// This file (RequirementHandler.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.Requirement.Context;

namespace IBBoard.WarFoundry.API.Objects.Requirement
{
	/// <summary>
	/// The requirement handler that tests the validity of armies.
	/// </summary>
	public class RequirementHandler
	{
		private RequirementHandler()
		{
		}


		public static Validation ValidateArmy(Army army)
		{
			ICollection<string> ignored;
			return ValidateArmy(army, out ignored);
		}

		public static Validation ValidateArmy(Army army, out ICollection<string> failureMessages)
		{
			Validation result = Validation.Passed;
			failureMessages = new List<string>();

			foreach (IRequirement requirement in army.GetRequirements())
			{
				if (!Validates.AsOkay(requirement.ValidatesArmy(army)))
				{
					result = Validation.Failed;
					failureMessages.Add(requirement.GetValidationMessage(army));
				}
			}

			return result;
		}

		public static Validation AllowsAdding(UnitType unitType, Army army)
		{
			return AllowsAdding(unitType, army, new NullAddingContext());
		}

		public static Validation AllowsAdding(UnitType unitType, Army army, AddingContext context)
		{
			ICollection<string> ignored;
			return AllowsAdding(unitType, army, context, out ignored);
		}
		
		public static Validation AllowsAdding(UnitType unitType, Army army, out ICollection<string> failureMessages)
		{
			return AllowsAdding(unitType, army, new NullAddingContext(), out failureMessages);
		}

		public static Validation AllowsAdding(UnitType unitType, Army army, AddingContext context, out ICollection<string> failureMessages)
		{
			Validation result = Validation.Passed;
			failureMessages = new List<string>();
			
			foreach (IRequirement requirement in army.GetAddingUnitRequirements(unitType))
			{
				if (!Validates.AsOkay(requirement.AllowsAdding(unitType, army, context)))
				{
					result = Validation.Failed;
					failureMessages.Add(requirement.GetAllowsAddingMessage(unitType, army, context));
				}
			}

			return result;
		}
	}
}