using System.Text.Json;
using View_by_Distance.Shared.Models;

namespace View_by_Distance.Property.Models.Stateless;

public class Container
{

    public static (int t, List<(int g, string sourceDirectory, string[] sourceDirectoryFiles)>) GetGroupCollection(string rootDirectory, int maxImagesInDirectoryForTopLevelFirstPass, bool reverse, string searchPattern, List<string> topDirectories)
    {
        int result = 0;
        List<(int g, string sourceDirectory, string[] sourceDirectoryFiles)> results = new();
        string? parentDirectory;
        string[] subDirectories;
        string[] sourceDirectoryFiles;
        List<string[]> fileCollections = new();
        if (!topDirectories.Any())
        {
            if (!Directory.Exists(rootDirectory))
                _ = Directory.CreateDirectory(rootDirectory);
            topDirectories.AddRange(from l in Directory.GetDirectories(rootDirectory, "*", SearchOption.TopDirectoryOnly) select Path.GetFullPath(l));
        }
        for (int g = 1; g < 5; g++)
        {
            if (g == 4)
            {
                for (int i = fileCollections.Count - 1; i > -1; i--)
                {
                    parentDirectory = Path.GetDirectoryName(fileCollections[i][0]);
                    if (string.IsNullOrEmpty(parentDirectory))
                        continue;
                    results.Add(new(g, parentDirectory, fileCollections[i]));
                    fileCollections.RemoveAt(i);
                }
            }
            else if (g == 2)
            {
                for (int i = fileCollections.Count - 1; i > -1; i--)
                {
                    if (fileCollections[i].Length > maxImagesInDirectoryForTopLevelFirstPass * g)
                        break;
                    parentDirectory = Path.GetDirectoryName(fileCollections[i][0]);
                    if (string.IsNullOrEmpty(parentDirectory))
                        continue;
                    results.Add(new(g, parentDirectory, fileCollections[i]));
                    fileCollections.RemoveAt(i);
                }
            }
            else if (g == 3)
            {
                subDirectories = Directory.GetDirectories(rootDirectory, "*", SearchOption.AllDirectories);
                if (reverse)
                    subDirectories = subDirectories.Reverse().ToArray();
                foreach (string subDirectory in subDirectories)
                {
                    sourceDirectoryFiles = Directory.GetFiles(subDirectory, "*", SearchOption.TopDirectoryOnly);
                    result += sourceDirectoryFiles.Length;
                    if (!topDirectories.Contains(subDirectory))
                        results.Add(new(g, subDirectory, sourceDirectoryFiles));
                }
            }
            else if (g == 1)
            {
                sourceDirectoryFiles = Directory.GetFiles(rootDirectory, searchPattern, SearchOption.TopDirectoryOnly);
                result += sourceDirectoryFiles.Length;
                if (sourceDirectoryFiles.Length > maxImagesInDirectoryForTopLevelFirstPass)
                    fileCollections.Add(sourceDirectoryFiles);
                else
                    results.Add(new(g, rootDirectory, sourceDirectoryFiles));
                if (reverse)
                    topDirectories.Reverse();
                subDirectories = topDirectories.ToArray();
                foreach (string subDirectory in subDirectories)
                {
                    sourceDirectoryFiles = Directory.GetFiles(subDirectory, searchPattern, SearchOption.TopDirectoryOnly);
                    result += sourceDirectoryFiles.Length;
                    if (sourceDirectoryFiles.Length > maxImagesInDirectoryForTopLevelFirstPass)
                        fileCollections.Add(sourceDirectoryFiles);
                    else
                    {
                        if (sourceDirectoryFiles.Any() || Directory.GetDirectories(subDirectory, "*", SearchOption.TopDirectoryOnly).Any())
                            results.Add(new(g, subDirectory, sourceDirectoryFiles));
                        else if (searchPattern == "*" && subDirectory != rootDirectory)
                            Directory.Delete(subDirectory);
                    }
                }
                fileCollections.Reverse();
            }
            else
                throw new Exception();
        }
        return new(result, results);
    }

    public static (int t, List<(int g, string sourceDirectory, string[] sourceDirectoryFiles)>) GetGroupCollection(string rootDirectory, string searchPattern, List<string> topDirectories)
    {
        (int t, List<(int g, string sourceDirectory, string[] sourceDirectoryFiles)>) results;
        int maxImagesInDirectoryForTopLevelFirstPass = 50;
        bool reverse = false;
        results = GetGroupCollection(rootDirectory, maxImagesInDirectoryForTopLevelFirstPass, reverse, searchPattern, topDirectories);
        return results;
    }

    private static (int j, List<(int g, string sourceDirectory, string[] sourceDirectoryFiles)>) GetJsonGroupCollection(Configuration configuration, A_Property propertyLogic, string rootDirectory)
    {
        (int j, List<(int g, string sourceDirectory, string[] sourceDirectoryFiles)>) results;
        string searchPattern = "*.json";
        List<string> topDirectories = new();
        results = GetGroupCollection(rootDirectory, configuration.MaxImagesInDirectoryForTopLevelFirstPass, propertyLogic.Reverse, searchPattern, topDirectories);
        return results;
    }

