using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Threading.Tasks;
using System.Windows.Data;
using CUE4Parse.UE4.Objects.Core.Misc;
using FModel.Framework;
using FModel.Services;
using FModel.Settings;
using FModel.ViewModels.ApiEndpoints.Models;
using Serilog;

namespace FModel.ViewModels
{
    public class AesManagerViewModel : ViewModel
    {
        private ThreadWorkerViewModel _threadWorkerView => ApplicationService.ThreadWorkerView;

        public FullyObservableCollection<FileItem> AesKeys { get; private set; } // holds all aes keys even the main one
        public ICollectionView AesKeysView { get; private set; } // holds all aes key ordered by name for the ui
        public bool HasChange { get; set; }

        private AesResponse _keysFromSettings;
        private HashSet<FGuid> _uniqueGuids;
        private readonly CUE4ParseViewModel _cue4Parse;
        private readonly FileItem _mainKey = new("Main Static Key", 0) {Guid = Constants.ZERO_GUID}; // just so main key gets refreshed in the ui

        public AesManagerViewModel(CUE4ParseViewModel cue4Parse)
        {
            _cue4Parse = cue4Parse;
            HasChange = false;
        }

        public async Task InitAes()
        {
            await _threadWorkerView.Begin(_ =>
            {
                if (!UserSettings.Default.AesKeys.TryGetValue(_cue4Parse.Game, out _keysFromSettings) || _keysFromSettings == null)
                {
                    _keysFromSettings = new AesResponse
                    {
                        MainKey = string.Empty,
                        DynamicKeys = null
                    };
                }

                _mainKey.Key = FixKey(_keysFromSettings.MainKey);
                AesKeys = new FullyObservableCollection<FileItem>(EnumerateAesKeys());
                AesKeys.ItemPropertyChanged += AesKeysOnItemPropertyChanged;
                AesKeysView = new ListCollectionView(AesKeys) {SortDescriptions = {new SortDescription("Name", ListSortDirection.Ascending)}};
            });
        }

        private void AesKeysOnItemPropertyChanged(object sender, ItemPropertyChangedEventArgs e)
        {
            if (e.PropertyName != "Key" || sender is not FullyObservableCollection<FileItem> collection)
                return;

            var key = collection[e.CollectionIndex].Key = FixKey(collection[e.CollectionIndex].Key);
            if (e.CollectionIndex == 0)
            {
                if (!HasChange)
                    HasChange = FixKey(_keysFromSettings.MainKey) != key;

                _keysFromSettings.MainKey = key;
            }
            else if (!_keysFromSettings.HasDynamicKeys)
            {
                HasChange = true;
                _keysFromSettings.DynamicKeys = new List<DynamicKey>
                {
                    new()
                    {
                        Key = key,
                        FileName = collection[e.CollectionIndex].Name,
                        Guid = collection[e.CollectionIndex].Guid.ToString()
                    }
                };
            }
            else if (_keysFromSettings.DynamicKeys.FirstOrDefault(x => x.Guid == collection[e.CollectionIndex].Guid.ToString()) is { } d)
            {
                if (!HasChange)
                    HasChange = FixKey(d.Key) != key;

                d.Key = key;
            }
            else
            {
                HasChange = true;
                _keysFromSettings.DynamicKeys.Add(new DynamicKey
                {
                    Key = key,
                    FileName = collection[e.CollectionIndex].Name,
                    Guid = collection[e.CollectionIndex].Guid.ToString()
                });
            }
        }

        public async Task UpdateProvider(bool isLaunch)
        {
            if (!isLaunch && !HasChange) return;

            _cue4Parse.ClearProvider();
            await _cue4Parse.LoadVfs(AesKeys);
            UserSettings.Default.AesKeys[_cue4Parse.Game] = _keysFromSettings;
            Log.Information("{@Json}", UserSettings.Default);
        }

        private string FixKey(string key)
        {
            if (string.IsNullOrEmpty(key))
                return string.Empty;

            if (key.StartsWith("0x"))
                key = key[2..];

            return "0x" + key.ToUpper().Trim();
        }

        private IEnumerable<FileItem> EnumerateAesKeys()
        {
            yield return _mainKey;
            _uniqueGuids = new HashSet<FGuid> {Constants.ZERO_GUID};

            var hasDynamicKeys = _keysFromSettings.HasDynamicKeys;
            foreach (var file in _cue4Parse.GameDirectory.DirectoryFiles)
            {
                if (file.Guid == Constants.ZERO_GUID || !_uniqueGuids.Add(file.Guid))
                    continue;

                var k = string.Empty;
                if (hasDynamicKeys && _keysFromSettings.DynamicKeys.FirstOrDefault(x => x.Guid == file.Guid.ToString()) is { } dynamicKey)
                {
                    k = dynamicKey.Key;
                }

                file.Key = FixKey(k);
                yield return file;
            }
        }
    }
}