using MareSynchronos.API.Data;
using MareSynchronos.API.Data.Enum;
using MareSynchronos.FileCache;
using MareSynchronos.Services.Mediator;
using MareSynchronos.UI;
using MareSynchronos.Utils;
using Microsoft.Extensions.Logging;

namespace MareSynchronos.Services;

public sealed class CharacterAnalyzer : MediatorSubscriberBase, IDisposable
{
    private readonly FileCacheManager _fileCacheManager;
    private CancellationTokenSource? _analysisCts;
    private string _lastDataHash = string.Empty;
    internal Dictionary<ObjectKind, Dictionary<string, FileDataEntry>> LastAnalysis { get; } = new();

    public CharacterAnalyzer(ILogger<CharacterAnalyzer> logger, MareMediator mediator, FileCacheManager fileCacheManager) : base(logger, mediator)
    {
        Mediator.Subscribe<CharacterDataCreatedMessage>(this, (msg) =>
        {
            _ = Task.Run(() => BaseAnalysis(msg.CharacterData.DeepClone()));
        });
        _fileCacheManager = fileCacheManager;
    }

    public bool IsAnalysisRunning => _analysisCts != null;

    public int CurrentFile { get; internal set; }
    public int TotalFiles { get; internal set; }

    public void CancelAnalyze()
    {
        _analysisCts?.CancelDispose();
        _analysisCts = null;
    }

    public async Task ComputeAnalysis(bool print = true)
    {
        Logger.LogDebug("=== Calculating Character Analysis ===");

        _analysisCts = _analysisCts?.CancelRecreate() ?? new();

        var cancelToken = _analysisCts.Token;

        var allFiles = LastAnalysis.SelectMany(v => v.Value.Select(d => d.Value)).ToList();
        if (allFiles.Exists(c => !c.IsComputed))
        {
            var remaining = allFiles.Where(c => !c.IsComputed).ToList();
            TotalFiles = remaining.Count;
            CurrentFile = 1;
            Logger.LogDebug("=== Computing {amount} remaining files ===", remaining.Count);

            Mediator.Publish(new HaltScanMessage("CharacterAnalyzer"));

            foreach (var file in remaining)
            {
                await file.ComputeSizes(_fileCacheManager, cancelToken).ConfigureAwait(false);
                CurrentFile++;
            }

            _fileCacheManager.WriteOutFullCsv();

            Mediator.Publish(new ResumeScanMessage("CharacterAnalzyer"));
        }

        Mediator.Publish(new CharacterDataAnalyzedMessage());

        _analysisCts.CancelDispose();
        _analysisCts = null;

        if (print) PrintAnalysis();
    }

    private void BaseAnalysis(CharacterData charaData)
    {
        if (string.Equals(charaData.DataHash.Value, _lastDataHash, StringComparison.Ordinal)) return;

        LastAnalysis.Clear();

        foreach (var obj in charaData.FileReplacements)
        {
            Dictionary<string, FileDataEntry> data = new(StringComparer.OrdinalIgnoreCase);
            foreach (var fileEntry in obj.Value)
            {
                var fileCacheEntries = _fileCacheManager.GetAllFileCachesByHash(fileEntry.Hash);
                if (fileCacheEntries.Count == 0) continue;

                var filePath = fileCacheEntries[0].ResolvedFilepath;
                FileInfo fi = new(filePath);
                var ext = fi.Extension[1..];

                foreach (var entry in fileCacheEntries)
                {
                    data[fileEntry.Hash] = new FileDataEntry(fileEntry.Hash, ext,
                        fileEntry.GamePaths.ToList(),
                        fileCacheEntries.Select(c => c.ResolvedFilepath).ToList(),
                        entry.Size > 0 ? entry.Size.Value : 0, entry.CompressedSize > 0 ? entry.CompressedSize.Value : 0);
                }
            }

            LastAnalysis[obj.Key] = data;
        }

        Mediator.Publish(new CharacterDataAnalyzedMessage());

