// ****************************************************************

// Copyright 2008, Charlie Poole

// This is free software licensed under the NUnit license. You may

// obtain a copy of the license at http://nunit.org.

// ****************************************************************



using System;

using System.Collections;

using System.Reflection;

using NUnit.Core.Extensibility;



namespace NUnit.Core.Builders

{

    public abstract class CombiningStrategy

    {

        protected IDataPointProvider dataPointProvider =

            (IDataPointProvider)CoreExtensions.Host.GetExtensionPoint("DataPointProviders");



        private IEnumerable[] sources;

        private IEnumerator[] enumerators;



        public CombiningStrategy(IEnumerable[] sources)

        {

            this.sources = sources;

        }



        public IEnumerable[] Sources

        {

            get { return sources; }

        }



        public IEnumerator[] Enumerators

        {

            get

            {

                if (enumerators == null)

                {

                    enumerators = new IEnumerator[Sources.Length];

                    for (int i = 0; i < Sources.Length; i++)

                        enumerators[i] = Sources[i].GetEnumerator();

                }



                return enumerators;

            }

        }



        public abstract IEnumerable GetTestCases();

    }

}