#region
/* -----------------------------------------------------------------------
 * <copyright file="PithosWorkflow.cs" company="GRNet">
 * 
 * Copyright 2011-2012 GRNET S.A. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or
 * without modification, are permitted provided that the following
 * conditions are met:
 *
 *   1. Redistributions of source code must retain the above
 *      copyright notice, this list of conditions and the following
 *      disclaimer.
 *
 *   2. 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 GRNET S.A. ``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 GRNET S.A 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.
 *
 * The views and conclusions contained in the software and
 * documentation are those of the authors and should not be
 * interpreted as representing official policies, either expressed
 * or implied, of GRNET S.A.
 * </copyright>
 * -----------------------------------------------------------------------
 */
#endregion
using System;
using System.Collections.Generic;
using System.ComponentModel.Composition;
using System.Linq;
using System.Runtime.InteropServices;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using Pithos.Interfaces;
using System.IO;
using System.Diagnostics;
using Pithos.Network;

namespace Pithos.Core
{
    [Export(typeof(IPithosWorkflow))]
    public class PithosWorkflow:IPithosWorkflow
    {
        [Import]
        public IPithosSettings Settings { get; set; }

        [Import]
        public IStatusKeeper StatusKeeper { get; set; }

        public FileStatus SetFileStatus(string path, FileStatus status)
        {
            Debug.Assert(!path.Contains(FolderConstants.CacheFolder));
            Debug.Assert(!path.EndsWith(".ignore",StringComparison.InvariantCultureIgnoreCase));

            if (String.IsNullOrWhiteSpace(path))
                throw new ArgumentNullException("path", "The path parameter must not be emtpy");

            var oldStatus=StatusKeeper.GetFileStatus(path);

            if (oldStatus == status)
                return oldStatus;

            switch(oldStatus)
            {
                case FileStatus.Unchanged :
                    break;
                case FileStatus.Created:
                    if (status == FileStatus.Modified)
                        return oldStatus;
                    break;
                case FileStatus.Modified:
                case FileStatus.Renamed:
                    if (status == FileStatus.Created)
                        return oldStatus;
                    break;
            }
            StatusKeeper.SetFileStatus(path, status);
            return status;
        }

        public void ClearFileStatus(string path)
        {
            if (String.IsNullOrWhiteSpace(path))
                throw new ArgumentNullException("path", "The path parameter must not be emtpy");

            StatusKeeper.ClearFileStatus(path.ToLower());
        }
       

        public Task<FileStream> OpenStreamWithWaiting(string path)
        {
            if (String.IsNullOrWhiteSpace(path))
                throw new ArgumentNullException("path","The path parameter must not be emtpy");

            if (!File.Exists(path))
                throw new FileNotFoundException("The specified file or path does not exist", path);

            return new Task<FileStream>(() =>
                    {
                        int counter = 0;
                        while (true)
                        {
                            try
                            {
                                var stream=File.OpenRead(path);
                                return stream;                                
                            }
                            catch 
                            {
                                Thread.Sleep(500);
                                if (++counter > 10)
                                    throw;
                            }
                        }
                    });
        }
    }
}