    private static (int f, List<(int g, string sourceDirectory, FileHolder[] sourceDirectoryFiles)>) GetFileHolderGroupCollection(Configuration configuration, A_Property propertyLogic, string searchPattern, List<string> topDirectories)
    {
        List<(int g, string sourceDirectory, FileHolder[] sourceDirectoryFiles)> results = new();
        List<(int g, string sourceDirectory, string[] sourceDirectoryFiles)> collection;
        (int f, collection) = GetGroupCollection(configuration.RootDirectory, configuration.MaxImagesInDirectoryForTopLevelFirstPass, propertyLogic.Reverse, searchPattern, topDirectories);
        foreach ((int g, string sourceDirectory, string[] sourceDirectoryFiles) in collection)
            results.Add(new(g, sourceDirectory, (from l in sourceDirectoryFiles select new FileHolder(l)).ToArray()));
        return new(f, results);
    }

    private static void ParallelFor(List<(int, string, string[])> jsonCollection, int i, int length, List<(int, string, List<(string, Shared.Models.Property?)>)> results)
    {
        string key;
        string json;
        Shared.Models.Property? property;
        (int g, string sourceDirectory, string[] sourceDirectoryFiles) = jsonCollection[i];
        List<(string, Shared.Models.Property?)> collection = new();
        foreach (string sourceDirectoryFile in sourceDirectoryFiles)
        {
            json = File.ReadAllText(sourceDirectoryFile);
            key = Shared.Models.Stateless.Methods.IPath.GetRelativePath(sourceDirectoryFile, length);
            property = JsonSerializer.Deserialize<Shared.Models.Property>(json);
            collection.Add(new(sourceDirectoryFile, property));
        }
        lock (results)
            results.Add(new(g, sourceDirectory, collection));
    }

    private static List<(int g, string sourceDirectory, List<(string sourceDirectoryFile, Shared.Models.Property? property)> collection)> GetCollection(string rootDirectory, List<(int g, string sourceDirectory, string[] SourceDirectoryFiles)> jsonCollection)
    {
        List<(int, string, List<(string, Shared.Models.Property?)>)> results = new();
        int length = rootDirectory.Length;
        ParallelOptions parallelOptions = new() { MaxDegreeOfParallelism = Environment.ProcessorCount };
        _ = Parallel.For(0, jsonCollection.Count, parallelOptions, (i, state) => ParallelFor(jsonCollection, i, length, results));
        return results;
    }

