using FaceRecognitionDotNet;
using System.Text;
using System.Text.Json;
using View_by_Distance.Metadata.Models;
using View_by_Distance.Property.Models;
using View_by_Distance.Resize.Models;

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(string[] subFiles, 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 < subFiles.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 Exception();
        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, double[] faceDistances)
    {
        List<double[]> results = new();
        if (_Configuration.LocationConfidenceFactor is null)
            throw new Exception();
        if (_Configuration.DistanceFactor is null)
            throw new Exception();
        D_Face face;
        int[] locationIndices;
        for (int d = 0; d < faceDistances.Length; 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 Exception();
        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 LoadOrCreateThenSaveDistanceResultsLoop(Property.Models.Configuration configuration, 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)
    {
        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, compareBeforeWrite: true))
                subFileTuples.Add(new Tuple<string, DateTime>(nameof(E_Distance), DateTime.Now));
        }
        else
        {
            string tvsFile;
            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]).ToArray();
                indicesAndValues = GetValues(faceCollections, locationIndicesCollection, faceDistances);
                orderedFaceCollection = GetOrderedFaceCollection(faceCollections, locationIndicesCollection, indicesAndValues);
                text = GetText(fileNameWithoutExtension, faceCollections, locationIndicesCollection, indicesAndValues);
                if (Property.Models.Stateless.IPath.WriteAllText(tvsFile, text, 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, compareBeforeWrite: true))
                    subFileTuples.Add(new Tuple<string, DateTime>(nameof(E_Distance), DateTime.Now));
            }
        }
    }

    private void LoadOrCreateThenSaveDistanceResults(Property.Models.Configuration configuration, string[] subFiles, List<List<D_Face>> faceCollections, List<string[]> directories)
    {
        string fileNameWithoutExtension;
        List<int[]> locationIndicesCollection = new();
        List<Tuple<string, DateTime>> subFileTuples = new();
        List<FaceEncoding> faceEncodingCollection = new();
        List<List<FaceEncoding>> faceEncodingCollections = new();
        LoadFaceEncodingCollections(subFiles, 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 < subFiles.Length; i++)
        {
            fileNameWithoutExtension = Path.GetFileNameWithoutExtension(subFiles[i]);
            LoadOrCreateThenSaveDistanceResultsLoop(configuration, faceCollections, subFiles.Length, i, faceCollections[i], locationIndicesCollection, subFileTuples, faceEncodingCollection, faceEncodingCollections[i], fileNameWithoutExtension, directories[i][0], directories[i][1]);
        }
    }

    internal void LoadOrCreateThenSaveDistanceResults(Property.Models.Configuration configuration, string sourceDirectory, string outputResolution, List<Tuple<string, DateTime>> sourceDirectoryChanges, string[] subFiles, List<List<D_Face>> faceCollections)
    {
        if (_Configuration.CheckJsonForDistanceResults is null)
            throw new Exception();
        if (_Configuration.PropertiesChangedForDistance is null)
            throw new Exception();
        string json;
        bool check = false;
        string parentCheck;
        DirectoryInfo directoryInfo;
        DirectoryInfo tvsDirectoryInfo;
        string fileNameWithoutExtension;
        List<string[]> directories = new();
        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,
                                                                                                       nameof(E_Distance),
                                                                                                       outputResolution,
                                                                                                       includeResizeGroup: true,
                                                                                                       includeModel: true,
                                                                                                       includePredictorModel: true,
                                                                                                       contentDescription: ".tvs File",
                                                                                                       singletonDescription: string.Empty,
                                                                                                       collectionDescription: "n json file(s) for each face found (one to many)");
        for (int i = 0; i < subFiles.Length; i++)
        {
            fileNameWithoutExtension = Path.GetFileNameWithoutExtension(subFiles[i]);
            directoryInfo = new DirectoryInfo(Path.Combine(directoryInfoCollection[0].Replace("<>", "[]"), fileNameWithoutExtension));
            if (!directoryInfo.Exists)
            {
                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 DirectoryInfo(Path.Combine(directoryInfoCollection[0].Replace("<>", "()"), fileNameWithoutExtension));
            directories.Add(new string[] { directoryInfo.FullName, tvsDirectoryInfo.FullName });
            if (_Configuration.CheckJsonForDistanceResults.Value && directoryInfo.Exists)
            {
                foreach (FileInfo fileInfo in directoryInfo.GetFiles("*.json", SearchOption.AllDirectories))
                {
                    json = Shared.Models.Stateless.Methods.IIndex.GetJson(fileInfo.FullName, fileInfo);
                    if (!_Configuration.PropertiesChangedForDistance.Value && Shared.Models.Stateless.Methods.IFace.GetFace(fileInfo.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)
            LoadOrCreateThenSaveDistanceResults(configuration, subFiles, faceCollections, directories);
        _ = Property.Models.Stateless.IPath.DeleteEmptyDirectories(directoryInfoCollection[0].Replace("<>", "()"));
    }

    private List<(string, List<KeyValuePair<string, Shared.Models.Face[]>>)> GetFiles(Property.Models.Configuration configuration, 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, 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();
        List<Shared.Models.Face> faces;
        FaceEncoding faceEncoding;
        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, 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, 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, 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 LoadOrCreateThenSaveDirectoryDistanceResults(Property.Models.Configuration configuration, string outputResolution)
    {
        if (_Log is null)
            throw new Exception($"{nameof(_Log)} is null!");
        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, 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("LoadOrCreateThenSaveDirectoryDistanceResults - ", 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, outputResolution, eDistanceCollectionDirectory, k, relativePath, face, faceAndFaceDistanceCollection);
                    }
                }
            }
        }
    }

}