#region Copyright & License Information
/*
 * Copyright 2007-2014 The OpenRA Developers (see AUTHORS)
 * This file is part of OpenRA, which is free software. It is made
 * available to you under the terms of the GNU General Public License
 * as published by the Free Software Foundation. For more information,
 * see COPYING.
 */
#endregion

using System;
using System.Collections.Generic;
using System.Linq;
using OpenRA.Mods.RA;
using OpenRA.Traits;

namespace OpenRA.Mods.D2k
{
	[Desc("Used to render spice with round borders.")]
	public class D2kResourceLayerInfo : TraitInfo<D2kResourceLayer> { }

	public class D2kResourceLayer : ResourceLayer
	{
		[Flags] enum ClearSides : byte
		{
			None = 0x0,
			Left = 0x1,
			Top = 0x2,
			Right = 0x4,
			Bottom = 0x8,

			TopLeft = 0x10,
			TopRight = 0x20,
			BottomLeft = 0x40,
			BottomRight = 0x80,

			All = 0xFF
		}

		static readonly Dictionary<string, int[]> Variants = new Dictionary<string, int[]>()
		{
			{ "cleara", new[] { 0, 50 } },
			{ "clearb", new[] { 1, 51 } },
			{ "clearc", new[] { 43, 52 } },
			{ "cleard", new[] { 0, 53 } },
		};

		static readonly Dictionary<ClearSides, int> SpriteMap = new Dictionary<ClearSides, int>()
		{
			{ ClearSides.None, 0 },
			{ ClearSides.Left | ClearSides.Top | ClearSides.TopLeft | ClearSides.TopRight | ClearSides.BottomLeft | ClearSides.BottomRight, 2 },
			{ ClearSides.Top | ClearSides.Right | ClearSides.TopLeft | ClearSides.TopRight | ClearSides.BottomLeft | ClearSides.BottomRight, 3 },
			{ ClearSides.Left | ClearSides.Bottom | ClearSides.TopLeft | ClearSides.TopRight | ClearSides.BottomLeft | ClearSides.BottomRight, 4 },
			{ ClearSides.Right | ClearSides.Bottom | ClearSides.TopLeft | ClearSides.TopRight | ClearSides.BottomLeft | ClearSides.BottomRight, 5 },
			{ ClearSides.Left | ClearSides.TopLeft | ClearSides.TopRight | ClearSides.BottomLeft | ClearSides.BottomRight, 6 },
			{ ClearSides.Right | ClearSides.TopLeft | ClearSides.TopRight | ClearSides.BottomLeft | ClearSides.BottomRight, 7 },
			{ ClearSides.Top | ClearSides.TopLeft | ClearSides.TopRight | ClearSides.BottomLeft | ClearSides.BottomRight, 8 },
			{ ClearSides.Bottom | ClearSides.TopLeft | ClearSides.TopRight | ClearSides.BottomLeft | ClearSides.BottomRight, 9 },
			{ ClearSides.Left | ClearSides.Top | ClearSides.TopLeft | ClearSides.TopRight | ClearSides.BottomLeft, 10 },
			{ ClearSides.Top | ClearSides.Right | ClearSides.TopLeft | ClearSides.TopRight | ClearSides.BottomRight, 11 },
			{ ClearSides.Left | ClearSides.Bottom | ClearSides.TopLeft | ClearSides.BottomLeft | ClearSides.BottomRight, 12 },
			{ ClearSides.Right | ClearSides.Bottom | ClearSides.TopRight | ClearSides.BottomLeft | ClearSides.BottomRight, 13 },
			{ ClearSides.Left | ClearSides.Top | ClearSides.Right | ClearSides.TopLeft | ClearSides.TopRight | ClearSides.BottomLeft | ClearSides.BottomRight, 14 },
			{ ClearSides.Left | ClearSides.Right | ClearSides.Bottom | ClearSides.TopLeft | ClearSides.TopRight | ClearSides.BottomLeft | ClearSides.BottomRight, 15 },
			{ ClearSides.Left | ClearSides.Top | ClearSides.Bottom | ClearSides.TopLeft | ClearSides.TopRight | ClearSides.BottomLeft | ClearSides.BottomRight, 16 },
			{ ClearSides.Top | ClearSides.Right | ClearSides.Bottom | ClearSides.TopLeft | ClearSides.TopRight | ClearSides.BottomLeft | ClearSides.BottomRight, 17 },
			{ ClearSides.Top | ClearSides.TopLeft | ClearSides.TopRight, 18 },
			{ ClearSides.Right | ClearSides.TopRight | ClearSides.BottomRight, 19 },
			{ ClearSides.Left | ClearSides.TopLeft | ClearSides.BottomLeft, 20 },
			{ ClearSides.Bottom | ClearSides.BottomLeft | ClearSides.BottomRight, 21 },
			{ ClearSides.TopLeft, 22 },
			{ ClearSides.TopRight, 23 },
			{ ClearSides.BottomLeft, 24 },
			{ ClearSides.BottomRight, 25 },
			{ ClearSides.Left | ClearSides.TopLeft | ClearSides.BottomLeft | ClearSides.BottomRight, 26 },
			{ ClearSides.Right | ClearSides.TopRight | ClearSides.BottomLeft | ClearSides.BottomRight, 27 },
			{ ClearSides.Top | ClearSides.TopLeft | ClearSides.TopRight | ClearSides.BottomRight, 28 },
			{ ClearSides.Top | ClearSides.TopLeft | ClearSides.TopRight | ClearSides.BottomLeft, 29 },
			{ ClearSides.TopRight | ClearSides.BottomLeft | ClearSides.BottomRight, 30 },
			{ ClearSides.TopLeft | ClearSides.BottomLeft | ClearSides.BottomRight, 31 },
			{ ClearSides.TopLeft | ClearSides.TopRight | ClearSides.BottomRight, 32 },
			{ ClearSides.TopLeft | ClearSides.TopRight | ClearSides.BottomLeft, 33 },
			{ ClearSides.TopRight | ClearSides.BottomRight, 34 },
			{ ClearSides.TopLeft | ClearSides.TopRight, 35 },
			{ ClearSides.TopRight | ClearSides.BottomLeft, 36 },
			{ ClearSides.TopLeft | ClearSides.BottomLeft, 37 },
			{ ClearSides.BottomLeft | ClearSides.BottomRight, 38 },
			{ ClearSides.TopLeft | ClearSides.BottomRight, 39 },
			{ ClearSides.TopLeft | ClearSides.TopRight | ClearSides.BottomLeft | ClearSides.BottomRight, 40 },
			{ ClearSides.Left | ClearSides.Right | ClearSides.TopLeft | ClearSides.TopRight | ClearSides.BottomLeft | ClearSides.BottomRight, 41 },
			{ ClearSides.Top | ClearSides.Bottom | ClearSides.TopLeft | ClearSides.TopRight | ClearSides.BottomLeft | ClearSides.BottomRight, 42 },
			{ ClearSides.All, 44 },
			{ ClearSides.Left | ClearSides.TopLeft | ClearSides.TopRight | ClearSides.BottomLeft, 46 },
			{ ClearSides.Right | ClearSides.TopLeft | ClearSides.TopRight | ClearSides.BottomRight, 47 },
			{ ClearSides.Bottom | ClearSides.TopRight | ClearSides.BottomLeft | ClearSides.BottomRight, 48 },
			{ ClearSides.Bottom | ClearSides.TopLeft | ClearSides.BottomLeft | ClearSides.BottomRight, 49 },
		};

