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#region
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/* -----------------------------------------------------------------------
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 * <copyright file="PollAgent.cs" company="GRNet">
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 * 
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 * Copyright 2011-2012 GRNET S.A. All rights reserved.
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 *
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 * Redistribution and use in source and binary forms, with or
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 * without modification, are permitted provided that the following
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 * conditions are met:
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 *
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 *   1. Redistributions of source code must retain the above
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 *      copyright notice, this list of conditions and the following
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 *      disclaimer.
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 *
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 *   2. Redistributions in binary form must reproduce the above
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 *      copyright notice, this list of conditions and the following
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 *      disclaimer in the documentation and/or other materials
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 *      provided with the distribution.
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 *
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 *
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 * THIS SOFTWARE IS PROVIDED BY GRNET S.A. ``AS IS'' AND ANY EXPRESS
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 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL GRNET S.A OR
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 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
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 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
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 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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 * POSSIBILITY OF SUCH DAMAGE.
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 *
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 * The views and conclusions contained in the software and
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 * documentation are those of the authors and should not be
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 * interpreted as representing official policies, either expressed
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 * or implied, of GRNET S.A.
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 * </copyright>
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 * -----------------------------------------------------------------------
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 */
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#endregion
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43
using System.Collections.Concurrent;
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using System.ComponentModel.Composition;
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using System.Diagnostics;
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using System.Diagnostics.Contracts;
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using System.IO;
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using System.Reflection;
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using System.Threading;
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using System.Threading.Tasks;
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using Castle.ActiveRecord;
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using Pithos.Interfaces;
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using Pithos.Network;
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using log4net;
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56
namespace Pithos.Core.Agents
57
{
58
    using System;
59
    using System.Collections.Generic;
60
    using System.Linq;
61

    
62
    /// <summary>
63
    /// PollAgent periodically polls the server to detect object changes. The agent retrieves a listing of all
64
    /// objects and compares it with a previously cached version to detect differences. 
65
    /// New files are downloaded, missing files are deleted from the local file system and common files are compared
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    /// to determine the appropriate action
67
    /// </summary>
68
    [Export]
69
    public class PollAgent
70
    {
71
        private static readonly ILog Log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);
72

    
73
        [System.ComponentModel.Composition.Import]
74
        public IStatusKeeper StatusKeeper { get; set; }
75

    
76
        [System.ComponentModel.Composition.Import]
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        public IPithosSettings Settings { get; set; }
78

    
79
        [System.ComponentModel.Composition.Import]
80
        public NetworkAgent NetworkAgent { get; set; }
81

    
82
        [System.ComponentModel.Composition.Import]
83
        public Selectives Selectives { get; set; }
84

    
85
        public IStatusNotification StatusNotification { get; set; }
86

    
87
        public bool Pause
88
        {
89
            get {
90
                return _pause;
91
            }
92
            set {
93
                _pause = value;                
94
                if (!_pause)
95
                    _unPauseEvent.Set();
96
                else
97
                {
98
                    _unPauseEvent.Reset();
99
                }
100
            }
101
        }
102

    
103
        private bool _firstPoll = true;
104

    
105
        //The Sync Event signals a manual synchronisation
106
        private readonly AsyncManualResetEvent _syncEvent = new AsyncManualResetEvent();
107

    
108
        private readonly AsyncManualResetEvent _unPauseEvent = new AsyncManualResetEvent(true);
109

    
110
        private readonly ConcurrentDictionary<string, DateTime> _lastSeen = new ConcurrentDictionary<string, DateTime>();
111
        private readonly ConcurrentDictionary<Uri, AccountInfo> _accounts = new ConcurrentDictionary<Uri,AccountInfo>();
112

    
113

    
114
        /// <summary>
115
        /// Start a manual synchronization
116
        /// </summary>
117
        public void SynchNow()
118
        {            
119
            _syncEvent.Set();
120
        }
121

    
122
        /// <summary>
123
        /// Remote files are polled periodically. Any changes are processed
124
        /// </summary>
125
        /// <param name="since"></param>
126
        /// <returns></returns>
127
        public async Task PollRemoteFiles(DateTime? since = null)
128
        {
129
            if (Log.IsDebugEnabled)
130
                Log.DebugFormat("Polling changes after [{0}]",since);
131

