using System.Collections.ObjectModel;
using System.Text.Json;
using System.Text.Json.Serialization;

using Microsoft.Extensions.Logging;

using Phares.Shared.Models;
using Phares.Shared.Models.Stateless;

namespace File_Folder_Helper.ADO2025.PI6;

internal static partial class Helper20250726 {

    private record Settings(ResultSettings? ResultSettings, MetadataSettings? MetadataSettings);

    private record Record(CombinedEnumAndIndex CombinedEnumAndIndex, FilePath FilePath, bool HasFlagHidden);

    [JsonSourceGenerationOptions(WriteIndented = true)]
    [JsonSerializable(typeof(Settings))]
    private partial class SettingsSourceGenerationContext : JsonSerializerContext {
    }

    internal static void CopyToCombinedEnumAndIndexFormat(ILogger<Worker> logger, List<string> args) {
        logger.LogInformation(args[0]);
        logger.LogInformation(args[1]);
        logger.LogInformation(args[2]);
        logger.LogInformation(args[3]);
        logger.LogInformation(args[4]);
        string searchPattern = args[3];
        string jsonFile = Path.GetFullPath(args[2]);
        if (!File.Exists(jsonFile)) {
            throw new Exception($"json file doesn't exist! <{jsonFile}>");
        }
        string json = File.ReadAllText(jsonFile);
        string sourceDirectory = Path.GetFullPath(args[0].Split('~')[0]);
        string destinationDirectory = Path.GetFullPath(args[4].Split('~')[0]);
        Settings? settings = JsonSerializer.Deserialize(json, SettingsSourceGenerationContext.Default.Settings);
        if (settings.ResultSettings is null || settings.ResultSettings.ResultAllInOneSubdirectoryLength < 1 || settings.MetadataSettings is null) {
            throw new Exception(nameof(Settings));
        }
        string[] files = Directory.GetFiles(sourceDirectory, searchPattern, SearchOption.AllDirectories);
        ReadOnlyDictionary<int, ReadOnlyDictionary<byte, ReadOnlyCollection<string>>> keyValuePairs = GetKeyValuePairs(destinationDirectory, settings.ResultSettings);
        ReadOnlyCollection<Record> records = GetRecords(logger, settings.ResultSettings, settings.MetadataSettings, files);
        ReadOnlyDictionary<byte, ReadOnlyCollection<string>> keyValues = keyValuePairs.ElementAt(0).Value;
        CopyToCombinedEnumAndIndexFormat(logger, records, keyValues);
        Helpers.HelperDeleteEmptyDirectories.DeleteEmptyDirectories(logger, destinationDirectory);
    }

    private static ReadOnlyDictionary<int, ReadOnlyDictionary<byte, ReadOnlyCollection<string>>> GetKeyValuePairs(string destinationDirectory, ResultSettings resultSettings) {
        Dictionary<int, ReadOnlyDictionary<byte, ReadOnlyCollection<string>>> results = [];
        ReadOnlyDictionary<int, ReadOnlyDictionary<string, ReadOnlyDictionary<byte, ReadOnlyCollection<string>>>> keyValuePairs = IPath.GetKeyValuePairs(resultSettings, destinationDirectory, [resultSettings.ResultSingleton]);
        foreach (KeyValuePair<int, ReadOnlyDictionary<string, ReadOnlyDictionary<byte, ReadOnlyCollection<string>>>> keyValuePair in keyValuePairs) {
            foreach (KeyValuePair<string, ReadOnlyDictionary<byte, ReadOnlyCollection<string>>> keyValue in keyValuePair.Value) {
                if (keyValue.Key != resultSettings.ResultSingleton)
                    throw new Exception("Never should happen!");
                results.Add(keyValuePair.Key, keyValue.Value);
            }
        }
        return results.AsReadOnly();
    }

    private static ReadOnlyCollection<Record> GetRecords(ILogger<Worker> logger, ResultSettings resultSettings, MetadataSettings metadataSettings, string[] files) {
        List<Record> results = [];
        Record record;
        FileInfo fileInfo;
        FilePath filePath;
        bool hasFlagHidden;
        FileHolder fileHolder;
        CombinedEnumAndIndex combinedEnumAndIndex;
        foreach (string file in files) {
            fileInfo = new(file);
            fileHolder = FileHolder.Get(fileInfo, id: null);
            filePath = FilePath.Get(resultSettings, metadataSettings, fileHolder, index: null);
            if (!filePath.IsIntelligentIdFormat) {
                logger.LogWarning("<{file}> skipped because of name format!", filePath.Name);
                continue;
            }
            hasFlagHidden = fileInfo.Attributes.HasFlag(FileAttributes.Hidden);
            combinedEnumAndIndex = IPath.GetCombinedEnumAndIndex(resultSettings, filePath);
            record = new(CombinedEnumAndIndex: combinedEnumAndIndex, FilePath: filePath, HasFlagHidden: hasFlagHidden);
            results.Add(record);
        }
        return results.AsReadOnly();
    }

    private static void CopyToCombinedEnumAndIndexFormat(ILogger<Worker> logger, ReadOnlyCollection<Record> records, ReadOnlyDictionary<byte, ReadOnlyCollection<string>> keyValuePairs) {
        string checkFile;
        FileInfo fileInfo;
        FileAttributes fileAttributes;
        foreach (Record record in records) {
            checkFile = Path.Combine(keyValuePairs[record.CombinedEnumAndIndex.Enum][record.CombinedEnumAndIndex.Index], record.FilePath.Name);
            if (File.Exists(checkFile)) {
                logger.LogWarning("<{file}> skipped because it already exists!", record.FilePath.Name);
                continue;
            }
            File.Copy(record.FilePath.FullName, checkFile);
            if (record.HasFlagHidden) {
                fileInfo = new(checkFile);
                fileAttributes = fileInfo.Attributes & ~FileAttributes.Hidden;
                File.SetAttributes(fileInfo.FullName, fileAttributes);
            }
        }
    }

}