    private static (int, Shared.Models.Container[]) GetContainers(Configuration configuration, string aPropertySingletonDirectory, List<(int, string, FileHolder[])> fileHolderGroupCollection, List<(int, string, List<(string, Shared.Models.Property?)>)> collectionFromJson)
    {
        int result = 0;
        Shared.Models.Container[] results;
        Item item;
        int length;
        int additional;
        string inferred;
        List<Item> items;
        string keyWithJson;
        string relativePath;
        FileHolder keyFileHolder;
        bool isValidImageFormatExtension;
        Shared.Models.Container container;
        List<string> keySourceDirectories;
        Dictionary<string, Shared.Models.Container> keyValuePairs = new();
        Dictionary<string, (string SourceDirectory, FileHolder FileHolder)> fileHolderKeyValuePairs = new();
        length = configuration.RootDirectory.Length;
        foreach ((int g, string sourceDirectory, FileHolder[] sourceDirectoryFileHolderCollection) in fileHolderGroupCollection)
        {
            foreach (FileHolder sourceDirectoryFileHolder in sourceDirectoryFileHolderCollection)
            {
                relativePath = Shared.Models.Stateless.Methods.IPath.GetRelativePath(sourceDirectoryFileHolder.FullName, length, forceExtensionToLower: true);
                fileHolderKeyValuePairs.Add(relativePath, new(sourceDirectory, sourceDirectoryFileHolder));
            }
        }
        length = aPropertySingletonDirectory.Length;
        foreach ((int g, string _, List<(string, Shared.Models.Property?)> collection) in collectionFromJson)
        {
            if (!collection.Any())
                continue;
            items = new();
            keySourceDirectories = new();
            foreach ((string sourceDirectoryFile, Shared.Models.Property? property) in collection)
            {
                keyWithJson = Shared.Models.Stateless.Methods.IPath.GetRelativePath(sourceDirectoryFile, length, forceExtensionToLower: false);
                relativePath = keyWithJson[..^5];
                if (!fileHolderKeyValuePairs.ContainsKey(relativePath))
                {
                    inferred = string.Concat(configuration.RootDirectory, relativePath);
                    keyFileHolder = new(inferred);
                    if (keyFileHolder.ExtensionLowered is ".json")
                        continue;
                    keySourceDirectories.Add(string.Concat(keyFileHolder.DirectoryName));
                    isValidImageFormatExtension = configuration.ValidImageFormatExtensions.Contains(keyFileHolder.ExtensionLowered);
                    item = new(sourceDirectoryFile, relativePath, keyFileHolder, isValidImageFormatExtension, property, true, null);
                    items.Add(item);
                }
                else
                {
                    keyFileHolder = fileHolderKeyValuePairs[relativePath].FileHolder;
                    keySourceDirectories.Add(fileHolderKeyValuePairs[relativePath].SourceDirectory);
                    if (!fileHolderKeyValuePairs.Remove(relativePath))
                        throw new Exception();
                    if (keyFileHolder.ExtensionLowered is ".json")
                        continue;
                    isValidImageFormatExtension = configuration.ValidImageFormatExtensions.Contains(keyFileHolder.ExtensionLowered);
                    if (property?.Id is null || property?.Width is null || property?.Height is null)
                        item = new(sourceDirectoryFile, relativePath, keyFileHolder, isValidImageFormatExtension, property, false, null);
                    else if (configuration.PropertiesChangedForProperty || property.LastWriteTime != keyFileHolder.LastWriteTime || property.FileSize != keyFileHolder.Length)
                        item = new(sourceDirectoryFile, relativePath, keyFileHolder, isValidImageFormatExtension, property, false, true);
                    else
                        item = new(sourceDirectoryFile, relativePath, keyFileHolder, isValidImageFormatExtension, property, false, false);
                    items.Add(item);
                }
            }
            if (items.Any())
            {
                result += items.Count;
                if (keySourceDirectories.Distinct().Count() != 1)
                    continue;
                container = new(g, items, keySourceDirectories[0]);
                keyValuePairs.Add(keySourceDirectories[0], container);
            }
        }
        length = configuration.RootDirectory.Length;
        foreach ((int g, string sourceDirectory, FileHolder[] sourceDirectoryFileHolderCollection) in fileHolderGroupCollection)
        {
            items = new();
            foreach (FileHolder sourceDirectoryFileHolder in sourceDirectoryFileHolderCollection)
            {
                relativePath = Shared.Models.Stateless.Methods.IPath.GetRelativePath(sourceDirectoryFileHolder.FullName, length, forceExtensionToLower: true);
                if (!fileHolderKeyValuePairs.ContainsKey(relativePath))
                    continue;
                if (!fileHolderKeyValuePairs.Remove(relativePath))
                    throw new Exception();
                if (sourceDirectoryFileHolder.ExtensionLowered is ".json")
                    continue;
                isValidImageFormatExtension = configuration.ValidImageFormatExtensions.Contains(sourceDirectoryFileHolder.ExtensionLowered);
                item = new(sourceDirectoryFileHolder.FullName, relativePath, sourceDirectoryFileHolder, isValidImageFormatExtension, null, null, null);
                items.Add(item);
            }
            if (sourceDirectory == configuration.RootDirectory || items.Any())
            {
                if (!keyValuePairs.ContainsKey(sourceDirectory))
                {
                    result += items.Count;
                    container = new(g, items, sourceDirectory);
                    keyValuePairs.Add(sourceDirectory, container);
                }
                else
                {
                    container = keyValuePairs[sourceDirectory];
                    (items, additional) = Shared.Models.Stateless.Methods.IItem.GetMerged(container.Items, items);
                    result += additional;
                    container = new(container.G, items, container.SourceDirectory);
                    keyValuePairs[sourceDirectory] = container;
                }
            }
        }
        if (fileHolderKeyValuePairs.Any())
            throw new NotSupportedException("Unmapped left!");
        results = (from l in keyValuePairs orderby l.Value.G, l.Value.Items.Count select l.Value).ToArray();
        return new(result, results);
    }

    public static (int, int, int, Shared.Models.Container[]) GetContainers(Configuration configuration, A_Property propertyLogic)
    {
        Shared.Models.Container[] results;
        string searchPattern = "*";
        List<string> topDirectories = new();
        List<(int g, string sourceDirectory, string[] sourceDirectoryFiles)> jsonCollection;
        List<(int g, string sourceDirectory, FileHolder[] sourceDirectoryFiles)> fileHolderGroupCollection;
        string aPropertySingletonDirectory = IResult.GetResultsDateGroupDirectory(configuration, nameof(A_Property), "{}");
        List<(int g, string sourceDirectory, List<(string sourceDirectoryFile, Shared.Models.Property? property)> collection)> collectionFromJson;
        (int j, jsonCollection) = GetJsonGroupCollection(configuration, propertyLogic, aPropertySingletonDirectory);
        (int f, fileHolderGroupCollection) = GetFileHolderGroupCollection(configuration, propertyLogic, searchPattern, topDirectories);
        collectionFromJson = GetCollection(aPropertySingletonDirectory, jsonCollection);
        (int t, results) = GetContainers(configuration, aPropertySingletonDirectory, fileHolderGroupCollection, collectionFromJson);
        return (j, f, t, results);
    }

}