    
132
            Debug.Assert(Thread.CurrentThread.IsBackground, "Polling Ended up in the main thread!");
133
            
134

    
135
            using (ThreadContext.Stacks["Retrieve Remote"].Push("All accounts"))
136
            {
137
                //If this poll fails, we will retry with the same since value
138
                var nextSince = since;
139
                try
140
                {
141
                    await _unPauseEvent.WaitAsync();
142
                    UpdateStatus(PithosStatus.PollSyncing);
143

    
144
                    var tasks = from accountInfo in _accounts.Values
145
                                select ProcessAccountFiles(accountInfo, since);
146

    
147
                    var nextTimes=await TaskEx.WhenAll(tasks.ToList());
148

    
149
                    _firstPoll = false;
150
                    //Reschedule the poll with the current timestamp as a "since" value
151

    
152
                    if (nextTimes.Length>0)
153
                        nextSince = nextTimes.Min();
154
                    if (Log.IsDebugEnabled)
155
                        Log.DebugFormat("Next Poll at [{0}]",nextSince);
156
                }
157
                catch (Exception ex)
158
                {
159
                    Log.ErrorFormat("Error while processing accounts\r\n{0}", ex);
160
                    //In case of failure retry with the same "since" value
161
                }
162

    
163
                UpdateStatus(PithosStatus.PollComplete);
164
                //The multiple try blocks are required because we can't have an await call
165
                //inside a finally block
166
                //TODO: Find a more elegant solution for reschedulling in the event of an exception
167
                try
168
                {
169
                    //Wait for the polling interval to pass or the Sync event to be signalled
170
                    nextSince = await WaitForScheduledOrManualPoll(nextSince);
171
                }
172
                finally
173
                {
174
                    //Ensure polling is scheduled even in case of error
175
                    TaskEx.Run(() => PollRemoteFiles(nextSince));                        
176
                }
177
            }
178
        }
179

    
180
        /// <summary>
181
        /// Wait for the polling period to expire or a manual sync request
182
        /// </summary>
183
        /// <param name="since"></param>
184
        /// <returns></returns>
185
        private async Task<DateTime?> WaitForScheduledOrManualPoll(DateTime? since)
186
        {
187
            var sync = _syncEvent.WaitAsync();
188
            var wait = TaskEx.Delay(TimeSpan.FromSeconds(Settings.PollingInterval), NetworkAgent.CancellationToken);
189
            
190
            var signaledTask = await TaskEx.WhenAny(sync, wait);
191
            
192
            //Pausing takes precedence over manual sync or awaiting
193
            _unPauseEvent.Wait();
194
            
195
            //Wait for network processing to finish before polling
196
            var pauseTask=NetworkAgent.ProceedEvent.WaitAsync();
197
            await TaskEx.WhenAll(signaledTask, pauseTask);
198

    
199
            //If polling is signalled by SynchNow, ignore the since tag
200
            if (sync.IsCompleted)
201
            {
202
                //TODO: Must convert to AutoReset
203
                _syncEvent.Reset();
204
                return null;
205
            }
206
            return since;
207
        }
208

    
209
        public async Task<DateTime?> ProcessAccountFiles(AccountInfo accountInfo, DateTime? since = null)
210
        {
211
            if (accountInfo == null)
212
                throw new ArgumentNullException("accountInfo");
213
            if (String.IsNullOrWhiteSpace(accountInfo.AccountPath))
214
                throw new ArgumentException("The AccountInfo.AccountPath is empty", "accountInfo");
215
            Contract.EndContractBlock();
216

    
217

    
218
            using (ThreadContext.Stacks["Retrieve Remote"].Push(accountInfo.UserName))
219
            {
220

    
221
                await NetworkAgent.GetDeleteAwaiter();
222

    
223
                Log.Info("Scheduled");
224
                var client = new CloudFilesClient(accountInfo);
225

    
226
                //We don't need to check the trash container
227
                var containers = client.ListContainers(accountInfo.UserName)
228
                    .Where(c=>c.Name!="trash")
229
                    .ToList();
230

    
231

    
232
                CreateContainerFolders(accountInfo, containers);
233

    
234
                //The nextSince time fallback time is the same as the current.
235
                //If polling succeeds, the next Since time will be the smallest of the maximum modification times
236
                //of the shared and account objects
237
                var nextSince = since;
238

