#region Copyright & License Information
/*
 * Copyright 2007-2016 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, either version 3 of
 * the License, or (at your option) any later version. For more
 * information, see COPYING.
 */
#endregion

using OpenRA.Traits;

namespace OpenRA.Mods.Common.Traits
{
	[Desc("Applies an upgrade to actors within a specified range.")]
	public class UpgradeOnDamageInfo : ITraitInfo, Requires<UpgradeManagerInfo>
	{
		[UpgradeGrantedReference, FieldLoader.Require]
		[Desc("The upgrades to grant.")]
		public readonly string[] Upgrades = { };

		[Desc("Play a random sound from this list when enabled.")]
		public readonly string[] EnabledSounds = { };

		[Desc("Play a random sound from this list when disabled.")]
		public readonly string[] DisabledSounds = { };

		[Desc("Levels of damage at which to grant upgrades.")]
		public readonly DamageState ValidDamageStates = DamageState.Heavy | DamageState.Critical;

		[Desc("Are upgrades irrevocable once the conditions have been met?")]
		public readonly bool GrantPermanently = false;

		public object Create(ActorInitializer init) { return new UpgradeOnDamage(init.Self, this); }
	}

	public class UpgradeOnDamage : INotifyDamageStateChanged
	{
		readonly UpgradeOnDamageInfo info;
		readonly UpgradeManager um;
		bool granted;

		public UpgradeOnDamage(Actor self, UpgradeOnDamageInfo info)
		{
			this.info = info;
			um = self.TraitOrDefault<UpgradeManager>();
		}

		void INotifyDamageStateChanged.DamageStateChanged(Actor self, AttackInfo e)
		{
			if (um == null)
				return;

			if (granted && info.GrantPermanently)
				return;

			var rand = Game.CosmeticRandom;
			if (!granted && info.ValidDamageStates.HasFlag(e.DamageState) && !info.ValidDamageStates.HasFlag(e.PreviousDamageState))
			{
				granted = true;
				var sound = info.EnabledSounds.RandomOrDefault(rand);
				Game.Sound.Play(sound, self.CenterPosition);
				foreach (var u in info.Upgrades)
					um.GrantUpgrade(self, u, this);
			}
			else if (granted && !info.ValidDamageStates.HasFlag(e.DamageState) && info.ValidDamageStates.HasFlag(e.PreviousDamageState))
			{
				granted = false;
				var sound = info.DisabledSounds.RandomOrDefault(rand);
				Game.Sound.Play(sound, self.CenterPosition);
				foreach (var u in info.Upgrades)
					um.RevokeUpgrade(self, u, this);
			}
		}
	}
}