		ClearSides FindClearSides(ResourceType t, CPos p)
		{
			var ret = ClearSides.None;
			if (render[p + new CVec(0, -1)].Type != t)
				ret |= ClearSides.Top | ClearSides.TopLeft | ClearSides.TopRight;

			if (render[p + new CVec(-1, 0)].Type != t)
				ret |= ClearSides.Left | ClearSides.TopLeft | ClearSides.BottomLeft;

			if (render[p + new CVec(1, 0)].Type != t)
				ret |= ClearSides.Right | ClearSides.TopRight | ClearSides.BottomRight;

			if (render[p + new CVec(0, 1)].Type != t)
				ret |= ClearSides.Bottom | ClearSides.BottomLeft | ClearSides.BottomRight;

			if (render[p + new CVec(-1, -1)].Type != t)
				ret |= ClearSides.TopLeft;

			if (render[p + new CVec(1, -1)].Type != t)
				ret |= ClearSides.TopRight;

			if (render[p + new CVec(-1, 1)].Type != t)
				ret |= ClearSides.BottomLeft;

			if (render[p + new CVec(1, 1)].Type != t)
				ret |= ClearSides.BottomRight;

			return ret;
		}

		void UpdateRenderedTileInner(CPos p)
		{
			var t = render[p];
			if (t.Density > 0)
			{
				var clear = FindClearSides(t.Type, p);
				int index;

				if (clear == ClearSides.None)
				{
					var sprites = Variants[t.Variant];
					var frame = t.Density > t.Type.Info.MaxDensity / 2 ? 1 : 0;
					t.Sprite = t.Type.Variants.First().Value[sprites[frame]];
				}
				else if (SpriteMap.TryGetValue(clear, out index))
					t.Sprite = t.Type.Variants.First().Value[index];
				else
					t.Sprite = null;
			}
			else
				t.Sprite = null;

			render[p] = t;
		}

		protected override void UpdateRenderedSprite(CPos p)
		{
			// Need to update neighbouring tiles too
			UpdateRenderedTileInner(p);
			UpdateRenderedTileInner(p + new CVec(-1, -1));
			UpdateRenderedTileInner(p + new CVec(0, -1));
			UpdateRenderedTileInner(p + new CVec(1, -1));
			UpdateRenderedTileInner(p + new CVec(-1, 0));
			UpdateRenderedTileInner(p + new CVec(1, 0));
			UpdateRenderedTileInner(p + new CVec(-1, 1));
			UpdateRenderedTileInner(p + new CVec(0, 1));
			UpdateRenderedTileInner(p + new CVec(1, 1));
		}

		protected override string ChooseRandomVariant(ResourceType t)
		{
			return Variants.Keys.Random(Game.CosmeticRandom);
		}
	}
}