using Avalonia;
using Avalonia.Threading;
using FluentAvalonia.UI.Controls;
using LibHac.Common;
using LibHac.Fs;
using LibHac.Fs.Shim;
using Ryujinx.Ava.Common.Locale;
using Ryujinx.Ava.UI.Controls;
using Ryujinx.Ava.UI.Helpers;
using Ryujinx.HLE.HOS.Services.Account.Acc;
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Linq;
using UserId = Ryujinx.HLE.HOS.Services.Account.Acc.UserId;
using UserProfile = Ryujinx.Ava.UI.Models.UserProfile;

namespace Ryujinx.Ava.UI.ViewModels
{
    public class UserProfileViewModel : BaseModel, IDisposable
    {
        private readonly NavigationDialogHost _owner;

        private UserProfile _selectedProfile;
        private UserProfile _highlightedProfile;

        public UserProfileViewModel()
        {
            Profiles = new ObservableCollection<UserProfile>();
            LostProfiles = new ObservableCollection<UserProfile>();
        }

        public UserProfileViewModel(NavigationDialogHost owner) : this()
        {
            _owner = owner;

            LoadProfiles();
        }

        public ObservableCollection<UserProfile> Profiles { get; set; }

        public ObservableCollection<UserProfile> LostProfiles { get; set; }

        public UserProfile SelectedProfile
        {
            get => _selectedProfile;
            set
            {
                _selectedProfile = value;

                OnPropertyChanged();
                OnPropertyChanged(nameof(IsHighlightedProfileDeletable));
                OnPropertyChanged(nameof(IsHighlightedProfileEditable));
            }
        }

        public bool IsHighlightedProfileEditable => _highlightedProfile != null;

        public bool IsHighlightedProfileDeletable => _highlightedProfile != null && _highlightedProfile.UserId != AccountManager.DefaultUserId;

        public UserProfile HighlightedProfile
        {
            get => _highlightedProfile;
            set
            {
                _highlightedProfile = value;

                OnPropertyChanged();
                OnPropertyChanged(nameof(IsHighlightedProfileDeletable));
                OnPropertyChanged(nameof(IsHighlightedProfileEditable));
            }
        }

        public void Dispose() { }

        public void LoadProfiles()
        {
            Profiles.Clear();
            LostProfiles.Clear();

            var profiles = _owner.AccountManager.GetAllUsers().OrderByDescending(x => x.AccountState == AccountState.Open);

            foreach (var profile in profiles)
            {
                Profiles.Add(new UserProfile(profile, _owner));
            }

            SelectedProfile = Profiles.FirstOrDefault(x => x.UserId == _owner.AccountManager.LastOpenedUser.UserId);

            if (SelectedProfile == null)
            {
                SelectedProfile = Profiles.First();

                if (SelectedProfile != null)
                {
                    _owner.AccountManager.OpenUser(_selectedProfile.UserId);
                }
            }

            var saveDataFilter = SaveDataFilter.Make(programId: default, saveType: SaveDataType.Account,
                default, saveDataId: default, index: default);

            using var saveDataIterator = new UniqueRef<SaveDataIterator>();

            _owner.HorizonClient.Fs.OpenSaveDataIterator(ref saveDataIterator.Ref(), SaveDataSpaceId.User, in saveDataFilter).ThrowIfFailure();

            Span<SaveDataInfo> saveDataInfo = stackalloc SaveDataInfo[10];

            HashSet<UserId> lostAccounts = new HashSet<UserId>();

            while (true)
            {
                saveDataIterator.Get.ReadSaveDataInfo(out long readCount, saveDataInfo).ThrowIfFailure();

                if (readCount == 0)
                {
                    break;
                }

                for (int i = 0; i < readCount; i++)
                {
                    var save = saveDataInfo[i];
                    var id = new UserId((long)save.UserId.Id.Low, (long)save.UserId.Id.High);
                    if (Profiles.FirstOrDefault( x=> x.UserId == id) == null)
                    {
                        lostAccounts.Add(id);
                    }
                }
            }

            foreach(var account in lostAccounts)
            {
                LostProfiles.Add(new UserProfile(new HLE.HOS.Services.Account.Acc.UserProfile(account, "", null), _owner));
            }
        }

        public void AddUser()
        {
            UserProfile userProfile = null;

            _owner.Navigate(typeof(UserEditor), (this._owner, userProfile, true));
        }

        public async void ManageSaves()
        {
            UserProfile userProfile = _highlightedProfile ?? SelectedProfile;

            SaveManager manager = new SaveManager(userProfile, _owner.HorizonClient, _owner.VirtualFileSystem);
            
            ContentDialog contentDialog = new ContentDialog
            {
                Title = string.Format(LocaleManager.Instance[LocaleKeys.SaveManagerHeading], userProfile.Name),
                PrimaryButtonText = "",
                SecondaryButtonText = "",
                CloseButtonText = LocaleManager.Instance[LocaleKeys.UserProfilesClose],
                Content = manager,
                Padding = new Thickness(0)
            };

            await contentDialog.ShowAsync();
        }

        public void EditUser()
        {
            _owner.Navigate(typeof(UserEditor), (this._owner, _highlightedProfile ?? SelectedProfile, false));
        }

        public async void DeleteUser()
        {
            if (_highlightedProfile != null)
            {
                var lastUserId = _owner.AccountManager.LastOpenedUser.UserId;

                if (_highlightedProfile.UserId == lastUserId)
                {
                    // If we are deleting the currently open profile, then we must open something else before deleting.
                    var profile = Profiles.FirstOrDefault(x => x.UserId != lastUserId);

                    if (profile == null)
                    {
                        Dispatcher.UIThread.Post(async () =>
                        {
                            await ContentDialogHelper.CreateErrorDialog(LocaleManager.Instance[LocaleKeys.DialogUserProfileDeletionWarningMessage]);
                        });

                        return;
                    }

                    _owner.AccountManager.OpenUser(profile.UserId);
                }

                var result =
                    await ContentDialogHelper.CreateConfirmationDialog(LocaleManager.Instance[LocaleKeys.DialogUserProfileDeletionConfirmMessage], "",
                        LocaleManager.Instance[LocaleKeys.InputDialogYes], LocaleManager.Instance[LocaleKeys.InputDialogNo], "");

                if (result == UserResult.Yes)
                {
                    _owner.AccountManager.DeleteUser(_highlightedProfile.UserId);
                }
            }

            LoadProfiles();
        }

        public void GoBack()
        {
            _owner.GoBack();
        }

        public void RecoverLostAccounts()
        {
            _owner.Navigate(typeof(UserRecoverer), (this._owner, this));
        }
    }
}