using System.Text;
using System.Text.Json;
using System.Text.RegularExpressions;
using View_by_Distance.FaceRecognitionDotNet;
using View_by_Distance.Metadata.Models;
using View_by_Distance.Property.Models;
using View_by_Distance.Resize.Models;
using View_by_Distance.Shared.Models.Stateless;
using WindowsShortcutFactory;

namespace View_by_Distance.Instance.Models;

/// <summary>
// List<D_Faces>
/// </summary>

internal class E_Distance
{

    private readonly Serilog.ILogger? _Log;
    private readonly Configuration _Configuration;
    private readonly JsonSerializerOptions _WriteIndentedJsonSerializerOptions;

    internal E_Distance(Configuration configuration)
    {
        _Configuration = configuration;
        _Log = Serilog.Log.ForContext<E_Distance>();
        _WriteIndentedJsonSerializerOptions = new JsonSerializerOptions { WriteIndented = true };
    }

    public override string ToString()
    {
        string result = JsonSerializer.Serialize(this, new JsonSerializerOptions() { WriteIndented = true });
        return result;
    }

    private static void LoadFaceEncodingCollections(Item[] filteredItems, List<List<D_Face>> faceCollections, List<int[]> locationIndicesCollection, List<FaceEncoding> faceEncodingCollection, List<List<FaceEncoding>> faceEncodingCollections)
    {
        List<D_Face> faceCollection;
        FaceEncoding faceEncoding;
        for (int i = 0; i < filteredItems.Length; i++)
        {
            faceCollection = faceCollections[i];
            if (!faceCollection.Any())
                throw new Exception();
            faceEncodingCollections.Add(new List<FaceEncoding>());
            for (int j = 0; j < faceCollection.Count; j++)
            {
                if (!faceCollection[j].Populated)
                    continue;
                faceEncoding = FaceRecognition.LoadFaceEncoding(faceCollection[j].FaceEncoding.RawEncoding);
                faceEncodingCollection.Add(faceEncoding);
                faceEncodingCollections[i].Add(faceEncoding);
                locationIndicesCollection.Add(new int[] { i, j });
            }
        }
    }

    private List<Tuple<Shared.Models.Properties.IFace, string>> GetOrderedNoFaceCollection(List<List<D_Face>> faceCollections, int i, D_Face face)
    {
        List<Tuple<Shared.Models.Properties.IFace, string>> results = new() { new(face, string.Empty) };
        if (_Configuration.MaxItemsInDistanceCollection is null)
            throw new NullReferenceException(nameof(_Configuration.MaxItemsInDistanceCollection));
        for (int n = 0; n < faceCollections.Count; n++)
        {
            if (i == n)
                continue;
            for (int j = 0; j < faceCollections[n].Count; j++)
                results.Add(new(faceCollections[n][j], string.Empty));
        }
        for (int r = results.Count - 1; r > _Configuration.MaxItemsInDistanceCollection.Value; r--)
            results.RemoveAt(r);
        return results;
    }

    private List<double[]> GetValues(List<List<D_Face>> faceCollections, List<int[]> locationIndicesCollection, List<double> faceDistances)
    {
        List<double[]> results = new();
        if (_Configuration.LocationConfidenceFactor is null)
            throw new NullReferenceException(nameof(_Configuration.LocationConfidenceFactor));
        if (_Configuration.DistanceFactor is null)
            throw new NullReferenceException(nameof(_Configuration.DistanceFactor));
        D_Face face;
        int[] locationIndices;
        for (int d = 0; d < faceDistances.Count; d++)
        {
            locationIndices = locationIndicesCollection[d];
            face = faceCollections[locationIndices[0]][locationIndices[1]];
            if (face.Populated && face.LocationIndex is not null && locationIndices[1] != face.LocationIndex)
                throw new Exception();
            results.Add(new double[] { d, faceDistances[d], (faceDistances[d] * _Configuration.DistanceFactor.Value) + face.Location.Confidence * _Configuration.LocationConfidenceFactor.Value / 10 });
        }
        results = (from l in results orderby l[2] select l).ToList();
        return results;
    }

    private List<Tuple<Shared.Models.Properties.IFace, string>> GetOrderedFaceCollection(List<List<D_Face>> faceCollections, List<int[]> locationIndicesCollection, List<double[]> indicesAndValues)
    {
        List<Tuple<Shared.Models.Properties.IFace, string>> results = new();
        if (_Configuration.MaxItemsInDistanceCollection is null)
            throw new NullReferenceException(nameof(_Configuration.MaxItemsInDistanceCollection));
        int[] locationIndices;
        for (int t = 0; t < indicesAndValues.Count; t++)
        {
            locationIndices = locationIndicesCollection[(int)indicesAndValues[t][0]];
            results.Add(new(faceCollections[locationIndices[0]][locationIndices[1]], string.Join('|', (from l in indicesAndValues[t] select l.ToString("0.000")).ToArray(), 1, indicesAndValues[t].Length - 1)));
        }
        for (int r = results.Count - 1; r > _Configuration.MaxItemsInDistanceCollection.Value; r--)
            results.RemoveAt(r);
        return results;
    }