        _lastDataHash = charaData.DataHash.Value;
    }

    private void PrintAnalysis()
    {
        if (LastAnalysis.Count == 0) return;
        foreach (var kvp in LastAnalysis)
        {
            int fileCounter = 1;
            int totalFiles = kvp.Value.Count;
            Logger.LogInformation("=== Analysis for {obj} ===", kvp.Key);

            foreach (var entry in kvp.Value.OrderBy(b => b.Value.GamePaths.OrderBy(p => p, StringComparer.Ordinal).First(), StringComparer.Ordinal))
            {
                Logger.LogInformation("File {x}/{y}: {hash}", fileCounter++, totalFiles, entry.Key);
                foreach (var path in entry.Value.GamePaths)
                {
                    Logger.LogInformation("  Game Path: {path}", path);
                }
                if (entry.Value.FilePaths.Count > 1) Logger.LogInformation("  Multiple fitting files detected", entry.Key);
                foreach (var filePath in entry.Value.FilePaths)
                {
                    Logger.LogInformation("  File Path: {path}", filePath);
                }
                Logger.LogInformation("  Size: {size}, Compressed: {compressed}", UiSharedService.ByteToString(entry.Value.OriginalSize),
                    UiSharedService.ByteToString(entry.Value.CompressedSize));
            }
        }
        foreach (var kvp in LastAnalysis)
        {
            Logger.LogInformation("=== Detailed summary by file type for {obj} ===", kvp.Key);
            foreach (var entry in kvp.Value.Select(v => v.Value).GroupBy(v => v.FileType, StringComparer.Ordinal))
            {
                Logger.LogInformation("{ext} files: {count}, size extracted: {size}, size compressed: {sizeComp}", entry.Key, entry.Count(),
                    UiSharedService.ByteToString(entry.Sum(v => v.OriginalSize)), UiSharedService.ByteToString(entry.Sum(v => v.CompressedSize)));
            }
            Logger.LogInformation("=== Total summary for {obj} ===", kvp.Key);
            Logger.LogInformation("Total files: {count}, size extracted: {size}, size compressed: {sizeComp}", kvp.Value.Count,
            UiSharedService.ByteToString(kvp.Value.Sum(v => v.Value.OriginalSize)), UiSharedService.ByteToString(kvp.Value.Sum(v => v.Value.CompressedSize)));
        }

        Logger.LogInformation("=== Total summary for all currently present objects ===");
        Logger.LogInformation("Total files: {count}, size extracted: {size}, size compressed: {sizeComp}",
            LastAnalysis.Values.Sum(v => v.Values.Count),
            UiSharedService.ByteToString(LastAnalysis.Values.Sum(c => c.Values.Sum(v => v.OriginalSize))),
            UiSharedService.ByteToString(LastAnalysis.Values.Sum(c => c.Values.Sum(v => v.CompressedSize))));
        Logger.LogInformation("IMPORTANT NOTES:\n\r- For Mare up- and downloads only the compressed size is relevant.\n\r- An unusually high total files count beyond 200 and up will also increase your download time to others significantly.");
    }

    public void Dispose()
    {
        _analysisCts.CancelDispose();
    }

    internal sealed record FileDataEntry(string Hash, string FileType, List<string> GamePaths, List<string> FilePaths, long OriginalSize, long CompressedSize)
    {
        public bool IsComputed => OriginalSize > 0 && CompressedSize > 0;
        public async Task ComputeSizes(FileCacheManager fileCacheManager, CancellationToken token)
        {
            var compressedsize = await fileCacheManager.GetCompressedFileData(Hash, token).ConfigureAwait(false);
            var normalSize = new FileInfo(FilePaths[0]).Length;
            var entries = fileCacheManager.GetAllFileCachesByHash(Hash);
            foreach (var entry in entries)
            {
                entry.Size = normalSize;
                entry.CompressedSize = compressedsize.Item2.LongLength;
            }
            OriginalSize = normalSize;
            CompressedSize = compressedsize.Item2.LongLength;
        }
        public long OriginalSize { get; private set; } = OriginalSize;
        public long CompressedSize { get; private set; } = CompressedSize;
    }
}