using System.Collections.Generic;

namespace JungleDB {
	public class NullJournal : Journal {

		private static NullChangeListWriter NULL_WRITER = new NullChangeListWriter();
		private static NullChangeListReader NULL_READER = new NullChangeListReader();

		public ChangeListReader getReader() {
			return NULL_READER;
		}

		public ChangeListWriter getWriter() {
			return NULL_WRITER;
		}

		private class NullChangeListWriter : ChangeListWriter{
			public Result write(ChangeList operations){
				return Result.SUCCESS;
			}
		}

		private class NullChangeListReader : ChangeListReader { 
			public ChangeListReader newReader() {
				return this;
			}

			public ChangeList read() {
				return null;
			}

			public IEnumerator<ChangeList> iterator() {
				return null;
			}
		}
	}
}