    
239
                try
240
                {
241
                    //Wait for any deletions to finish
242
                    await NetworkAgent.GetDeleteAwaiter();
243
                    //Get the poll time now. We may miss some deletions but it's better to keep a file that was deleted
244
                    //than delete a file that was created while we were executing the poll                    
245

    
246
                    //Get the list of server objects changed since the last check
247
                    //The name of the container is passed as state in order to create a dictionary of tasks in a subsequent step
248
                    var listObjects = (from container in containers
249
                                       select Task<IList<ObjectInfo>>.Factory.StartNew(_ =>
250
                                             client.ListObjects(accountInfo.UserName, container.Name, since), container.Name)).ToList();
251

    
252
                    var listShared = Task<IList<ObjectInfo>>.Factory.StartNew(_ => 
253
                        client.ListSharedObjects(since), "shared");
254
                    listObjects.Add(listShared);
255
                    var listTasks = await Task.Factory.WhenAll(listObjects.ToArray());
256

    
257
                    using (ThreadContext.Stacks["SCHEDULE"].Push("Process Results"))
258
                    {
259
                        var dict = listTasks.ToDictionary(t => t.AsyncState);
260

    
261
                        //Get all non-trash objects. Remember, the container name is stored in AsyncState
262
                        var remoteObjects = (from objectList in listTasks
263
                                            where (string)objectList.AsyncState != "trash"
264
                                            from obj in objectList.Result
265
                                            select obj).ToList();
266
                        
267
                        //Get the latest remote object modification date, only if it is after
268
                        //the original since date
269
                        nextSince = GetLatestDateAfter(nextSince, remoteObjects);
270

    
271
                        var sharedObjects = dict["shared"].Result;
272
                        nextSince = GetLatestDateBefore(nextSince, sharedObjects);
273

    
274
                        //DON'T process trashed files
275
                        //If some files are deleted and added again to a folder, they will be deleted
276
                        //even though they are new.
277
                        //We would have to check file dates and hashes to ensure that a trashed file
278
                        //can be deleted safely from the local hard drive.
279
                        /*
280
                        //Items with the same name, hash may be both in the container and the trash
281
                        //Don't delete items that exist in the container
282
                        var realTrash = from trash in trashObjects
283
                                        where
284
                                            !remoteObjects.Any(
285
                                                info => info.Name == trash.Name && info.Hash == trash.Hash)
286
                                        select trash;
287
                        ProcessTrashedFiles(accountInfo, realTrash);
288
*/
289

    
290
                        var cleanRemotes = (from info in remoteObjects.Union(sharedObjects)
291
                                            let name = info.Name??""
292
                                            where !name.EndsWith(".ignore", StringComparison.InvariantCultureIgnoreCase) &&
293
                                                  !name.StartsWith(FolderConstants.CacheFolder + "/",
294
                                                                   StringComparison.InvariantCultureIgnoreCase)
295
                                            select info).ToList();
296

    
297
                        if (_firstPoll)
298
                            StatusKeeper.CleanupOrphanStates();
299
                        StatusKeeper.CleanupStaleStates(accountInfo, cleanRemotes);
300
                        
301
                        var differencer = _differencer.PostSnapshot(accountInfo, cleanRemotes);
302

    
303
                        var filterUris = Selectives.SelectiveUris[accountInfo.AccountKey];
304

    
305
                        ProcessDeletedFiles(accountInfo, differencer.Deleted.FilterDirectlyBelow(filterUris));
306

    
307
                        // @@@ NEED To add previous state here as well, To compare with previous hash
308

    
309
                        
310

    
311
                        //Create a list of actions from the remote files
312
                        
313
                        var allActions = MovesToActions(accountInfo,differencer.Moved.FilterDirectlyBelow(filterUris))
314
                                        .Union(
315
                                        ChangesToActions(accountInfo, differencer.Changed.FilterDirectlyBelow(filterUris)))
316
                                        .Union(
317
                                        CreatesToActions(accountInfo, differencer.Created.FilterDirectlyBelow(filterUris)));
318

