/*
 * Created by SharpDevelop.
 * User: Student
 * Date: 13.11.2018
 * Time: 15:12
 *
 * To change this template use Tools | Options | Coding | Edit Standard Headers.
 */
using System;
using System.Collections.Generic;
using System.Drawing;
using System.Windows.Forms;

namespace wall_lab
{
    /// <summary>
    /// Description of MainForm.
    /// </summary>
    public partial class MainForm : Form
    {
        Random rand = new Random();

        public bool ValueInPointArray(bool[][] array, Point compare) {
            return array[compare.Y][compare.X];
        }

        public Point PointMod(Point pt, int x, int y) {
            pt.X += x;
            pt.Y += y;
            return pt;
        }

        public void SetWallsMove(ref bool[][] walls_w, ref bool[][] walls_h, Point from, Point to) {
            to.X -= from.X;
            to.Y -= from.Y;

            if(to.X != 0) {
                walls_w[from.Y][from.X+(to.X==1?1:0)] = false;
                g.DrawLine(wpen, (from.X + (to.X==1?1:0)) * (w_y), from.Y * (w_x), (from.X + (to.X==1?1:0)) * (w_y), (from.Y + 1) * (w_x) );
            }
            else if(to.Y != 0) {
                walls_h[from.Y+(to.Y==1?1:0)][from.X] = false;
                g.DrawLine(wpen, (from.X) * (w_y), (from.Y+(to.Y==1?1:0)) * (w_x), (from.X+1) * (w_y), (from.Y+(to.Y==1?1:0)) * (w_x) );
            }

        }

        public byte[] moves = new byte[4];
        byte counter = 0;

        public bool CanMakeMove(int width, int height, ref bool[][] oldpos, ref Point[] old, ref int old_length) {
            //no more moves
            if(old_length < 1) return false;

            counter = 0;
            if(old[old_length-1].Y > 0 && !ValueInPointArray(oldpos, PointMod(old[old_length-1], 0, -1))) moves[0] = ++counter;
            else moves[0] = 0;
            if(old[old_length-1].X < width-1 && !ValueInPointArray(oldpos, PointMod(old[old_length-1], 1, 0))) moves[1] = ++counter;
            else moves[1] = 0;
            if(old[old_length-1].Y < height-1 && !ValueInPointArray(oldpos, PointMod(old[old_length-1], 0, 1))) moves[2] = ++counter;
            else moves[2] = 0;
            if(old[old_length-1].X > 0 && !ValueInPointArray(oldpos, PointMod(old[old_length-1], -1, 0))) moves[3] = ++counter;
            else moves[3] = 0;
            return counter > 0;
        }

        public bool MakeMove(int width, int height, ref bool[][] walls_w, ref bool[][] walls_h, ref bool[][] oldpos, ref Point[] old, ref int old_length) {

            //move available?
            if(CanMakeMove(width, height, ref oldpos, ref old, ref old_length) && counter >= 1) {
                //make move
                counter = (byte)(rand.Next(1, (int)counter+1));
                for(int i = 0; i < 4; i++) {
                    if(moves[i] == counter) {
                        old[old_length] = PointMod(old[old_length-1], (i%2==1?(i==1?1:-1):0), (i%2==0?(i==0?-1:1):0));
                        oldpos[old[old_length].Y][old[old_length].X] = true;

                        SetWallsMove(ref walls_w, ref walls_h, old[old_length-1], old[old_length]);

                        old_length += 1;
                        return true;
                    }
                }
            }
            return --old_length > 0;
        }

        public Panel p = new Panel();
        public int width = 80;
        public int height = 60;
        public int w_x, w_y;
        public bool[][] walls_w, walls_h;
        public bool[][] oldpos;
        public Point[] old;
        public int pl_len = 1;

        public System.Windows.Forms.Timer drawer = new System.Windows.Forms.Timer();

        public SolidBrush b = new SolidBrush(Color.White);
        public Pen pen = new Pen(Color.Black);
        public Pen wpen = new Pen(Color.White);
        public Graphics g;

        public MainForm()
        {
            //
            // The InitializeComponent() call is required for Windows Forms designer support.
            //
            InitializeComponent();
            this.FormBorderStyle = FormBorderStyle.FixedSingle;

            //this.SetClientSizeCore(800, 600);
            this.ClientSize = new Size(800, 600);


            p.Location = new Point(0, 0);
            p.Size = new Size(800, 600);
            p.BackColor = Color.White;
            this.Controls.Add(p);
            g = p.CreateGraphics();

            walls_w = new bool[height + 1][];
            walls_h = new bool[height + 1][];
            for( int i = 0; i < height + 1; i++ ) {
                walls_w[i] = new bool[width + 1];
                walls_h[i] = new bool[width + 1];
                for(int j = 0; j <= width; j++) { walls_w[i][j] = true; walls_h[i][j] = true; }
            }

            oldpos = new bool[height][];
            for( int i = 0; i < height; i++ ) {
                oldpos[i] = new bool[width];
            }

            old = new Point[width * height];
            old[0] = new Point(rand.Next(width), rand.Next(height));
            oldpos[old[0].Y][old[0].X] = true;

            w_x = 800/(width);
            w_y = 600/(height);

            pen.Width = 6;
            wpen.Width = 6;
            drawer.Tick += new EventHandler(TimerEvent);
            drawer.Start();
            drawer.Interval = 1;
        }

        public void PaintMap() {
            for(int y = 0; y <= height; y++) {
                for(int x = 0; x <= width; x++) {
                    if( walls_w[y][x] ) g.DrawLine(pen, x * (w_y), y * (w_x), x * (w_y), (y + 1) * (w_x) );
                    if( walls_h[y][x] ) g.DrawLine(pen, x * (w_y), y * (w_x), (x + 1) * (w_y), y * (w_x) );
                }
            }
        }

        public void ClearMap() {
            //b.Color = Color.Red;
            g.FillRectangle(b, new RectangleF(0, 0, 800, 600));
        }

        public bool firstrun = true;
        public void TimerEvent(object sender, EventArgs e) {
            //PaintMap();
            if(firstrun) {
                ClearMap();
                PaintMap();
                firstrun = false;
            }
            if(!MakeMove(width, height, ref walls_w, ref walls_h, ref oldpos, ref old, ref pl_len)) {
                ClearMap();
                PaintMap();
                drawer.Stop();
                g.Dispose();
                pen.Dispose();
                wpen.Dispose();
            }
        }
    }
}