    private static string GetText(string fileNameWithoutExtension, List<List<D_Face>> faceCollections, List<int[]> locationIndicesCollection, List<double[]> indicesAndValues)
    {
        string result;
        D_Face face;
        int[] locationIndices;
        StringBuilder tvs = new();
        _ = tvs.Append("FileNameWithoutExtension").Append('\t').Append("LocationIndex").Append('\t').Append("FaceConfidence").Append('\t').Append("FaceDistance").Append('\t').Append("FactoredValue").AppendLine();
        for (int t = 0; t < indicesAndValues.Count; t++)
        {
            locationIndices = locationIndicesCollection[(int)indicesAndValues[t][0]];
            face = faceCollections[locationIndices[0]][locationIndices[1]];
            if (face.Populated && face.LocationIndex is not null && locationIndices[1] != face.LocationIndex)
                throw new Exception();
            _ = tvs.Append(fileNameWithoutExtension).Append('\t').Append(face.LocationIndex).Append('\t').Append(face.Location.Confidence).Append('\t').Append(indicesAndValues[t][1]).Append('\t').Append(indicesAndValues[t][2]).AppendLine();
        }
        result = tvs.ToString();
        return result;
    }

    private void LoadOrCreateThenSaveDistanceResultsForOutputResolutionsLoop(List<List<D_Face>> faceCollections, int subFilesCount, int i, List<D_Face> faceCollection, List<int[]> locationIndicesCollection, List<Tuple<string, DateTime>> subFileTuples, List<FaceEncoding> faceEncodingCollection, List<FaceEncoding> faceEncodingCollections, string fileNameWithoutExtension, string jsonDirectory, string tvsDirectory, bool updateDateWhenMatches, DateTime? updateToWhenMatches)
    {
        string text;
        string json;
        string jsonFile;
        List<Tuple<Shared.Models.Properties.IFace, string>> orderedFaceCollection;
        if (!Directory.Exists(jsonDirectory))
            _ = Directory.CreateDirectory(jsonDirectory);
        if (!Directory.Exists(tvsDirectory))
            _ = Directory.CreateDirectory(tvsDirectory);
        if (!faceEncodingCollections.Any())
        {
            int j = 0;
            orderedFaceCollection = GetOrderedNoFaceCollection(faceCollections, i, faceCollection[j]);
            json = JsonSerializer.Serialize(orderedFaceCollection, _WriteIndentedJsonSerializerOptions);
            jsonFile = Path.Combine(jsonDirectory, $"{j} - {fileNameWithoutExtension}.json");
            if (Property.Models.Stateless.IPath.WriteAllText(jsonFile, json, updateDateWhenMatches, compareBeforeWrite: true, updateToWhenMatches: updateToWhenMatches))
                subFileTuples.Add(new Tuple<string, DateTime>(nameof(E_Distance), DateTime.Now));
        }
        else
        {
            string tvsFile;
            List<double> faceDistances;
            List<double[]> indicesAndValues;
            for (int j = 0; j < faceEncodingCollections.Count; j++)
            {
                if (!faceCollection[j].Populated)
                    continue;
                tvsFile = Path.Combine(tvsDirectory, $"{j} - {fileNameWithoutExtension}.tvs");
                jsonFile = Path.Combine(jsonDirectory, $"{j} - {fileNameWithoutExtension}.json");
                faceDistances = FaceRecognition.FaceDistances(faceEncodingCollection, faceEncodingCollections[j]);
                indicesAndValues = GetValues(faceCollections, locationIndicesCollection, faceDistances);
                orderedFaceCollection = GetOrderedFaceCollection(faceCollections, locationIndicesCollection, indicesAndValues);
                text = GetText(fileNameWithoutExtension, faceCollections, locationIndicesCollection, indicesAndValues);
                if (Property.Models.Stateless.IPath.WriteAllText(tvsFile, text, updateDateWhenMatches, compareBeforeWrite: true))
                    subFileTuples.Add(new Tuple<string, DateTime>(nameof(E_Distance), DateTime.Now));
                json = JsonSerializer.Serialize(orderedFaceCollection, _WriteIndentedJsonSerializerOptions);
                if (Property.Models.Stateless.IPath.WriteAllText(jsonFile, json, updateDateWhenMatches, compareBeforeWrite: true))
                    subFileTuples.Add(new Tuple<string, DateTime>(nameof(E_Distance), DateTime.Now));
            }
        }
    }

    private void LoadOrCreateThenSaveDistanceResultsForOutputResolutions(Item[] filteredItems, List<List<D_Face>> faceCollections, List<string[]> directories, bool updateDateWhenMatches, DateTime? updateToWhenMatches)
    {
        FileHolder? fileHolder;
        List<int[]> locationIndicesCollection = new();
        List<Tuple<string, DateTime>> subFileTuples = new();
        List<FaceEncoding> faceEncodingCollection = new();
        List<List<FaceEncoding>> faceEncodingCollections = new();
        LoadFaceEncodingCollections(filteredItems, faceCollections, locationIndicesCollection, faceEncodingCollection, faceEncodingCollections);
        if (faceEncodingCollections.Count != faceCollections.Count)
            throw new Exception();
        if (locationIndicesCollection.Count != faceEncodingCollection.Count)
            throw new Exception();
        for (int i = 0; i < filteredItems.Length; i++)
        {
            fileHolder = filteredItems[i].ImageFileHolder;
            if (fileHolder is null)
                continue;
            LoadOrCreateThenSaveDistanceResultsForOutputResolutionsLoop(faceCollections, filteredItems.Length, i, faceCollections[i], locationIndicesCollection, subFileTuples, faceEncodingCollection, faceEncodingCollections[i], fileHolder.NameWithoutExtension, directories[i][0], directories[i][1], updateDateWhenMatches, updateToWhenMatches);
        }
    }