    
319
                        //And remove those that are already being processed by the agent
320
                        var distinctActions = allActions
321
                            .Except(NetworkAgent.GetEnumerable(), new LocalFileComparer())
322
                            .ToList();
323

    
324
                        await _unPauseEvent.WaitAsync();
325
                        //Queue all the actions
326
                        foreach (var message in distinctActions)
327
                        {
328
                            NetworkAgent.Post(message);
329
                        }
330

    
331
                        Log.Info("[LISTENER] End Processing");
332
                    }
333
                }
334
                catch (Exception ex)
335
                {
336
                    Log.ErrorFormat("[FAIL] ListObjects for{0} in ProcessRemoteFiles with {1}", accountInfo.UserName, ex);
337
                    return nextSince;
338
                }
339

    
340
                Log.Info("[LISTENER] Finished");
341
                return nextSince;
342
            }
343
        }
344

    
345
        /// <summary>
346
        /// Returns the latest LastModified date from the list of objects, but only if it is before
347
        /// than the threshold value
348
        /// </summary>
349
        /// <param name="threshold"></param>
350
        /// <param name="cloudObjects"></param>
351
        /// <returns></returns>
352
        private static DateTime? GetLatestDateBefore(DateTime? threshold, IList<ObjectInfo> cloudObjects)
353
        {
354
            DateTime? maxDate = null;
355
            if (cloudObjects!=null &&  cloudObjects.Count > 0)
356
                maxDate = cloudObjects.Max(obj => obj.Last_Modified);
357
            if (maxDate == null || maxDate == DateTime.MinValue)
358
                return threshold;
359
            if (threshold == null || threshold == DateTime.MinValue || threshold > maxDate)
360
                return maxDate;
361
            return threshold;
362
        }
363

    
364
        /// <summary>
365
        /// Returns the latest LastModified date from the list of objects, but only if it is after
366
        /// the threshold value
367
        /// </summary>
368
        /// <param name="threshold"></param>
369
        /// <param name="cloudObjects"></param>
370
        /// <returns></returns>
371
        private static DateTime? GetLatestDateAfter(DateTime? threshold, IList<ObjectInfo> cloudObjects)
372
        {
373
            DateTime? maxDate = null;
374
            if (cloudObjects!=null &&  cloudObjects.Count > 0)
375
                maxDate = cloudObjects.Max(obj => obj.Last_Modified);
376
            if (maxDate == null || maxDate == DateTime.MinValue)
377
                return threshold;
378
            if (threshold == null || threshold == DateTime.MinValue || threshold < maxDate)
379
                return maxDate;
380
            return threshold;
381
        }
382

    
383
        readonly AccountsDifferencer _differencer = new AccountsDifferencer();
384
        private Dictionary<Uri, List<Uri>> _selectiveUris = new Dictionary<Uri, List<Uri>>();
385
        private bool _pause;
386

    
387
        /// <summary>
388
        /// Deletes local files that are not found in the list of cloud files
389
        /// </summary>
390
        /// <param name="accountInfo"></param>
391
        /// <param name="cloudFiles"></param>
392
        private void ProcessDeletedFiles(AccountInfo accountInfo, IEnumerable<ObjectInfo> cloudFiles)
393
        {
394
            if (accountInfo == null)
395
                throw new ArgumentNullException("accountInfo");
396
            if (String.IsNullOrWhiteSpace(accountInfo.AccountPath))
397
                throw new ArgumentException("The AccountInfo.AccountPath is empty", "accountInfo");
398
            if (cloudFiles == null)
399
                throw new ArgumentNullException("cloudFiles");
400
            Contract.EndContractBlock();
401

    
402
            //On the first run
403
            if (_firstPoll)
404
            {
405
                //Only consider files that are not being modified, ie they are in the Unchanged state            
406
                var deleteCandidates = FileState.Queryable.Where(state =>
407
                    state.FilePath.StartsWith(accountInfo.AccountPath)
408
                    && state.FileStatus == FileStatus.Unchanged).ToList();
409

    
410

    
411
                //TODO: filesToDelete must take into account the Others container            
412
                var filesToDelete = (from deleteCandidate in deleteCandidates
413
                                     let localFile = FileInfoExtensions.FromPath(deleteCandidate.FilePath)
414
                                     let relativeFilePath = localFile.AsRelativeTo(accountInfo.AccountPath)
415
                                     where
416
                                         !cloudFiles.Any(r => r.RelativeUrlToFilePath(accountInfo.UserName) == relativeFilePath)
417
                                     select localFile).ToList();
418

