using System.Drawing;
using System.Linq;
using System.Windows.Forms;
using IjwFramework.Types;
using System.Collections.Generic;
using OpenRa.Game.Traits;
using OpenRa.Game.Support;
using Ijw.DirectX;

namespace OpenRa.Game.Graphics
{
	class WorldRenderer
	{
		public readonly TerrainRenderer terrainRenderer;
		public readonly SpriteRenderer spriteRenderer;
        public readonly LineRenderer lineRenderer;
		public readonly Region region;
		public readonly UiOverlay uiOverlay;
		readonly Renderer renderer;
		readonly Texture specialbin;

		public static bool ShowUnitPaths = false;

		public WorldRenderer(Renderer renderer)
		{
			terrainRenderer = new TerrainRenderer( renderer, Game.map );

			// TODO: this is layout policy. it belongs at a higher level than this.
			region = Region.Create(Game.viewport, DockStyle.Left,
				Game.viewport.Width - /*128*/ 0, Draw, 
                Game.controller.HandleMouseInput);		

			Game.viewport.AddRegion(region);

			this.renderer = renderer;
			spriteRenderer = new SpriteRenderer(renderer, true);
            lineRenderer = new LineRenderer(renderer);
			uiOverlay = new UiOverlay(spriteRenderer);

			specialbin = renderer.LoadTexture("specialbin.png");
		}

		void DrawSpriteList(RectangleF rect,
			IEnumerable<Tuple<Sprite, float2, int>> images)
		{
			foreach (var image in images)
			{
				var loc = image.b;

				if (loc.X > rect.Right || loc.X < rect.Left
					- image.a.bounds.Width)
					continue;
				if (loc.Y > rect.Bottom || loc.Y < rect.Top
					- image.a.bounds.Height)
					continue;

				spriteRenderer.DrawSprite(image.a, loc, image.c);
			}
		}

		public void Draw()
		{
			terrainRenderer.Draw(Game.viewport);

			var rect = new RectangleF((region.Position + Game.viewport.Location).ToPointF(),
				region.Size.ToSizeF());

			foreach (Actor a in Game.world.Actors.OrderBy(u => u.CenterLocation.Y))
				DrawSpriteList(rect, a.Render());

			foreach (var a in Game.world.Actors
				.Where(u => u.traits.Contains<Traits.RenderWarFactory>())
				.Select(u => u.traits.Get<Traits.RenderWarFactory>()))
				DrawSpriteList(rect, a.RenderRoof(a.self));	

			foreach (IEffect e in Game.world.Effects)
				DrawSpriteList(rect, e.Render());

			uiOverlay.Draw();

			spriteRenderer.Flush();

			var selbox = Game.controller.SelectionBox;
			if (selbox != null)
			{
				var a = selbox.Value.First;
				var b = new float2(selbox.Value.Second.X - a.X, 0);
				var c = new float2(0, selbox.Value.Second.Y - a.Y);

				lineRenderer.DrawLine(a, a + b, Color.White, Color.White);
				lineRenderer.DrawLine(a + b, a + b + c, Color.White, Color.White);
				lineRenderer.DrawLine(a + b + c, a + c, Color.White, Color.White);
				lineRenderer.DrawLine(a, a + c, Color.White, Color.White);

				foreach (var u in Game.SelectUnitsInBox(selbox.Value.First, selbox.Value.Second))
					DrawSelectionBox(u, Color.Yellow, false);
			}

			var uog = Game.controller.orderGenerator as UnitOrderGenerator;
			if (uog != null)
				foreach (var a in uog.selection)
					DrawSelectionBox(a, Color.White, true);

			lineRenderer.Flush();
		}

        void DrawSelectionBox(Actor selectedUnit, Color c, bool drawHealthBar)
        {
            var center = selectedUnit.CenterLocation;
            var size = selectedUnit.SelectedSize;

            var xy = center - 0.5f * size;
            var XY = center + 0.5f * size;
            var Xy = new float2(XY.X, xy.Y);
            var xY = new float2(xy.X, XY.Y);

            lineRenderer.DrawLine(xy, xy + new float2(4, 0), c, c);
            lineRenderer.DrawLine(xy, xy + new float2(0, 4), c, c);
            lineRenderer.DrawLine(Xy, Xy + new float2(-4, 0), c, c);
            lineRenderer.DrawLine(Xy, Xy + new float2(0, 4), c, c);

            lineRenderer.DrawLine(xY, xY + new float2(4, 0), c, c);
            lineRenderer.DrawLine(xY, xY + new float2(0, -4), c, c);
            lineRenderer.DrawLine(XY, XY + new float2(-4, 0), c, c);
            lineRenderer.DrawLine(XY, XY + new float2(0, -4), c, c);

			if (drawHealthBar)
			{
				c = Color.Gray;
				lineRenderer.DrawLine(xy + new float2(0, -2), xy + new float2(0, -4), c, c);
				lineRenderer.DrawLine(Xy + new float2(0, -2), Xy + new float2(0, -4), c, c);

				var healthAmount = (float)selectedUnit.Health / selectedUnit.unitInfo.Strength;
				var healthColor = (healthAmount < Rules.General.ConditionRed) ? Color.Red
					: (healthAmount < Rules.General.ConditionYellow) ? Color.Yellow
					: Color.LimeGreen;

				var healthColor2 = Color.FromArgb(
					255,
					healthColor.R / 2,
					healthColor.G / 2,
					healthColor.B / 2);

				var z = float2.Lerp(xy, Xy, healthAmount);

				lineRenderer.DrawLine(z + new float2(0, -4), Xy + new float2(0,-4), c, c);
				lineRenderer.DrawLine(z + new float2(0, -2), Xy + new float2(0, -2), c, c);

				lineRenderer.DrawLine(xy + new float2(0, -3), 
					z + new float2(0, -3), 
					healthColor, healthColor);

				lineRenderer.DrawLine(xy + new float2(0, -2),
					z + new float2(0, -2),
					healthColor2, healthColor2);

				lineRenderer.DrawLine(xy + new float2(0, -4),
					z + new float2(0, -4),
					healthColor2, healthColor2);
			}

			if (ShowUnitPaths)
			{
				var mobile = selectedUnit.traits.GetOrDefault<Mobile>();
				if (mobile != null)
				{
					var path = mobile.GetCurrentPath();
					var start = selectedUnit.Location;

					foreach (var step in path)
					{
						lineRenderer.DrawLine(
							Game.CellSize * start + new float2(12, 12),
							Game.CellSize * step + new float2(12, 12),
							Color.Red, Color.Red);
						start = step;
					}
				}
			}
        }
	}
}