#region Copyright & License Information
/*
 * Copyright 2007-2015 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.Collections.Generic;
using System.Linq;
using OpenRA.Graphics;
using OpenRA.Mods.Common.Traits;
using OpenRA.Traits;

namespace OpenRA.Mods.Common.Orders
{
	public class GlobalButtonOrderGenerator<T> : IOrderGenerator
	{
		string cursor;
		string order;

		public GlobalButtonOrderGenerator(string cursor, string order)
		{
			this.cursor = cursor;
			this.order = order;
		}

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

			return OrderInner(world, mi);
		}

		IEnumerable<Order> OrderInner(World world, MouseInput mi)
		{
			if (mi.Button == MouseButton.Left)
			{
				var underCursor = world.ScreenMap.ActorsAt(mi)
					.FirstOrDefault(a => a.Owner == world.LocalPlayer && a.TraitsImplementing<T>()
						.Any(Exts.IsTraitEnabled));

				if (underCursor == null)
					yield break;

				var building = underCursor.TraitOrDefault<Building>();
				if (building != null && building.Locked)
					yield break;

				yield return new Order(order, underCursor, false);
			}
		}

		public void Tick(World world)
		{
			if (world.LocalPlayer != null &&
				world.LocalPlayer.WinState != WinState.Undefined)
				world.CancelInputMode();
		}

		public IEnumerable<IRenderable> Render(WorldRenderer wr, World world) { yield break; }
		public IEnumerable<IRenderable> RenderAfterWorld(WorldRenderer wr, World world) { yield break; }

		public string GetCursor(World world, CPos xy, MouseInput mi)
		{
			mi.Button = MouseButton.Left;
			return cursor + (OrderInner(world, mi).Any() ? "" : "-blocked");
		}
	}

	public class PowerDownOrderGenerator : GlobalButtonOrderGenerator<CanPowerDown>
	{
		public PowerDownOrderGenerator() : base("powerdown", "PowerDown") { }
	}

	public class SellOrderGenerator : GlobalButtonOrderGenerator<Sellable>
	{
		public SellOrderGenerator() : base("sell", "Sell") { }
	}
}
