using AIPractice.LabelEditor.Annotations;
using AIPractice.Shared.Labels;
using System.Collections.ObjectModel;
using System.Collections.Specialized;
using System.ComponentModel;
using System.Linq;
using System.Runtime.CompilerServices;

namespace AIPractice.LabelEditor
{
    public class ViewModel : INotifyPropertyChanged
    {
        public event PropertyChangedEventHandler PropertyChanged;

        [NotifyPropertyChangedInvocator]
        protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
        {
            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
        }
    }

    public class LabelObjectViewModel : ViewModel
    {
        public string Id { get; }

        public virtual string Title { get; set; }

        public LabelObjectViewModel(string id, string title)
        {
            Id = id;
            Title = title;
        }

        public override string ToString()
        {
            return Title;
        }
    }

    public class ImageLabelViewModel : LabelObjectViewModel
    {
        private ImageLabelViewModel _linked;

        public RootLabelViewModel Root { get; set; }

        public ImageLabelViewModel Linked
        {
            get => _linked;
            set
            {
                if(_linked != value)
                {
                    _linked = value;
                    OnPropertyChanged();
                }
            }
        }

        public ImageLabelViewModel(string id, string title)
            : base(id, title)
        {
        }
    }

    public class DescriptionLabelViewModel : ImageLabelViewModel
    {
        public override string Title
        {
            get { return Description.Title; }
            set
            {
                if (Description != null)
                {
                    Description.Title = value;
                }
            }
        }

        public DescriptionLabel Description { get; }

        public DescriptionLabelViewModel(DescriptionLabel description)
            : base(description.Id, description.Title)
        {
            Description = description;
        }
    }

    public class ConclusionLabelViewModel : ImageLabelViewModel
    {

        public override string Title
        {
            get => Conclusion.Title;
            set
            {
                if (Conclusion != null)
                {
                    Conclusion.Title = value;
                }
            }
        }

        public bool IsParts
        {
            get => Conclusion.IsParts;
            set
            {
                if (Conclusion.IsParts != value)
                {
                    Conclusion.IsParts = value;
                    OnPropertyChanged();
                }
            }
        }


        public bool IsUnique
        {
            get => Conclusion.IsUnique;
            set
            {
                if (Conclusion.IsUnique != value)
                {
                    Conclusion.IsUnique = value;
                    OnPropertyChanged();
                }
            }
        }

        public ConclusionLabel Conclusion { get; }

        public int Level
        {
            get => (int)Conclusion.Level;
            set
            {
                if (Conclusion != null)
                {
                    Conclusion.Level = (MalignantLevel) value;
                }
                OnPropertyChanged();
            }
        }

        public ConclusionLabelViewModel(ConclusionLabel conclusion)
            : base(conclusion.Id, conclusion.Title)
        {
            Conclusion = conclusion;
        }
    }

    public class LabelGroupViewModel : LabelObjectViewModel
    {
        private RootLabelViewModel _root;

        public RootLabelViewModel Root
        {
            get => _root;
            set
            {
                if (_root != value)
                {
                    _root = value;
                    foreach(var label in Labels)
                    {
                        label.Root = _root;
                    }
                }
            }
        }

        public LabelGroup Group { get; }

        public override string Title
        {
            get => Group.Title;
            set
            {
                if (Group != null)
                {
                    Group.Title = value;
                }
            }
        }

        public int Type
        {
            get { return (int)Group.Type; }
            set { Group.Type = (GroupType)value; }
        }

        public ObservableCollection<ImageLabelViewModel> Labels { get; protected set; }


        public LabelGroupViewModel(LabelGroup group)
            : base(group.Id, group.Title)
        {
            Group = group;
            Labels = new ObservableCollection<ImageLabelViewModel>(from x in Group.Labels
                                                                   select (x is DescriptionLabel)
                                                                       ? ((ImageLabelViewModel)new DescriptionLabelViewModel((DescriptionLabel)x))
                                                                       : new ConclusionLabelViewModel((ConclusionLabel)x));
            Labels.CollectionChanged += OnLabelsCollectionChanged;

        }

        private void OnLabelsCollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
        {
            if (e.OldItems != null)
            {
                foreach (var item in e.OldItems)
                {
                    if (item is ImageLabelViewModel label)
                    {
                        var exists = Group.Labels.FirstOrDefault(x => x.Id == label.Id);
                        if (exists != null)
                        {
                            Group.RemoveLabel(exists);
                        }
                    }
                }
            }

            if (e.NewItems != null)
            {
                foreach (var item in e.NewItems)
                {
                    if (item is ImageLabelViewModel label)
                    {
                        var exists = Group.Labels.FirstOrDefault(x => x.Id == label.Id);
                        if (exists == null)
                        {
                            if (label is DescriptionLabelViewModel description)
                            {
                                Group.AddLabel(description.Description);
                            }
                            else if (label is ConclusionLabelViewModel conclusion)
                            {
                                Group.AddLabel(conclusion.Conclusion);
                            }
                        }
                    }
                }
            }
        }

    }

    public class MultiSelectionLabelGroupViewModel : LabelGroupViewModel
    {

        public MultiSelectionLabelGroupViewModel(MultiSelectionLabelGroup group)
            : base(group)
        {

        }
    }

    public class SingleSelectionLabelGroupViewModel : LabelGroupViewModel
    {
        public SingleSelectionLabelGroupViewModel(SingleSelectionLabelGroup group)
            : base(group)
        {

