// This file (UnitRequiresAtLeastNUnitsRequirement.cs) is a part of the IBBoard.WarFoundry.API project and is copyright 2011 IBBoard
// 
// The file and the library/program it is in are licensed and distributed, without warranty, under the GNU Affero GPL license, either version 3 of the License or (at your option) any later version. Please see COPYING for more information and the full license.
using System;
using System.Collections.Generic;
using IBBoard.WarFoundry.API.Objects;

namespace IBBoard.WarFoundry.API.Objects.Requirement
{
	/// <summary>
	/// A requirement where a UnitType can only be taken if there are no more than N units of one or more unit in an army.
	/// </summary>
	public class UnitRequiresNoMoreThanNOfUnitTypeRequirement : RequiresNoMoreThanNOfUnitTypeRequirement<UnitType>
	{
		public UnitRequiresNoMoreThanNOfUnitTypeRequirement(UnitType allowedObject, params UnitType[] unitTypes) : base(allowedObject, unitTypes)
		{
			//Do nothing special
		}

		/// <summary>
		/// Checks whether the supplied WarFoundryObject can be added to the supplied army.
		/// </summary>
		/// <returns>
		/// A <code>Validation</code> enum to show the result of the validation
		/// </returns>
		/// <param name='wfObject'>
		/// The object that we want to add. This may be involved in the check, or it may not affect the evaluation of the requirement
		/// </param>
		/// <param name='toArmy'>
		/// The army to add the object to.
		/// </param>
		public override Validation AllowsAdding(IWarFoundryObject wfObject, Army toArmy)
		{
			return IsApplicable(wfObject, toArmy) ? base.AllowsAdding(wfObject, toArmy) : Validation.NotApplicable;
		}

		protected override bool IsApplicable(IWarFoundryObject toObject, Army toArmy)
		{
			return IsApplicable(toObject) || IsApplicableForRequiredType(toObject, toArmy);
		}

		protected override bool IsApplicable(IWarFoundryObject toObject)
		{
			return AllowedObject.Equals(toObject) || (toObject is Unit && AllowedObject.Equals(((Unit)toObject).UnitType));
		}

		private bool IsApplicableForRequiredType(IWarFoundryObject toObject, Army toArmy)
		{
			bool isApplicable = false;
			UnitType addedType = toObject as UnitType;

			if (addedType == null)
			{
				addedType = (toObject is Unit) ? ((Unit)toObject).UnitType : null;
			}

			if (addedType != null && toArmy.GetUnitTypeCount(AllowedObject) > 0)
			{
				foreach (UnitCountRequirementData limit in ConstraintTypes)
				{
					if (Arrays.Contains(limit.UnitTypes, addedType))
					{
						isApplicable = true;
						break;
					}
				}
			}

			return isApplicable;
		}
	}
}