// Copyright (C) 2024, The Duplicati Team
// https://duplicati.com, hello@duplicati.com
// 
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// copy of this software and associated documentation files (the "Software"), 
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// and/or sell copies of the Software, and to permit persons to whom the 
// Software is furnished to do so, subject to the following conditions:
// 
// The above copyright notice and this permission notice shall be included in 
// all copies or substantial portions of the Software.
// 
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// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 
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using System.Collections.Generic;
using System.Threading.Tasks;
using Duplicati.Library.Utility;
using Duplicati.Library.Snapshots;
using CoCoL;

namespace Duplicati.Library.Main.Operation.Backup
{
    internal static class CountFilesHandler
    {
        public static async Task Run(IEnumerable<string> sources, Snapshots.ISnapshotService snapshot, UsnJournalService journalService, BackupResults result, Options options, IFilter sourcefilter, IFilter filter, Common.ITaskReader taskreader, System.Threading.CancellationToken token)
        {
            // Make sure we create the enumeration process in a separate scope,
            // but keep the log channel from the parent scope
            using(Logging.Log.StartIsolatingScope(true))
            using (new IsolatedChannelScope())
            {
                var enumeratorTask = Backup.FileEnumerationProcess.Run(sources, snapshot, journalService, options.FileAttributeFilter, sourcefilter, filter, options.SymlinkPolicy, options.HardlinkPolicy, options.ExcludeEmptyFolders, options.IgnoreFilenames, options.ChangedFilelist, taskreader, token);
                var counterTask = AutomationExtensions.RunTask(new
                {
                    Input = Backup.Channels.SourcePaths.ForRead
                },
                    
                async self =>
                {
                    var count = 0L;
                    var size = 0L;

                    try
                    {
                        while (await taskreader.ProgressAsync && !token.IsCancellationRequested)
                        {
                            var path = await self.Input.ReadAsync();

                            count++;

                            try
                            {
                                size += snapshot.GetFileSize(path);
                            }
                            catch
                            {
                            }

                            result.OperationProgressUpdater.UpdatefileCount(count, size, false);
                        }
                    }
                    finally
                    {
                        result.OperationProgressUpdater.UpdatefileCount(count, size, true);
                    }
                });

                await Task.WhenAll(enumeratorTask, counterTask);
            }
        }
    }
}