        }
    }

    public class RootLabelViewModel : LabelObjectViewModel
    {

        public override string Title
        {
            get => RootLabel.Title;
            set
            {
                if (RootLabel != null)
                {
                    RootLabel.Title = value;
                }
            }
        }

        public bool NeedPartsConclusion
        {
            get => RootLabel.NeedPartsConclusion;
            set
            {
                if (RootLabel.NeedPartsConclusion != value)
                {
                    RootLabel.NeedPartsConclusion = value;
                    OnPropertyChanged();
                }
            }
        }

        public RootLabel RootLabel { get; }

        public ObservableCollection<LabelGroupViewModel> Descriptions { get; }

        public ObservableCollection<LabelGroupViewModel> Conclusions { get; }

        public RootLabelViewModel(RootLabel rootLabel)
            : base(rootLabel.Id, rootLabel.Title)
        {
            RootLabel = rootLabel;
            Descriptions = new ObservableCollection<LabelGroupViewModel>(from x in RootLabel.Descriptions
                                                                         select (x is MultiSelectionLabelGroup)
                                                                             ? new MultiSelectionLabelGroupViewModel((MultiSelectionLabelGroup)x) { Root = this }
                                                             : ((LabelGroupViewModel)new SingleSelectionLabelGroupViewModel((SingleSelectionLabelGroup)x) { Root = this }));
            Conclusions = new ObservableCollection<LabelGroupViewModel>(from x in RootLabel.Conclusions
                                                        select (x is MultiSelectionLabelGroup)
                                                            ? new MultiSelectionLabelGroupViewModel((MultiSelectionLabelGroup)x) { Root = this }
                                                            : ((LabelGroupViewModel)new SingleSelectionLabelGroupViewModel((SingleSelectionLabelGroup)x) { Root = this }));

            Descriptions.CollectionChanged += OnDescriptionsCollectionChanged;
            Conclusions.CollectionChanged += OnConclusionsCollectionChanged;
            foreach(var descGroup in Descriptions)
            {
                foreach(var descLabel in descGroup.Labels)
                {
                    var association = rootLabel.LabelAssociations.FirstOrDefault(x => x.Left.Id == descLabel.Id);
                    if(association != null)
                    {
                        var conclusionId = association.Right.Id;
                        foreach (var conGroup in Conclusions)
                        {
                            foreach (var conLabel in conGroup.Labels)
                            {
                                if(conLabel.Id == conclusionId)
                                {
                                    descLabel.Linked = conLabel;
                                }
                            }
                        }
                    }
                }
            }
        }

        private void OnConclusionsCollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
        {
            if (e.OldItems != null)
            {
                foreach (var item in e.OldItems)
                {
                    if (item is LabelGroupViewModel group)
                    {
                        var exists = RootLabel.Conclusions.FirstOrDefault(x => x.Id == group.Id);
                        if (exists != null)
                        {
                            RootLabel.RemoveConclusionGroup(exists);
                        }
                    }
                }
            }

            if (e.NewItems != null)
            {
                var index = e.NewStartingIndex;
                foreach (var item in e.NewItems)
                {
                    if (item is LabelGroupViewModel group)
                    {
                        var exists = RootLabel.Conclusions.FirstOrDefault(x => x.Id == group.Id);
                        if (exists == null)
                        {
                            RootLabel.InsertConclusionGroup(index, group.Group);
                        }
                    }
                    index++;
                }
            }
        }

        private void OnDescriptionsCollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
        {
            if (e.OldItems != null)
            {
                foreach (var item in e.OldItems)
                {
                    if (item is LabelGroupViewModel group)
                    {
                        var exists = RootLabel.Descriptions.FirstOrDefault(x => x.Id == group.Id);
                        if (exists != null)
                        {
                            RootLabel.RemoveDescriptionGroup(exists);
                        }
                    }
                }
            }

            if (e.NewItems != null)
            {
                var index = e.NewStartingIndex;
                foreach (var item in e.NewItems)
                {
                    if (item is LabelGroupViewModel group)
                    {
                        var exists = RootLabel.Descriptions.FirstOrDefault(x => x.Id == group.Id);
                        if (exists == null)
                        {
                            RootLabel.InsertDescriptionGroup(index,group.Group);
                        }
                    }
                    index++;
                }

            }
        }
    }

    public class LabelContainerViewModel : ViewModel
    {
        private RootLabelViewModel _selectedRootLabel;

        public LabelContainer Container { get; }

        public RootLabelViewModel SelectedRootLabel
        {
            get => _selectedRootLabel;
            set
            {
                if (_selectedRootLabel != value)
                {
                    _selectedRootLabel = value;
                    OnPropertyChanged();
                }
            }
        }

        public ObservableCollection<RootLabelViewModel> Labels { get; }

        public LabelContainerViewModel(LabelContainer container)
        {
            Container = container;
            Labels = new ObservableCollection<RootLabelViewModel>(from x in container.Labels
                                                  select new RootLabelViewModel(x));
            Labels.CollectionChanged += OnLabelsCollectionChanged;
        }

        private void OnLabelsCollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
        {
            if (e.OldItems != null)
            {
                foreach (var item in e.OldItems)
                {
                    if (item is RootLabelViewModel label)
                    {
                        var exists = Container.Labels.FirstOrDefault(x => x.Id == label.Id);
                        if (exists != null)
                        {
                            Container.Labels.Remove(exists);
                        }
                    }
                }
            }

            if (e.NewItems != null)
            {
                foreach (var item in e.NewItems)
                {
                    if (item is RootLabelViewModel label)
                    {
                        var exists = Container.Labels.FirstOrDefault(x => x.Id == label.Id);
                        if (exists == null)
                        {
                            Container.Labels.Add(label.RootLabel);
                        }
                    }
                }
            }
        }
    }
}