    internal void LoadOrCreateThenSaveDistanceResultsForOutputResolutions(Property.Models.Configuration configuration, string eResultsFullGroupDirectory, string sourceDirectory, string outputResolution, List<Tuple<string, DateTime>> sourceDirectoryChanges, Item[] filteredItems, List<List<D_Face>> faceCollections)
    {
        if (_Configuration.CheckJsonForDistanceResults is null)
            throw new NullReferenceException(nameof(_Configuration.CheckJsonForDistanceResults));
        if (_Configuration.PropertiesChangedForDistance is null)
            throw new NullReferenceException(nameof(_Configuration.PropertiesChangedForDistance));
        Item item;
        string json;
        bool check = false;
        string parentCheck;
        string usingRelativePath;
        DateTime? dateTime = null;
        string dCollectionDirectory;
        FileInfo[] fileInfoCollection;
        bool updateDateWhenMatches = false;
        List<string[]> directories = new();
        System.IO.DirectoryInfo directoryInfo;
        System.IO.DirectoryInfo tvsDirectoryInfo;
        string[] changesFrom = new string[] { nameof(A_Property), nameof(B_Metadata), nameof(C_Resize), nameof(D_Face) };
        List<DateTime> dateTimes = (from l in sourceDirectoryChanges where changesFrom.Contains(l.Item1) select l.Item2).ToList();
        List<string> directoryInfoCollection = Property.Models.Stateless.IResult.GetDirectoryInfoCollection(
            configuration,
            sourceDirectory,
            eResultsFullGroupDirectory,
            contentDescription: ".tvs File",
            singletonDescription: string.Empty,
            collectionDescription: "n json file(s) for each face found (one to many)",
            converted: true);
        for (int i = 0; i < filteredItems.Length; i++)
        {
            item = filteredItems[i];
            if (item.ImageFileHolder is null || item.Property?.Id is null)
                continue;
            usingRelativePath = Path.Combine(directoryInfoCollection[0].Replace("<>", "[]"), item.ImageFileHolder.NameWithoutExtension);
            dCollectionDirectory = Path.Combine(eResultsFullGroupDirectory, "[]", Property.Models.Stateless.IResult.AllInOne, $"{item.Property.Id.Value}{item.ImageFileHolder.ExtensionLowered}");
            directoryInfo = new System.IO.DirectoryInfo(dCollectionDirectory);
            if (!directoryInfo.Exists)
            {
                if (Directory.Exists(usingRelativePath))
                {
                    Directory.Move(usingRelativePath, directoryInfo.FullName);
                    directoryInfo.Refresh();
                }
                if (!Directory.Exists(dCollectionDirectory))
                {
                    if (directoryInfo.Parent?.Parent is null)
                        throw new Exception();
                    parentCheck = Path.Combine(directoryInfo.Parent.Parent.FullName, directoryInfo.Name);
                    if (Directory.Exists(parentCheck))
                    {
                        foreach (string file in Directory.GetFiles(parentCheck))
                            File.Delete(file);
                        Directory.Delete(parentCheck);
                    }
                }
            }
            tvsDirectoryInfo = new System.IO.DirectoryInfo(Path.Combine(directoryInfoCollection[0].Replace("<>", "()"), item.ImageFileHolder.NameWithoutExtension));
            directories.Add(new string[] { directoryInfo.FullName, tvsDirectoryInfo.FullName });
            if (_Configuration.CheckJsonForDistanceResults.Value && directoryInfo.Exists)
            {
                fileInfoCollection = directoryInfo.GetFiles("*.json", SearchOption.AllDirectories);
                for (int j = 0; j < fileInfoCollection.Length; j++)
                {
                    json = Shared.Models.Stateless.Methods.IIndex.GetJson(fileInfoCollection[j].FullName, fileInfoCollection[j]);
                    if (!_Configuration.PropertiesChangedForDistance.Value && Shared.Models.Stateless.Methods.IFace.GetFace(fileInfoCollection[j].FullName) is null)
                        check = true;
                }
            }
            if (check)
                continue;
            if (_Configuration.PropertiesChangedForDistance.Value)
                check = true;
            else if (!directoryInfo.Exists)
                check = true;
            else if (!tvsDirectoryInfo.Exists)
                check = true;
            else if (dateTimes.Any() && dateTimes.Max() > directoryInfo.LastWriteTime)
                check = true;
            if (check && !updateDateWhenMatches)
            {
                updateDateWhenMatches = dateTimes.Any() && directoryInfo.Exists && dateTimes.Max() > directoryInfo.LastWriteTime;
                dateTime = !updateDateWhenMatches ? null : dateTimes.Max();
            }
        }
        if (check)
            LoadOrCreateThenSaveDistanceResultsForOutputResolutions(filteredItems, faceCollections, directories, updateDateWhenMatches, updateToWhenMatches: dateTime);
        _ = Property.Models.Stateless.IPath.DeleteEmptyDirectories(directoryInfoCollection[0].Replace("<>", "()"));
    }