    
419

    
420

    
421
                //Set the status of missing files to Conflict
422
                foreach (var item in filesToDelete)
423
                {
424
                    //Try to acquire a gate on the file, to take into account files that have been dequeued
425
                    //and are being processed
426
                    using (var gate = NetworkGate.Acquire(item.FullName, NetworkOperation.Deleting))
427
                    {
428
                        if (gate.Failed)
429
                            continue;
430
                        StatusKeeper.SetFileState(item.FullName, FileStatus.Conflict, FileOverlayStatus.Deleted,"Local file missing from server");
431
                    }
432
                }
433
                UpdateStatus(PithosStatus.HasConflicts);
434
                StatusNotification.NotifyConflicts(filesToDelete, String.Format("{0} local files are missing from Pithos, possibly because they were deleted", filesToDelete.Count));
435
                StatusNotification.NotifyForFiles(filesToDelete, String.Format("{0} files were deleted", filesToDelete.Count), TraceLevel.Info);
436
            }
437
            else
438
            {
439
                var deletedFiles = new List<FileSystemInfo>();
440
                foreach (var objectInfo in cloudFiles)
441
                {
442
                    if (Log.IsDebugEnabled)
443
                        Log.DebugFormat("Handle deleted [{0}]",objectInfo.Uri);
444
                    var relativePath = objectInfo.RelativeUrlToFilePath(accountInfo.UserName);
445
                    var item = FileAgent.GetFileAgent(accountInfo).GetFileSystemInfo(relativePath);
446
                    if (Log.IsDebugEnabled)
447
                        Log.DebugFormat("Will delete [{0}] for [{1}]", item.FullName,objectInfo.Uri);
448
                    if (item.Exists)
449
                    {
450
                        if ((item.Attributes & FileAttributes.ReadOnly) == FileAttributes.ReadOnly)
451
                        {
452
                            item.Attributes = item.Attributes & ~FileAttributes.ReadOnly;
453

    
454
                        }
455
                        
456
                        
457
                        Log.DebugFormat("Deleting {0}", item.FullName);
458

    
459
                        var directory = item as DirectoryInfo;
460
                        if (directory!=null)
461
                            directory.Delete(true);
462
                        else
463
                            item.Delete();
464
                        Log.DebugFormat("Deleted [{0}] for [{1}]", item.FullName, objectInfo.Uri);
465
                        DateTime lastDate;
466
                        _lastSeen.TryRemove(item.FullName, out lastDate);
467
                        deletedFiles.Add(item);
468
                    }
469
                    StatusKeeper.SetFileState(item.FullName, FileStatus.Deleted, FileOverlayStatus.Deleted, "File Deleted");
470
                }
471
                Log.InfoFormat("[{0}] files were deleted",deletedFiles.Count);
472
                StatusNotification.NotifyForFiles(deletedFiles, String.Format("{0} files were deleted", deletedFiles.Count), TraceLevel.Info);
473
            }
474

    
475
        }
476

    
477
        /// <summary>
478
        /// Creates a Sync action for each changed server file
479
        /// </summary>
480
        /// <param name="accountInfo"></param>
481
        /// <param name="changes"></param>
482
        /// <returns></returns>
483
        private IEnumerable<CloudAction> ChangesToActions(AccountInfo accountInfo, IEnumerable<ObjectInfo> changes)
484
        {
485
            if (changes == null)
486
                throw new ArgumentNullException();
487
            Contract.EndContractBlock();
488
            var fileAgent = FileAgent.GetFileAgent(accountInfo);
489

    
490
            //In order to avoid multiple iterations over the files, we iterate only once
491
            //over the remote files
492
            foreach (var objectInfo in changes)
493
            {
494
                var relativePath = objectInfo.RelativeUrlToFilePath(accountInfo.UserName);
495
                //If a directory object already exists, we may need to sync it
496
                if (fileAgent.Exists(relativePath))
497
                {
498
                    var localFile = fileAgent.GetFileSystemInfo(relativePath);
499
                    //We don't need to sync directories
500
                    if (objectInfo.IsDirectory && localFile is DirectoryInfo)
501
                        continue;
502
                    using (new SessionScope(FlushAction.Never))
503
                    {
504
                        var state = StatusKeeper.GetStateByFilePath(localFile.FullName);
505
                        _lastSeen[localFile.FullName] = DateTime.Now;
506
                        //Common files should be checked on a per-case basis to detect differences, which is newer
507

