaz.PEN:
                        pen = p.parameters[0];
                        break;
                    case prikaz.COLOR:
                        int r, gg, b;
                        r = Math.Max(0, Math.Min(255, p.parameters[0]));
                        gg = Math.Max(0, Math.Min(255, p.parameters[1]));
                        b = Math.Max(0, Math.Min(255, p.parameters[2]));
                        c = Color.FromArgb(r, gg, b);
                        break;
                }

                if (stepsDone == maxSteps)
                    break;                
            }
            result.Save(tbOutput.Text);
            MessageBox.Show("Soubor byl uložen.");
        }

        /// <summary>
        /// Rutina pro spojení řádků a odstranění bílých mezer
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void button1_Click(object sender, EventArgs e)
        {
            string path = tbInput.Text;
            string[] prog = File.ReadAllLines(path);
            string input = String.Join("", prog);
            input = input.Replace(" ", "");
            List<pair> lp = parse(input);
            draw(lp);
        }

        /// <summary>
        /// Dialog pro otevření souboru
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void button2_Click(object sender, EventArgs e)
        {
            if (openFile.ShowDialog() == DialogResult.OK)
            {
                tbInput.Text = openFile.FileName;
            }
        }

        /// <summary>
        /// Dialog pro uložení souboru
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void button3_Click(object sender, EventArgs e)
        {
            if (saveFile.ShowDialog() == DialogResult.OK)
            {
                tbOutput.Text = saveFile.FileName;
            }
        }

        /// <summary>
        /// Zobrazení interaktivního režimu
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void button4_Click(object sender, EventArgs e)
        {
            iv = new InteractiveViewForm();
            string path = tbInput.Text;
            string[] prog = File.ReadAllLines(path);
            string input = String.Join("", prog);
            input = input.Replace(" ", "");
            iv.prog = parse(input);
            iv.Show();
        }
    }
}