using Newtonsoft.Json;
using OtterGui;
using Penumbra.Api.Enums;
using Penumbra.Import.Structs;
using Penumbra.Mods;
using Penumbra.Mods.Subclasses;
using Penumbra.Util;
using ZipArchive = SharpCompress.Archives.Zip.ZipArchive;

namespace Penumbra.Import;

public partial class TexToolsImporter
{
    private DirectoryInfo? _currentModDirectory;

    // Version 1 mod packs are a simple collection of files without much information.
    private DirectoryInfo ImportV1ModPack(FileInfo modPackFile, ZipArchive extractedModPack, string modRaw)
    {
        _currentOptionIdx  = 0;
        _currentNumOptions = 1;
        _currentModName    = modPackFile.Name.Length > 0 ? modPackFile.Name : DefaultTexToolsData.Name;
        _currentGroupName  = string.Empty;
        _currentOptionName = DefaultTexToolsData.DefaultOption;

        Penumbra.Log.Information("    -> Importing V1 ModPack");

        var modListRaw = modRaw.Split(
            new[]
            {
                "\r\n",
                "\r",
                "\n",
            },
            StringSplitOptions.RemoveEmptyEntries
        );

        var modList = modListRaw.Select(m => JsonConvert.DeserializeObject<SimpleMod>(m, JsonSettings)!).ToList();

        _currentModDirectory = ModCreator.CreateModFolder(_baseDirectory, Path.GetFileNameWithoutExtension(modPackFile.Name),
            _config.ReplaceNonAsciiOnImport, true);
        // Create a new ModMeta from the TTMP mod list info
        _modManager.DataEditor.CreateMeta(_currentModDirectory, _currentModName, DefaultTexToolsData.Author, DefaultTexToolsData.Description,
            null, null);

        // Open the mod data file from the mod pack as a SqPackStream
        _streamDisposer = GetSqPackStreamStream(extractedModPack, "TTMPD.mpd");
        ExtractSimpleModList(_currentModDirectory, modList);
        _modManager.Creator.CreateDefaultFiles(_currentModDirectory);
        ResetStreamDisposer();
        return _currentModDirectory;
    }

    // Version 2 mod packs can either be simple or extended, import accordingly.
    private DirectoryInfo ImportV2ModPack(FileInfo _, ZipArchive extractedModPack, string modRaw)
    {
        var modList = JsonConvert.DeserializeObject<SimpleModPack>(modRaw, JsonSettings)!;

        if (modList.TtmpVersion.EndsWith("s"))
            return ImportSimpleV2ModPack(extractedModPack, modList);

        if (modList.TtmpVersion.EndsWith("w"))
            return ImportExtendedV2ModPack(extractedModPack, modRaw);

        try
        {
            Penumbra.Log.Warning($"Unknown TTMPVersion <{modList.TtmpVersion}> given, trying to export as simple mod pack.");
            return ImportSimpleV2ModPack(extractedModPack, modList);
        }
        catch (Exception e1)
        {
            Penumbra.Log.Warning($"Exporting as simple mod pack failed with following error, retrying as extended mod pack:\n{e1}");
            try
            {
                return ImportExtendedV2ModPack(extractedModPack, modRaw);
            }
            catch (Exception e2)
            {
                throw new IOException("Exporting as extended mod pack failed, too. Version unsupported or file defect.", e2);
            }
        }
    }

    // Simple V2 mod packs are basically the same as V1 mod packs.
    private DirectoryInfo ImportSimpleV2ModPack(ZipArchive extractedModPack, SimpleModPack modList)
    {
        _currentOptionIdx  = 0;
        _currentNumOptions = 1;
        _currentModName    = modList.Name;
        _currentGroupName  = string.Empty;
        _currentOptionName = DefaultTexToolsData.DefaultOption;
        Penumbra.Log.Information("    -> Importing Simple V2 ModPack");

        _currentModDirectory = ModCreator.CreateModFolder(_baseDirectory, _currentModName, _config.ReplaceNonAsciiOnImport, true);
        _modManager.DataEditor.CreateMeta(_currentModDirectory, _currentModName, modList.Author, string.IsNullOrEmpty(modList.Description)
            ? "Mod imported from TexTools mod pack"
            : modList.Description, modList.Version, modList.Url);

