// AbstractWarFoundryFactory.cs
//
//  Copyright (C) 2008 IBBoard
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 
//
//

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 bool CanHandleFileFormat (FileInfo file)
		{
			return CheckCanHandleFileFormat(GetFileAsSupportedType(file));
		}
		
		/// <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. 
		/// </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);
		
		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.
		/// </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);
	}
}