#region Copyright & License Information
/*
 * Copyright 2007-2010 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 LICENSE.
 */
#endregion

using System.Collections.Generic;
using System.Linq;
using OpenRA.Graphics;
using OpenRA.Mods.RA.Buildings;
using OpenRA.Traits;
using OpenRA.Mods.RA.Render;

namespace OpenRA.Mods.RA.Orders
{
	public class PlaceBuildingOrderGenerator : IOrderGenerator
	{
		readonly Actor Producer;
		readonly string Building;
		readonly IEnumerable<Renderable> Preview;
		BuildingInfo BuildingInfo { get { return Rules.Info[ Building ].Traits.Get<BuildingInfo>(); } }

		public PlaceBuildingOrderGenerator(Actor producer, string name)
		{
			Producer = producer;
			Building = name;
			
			Preview = Rules.Info[Building].Traits.Get<RenderBuildingInfo>()
								.BuildingPreview(Rules.Info[Building], producer.World.Map.Tileset);
		}

		public IEnumerable<Order> Order(World world, int2 xy, MouseInput mi)
		{
			if (mi.Button == MouseButton.Right)
				world.CancelInputMode();

			var ret = InnerOrder( world, xy, mi ).ToList();
			if (ret.Count > 0)
				world.CancelInputMode();

			return ret;
		}

		IEnumerable<Order> InnerOrder(World world, int2 xy, MouseInput mi)
		{
			if (mi.Button == MouseButton.Left)
			{
				var topLeft = xy - FootprintUtils.AdjustForBuildingSize( BuildingInfo );
				if (!world.CanPlaceBuilding( Building, BuildingInfo, topLeft, null)
					|| !BuildingInfo.IsCloseEnoughToBase(world, Producer.Owner, Building, topLeft))
				{
					var eva = world.WorldActor.Info.Traits.Get<EvaAlertsInfo>();
					Sound.Play(eva.BuildingCannotPlaceAudio);
					yield break;
				}
				
				var isLineBuild = Rules.Info[ Building ].Traits.Contains<LineBuildInfo>();
				yield return new Order(isLineBuild ? "LineBuild" : "PlaceBuilding",
					Producer.Owner.PlayerActor, false) { TargetLocation = topLeft, TargetString = Building };
			}
		}
		
		public void Tick( World world ) {}
		public void RenderAfterWorld( WorldRenderer wr, World world ) {}
		public void RenderBeforeWorld( WorldRenderer wr, World world )
		{
			
			var position = Game.viewport.ViewToWorld(Viewport.LastMousePos).ToInt2();
			var topLeft = position - FootprintUtils.AdjustForBuildingSize( BuildingInfo );
			
			
			
			var cells = new Dictionary<int2, bool>();
			// Linebuild for walls.
			// Assumes a 1x1 footprint; weird things will happen for other footprints
			if (Rules.Info[Building].Traits.Contains<LineBuildInfo>())
			{
				foreach( var t in BuildingUtils.GetLineBuildCells( world, topLeft, Building, BuildingInfo ) )
				{
					cells.Add( t, BuildingInfo.IsCloseEnoughToBase( world, world.LocalPlayer, Building, t ) );
					foreach (var r in Preview)
						r.Sprite.DrawAt(wr,Game.CellSize*t + r.Pos,  r.Palette ?? world.LocalPlayer.Palette);
				}
			}
			else
			{
				foreach (var r in Preview)
					r.Sprite.DrawAt(wr,Game.CellSize*topLeft + r.Pos,  r.Palette ?? world.LocalPlayer.Palette);
				
				var res = world.WorldActor.Trait<ResourceLayer>();
				var isCloseEnough = BuildingInfo.IsCloseEnoughToBase(world, world.LocalPlayer, Building, topLeft);
				foreach (var t in FootprintUtils.Tiles(Building, BuildingInfo, topLeft))
					cells.Add( t, isCloseEnough && world.IsCellBuildable(t, BuildingInfo.WaterBound) && res.GetResource(t) == null );
			}
			
			wr.uiOverlay.DrawGrid( wr, cells );
		}

		public string GetCursor(World world, int2 xy, MouseInput mi) { return "default"; }
	}
}