    private List<(string, List<KeyValuePair<string, Shared.Models.Face[]>>)> GetFiles(Property.Models.Configuration configuration, Model? model, PredictorModel? predictorModel, string outputResolution)
    {
        string json;
        List<KeyValuePair<string, Shared.Models.Face[]>>? facesKeyValuePairCollection;
        List<(string, List<KeyValuePair<string, Shared.Models.Face[]>>)> results = new();
        string dFacesCollectionDirectory = Path.Combine(Property.Models.Stateless.IResult.GetResultsFullGroupDirectory(configuration, model, predictorModel, nameof(D_Face), outputResolution, includeResizeGroup: true, includeModel: true, includePredictorModel: true), "[[]]");
        string[] dFacesCollectionFiles = Directory.GetFiles(dFacesCollectionDirectory, "*.json", SearchOption.TopDirectoryOnly);
        foreach (string dFacesCollectionFile in dFacesCollectionFiles)
        {
            json = File.ReadAllText(dFacesCollectionFile);
            facesKeyValuePairCollection = JsonSerializer.Deserialize<List<KeyValuePair<string, Shared.Models.Face[]>>>(json);
            if (facesKeyValuePairCollection is null)
                continue;
            results.Add(new(dFacesCollectionFile, facesKeyValuePairCollection));
        }
        return results;
    }

    private static List<(string, List<Shared.Models.Face>, List<FaceEncoding>)> GetMatches(List<(string, List<KeyValuePair<string, Shared.Models.Face[]>>)> files)
    {
        List<(string, List<Shared.Models.Face>, List<FaceEncoding>)> results = new();
        FaceEncoding faceEncoding;
        List<Shared.Models.Face> faces;
        List<FaceEncoding> faceEncodings;
        foreach ((string, List<KeyValuePair<string, Shared.Models.Face[]>>) file in files)
        {
            faces = new();
            faceEncodings = new();
            foreach (KeyValuePair<string, Shared.Models.Face[]> keyValuePair in file.Item2)
            {
                foreach (Shared.Models.Face face in keyValuePair.Value)
                {
                    if (!face.Populated)
                        continue;
                    faces.Add(face);
                    faceEncoding = FaceRecognition.LoadFaceEncoding(face.FaceEncoding.RawEncoding);
                    faceEncodings.Add(faceEncoding);
                }
            }
            results.Add(new(file.Item1, faces, faceEncodings));
        }
        return results;
    }

    private static int GetIndex(double[] faceDistances)
    {
        int result;
        List<double[]> faceDistancesWithIndex = new();
        for (int y = 0; y < faceDistances.Length; y++)
            faceDistancesWithIndex.Add(new double[] { faceDistances[y], y });
        faceDistancesWithIndex = (from l in faceDistancesWithIndex orderby l[0] select l).ToList();
        result = (int)faceDistancesWithIndex[0][1];
        return result;
    }

    private void Save(Property.Models.Configuration configuration, Model? model, PredictorModel? predictorModel, string outputResolution, string eDistanceCollectionDirectory, int k, string relativePath, Shared.Models.Face face, List<Tuple<Shared.Models.Face, string>> faceAndFaceDistanceCollection)
    {
        if (string.IsNullOrEmpty(eDistanceCollectionDirectory))
            eDistanceCollectionDirectory = Path.Combine(Property.Models.Stateless.IResult.GetResultsFullGroupDirectory(configuration, model, predictorModel, nameof(E_Distance), outputResolution, includeResizeGroup: true, includeModel: true, includePredictorModel: true), "[]");
        string fileNameWithoutExtension = Path.GetFileNameWithoutExtension(face.RelativePath);
        string jsonDirectory = string.Concat(eDistanceCollectionDirectory, Path.Combine(relativePath, fileNameWithoutExtension));
        if (!Directory.Exists(jsonDirectory))
            _ = Directory.CreateDirectory(jsonDirectory);
        string json = JsonSerializer.Serialize(faceAndFaceDistanceCollection, _WriteIndentedJsonSerializerOptions);
        string jsonFile = Path.Combine(jsonDirectory, $"{k} - {fileNameWithoutExtension}.nosj");
        _ = Property.Models.Stateless.IPath.WriteAllText(jsonFile, json, updateDateWhenMatches: true, compareBeforeWrite: true);
    }

    private static Tuple<Shared.Models.Face, double> Get(FaceEncoding faceEncoding, (string, List<Shared.Models.Face>, List<FaceEncoding>) match)
    {
        Tuple<Shared.Models.Face, double> result;
        double[] faceDistances = FaceRecognition.FaceDistances(match.Item3, faceEncoding).ToArray();
        int index = GetIndex(faceDistances);
        result = new(match.Item2[index], faceDistances[index]);
        return result;
    }