        // Open the mod data file from the mod pack as a SqPackStream
        _streamDisposer = GetSqPackStreamStream(extractedModPack, "TTMPD.mpd");
        ExtractSimpleModList(_currentModDirectory, modList.SimpleModsList);
        _modManager.Creator.CreateDefaultFiles(_currentModDirectory);
        ResetStreamDisposer();
        return _currentModDirectory;
    }

    // Obtain the number of relevant options to extract.
    private static int GetOptionCount(ExtendedModPack pack)
        => (pack.SimpleModsList.Length > 0 ? 1 : 0)
          + pack.ModPackPages
                .Sum(page => page.ModGroups
                    .Where(g => g.GroupName.Length > 0 && g.OptionList.Length > 0)
                    .Sum(group => group.OptionList
                            .Count(o => o.Name.Length > 0 && o.ModsJsons.Length > 0)
                      + (group.OptionList.Any(o => o.Name.Length > 0 && o.ModsJsons.Length == 0) ? 1 : 0)));

    private static string GetGroupName(string groupName, ISet<string> names)
    {
        var baseName = groupName;
        var i        = 2;
        while (!names.Add(groupName))
            groupName = $"{baseName} ({i++})";

        return groupName;
    }

    // Extended V2 mod packs contain multiple options that need to be handled separately.
    private DirectoryInfo ImportExtendedV2ModPack(ZipArchive extractedModPack, string modRaw)
    {
        _currentOptionIdx = 0;
        Penumbra.Log.Information("    -> Importing Extended V2 ModPack");

        var modList = JsonConvert.DeserializeObject<ExtendedModPack>(modRaw, JsonSettings)!;
        _currentNumOptions = GetOptionCount(modList);
        _currentModName    = modList.Name;

        _currentModDirectory = ModCreator.CreateModFolder(_baseDirectory, _currentModName, _config.ReplaceNonAsciiOnImport, true);
        _modManager.DataEditor.CreateMeta(_currentModDirectory, _currentModName, modList.Author, modList.Description, modList.Version,
            modList.Url);

        if (_currentNumOptions == 0)
            return _currentModDirectory;

        // Open the mod data file from the mod pack as a SqPackStream
        _streamDisposer = GetSqPackStreamStream(extractedModPack, "TTMPD.mpd");

        // It can contain a simple list, still.
        if (modList.SimpleModsList.Length > 0)
        {
            _currentGroupName  = string.Empty;
            _currentOptionName = "Default";
            ExtractSimpleModList(_currentModDirectory, modList.SimpleModsList);
        }

        // Iterate through all pages
        var options       = new List<SubMod>();
        var groupPriority = ModPriority.Default;
        var groupNames    = new HashSet<string>();
        foreach (var page in modList.ModPackPages)
        {
            foreach (var group in page.ModGroups.Where(group => group.GroupName.Length > 0 && group.OptionList.Length > 0))
            {
                var allOptions = group.OptionList.Where(option => option.Name.Length > 0 && option.ModsJsons.Length > 0).ToList();
                var (numGroups, maxOptions) = group.SelectionType == GroupType.Single
                    ? (1, allOptions.Count)
                    : (1 + allOptions.Count / IModGroup.MaxMultiOptions, IModGroup.MaxMultiOptions);
                _currentGroupName = GetGroupName(group.GroupName, groupNames);

                var optionIdx = 0;
                for (var groupId = 0; groupId < numGroups; ++groupId)
                {
                    var name = numGroups == 1 ? _currentGroupName : $"{_currentGroupName}, Part {groupId + 1}";
                    options.Clear();
                    var groupFolder = ModCreator.NewSubFolderName(_currentModDirectory, name, _config.ReplaceNonAsciiOnImport)
                     ?? new DirectoryInfo(Path.Combine(_currentModDirectory.FullName,
                            numGroups == 1 ? $"Group {groupPriority + 1}" : $"Group {groupPriority + 1}, Part {groupId + 1}"));

