// ===========================================================
// Copyright (c) 2014-2015, Enrico Da Ros/kendar.org
// All rights reserved.
// 
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
// 
// * Redistributions of source code must retain the above copyright notice, this
//   list of conditions and the following disclaimer.
// 
// * Redistributions in binary form must reproduce the above copyright notice,
//   this list of conditions and the following disclaimer in the documentation
//   and/or other materials provided with the distribution.
// 
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
// OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
// ===========================================================


using System;
using Diary.CQRS.Commands;
using Diary.CQRS.Domain;
using ECQRS.Commons.Commands;
using ECQRS.Commons.Domain;

namespace Diary.CQRS.CommandHandlers
{
    public class ChangeItemCommandHandler : ICommandHandler<ChangeItemCommand>
    {
        private readonly IAggregateRepository<DiaryItem> _repository;

        public ChangeItemCommandHandler(IAggregateRepository<DiaryItem> repository)
        {
            _repository = repository;
        }

        public void Handle(ChangeItemCommand command)
        {
            if (command == null)
            {
                throw new ArgumentNullException("command");
            }
            if (_repository == null)
            {
                throw new InvalidOperationException("Repository is not initialized.");
            }

            var aggregate = _repository.GetById(command.Id);
            
            if(aggregate.Title!=command.Title)
                aggregate.ChangeTitle(command.Title);

            if(aggregate.Description!=command.Description)
                aggregate.ChangeDescription(command.Description);

            if(aggregate.From!=command.From)
                aggregate.ChangeFrom(command.From);

            if(aggregate.To!=command.To)
                aggregate.ChangeTo(command.To);

            _repository.Save(aggregate, command.Version);
        }
    }
}