    internal void LoadOrCreateThenSaveDirectoryDistanceResultsForOutputResolutions(Property.Models.Configuration configuration, Model? model, PredictorModel? predictorModel, string outputResolution)
    {
        if (_Log is null)
            throw new NullReferenceException(nameof(_Log));
        string? relativePath;
        Shared.Models.Face face;
        ParallelOptions parallelOptions = new();
        FaceEncoding faceEncoding;
        string eDistanceCollectionDirectory = string.Empty;
        Tuple<Shared.Models.Face, double> faceAndFaceDistance;
        List<Tuple<Shared.Models.Face, string>> faceAndFaceDistanceCollection;
        List<(string, List<KeyValuePair<string, Shared.Models.Face[]>>)> files = GetFiles(configuration, model, predictorModel, outputResolution);
        List<(string, List<Shared.Models.Face>, List<FaceEncoding>)> matches = GetMatches(files);
        if (files.Count != matches.Count)
            throw new Exception();
        int filesCount = files.Count;
        for (int i = 0; i < filesCount; i++)
        {
            if (_Configuration.CrossDirectoryMaxItemsInDistanceCollection is null)
                continue;
            _Log.Debug(string.Concat("LoadOrCreateThenSaveDirectoryDistanceResultsForOutputResolutions - ", nameof(outputResolution), ' ', outputResolution, " - ", i, " of ", filesCount));
            for (int j = 0; j < files[i].Item2.Count; j++)
            {
                if (!matches[i].Item2.Any())
                    continue;
                for (int k = 0; k < files[i].Item2[j].Value.Length; k++)
                {
                    if (!files[i].Item2[j].Value[k].Populated)
                        continue;
                    face = files[i].Item2[j].Value[k];
                    faceAndFaceDistanceCollection = new(matches.Count);
                    relativePath = Path.GetDirectoryName(face.RelativePath);
                    if (string.IsNullOrEmpty(relativePath))
                        continue;
                    faceEncoding = FaceRecognition.LoadFaceEncoding(face.FaceEncoding.RawEncoding);
                    _ = Parallel.For(0, matches.Count, parallelOptions, z =>
                      {
                          if (z != i && matches[z].Item2.Any())
                          {
                              faceAndFaceDistance = Get(faceEncoding, matches[z]);
                              // if (faceAndFaceDistance.Item2 < _Configuration.)
                              faceAndFaceDistanceCollection.Add(new(faceAndFaceDistance.Item1, faceAndFaceDistance.Item2.ToString("0.000")));
                          }
                      });
                    if (faceAndFaceDistanceCollection.Any())
                    {
                        faceAndFaceDistanceCollection = (from l in faceAndFaceDistanceCollection orderby l.Item2 select l).Take(_Configuration.CrossDirectoryMaxItemsInDistanceCollection.Value).ToList();
                        Save(configuration, model, predictorModel, outputResolution, eDistanceCollectionDirectory, k, relativePath, face, faceAndFaceDistanceCollection);
                    }
                }
            }
        }
    }

    public static double GetStandardDeviation(IEnumerable<double> values, double average)
    {
        double result = 0;
        if (!values.Any())
            throw new Exception("Collection must have at least one value!");
        double sum = values.Sum(l => (l - average) * (l - average));
        result = Math.Sqrt(sum / values.Count());
        return result;
    }

    private static FaceEncoding? GetFaceEncoding(Shared.Models.Properties.IFace face)
    {
        FaceEncoding? result;
        if (!face.Populated)
            result = null;
        else
            result = FaceRecognition.LoadFaceEncoding(face.FaceEncoding.RawEncoding);
        return result;
    }

    private static (int index, double sum) GetIndexAndSum(int i, List<FaceEncoding> results)
    {
        List<double> faceDistances = FaceRecognition.FaceDistances(results, results[i]);
        return new(i, faceDistances.Sum());
    }

    private static List<FaceEncoding> GetFaceEncodings(int maxDegreeOfParallelism, List<(DateTime MinimumDateTime, bool? IsWrongYear, Shared.Models.PersonBirthday PersonBirthday, Shared.Models.Properties.IFace Face)> collection)
    {
        List<FaceEncoding> results;
        if (maxDegreeOfParallelism == 1)
        {
            results = new();
            FaceEncoding faceEncoding;
            foreach ((DateTime _, bool? _, Shared.Models.PersonBirthday _, Shared.Models.Properties.IFace face) in collection)
            {
                if (!face.Populated)
                    continue;
                faceEncoding = FaceRecognition.LoadFaceEncoding(face.FaceEncoding.RawEncoding);
                results.Add(faceEncoding);
            }
        }
        else
        {
            results = new();
            ParallelOptions parallelOptions = new() { MaxDegreeOfParallelism = maxDegreeOfParallelism };
            _ = Parallel.For(0, collection.Count, parallelOptions, i =>
            {
                FaceEncoding? faceEncoding = GetFaceEncoding(collection[i].Face);
                if (faceEncoding is not null)
                {
                    lock (results)
                        results.Add(faceEncoding);
                }
            });
        }
        if (collection.Count == results.Count && results.Count > 1)
        {
            double sum;
            int lowestIndex;
            double lowestSum;
            List<double> faceDistances;
            if (maxDegreeOfParallelism == 1)
            {
                lowestIndex = 0;
                lowestSum = double.MaxValue;
                for (int i = 0; i < results.Count; i++)
                {
                    faceDistances = FaceRecognition.FaceDistances(results, results[i]);
                    sum = faceDistances.Sum();
                    if (sum >= lowestSum)
                        continue;
                    lowestIndex = i;
                    lowestSum = sum;
                }
            }
            else
            {
                List<(int Index, double Sum)> indicesAndSums = new();
                ParallelOptions parallelOptions = new() { MaxDegreeOfParallelism = maxDegreeOfParallelism };
                _ = Parallel.For(0, results.Count, parallelOptions, i =>
                {
                    (int index, double sum) = GetIndexAndSum(i, results);
                    lock (indicesAndSums)
                        indicesAndSums.Add(new(index, sum));
                });
                (lowestIndex, lowestSum) = (from l in indicesAndSums orderby l.Sum select l).First();
            }
            faceDistances = FaceRecognition.FaceDistances(results, results[lowestIndex]);
            sum = faceDistances.Sum();
            if (sum == lowestSum)
            {
                double average = faceDistances.Average();
                double standardDeviation = GetStandardDeviation(faceDistances, average);
                double lcl = average - (standardDeviation * 3);
                double ucl = average + (standardDeviation * 3);
                for (int i = results.Count - 1; i > -1; i--)
                {
                    if (faceDistances[i] < lcl || faceDistances[i] > ucl)
                        results.RemoveAt(i);
                }
            }
        }
        return results;
    }

