using System;
using System.Drawing;
using ClassicalSharp.GraphicsAPI;
using OpenTK.Input;

namespace ClassicalSharp {
	
	public sealed class BlockHotbarWidget : Widget {
		
		public BlockHotbarWidget( Game game ) : base( game ) {
			HorizontalAnchor = Anchor.Centre;
			VerticalAnchor = Anchor.BottomOrRight;
			hotbarCount = game.Inventory.Hotbar.Length;
		}
		
		int hotbarCount;
		Texture selectedBlock, background;
		int blockSize, borderSize;
		
		public override bool HandlesKeyDown( Key key ) {
			if( key >= Key.Number1 && key <= Key.Number9 ) {
				game.Inventory.HeldBlockIndex = (int)key - (int)Key.Number1;
				return true;
			}
			return false;
		}
		
		static FastColour backCol = new FastColour( 60, 60, 60, 160 );
		static FastColour outlineCol = new FastColour( 151, 120, 180 );
		static FastColour selCol = new FastColour( 213, 200, 223 );
		public override void Init() {
			blockSize = (int)(38 * game.GuiScale);
			borderSize = (int)(3 * game.GuiScale);
			int width = blockSize * hotbarCount;
			X = game.Width / 2 - width / 2;
			Y = game.Height - blockSize;
			
			Width = width;
			Height = blockSize;
			MakeBackgroundTexture( width );
			MakeSelectionTexture();
		}
		
		public override void Render( double delta ) {
			graphicsApi.Texturing = true;
			background.Render( graphicsApi );
			graphicsApi.BindTexture( game.TerrainAtlas.TexId );
			graphicsApi.SetBatchFormat( VertexFormat.Pos3fTex2fCol4b );
			
			for( int i = 0; i < hotbarCount; i++ ) {
				int x = X + i * blockSize;
				IsometricBlockDrawer.Draw( game, (byte)game.Inventory.Hotbar[i], blockSize / 2 - borderSize - 2,
				                          x + 1 + blockSize / 2, game.Height - blockSize / 2 );
				if( i == game.Inventory.HeldBlockIndex )
					selectedBlock.X1 = x;
			}
			
			selectedBlock.Render( graphicsApi );
			graphicsApi.Texturing = false;
		}
		
		public override void Dispose() {
			graphicsApi.DeleteTexture( ref selectedBlock );
			graphicsApi.DeleteTexture( ref background );
		}
		
		public override void MoveTo( int newX, int newY ) {
			int diffX = newX - X, diffY = newY - Y;
			X = newX; Y = newY;
			Dispose();
			Init();
		}
		
		void MakeBackgroundTexture( int width ) {
			Size size = new Size( width, blockSize );
			using( Bitmap bmp = IDrawer2D.CreatePow2Bitmap( size ) )
				using( IDrawer2D drawer = game.Drawer2D )
			{
				drawer.SetBitmap( bmp );
				drawer.Clear( backCol );
				for( int xx = 0; xx < hotbarCount; xx++ ) {
					drawer.DrawRectBounds( outlineCol, borderSize, xx * blockSize,
					                      0, blockSize, blockSize );
				}
				background = drawer.Make2DTexture( bmp, size, X, Y );
			}
		}
		
		void MakeSelectionTexture() {
			Size size = new Size( blockSize, blockSize );
			using( Bitmap bmp = IDrawer2D.CreatePow2Bitmap( size ) )
				using( IDrawer2D drawer = game.Drawer2D )
			{
				drawer.SetBitmap( bmp );
				drawer.DrawRectBounds( selCol, borderSize, 0, 0, blockSize, blockSize );
				selectedBlock = drawer.Make2DTexture( bmp, size, 0, Y );
			}
		}
	}
}