                    Setting? defaultSettings = group.SelectionType == GroupType.Multi ? Setting.Zero : null;
                    for (var i = 0; i + optionIdx < allOptions.Count && i < maxOptions; ++i)
                    {
                        var option = allOptions[i + optionIdx];
                        _token.ThrowIfCancellationRequested();
                        _currentOptionName = option.Name;
                        var optionFolder = ModCreator.NewSubFolderName(groupFolder, option.Name, _config.ReplaceNonAsciiOnImport)
                         ?? new DirectoryInfo(Path.Combine(groupFolder.FullName, $"Option {i + optionIdx + 1}"));
                        ExtractSimpleModList(optionFolder, option.ModsJsons);
                        options.Add(_modManager.Creator.CreateSubMod(_currentModDirectory, optionFolder, option));
                        if (option.IsChecked)
                            defaultSettings = group.SelectionType == GroupType.Multi
                                ? defaultSettings!.Value | Setting.Multi(i)
                                : Setting.Single(i);

                        ++_currentOptionIdx;
                    }

                    optionIdx += maxOptions;

                    // Handle empty options for single select groups without creating a folder for them.
                    // We only want one of those at most.
                    if (group.SelectionType == GroupType.Single)
                    {
                        var idx = group.OptionList.IndexOf(o => o.Name.Length > 0 && o.ModsJsons.Length == 0);
                        if (idx >= 0)
                        {
                            var option = group.OptionList[idx];
                            _currentOptionName = option.Name;
                            options.Insert(idx, SubMod.CreateForSaving(option.Name));
                            if (option.IsChecked)
                                defaultSettings = Setting.Single(idx);
                        }
                    }

                    _modManager.Creator.CreateOptionGroup(_currentModDirectory, group.SelectionType, name, groupPriority, groupPriority.Value,
                        defaultSettings ?? Setting.Zero, group.Description, options);
                    groupPriority += 1;
                }
            }
        }

        ResetStreamDisposer();
        _modManager.Creator.CreateDefaultFiles(_currentModDirectory);
        return _currentModDirectory;
    }

    private void ExtractSimpleModList(DirectoryInfo outDirectory, ICollection<SimpleMod> mods)
    {
        State = ImporterState.ExtractingModFiles;

        _currentFileIdx  = 0;
        _currentNumFiles = mods.Count(m => m.FullPath.Length > 0);

        // Extract each SimpleMod into the new mod folder
        foreach (var simpleMod in mods.Where(m => m.FullPath.Length > 0))
        {
            ExtractMod(outDirectory, simpleMod);
            ++_currentFileIdx;
        }
    }

    private void ExtractMod(DirectoryInfo outDirectory, SimpleMod mod)
    {
        if (_streamDisposer is not PenumbraSqPackStream stream)
            return;

        Penumbra.Log.Information($"        -> Extracting {mod.FullPath} at {mod.ModOffset:X}");

        _token.ThrowIfCancellationRequested();
        var data = stream.ReadFile<PenumbraSqPackStream.PenumbraFileResource>(mod.ModOffset);

        _currentFileName = mod.FullPath;
        var extractedFile = new FileInfo(Path.Combine(outDirectory.FullName, mod.FullPath));

        extractedFile.Directory?.Create();

        if (extractedFile.FullName.EndsWith(".mdl"))
            ProcessMdl(data.Data);

        _compactor.WriteAllBytesAsync(extractedFile.FullName, data.Data, _token).Wait(_token);
    }

    private static void ProcessMdl(byte[] mdl)
    {
        const int modelHeaderLodOffset = 22;

        // Model file header LOD num
        mdl[64] = 1;

        // Model header LOD num
        var stackSize           = BitConverter.ToUInt32(mdl, 4);
        var runtimeBegin        = stackSize + 0x44;
        var stringsLengthOffset = runtimeBegin + 4;
        var stringsLength       = BitConverter.ToUInt32(mdl, (int)stringsLengthOffset);
        var modelHeaderStart    = stringsLengthOffset + stringsLength + 4;
        mdl[modelHeaderStart + modelHeaderLodOffset] = 1;
    }
}