using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Snake
{
    public class Worm
    {
        public List<Cell> Body = new List<Cell>();

        public Worm(Cell startCell)
        {
            Body.Add(startCell);
            startCell.Color = ColorFromHue((float)(Body.Count * 8));
        }

        public void Move(int x, int y, Map map)
        {
            Cell swapCell = map.Cells[x, y];

            for (int i = 1; i < Body.Count; i++)
            {
                map.SwapCells(swapCell, Body[i]);
                swapCell = Body[i];
            }
        }

        public void Eat(ref Cell cell)
        {
            cell.Type = CellTypes.Snake;
            cell.Color = ColorFromHue((float)(Body.Count * 8));
            Body.Insert(1, cell);
        }

        public Color ColorFromHue(float hue)
        {
            hue = hue % 360f;
            float c = 1f;
            float x = c * (1 - Math.Abs((hue / 60f) % 2 - 1));
            float m = 0f;

            float r = 0, g = 0, b = 0;

            if (hue < 60) { r = c; g = x; }
            else if (hue < 120) { r = x; g = c; }
            else if (hue < 180) { g = c; b = x; }
            else if (hue < 240) { g = x; b = c; }
            else if (hue < 300) { r = x; b = c; }
            else { r = c; b = x; }

            return Color.FromArgb(
                (int)((r + m) * 255),
                (int)((g + m) * 255),
                (int)((b + m) * 255)
            );
        }
    }
}