using System.Windows.Media;
using CommunityToolkit.Mvvm.ComponentModel;
using CommunityToolkit.Mvvm.Messaging;
using Livia.Models.Data;
using Livia.Utility;
using Livia.Utility.DependencyInjection;
using Livia.ViewModels.Utility;
using Microsoft.Extensions.DependencyInjection;

namespace Livia.ViewModels;

public class RoiExpanderGroupSelectionChangedMessage(string? groupId, string? id)
{
    public string? GroupId { get; } = groupId;
    public string? Id { get; } = id;
}

public class RoiExpanderGroupControlViewModel : ObservableRecipient, ILiviaModuleViewModel, IRecipient<RoiExpanderGroupSelectionChangedMessage>
{
    public string Name { get; }
    //ID for mutual exclusion
    public string GroupId { get; }
    public string Id { get; }
    public float SelectedVolume { get => _selectedVolume; private set => SetProperty(ref _selectedVolume, value); }
    public float TotalVolume { get => _totalVolume; private set => SetProperty(ref _totalVolume, value); }
    public SelectableObservableCollection<RoiExpanderControlViewModel> RoiViewModelCollection { get; } = new();
    public int SelectedCount { get => _selectedCount; private set => SetProperty(ref _selectedCount, value); }
    public int TotalCount { get => _totalCount; private set => SetProperty(ref _totalCount, value); }
    public bool Visible { get => _visible; private set => SetProperty(ref _visible, value); }
    public bool ShowHeader { get => _showHeader; set => SetProperty(ref _showHeader, value); }
    public List<RoiData>? Regions { get; set; }
    public int ZIndex { get; set; }
    public Color Color { get; }
    public string RoiTabId { get; set; } = string.Empty;
    public static readonly HashSet<string> DefaultDeselectRoiSet = [];

    private float _selectedVolume;
    private float _totalVolume;
    private int _totalCount;
    private int _selectedCount;
    private bool _visible;
    private bool _showHeader = true;
    private readonly bool _isTwoSided;
    private readonly bool _defaultChecked;
    private static readonly Dictionary<string, string> GroupIdState = new();

    public RoiExpanderGroupControlViewModel(string name, string id, Color color, bool isTwoSided)
    {
        Name = LiviaUtility.ParseServerString(name);
        Color = color;
        _isTwoSided = isTwoSided;
        //We no longer need them to be mutually exclusive
        //GroupId = string.Concat(id.Where(char.IsLetter));
        GroupId = id;
        Id = id;
        _defaultChecked = !DefaultDeselectRoiSet.Contains(Id);

        WeakReferenceMessenger.Default.RegisterAll(this);
    }

    public async Task LoadData(DataBlock dataBlock)
    {
        //init dict
        if (_defaultChecked)
            GroupIdState[GroupId] = Id;

        if (Regions != null)
        {
            SolidColorBrush colorBrush = new(Color);
            List<RoiExpanderControlViewModel> list = [];
            foreach (RoiData data in Regions)
            {
                RoiExpanderControlViewModel viewModel = ActivatorUtilities.CreateInstance<RoiExpanderControlViewModel>(ServiceProviderFactory.ServiceProvider, _isTwoSided);
                viewModel.Color = colorBrush;
                viewModel.RoiData = data;
                viewModel.ZIndex = ZIndex;
                viewModel.RoiTabId = RoiTabId;
                await viewModel.LoadData(dataBlock);
                list.Add(viewModel);
            }

            RoiViewModelCollection.AddRange(list);
            foreach (RoiExpanderControlViewModel viewModel in list)
            {
                viewModel.PropertyChanged += (_, args) =>
                {
                    if (args.PropertyName != nameof(RoiExpanderControlViewModel.IsChecked) && args.PropertyName != nameof(RoiExpanderControlViewModel.Volume)) return;

                    UpdateCount();

                    //switch group
                    if (!viewModel.IsChecked || !GroupIdState.TryGetValue(GroupId, out string? oldId))
                        return;

                    if (oldId == Id)
                        return;

                    GroupIdState[GroupId] = Id;
                    WeakReferenceMessenger.Default.Send(new RoiExpanderGroupSelectionChangedMessage(GroupId, Id));
                };

                viewModel.IsChecked = _defaultChecked;
            }
        }

        Visible = RoiViewModelCollection.Items.Count != 0;
        TotalCount = RoiViewModelCollection.Items.Count;
        TotalVolume = RoiViewModelCollection.Items.Select(data => data.Volume).Sum();
        UpdateCount();
    }

    public void Init()
    {
    }

    private void UpdateCount()
    {
        SelectedCount = RoiViewModelCollection.Items.Count(data => data.IsChecked);
        SelectedVolume = RoiViewModelCollection.Items.Where(data => data.IsChecked).Select(data => data.Volume).Sum();
    }

    public void Receive(RoiExpanderGroupSelectionChangedMessage message)
    {
        if (GroupId != message.GroupId)
            return;

        bool newValue = Id == message.Id;

        if (newValue == RoiViewModelCollection.CheckBoxChecked)
            return;

        RoiViewModelCollection.CheckBoxChecked = newValue;
        UpdateCount();
    }

    public void ClearData()
    {
        foreach (RoiExpanderControlViewModel viewModel in RoiViewModelCollection.Items)
        {
            viewModel.ClearData();
        }

        RoiViewModelCollection.Items.Clear();
        WeakReferenceMessenger.Default.UnregisterAll(this);
    }
}