    private static List<(DateTime, bool?, Shared.Models.PersonBirthday, FaceEncoding[])> GetThreeSigmaFaceEncodings(int maxDegreeOfParallelism, Dictionary<string, List<(DateTime, bool?, Shared.Models.PersonBirthday, Shared.Models.Properties.IFace)>> keyValuePairs)
    {
        List<(DateTime, bool?, Shared.Models.PersonBirthday, FaceEncoding[])> results = new();
        const int zero = 0;
        List<FaceEncoding> faceEncodings;
        foreach (KeyValuePair<string, List<(DateTime MinimumDateTime, bool? IsWrongYear, Shared.Models.PersonBirthday PersonBirthday, Shared.Models.Properties.IFace _)>> keyValuePair in keyValuePairs)
        {
            faceEncodings = GetFaceEncodings(maxDegreeOfParallelism, keyValuePair.Value);
            results.Add(new(keyValuePair.Value[zero].MinimumDateTime, keyValuePair.Value[zero].IsWrongYear, keyValuePair.Value[zero].PersonBirthday, faceEncodings.ToArray()));
        }
        return results;
    }

    private static Closest? GetClosestParallelFor(DateTime minimumDateTime, bool? isWrongYear, Shared.Models.Properties.IFace face, FaceEncoding faceEncoding, (DateTime MinimumDateTime, bool? IsWrongYear, Shared.Models.PersonBirthday PersonBirthday, FaceEncoding[] FaceEncodings) tuple)
    {
        Closest? result;
        if (isWrongYear.HasValue && !isWrongYear.Value && minimumDateTime < tuple.PersonBirthday.Value)
            result = null;
        else
        {
            List<double> faceDistances = FaceRecognition.FaceDistances(tuple.FaceEncodings, faceEncoding);
            result = new(face.LocationIndex, tuple.MinimumDateTime, tuple.IsWrongYear, tuple.PersonBirthday, faceDistances);
            if (result.Minimum > Closest.MaximumMinimum)
                result = null;
        }
        return result;
    }

    private static Closest[] GetClosestCollection(int maxDegreeOfParallelism, List<(DateTime, bool?, Shared.Models.PersonBirthday, FaceEncoding[])> collection, DateTime itemMinimumDateTime, bool? itemIsWrongYear, Shared.Models.Properties.IFace face)
    {
        Closest[] results;
        List<Closest> closestCollection;
        FaceEncoding faceEncoding = FaceRecognition.LoadFaceEncoding(face.FaceEncoding.RawEncoding);
        if (maxDegreeOfParallelism == 1)
        {
            closestCollection = new();
            Closest closest;
            List<double> faceDistances;
            foreach ((DateTime minimumDateTime, bool? isWrongYear, Shared.Models.PersonBirthday personBirthday, FaceEncoding[] faceEncodings) in collection)
            {
                if (itemIsWrongYear.HasValue && !itemIsWrongYear.Value && itemMinimumDateTime < personBirthday.Value)
                    continue;
                faceDistances = FaceRecognition.FaceDistances(faceEncodings, faceEncoding);
                closest = new(face.LocationIndex, minimumDateTime, isWrongYear, personBirthday, faceDistances);
                if (closest.Minimum > Closest.MaximumMinimum)
                    continue;
                closestCollection.Add(closest);
            }
        }
        else
        {
            closestCollection = new();
            ParallelOptions parallelOptions = new() { MaxDegreeOfParallelism = maxDegreeOfParallelism };
            _ = Parallel.For(0, collection.Count, parallelOptions, i =>
            {
                Closest? closest = GetClosestParallelFor(itemMinimumDateTime, itemIsWrongYear, face, faceEncoding, collection[i]);
                if (closest is not null)
                {
                    lock (closestCollection)
                        closestCollection.Add(closest);
                }
            });
        }
        results = Closest.Get(closestCollection);
        return results;
    }

