using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using CatalogVbLib;
using Dasync.Collections;

namespace MaddoShared
{
    public class ImageCreationStuff
    {
        public class Options
        {
            public bool AggiornaSottodirectory { get; set; }
            public bool CreaSottocartelle { get; set; }

            public int FilePerCartella { get; set; }
            public string SuffissoCartelle { get; set; }
            public int CifreContatore { get; set; }
            public NumerazioneType NumerazioneType { get; set; }
            public string SourcePath { get; set; }
            public string DestinationPath { get; set; }

            public int MaxThreads { get; set; }
            public int ChunksSize { get; set; }
            public bool LinearExecution { get; set; }
        }

        public async Task<string> CreaCatalogoParallel(Options options, ConcurrentBag<string> results, EventHandler<Tuple<string,int>> updateEvent, CancellationToken cancellationToken = default(CancellationToken))
        {
            var stopwatch = new Stopwatch();
            stopwatch.Start();
            // todo immagini counter
            //todo set label
            await CreaImmaginiParallel(options, results, updateEvent, cancellationToken);

            // todo set finito label
            stopwatch.Stop();

            return $"{stopwatch.Elapsed.Hours}h {stopwatch.Elapsed.Minutes}m ${stopwatch.Elapsed.Seconds}s ({stopwatch.Elapsed.TotalSeconds}s)";


        }

        public async Task CreaImmaginiParallel(Options options, ConcurrentBag<string> results, EventHandler<Tuple<string, int>> updateEvent, CancellationToken cancellationToken = default(CancellationToken))
        {
            var dataToProcess = new List<FileData>();
            if (options.AggiornaSottodirectory && options.CreaSottocartelle)
            {
                var helper = new FileHelperSharp();
                dataToProcess = helper.GetFilesRecursive(new DirectoryInfo(options.SourcePath), new DirectoryInfo(options.DestinationPath),
                    "*.jpg", new FileHelperOptions()
                    {
                        FilesPerFolder = options.FilePerCartella,
                        Suffix = options.SuffissoCartelle,
                        CounterSize = options.CifreContatore,
                        NumerationType = options.NumerazioneType
                    });
            }
            else if (!options.CreaSottocartelle)
            {
                var files = Directory.EnumerateFiles(options.SourcePath, "*.jpg",
                    options.AggiornaSottodirectory
                        ? SearchOption.AllDirectories
                        : SearchOption.TopDirectoryOnly);

                dataToProcess = files.Select(x =>
                {
                    var fInfo = new FileInfo(x);
                    var filePath = fInfo.DirectoryName;
                    var trimmedSourcePath = options.SourcePath.TrimEnd('\\');
                    var newFilePath = fInfo.FullName.Replace(trimmedSourcePath, "").TrimStart('\\');
                    newFilePath = Path.Combine(options.DestinationPath, newFilePath);

                    var destFolderPath = new FileInfo(newFilePath).DirectoryName;
                    var destFolderInfo = new DirectoryInfo(destFolderPath);
                    destFolderInfo.EnsureDirectoryExists();

                    return new FileData(fInfo, new DirectoryInfo(new FileInfo(newFilePath).DirectoryName));
                }).ToList();

                //// TODO
                //dataToProcess =
                //    (from f in Directory.EnumerateFiles(options.SourcePath, "*.jpg",
                //            options.AggiornaSottodirectory
                //                ? SearchOption.AllDirectories
                //                : SearchOption.TopDirectoryOnly)
                //     select new FileData(new FileInfo(f),
                //         new DirectoryInfo(options.DestinationPath.PathCombine(
                //             new FileInfo(f).DirectoryName.Replace(options.SourcePath.TrimEnd(new char[] {'\\'}), "")
                //             )
                //         )
                //         )
                //        )
                //    .ToList();
            }

            var threads = options.MaxThreads == 0 ? Environment.ProcessorCount * 2 : options.MaxThreads;
            var scheduler = new ConcurrentExclusiveSchedulerPair(TaskScheduler.Default, threads)
                .ConcurrentScheduler;

            //var allTasks = new List<Task>();
            var test = from d in dataToProcess
                       select Task.Factory.StartNew(async () =>
                       {
                           await new ImageCreatorSharp(d.File, d.Directory).CreaImmagineThread(d.File.Name);

                           //var imgC = new ImageCreatorSharp(d.File, d.Directory);
                           //imgC.CreaImmagineThread(d.File.Name);
                           //imgC = null;
                       }, CancellationToken.None, TaskCreationOptions.None, scheduler);

            //int count = 0;

            if (options.LinearExecution)
            {
                foreach (var task in test)
                {
                    await task;
                }
            }
            else
            {
                if (options.ChunksSize == 0)
                {


                    //var opts = new ParallelOptions() { MaxDegreeOfParallelism = threads, CancellationToken = cancellationToken, TaskScheduler = scheduler};
                    await dataToProcess.ParallelForEachAsync(async fileData =>
                   {
                       await new ImageCreatorSharp(fileData.File, fileData.Directory).CreaImmagineThread(fileData.File.Name);
                       results.Add(fileData.File.Name);
                       //count = Interlocked.Increment(ref count);
                       try
                       {
                           updateEvent?.Invoke(this, new Tuple<string, int>(fileData.File.Name, dataToProcess.Count) );
                       }
                       catch (Exception e)
                       {
                           Console.WriteLine(e);
                           throw;
                       }

                   }, maxDegreeOfParallelism: threads, false, cancellationToken);


                }
                else
                {

                    var asdf = SplitList(dataToProcess.ToList(), options.ChunksSize).ToList();
                   

                    foreach (var sdaf in asdf)
                    {
                        await sdaf.ParallelForEachAsync(async fileData =>
                        {
                            await new ImageCreatorSharp(fileData.File, fileData.Directory).CreaImmagineThread(fileData.File.Name);
                            results.Add(fileData.File.Name);
                            //count = Interlocked.Increment(ref count);
                            try
                            {
                                updateEvent?.Invoke(this, new Tuple<string, int>(fileData.File.Name, dataToProcess.Count));
                            }
                            catch (Exception e)
                            {
                                Console.WriteLine(e);
                                throw;
                            }
                        }, maxDegreeOfParallelism: threads, false, cancellationToken);
                    }



                }
            }


        }

        public static IEnumerable<List<T>> SplitList<T>(List<T> bigList, int nSize = 3)
        {
            for (int i = 0; i < bigList.Count; i += nSize)
            {
                yield return bigList.GetRange(i, Math.Min(nSize, bigList.Count - i));
            }
        }
    }
}