    
508
                        yield return new CloudAction(accountInfo, CloudActionType.MustSynch,
509
                                                     localFile, objectInfo, state, accountInfo.BlockSize,
510
                                                     accountInfo.BlockHash);
511
                    }
512
                }
513
                else
514
                {
515
                    //Remote files should be downloaded
516
                    yield return new CloudDownloadAction(accountInfo, objectInfo);
517
                }
518
            }
519
        }
520

    
521
        /// <summary>
522
        /// Creates a Local Move action for each moved server file
523
        /// </summary>
524
        /// <param name="accountInfo"></param>
525
        /// <param name="moves"></param>
526
        /// <returns></returns>
527
        private IEnumerable<CloudAction> MovesToActions(AccountInfo accountInfo, IEnumerable<ObjectInfo> moves)
528
        {
529
            if (moves == null)
530
                throw new ArgumentNullException();
531
            Contract.EndContractBlock();
532
            var fileAgent = FileAgent.GetFileAgent(accountInfo);
533

    
534
            //In order to avoid multiple iterations over the files, we iterate only once
535
            //over the remote files
536
            foreach (var objectInfo in moves)
537
            {
538
                var previousRelativepath = objectInfo.Previous.RelativeUrlToFilePath(accountInfo.UserName);
539
                //If the previous file already exists, we can execute a Move operation
540
                if (fileAgent.Exists(previousRelativepath))
541
                {
542
                    var previousFile = fileAgent.GetFileSystemInfo(previousRelativepath);
543
                    using (new SessionScope(FlushAction.Never))
544
                    {
545
                        var state = StatusKeeper.GetStateByFilePath(previousFile.FullName);
546
                        _lastSeen[previousFile.FullName] = DateTime.Now;
547

    
548
                        //For each moved object we need to move both the local file and update                                                
549
                        yield return new CloudAction(accountInfo, CloudActionType.RenameLocal,
550
                                                     previousFile, objectInfo, state, accountInfo.BlockSize,
551
                                                     accountInfo.BlockHash);
552
                        //For modified files, we need to download the changes as well
553
                        if (objectInfo.Hash!=objectInfo.PreviousHash)
554
                            yield return new CloudDownloadAction(accountInfo,objectInfo);
555
                    }
556
                }
557
                //If the previous file does not exist, we need to download it in the new location
558
                else
559
                {
560
                    //Remote files should be downloaded
561
                    yield return new CloudDownloadAction(accountInfo, objectInfo);
562
                }
563
            }
564
        }
565

    
566

    
567
        /// <summary>
568
        /// Creates a download action for each new server file
569
        /// </summary>
570
        /// <param name="accountInfo"></param>
571
        /// <param name="creates"></param>
572
        /// <returns></returns>
573
        private IEnumerable<CloudAction> CreatesToActions(AccountInfo accountInfo, IEnumerable<ObjectInfo> creates)
574
        {
575
            if (creates == null)
576
                throw new ArgumentNullException();
577
            Contract.EndContractBlock();
578
            var fileAgent = FileAgent.GetFileAgent(accountInfo);
579

    
580
            //In order to avoid multiple iterations over the files, we iterate only once
581
            //over the remote files
582
            foreach (var objectInfo in creates)
583
            {
584
                if (Log.IsDebugEnabled)
585
                    Log.DebugFormat("[NEW INFO] {0}",objectInfo.Uri);
586

    
587
                var relativePath = objectInfo.RelativeUrlToFilePath(accountInfo.UserName);
588

