using System;
using System.Drawing;
using System.Windows.Forms;
using System.Runtime.InteropServices;

namespace WorldOfPeacecraft
{
	class Gui : Form, IGui
	{
		private const int tileSize = 16;
		private const int entitySize = 10;
		private IBackend Backend;

		private Panel Board = new Panel();

		public Gui ()
		{
			AllocConsole();
			InitializeComponents();
		}

		public void SetBackend (IBackend backend)
		{
			Backend = backend;
		}

		public void InitializeComponents ()
		{
			this.SuspendLayout();
			this.Size = new Size(400, 400);
			Board.Location = new Point(0,0);
			Board.Size = new Size(400, 400);
			Board.Paint += DoPaint;
			this.DoubleBuffered = true;
			this.MaximizeBox = false;
            this.FormBorderStyle = System.Windows.Forms.FormBorderStyle.FixedSingle;
			this.Name = "WorldOfPeacecraft";
            this.ShowIcon = false;

			this.Controls.Add(Board);
			this.ResumeLayout();
            this.PerformLayout();
		}

		public void DoPaint (object source, PaintEventArgs args)
		{
			BufferedGraphics buffer = BufferedGraphicsManager.Current.Allocate (Board.CreateGraphics (), Board.DisplayRectangle);
			Graphics g = buffer.Graphics;
			PaintMap(g);
			buffer.Render();
		}

		public void PaintMap (Graphics g)
		{
			ITile[,] Map = Backend.GetMap ();
			if (Map != null) {
				for (int y = 0; y < Map.GetLength(1); y++) {
					for (int x = 0; x < Map.GetLength(0); x++) {
						PaintTile (g, Map [x, y], x, y);
					}
				}
			}
			else {
				g.FillRectangle(new SolidBrush(Color.White), Board.DisplayRectangle);
			}
		}

		public void PaintTile (Graphics g, ITile tile, int x, int y)
		{
			int posx = x * tileSize;
			int posy = y * tileSize;
			Color color;
			if (tile.IsForest ()) {
				color = Color.Green;
			} // Stupid parenthesis
			else if (tile.IsHuntable ()) {
				color = Color.BurlyWood;
			} else if (tile.IsWalkable ()) {
				color = Color.Yellow;
			} else if (tile.IsWall ()) {
				color = Color.DarkGray;
			} else if (tile.IsWater ()) {
				color = Color.Blue;
			} else {
				color = Color.Black;
			}
			g.FillRectangle(new SolidBrush(color), posx, posy, tileSize, tileSize);
		}

		public void PerformRefresh ()
		{
			this.BeginInvoke(new MethodInvoker(delegate
			{
				ITile[,] map = Backend.GetMap();
				int mapWidth = (map.GetLength(0)) * tileSize;
				int mapHeight = (map.GetLength(1)) * tileSize;
				this.SuspendLayout();
				this.SetClientSizeCore(mapWidth, mapHeight);
				Board.Size = new Size(mapWidth, mapHeight);
				this.ResumeLayout();
				this.PerformLayout();
				this.Refresh();
			}));
		}

		[DllImport("kernel32.dll", SetLastError = true)]
		[return: MarshalAs(UnmanagedType.Bool)]
		static extern bool AllocConsole();
	}
}