// This file (UnitRequiresNParentModelsForMUnitsRequirementFactory.cs) is a part of the IBBoard.WarFoundry.API project and is copyright 2012 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 IBBoard.WarFoundry.API.Objects.Requirement;
using IBBoard.WarFoundry.API.Objects;

namespace IBBoard.WarFoundry.API.Factories.Requirement
{
	public class UnitRequiresNParentModelsForMUnitsRequirementFactory : IRequirementFactory
	{
		public UnitRequiresNParentModelsForMUnitsRequirementFactory()
		{
		}

		public IRequirement CreateRequirement<SOURCE_FILE_TYPE, ENTRY_TYPE>(IBBoard.WarFoundry.API.Objects.UnitType type, string data, IRaceFactory<SOURCE_FILE_TYPE, ENTRY_TYPE> raceFactory)
		{
			UnitRequiresNParentModelsForMUnitsRequirement req = new UnitRequiresNParentModelsForMUnitsRequirement(type);
			Race race = type.Race;
			AddRequirements(req, race, data, raceFactory);
			return req;
		}
		
		private void AddRequirements<SOURCE_FILE_TYPE, ENTRY_TYPE>(UnitRequiresNParentModelsForMUnitsRequirement req, Race race, string data, IRaceFactory<SOURCE_FILE_TYPE, ENTRY_TYPE> raceFactory)
		{
			foreach (string requirement in data.Split('|'))
			{
				string[] requirementParts = requirement.Split(':');
				string unitID = requirementParts[0];
				UnitType unitType = GetUnitTypeFromID(unitID, race, raceFactory);
				
				if (requirementParts.Length == 2)
				{
					string[] amounts = requirementParts[1].Split(';');
					
					if (amounts.Length == 1)
					{
						req.AddUnitTypeRequirement(unitType, ParseAllowedAmount(amounts[0], unitID));
					}
					else
					{
						req.AddUnitTypeRequirement(unitType, ParseAllowedAmount(amounts[0], unitID), ParseModelCount(amounts[1], unitID));
					}
				}
				else
				{
					req.AddUnitTypeRequirement(unitType);
				}
			}
		}

		private UnitType GetUnitTypeFromID<SOURCE_FILE_TYPE, ENTRY_TYPE>(string unitID, Race race, IRaceFactory<SOURCE_FILE_TYPE, ENTRY_TYPE> raceFactory)
		{
			UnitType unitType = raceFactory.GetUnitType(unitID, race);
			
			if (unitType == null)
			{
				throw new InvalidRequirementException(String.Format("Invalid unit type '{0}' for 'Requires N models in parent unit for M units' requirement", unitID));
			}

			return unitType;
		}
		
		private int ParseModelCount(string minCount, string unitID)
		{
			try
			{
				return Int32.Parse(minCount);
			}
			catch (FormatException)
			{
				throw new InvalidRequirementException(String.Format("Invalid model amount '{0}' for unit types '{1}' for 'Requires N models in parent unit for M units' requirement", minCount, unitID));
			}
		}
		
		private int ParseAllowedAmount(string allowedAmount, string unitID)
		{
			try
			{
				return Int32.Parse(allowedAmount);
			}
			catch (FormatException)
			{
				throw new InvalidRequirementException(String.Format("Invalid allowed amount '{0}' for unit types '{1}' for 'Requires N models in parent unit for M units' requirement", allowedAmount, unitID));
			}
		}

		public string AppliesToID
		{
			get
			{
				return UnitRequiresNParentModelsForMUnitsRequirement.REQUIREMENT_ID;
			}
		}
	}
}