    
589
                //If the object already exists, we should check before uploading or downloading
590
                if (fileAgent.Exists(relativePath))
591
                {
592
                    var localFile= fileAgent.GetFileSystemInfo(relativePath);
593
                    var state = StatusKeeper.GetStateByFilePath(localFile.WithProperCapitalization().FullName);
594
                    yield return new CloudAction(accountInfo, CloudActionType.MustSynch,
595
                                                     localFile, objectInfo, state, accountInfo.BlockSize,
596
                                                     accountInfo.BlockHash);                    
597
                }
598
                else
599
                {
600
                    //Remote files should be downloaded
601
                    yield return new CloudDownloadAction(accountInfo, objectInfo);
602
                }
603

    
604
            }
605
        }
606

    
607
        /// <summary>
608
        /// Notify the UI to update the visual status
609
        /// </summary>
610
        /// <param name="status"></param>
611
        private void UpdateStatus(PithosStatus status)
612
        {
613
            try
614
            {
615
                StatusNotification.SetPithosStatus(status);
616
                //StatusNotification.Notify(new Notification());
617
            }
618
            catch (Exception exc)
619
            {
620
                //Failure is not critical, just log it
621
                Log.Warn("Error while updating status", exc);
622
            }
623
        }
624

    
625
        private static void CreateContainerFolders(AccountInfo accountInfo, IEnumerable<ContainerInfo> containers)
626
        {
627
            var containerPaths = from container in containers
628
                                 let containerPath = Path.Combine(accountInfo.AccountPath, container.Name)
629
                                 where container.Name != FolderConstants.TrashContainer && !Directory.Exists(containerPath)
630
                                 select containerPath;
631

    
632
            foreach (var path in containerPaths)
633
            {
634
                Directory.CreateDirectory(path);
635
            }
636
        }
637

    
638
        public void AddAccount(AccountInfo accountInfo)
639
        {
640
            //Avoid adding a duplicate accountInfo
641
            _accounts.TryAdd(accountInfo.AccountKey, accountInfo);
642
        }
643

    
644
        public void RemoveAccount(AccountInfo accountInfo)
645
        {
646
            AccountInfo account;
647
            _accounts.TryRemove(accountInfo.AccountKey, out account);
648
            SnapshotDifferencer differencer;
649
            _differencer.Differencers.TryRemove(accountInfo.AccountKey, out differencer);
650
        }
651

    
652
        public void SetSelectivePaths(AccountInfo accountInfo,Uri[] added, Uri[] removed)
653
        {
654
            AbortRemovedPaths(accountInfo,removed);
655
            DownloadNewPaths(accountInfo,added);
656
        }
657

    
658
        private void DownloadNewPaths(AccountInfo accountInfo, Uri[] added)
659
        {
660
            var client = new CloudFilesClient(accountInfo);
661
            foreach (var folderUri in added)
662
            {
663
                try
664
                {
665

    
666
                    string account;
667
                    string container;
668
                    var segmentsCount = folderUri.Segments.Length;
669
                    if (segmentsCount < 3)
670
                        continue;
671
                    if (segmentsCount == 3)
672
                    {
673
                        account = folderUri.Segments[1].TrimEnd('/');
674
                        container = folderUri.Segments[2].TrimEnd('/');
675
                    }
676
                    else
677
                    {
678
                        account = folderUri.Segments[2].TrimEnd('/');
679
                        container = folderUri.Segments[3].TrimEnd('/');
680
                    }
681
                    IList<ObjectInfo> items;
682
                    if (segmentsCount > 3)
683
                    {
684
                        var folder = String.Join("", folderUri.Segments.Splice(4));
685
                        items = client.ListObjects(account, container, folder);
686
                    }
687
                    else
688
                    {
689
                        items = client.ListObjects(account, container);
690
                    }
691
                    var actions = CreatesToActions(accountInfo, items);
692
                    foreach (var action in actions)
693
                    {
694
                        NetworkAgent.Post(action);
695
                    }
696
                }
697
                catch (Exception exc)
698
                {
699
                    Log.WarnFormat("Listing of new selective path [{0}] failed with \r\n{1}", folderUri, exc);
700
                }
701
            }
702

    
703
            //Need to get a listing of each of the URLs, then post them to the NetworkAgent
704
            //CreatesToActions(accountInfo,)
705

    
706
/*            NetworkAgent.Post();*/
707
        }
708

    
709
        private void AbortRemovedPaths(AccountInfo accountInfo, Uri[] removed)
710
        {
711
            /*this.NetworkAgent.*/
712
        }
713
    }
714
}