    private static void AddClosest(int maxDegreeOfParallelism, string argZero, List<Container> containers, List<(DateTime, bool?, Shared.Models.PersonBirthday, FaceEncoding[])> collection)
    {
        string key;
        Closest closest;
        bool? itemIsWrongYear;
        Closest[] closestCollection;
        DateTime? itemMinimumDateTime;
        Shared.Models.Properties.IFace face;
        Dictionary<string, int> results = new();
        foreach (Container container in containers)
        {
            if (!container.Items.Any())
                continue;
            if (!container.SourceDirectory.StartsWith(argZero))
                continue;
            foreach (Item item in container.Items)
            {
                if (item.ImageFileHolder is null || item.Property is null || item.Named.Any())
                    continue;
                itemMinimumDateTime = Property.Models.Stateless.A_Property.GetMinimumDateTime(item.Property);
                if (itemMinimumDateTime is null)
                    continue;
                (itemIsWrongYear, _) = item.IsWrongYear();
                if (Closest.SkipIsWrongYear && itemIsWrongYear.HasValue && itemIsWrongYear.Value)
                    continue;
                item.Closest.Clear();
                for (int i = 0; i < item.Faces.Count; i++)
                {
                    face = item.Faces[i];
                    closest = new(face.LocationIndex, itemMinimumDateTime.Value, itemIsWrongYear);
                    item.Closest.Add(closest);
                    if (!face.Populated)
                        continue;
                    closestCollection = GetClosestCollection(maxDegreeOfParallelism, collection, itemMinimumDateTime.Value, itemIsWrongYear, face);
                    for (int j = 0; j < closestCollection.Length; j++)
                    {
                        closest = closestCollection[j];
                        if (closest.PersonBirthday is null)
                            continue;
                        key = Item.GetKey(closest.MinimumDateTime, closest.IsWrongYear, closest.PersonBirthday);
                        if (!results.ContainsKey(key))
                            results.Add(key, 0);
                        else if (results[key] > Closest.MaximumPer)
                            continue;
                        results[key] += 1;
                        item.Closest[0] = closest;
                        break;
                    }
                }
            }
        }
    }

    internal static List<(DateTime, bool?, Shared.Models.PersonBirthday, FaceEncoding[])> ParallelWork(int maxDegreeOfParallelism, string argZero, List<Container> containers)
    {
        List<(DateTime, bool?, Shared.Models.PersonBirthday, FaceEncoding[])> results;
        Dictionary<string, List<(DateTime, bool?, Shared.Models.PersonBirthday, Shared.Models.Properties.IFace)>> keyValuePairs = Item.GetKeyValuePairs(argZero, containers);
        results = GetThreeSigmaFaceEncodings(maxDegreeOfParallelism, keyValuePairs);
        AddClosest(maxDegreeOfParallelism, argZero, containers, results);
        return results;
    }

    public static void SavePropertyHolders(string argZero, List<Container> containers, string zPropertyHolderSingletonDirectory)
    {
        string json;
        FileInfo fileInfo;
        bool updateDateWhenMatches = false;
        JsonSerializerOptions jsonSerializerOptions = new() { WriteIndented = true };
        foreach (Container container in containers)
        {
            if (!container.Items.Any())
                continue;
            if (!container.SourceDirectory.StartsWith(argZero))
                continue;
            foreach (Item item in container.Items)
            {
                if (item.ImageFileHolder is null || item.Property is null || !item.Faces.Any() || !item.Closest.Any())
                    continue;
                if (!(from l in item.Closest where l.Average.HasValue select true).Any())
                    continue;
                json = JsonSerializer.Serialize(item, jsonSerializerOptions);
                fileInfo = new(string.Concat(zPropertyHolderSingletonDirectory, item.RelativePath, ".json"));
                if (fileInfo.Directory is null)
                    continue;
                if (!fileInfo.Directory.Exists)
                    fileInfo.Directory.Create();
                _ = Property.Models.Stateless.IPath.WriteAllText(fileInfo.FullName, json, updateDateWhenMatches, compareBeforeWrite: true);
            }
        }
    }

    internal static void SaveThreeSigmaFaceEncodings(List<(DateTime, bool?, Shared.Models.PersonBirthday, FaceEncoding[])> collection, Dictionary<string, List<Shared.Models.Person>> peopleCollection, string eDistanceCollectionDirectory)
    {
        string json;
        string checkFile;
        string personKey;
        string directory;
        List<double[]> rawEncodings;
        Shared.Models.Person person;
        const string facePopulatedKey = "ThreeSigma";
        const string pattern = @"[\\,\/,\:,\*,\?,\"",\<,\>,\|]";
        foreach ((DateTime minimumDateTime, bool? isWrongYear, Shared.Models.PersonBirthday personBirthday, FaceEncoding[] faceEncodings) in collection)
        {
            rawEncodings = new();
            checkFile = string.Empty;
            personKey = Shared.Models.Stateless.Methods.IPersonBirthday.GetFormatted(personBirthday);
            directory = Item.GetDirectory(eDistanceCollectionDirectory, facePopulatedKey, minimumDateTime, isWrongYear, personBirthday, personKey);
            if (!peopleCollection.ContainsKey(personKey))
                continue;
            person = peopleCollection[personKey][0];
            checkFile = string.Concat(directory, " - ", Regex.Replace(Shared.Models.Stateless.Methods.IPersonName.GetFullName(person.Name), pattern, string.Empty), ".json");
            if (string.IsNullOrEmpty(checkFile))
                continue;
            if (!Directory.Exists(directory))
                _ = Directory.CreateDirectory(directory);
            for (int i = 0; i < faceEncodings.Length; i++)
                rawEncodings.Add(faceEncodings[i].GetRawEncoding());
            json = JsonSerializer.Serialize(rawEncodings, new JsonSerializerOptions { WriteIndented = true });
            _ = Property.Models.Stateless.IPath.WriteAllText(checkFile, json, updateDateWhenMatches: true, compareBeforeWrite: true);
        }
    }

