// This file (AbstractWarFoundryFactory.cs) is a part of the IBBoard.WarFoundry.API project and is copyright 2007, 2008, 2009 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.IO;
using System.Collections.Generic;
using IBBoard.WarFoundry.API.Objects;

namespace IBBoard.WarFoundry.API.Factories
{
	public abstract class AbstractWarFoundryFactory<FILE_TYPE> : IWarFoundryFactory
	{		
		public event SingleArgMethodInvoker<GameSystem> GameSystemLoaded;
		
		public event SingleArgMethodInvoker<Race> RaceLoaded;
		
		public event SingleArgMethodInvoker<Army> ArmyLoaded;
		
		public virtual void CompleteLoading(IWarFoundryStagedLoadObject obj)
		{
			//Pretend we've fully loaded, as this will probably be standard for non-native factories and some native factories
			obj.SetAsFullyLoaded();
		}

		public bool CanHandleFileFormat (FileInfo file)
		{
			FILE_TYPE typedFile = GetFileAsSupportedType(file);
			bool canHandle = typedFile != null && CheckCanHandleFileFormat(typedFile);

			if (typedFile != null)
			{
				CleanUpFileAsSupportedType(typedFile);
			}

			return canHandle;
		}

		public bool CanHandleFileAsRace(FileInfo file)
		{
			FILE_TYPE typedFile = GetFileAsSupportedType(file);
			bool canHandle = typedFile != null && CheckCanHandleFileAsRace(typedFile);

			if (typedFile != null)
			{
				CleanUpFileAsSupportedType(typedFile);
			}

			return canHandle;
		}

		public bool CanHandleFileAsGameSystem(FileInfo file)
		{
			FILE_TYPE typedFile = GetFileAsSupportedType(file);
			bool canHandle = typedFile != null && CheckCanHandleFileAsGameSystem(typedFile);

			if (typedFile != null)
			{
				CleanUpFileAsSupportedType(typedFile);
			}

			return canHandle;
		}

		public bool CanHandleFileAsArmy(FileInfo file)
		{
			FILE_TYPE typedFile = GetFileAsSupportedType(file);
			bool canHandle = typedFile != null && CheckCanHandleFileAsArmy(typedFile);

			if (typedFile != null)
			{
				CleanUpFileAsSupportedType(typedFile);
			}

			return canHandle;
		}

		protected virtual void CleanUpFileAsSupportedType(FILE_TYPE typedFile)
		{
			//Do nothing by default
		}
		
		/// <summary>
		/// Converts the <see cref="FileInfo"/> object in to the appropriate type for this class so that it can perform its checks. If no conversion is required (the test can be performed on a <see cref="FileInfo"/> object) the object should be returned with no modification. 
		/// If the file is not of supported type the <code>null</code> should be returned.
		/// </summary>
		/// <param name="file">
		/// A <see cref="FileInfo"/> to get the supported source object from.
		/// </param>
		/// <returns>
		/// An object of type <see cref="FILE_TYPE"/> that has been converted from the input <see cref="FileInfo"/> object, or <code>null</code> if the conversion cannot be made.
		/// </returns>
		protected abstract FILE_TYPE GetFileAsSupportedType(FileInfo file);
		
		/// <summary>
		/// Checks whether the factory thinks it can load data from the file in its paramaterised type.
		/// </summary>
		/// <param name="file">
		/// An object of the converted <see cref="FILE_TYPE"/> to check support for
		/// </param>
		/// <returns>
		/// <code>true</code> if the factory thinks it can support the file, else <code>false</code>
		/// </returns>
		protected abstract bool CheckCanHandleFileFormat(FILE_TYPE file);

		/// <summary>
		/// Checks whether the factory thinks it can load data from the file in its paramaterised type as a Race object.
		/// </summary>
		/// <param name="file">
		/// An object of the converted <see cref="FILE_TYPE"/> to check support for
		/// </param>
		/// <returns>
		/// <code>true</code> if the factory thinks it can support the file as a Race, else <code>false</code>
		/// </returns>
		protected abstract bool CheckCanHandleFileAsRace(FILE_TYPE file);

		/// <summary>
		/// Checks whether the factory thinks it can load data from the file in its paramaterised type as a GameSystem object.
		/// </summary>
		/// <param name="file">
		/// An object of the converted <see cref="FILE_TYPE"/> to check support for
		/// </param>
		/// <returns>
		/// <code>true</code> if the factory thinks it can support the file as a GameSystem, else <code>false</code>
		/// </returns>
		protected abstract bool CheckCanHandleFileAsGameSystem(FILE_TYPE file);

		/// <summary>
		/// Checks whether the factory thinks it can load data from the file in its paramaterised type as an Army object.
		/// </summary>
		/// <param name="file">
		/// An object of the converted <see cref="FILE_TYPE"/> to check support for
		/// </param>
		/// <returns>
		/// <code>true</code> if the factory thinks it can support the file as a Army, else <code>false</code>
		/// </returns>
		protected abstract bool CheckCanHandleFileAsArmy(FILE_TYPE file);
		
		
		public ICollection<IWarFoundryObject> CreateObjectsFromFile(FileInfo file)
		{
			return DoCreateObjectsFromFile(GetFileAsSupportedType(file));
		}
		
		/// <summary>
		/// Reads the data from the supplied converted <see cref="FILE_TYPE"/> object and returns it as a collection of loadable objects.
		/// In addition, the method fires the appropriate XxxLoaded event for each object created for asynchronous use.
		/// </summary>
		/// <param name="file">
		/// An object of the converted <see cref="FILE_TYPE"/> for the file to load data from
		/// </param>
		/// <returns>
		/// A <see cref="ICollection`1"/> of <see cref="IWarFoundryObject"/>s that were loaded from the file object
		/// </returns>
		protected abstract ICollection<IWarFoundryObject> DoCreateObjectsFromFile(FILE_TYPE file);
		
		protected void OnGameSystemLoaded(GameSystem system)
		{
			if (GameSystemLoaded != null)
			{
				GameSystemLoaded(system);
			}
		}
		
		protected void OnRaceLoaded(Race race)
		{
			if (RaceLoaded != null)
			{
				RaceLoaded(race);
			}
		}
		
		protected void OnArmyLoaded(Army army)
		{
			if (ArmyLoaded != null)
			{
				ArmyLoaded(army);
			}
		}
	}
}