    internal static List<(FileHolder? resizedFileHolder, string directory, FileInfo? faceFileInfo, string checkFile, string shortcutFile)> GetClosest(string argZero, List<Container> containers, Dictionary<string, List<Shared.Models.Person>> peopleCollection, PropertyLogic propertyLogic, string eDistanceContentDirectory, string dFacesContentDirectory)
    {
        List<(FileHolder?, string, FileInfo?, string, string)> results = new();
        string checkFile;
        string directory;
        string personKey;
        string personName;
        string shortcutFile;
        FileInfo faceFileInfo;
        string? directoryName;
        string facesDirectory;
        string personDirectory;
        Shared.Models.Person person;
        const string facePopulatedKey = "Closest";
        string deterministicHashCodeIdAndFaceLocationIndex;
        const string pattern = @"[\\,\/,\:,\*,\?,\"",\<,\>,\|]";
        foreach (Container container in containers)
        {
            if (!container.Items.Any())
                continue;
            if (!container.SourceDirectory.StartsWith(argZero))
                continue;
            foreach (Item item in container.Items)
            {
                if (item.ImageFileHolder is null || item.Property?.Id is null || item.ResizedFileHolder is null || item.Named.Any())
                    continue;
                if (!item.Closest.Any())
                    continue;
                directoryName = Path.GetDirectoryName(item.RelativePath);
                if (directoryName is null)
                    throw new Exception();
                foreach (Closest closest in item.Closest)
                {
                    if (closest.Average is null || closest.FaceLocationIndex is null || closest.PersonBirthday is null)
                        continue;
                    deterministicHashCodeIdAndFaceLocationIndex = $"{closest.FaceLocationIndex.Value} - {item.Property.Id.Value}";
                    if (propertyLogic.NamedDeterministicHashCodeIdAndFaceLocationIndex.Contains(deterministicHashCodeIdAndFaceLocationIndex))
                        continue;
                    personKey = Shared.Models.Stateless.Methods.IPersonBirthday.GetFormatted(closest.PersonBirthday);
                    directory = Item.GetDirectory(eDistanceContentDirectory, facePopulatedKey, closest.MinimumDateTime, closest.IsWrongYear, closest.PersonBirthday, personKey);
                    // checkFile = Path.Combine(directory, item.ImageFileHolder.Name);
                    if (!peopleCollection.ContainsKey(personKey))
                        personDirectory = string.Empty;
                    else
                    {
                        person = peopleCollection[personKey][0];
                        personName = Shared.Models.Stateless.Methods.IPersonName.GetFullName(person.Name);
                        personDirectory = Path.Combine(directory, Regex.Replace(personName, pattern, string.Empty));
                        results.Add(new(null, personDirectory, null, string.Empty, string.Empty));
                    }
                    facesDirectory = string.Concat(dFacesContentDirectory, Path.Combine(directoryName, item.ImageFileHolder.NameWithoutExtension));
                    faceFileInfo = new(Path.Combine(facesDirectory, $"{closest.FaceLocationIndex.Value} - {item.ImageFileHolder.NameWithoutExtension}.png"));
                    checkFile = Path.Combine(directory, $"{deterministicHashCodeIdAndFaceLocationIndex}{item.ImageFileHolder.ExtensionLowered}");
                    if (string.IsNullOrEmpty(personDirectory))
                        shortcutFile = string.Empty;
                    else
                        shortcutFile = Path.Combine(personDirectory, $"{deterministicHashCodeIdAndFaceLocationIndex}{item.ImageFileHolder.ExtensionLowered}.lnk");
                    results.Add(new(item.ResizedFileHolder, directory, faceFileInfo, checkFile, shortcutFile));
                }
            }
        }
        return results;
    }

    internal static void SaveClosest(string argZero, List<Container> containers, Dictionary<string, List<Shared.Models.Person>> peopleCollection, PropertyLogic propertyLogic, string eDistanceContentDirectory, string dFacesContentDirectory)
    {
        WindowsShortcut windowsShortcut;
        List<(FileHolder? resizedFileHolder, string directory, FileInfo? faceFileInfo, string checkFile, string shortcutFile)> collection = GetClosest(argZero, containers, peopleCollection, propertyLogic, eDistanceContentDirectory, dFacesContentDirectory);
        string[] directories = (from l in collection select l.directory).Distinct().ToArray();
        foreach (string directory in directories)
        {
            if (string.IsNullOrEmpty(directory))
                continue;
            if (!Directory.Exists(directory))
                _ = Directory.CreateDirectory(directory);
        }
        foreach ((FileHolder? resizedFileHolder, string directory, FileInfo? faceFileInfo, string checkFile, string shortcutFile) in collection)
        {
            if (string.IsNullOrEmpty(directory) || string.IsNullOrEmpty(checkFile) || resizedFileHolder is null || faceFileInfo is null)
                continue;
            if (File.Exists(checkFile))
                continue;
            if (faceFileInfo.Directory is not null && faceFileInfo.Directory.Exists && faceFileInfo.Exists)
                File.Copy(faceFileInfo.FullName, checkFile);
            else
                File.Copy(resizedFileHolder.FullName, checkFile);
        }
        foreach ((FileHolder? resizedFileHolder, string directory, FileInfo? faceFileInfo, string checkFile, string shortcutFile) in collection)
        {
            if (string.IsNullOrEmpty(directory) || string.IsNullOrEmpty(checkFile) || resizedFileHolder is null || faceFileInfo is null)
                continue;
            if (string.IsNullOrEmpty(shortcutFile))
                continue;
            try
            {
                windowsShortcut = new() { Path = resizedFileHolder.FullName };
                windowsShortcut.Save(shortcutFile);
                windowsShortcut.Dispose();
            }
            catch (Exception)
            { }
        }
    }

}