using System.Collections;
using System.Collections.Generic;
using System.Collections.Specialized;
using System.ComponentModel;
using System.Diagnostics.CodeAnalysis;

namespace StabilityMatrix.Avalonia.Models;

public class ObservableDictionary<TKey, TValue> : IDictionary<TKey, TValue>,
    INotifyCollectionChanged, INotifyPropertyChanged where TKey : notnull
{
    private readonly IDictionary<TKey, TValue> dictionary;

    public event NotifyCollectionChangedEventHandler? CollectionChanged;
    public event PropertyChangedEventHandler? PropertyChanged;
    public IEnumerator<KeyValuePair<TKey, TValue>> GetEnumerator() => dictionary.GetEnumerator();

    IEnumerator IEnumerable.GetEnumerator() => GetEnumerator();

    public ObservableDictionary()
    {
        dictionary = new Dictionary<TKey, TValue>();
    }

    public ObservableDictionary(Dictionary<TKey, TValue> dictionary)
    {
        this.dictionary = dictionary;
    }

    public void Add(KeyValuePair<TKey, TValue> item)
    {
        dictionary.Add(item);
        CollectionChanged?.Invoke(this,
            new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Add, item));
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(Count)));
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(Keys)));
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(Values)));
    }

    public void Clear()
    {
        dictionary.Clear();
        CollectionChanged?.Invoke(this,
            new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset));
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(Count)));
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(Keys)));
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(Values)));
    }

    public bool Contains(KeyValuePair<TKey, TValue> item) => dictionary.Contains(item);

    public void CopyTo(KeyValuePair<TKey, TValue>[] array, int arrayIndex)
    {
        dictionary.CopyTo(array, arrayIndex);
    }

    public bool Remove(KeyValuePair<TKey, TValue> item)
    {
        var success = dictionary.Remove(item);
        if (!success) return false;

        CollectionChanged?.Invoke(this,
            new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Remove, item));
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(Count)));
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(Keys)));
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(Values)));

        return success;
    }

    public int Count => dictionary.Count;
    public bool IsReadOnly => dictionary.IsReadOnly;

    public void Add(TKey key, TValue value)
    {
        dictionary.Add(key, value);
        CollectionChanged?.Invoke(this,
            new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Add,
                new KeyValuePair<TKey, TValue>(key, value)));
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(Count)));
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(Keys)));
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(Values)));
    }

    public bool ContainsKey(TKey key) => dictionary.ContainsKey(key);

    public bool Remove(TKey key)
    {
        var success = dictionary.TryGetValue(key, out var value) && dictionary.Remove(key);
        if (!success) return false;

        CollectionChanged?.Invoke(this,
            new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Remove,
                new KeyValuePair<TKey, TValue>(key, value!)));
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(Count)));
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(Keys)));
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(Values)));

        return success;
    }

    public bool TryGetValue([NotNull] TKey key, [MaybeNullWhen(false)] out TValue value) 
        => dictionary.TryGetValue(key, out value);

    public TValue this[TKey key]
    {
        get => dictionary[key];
        set
        {
            var exists = dictionary.ContainsKey(key);
            var action = exists
                ? NotifyCollectionChangedAction.Replace
                : NotifyCollectionChangedAction.Add;
            dictionary[key] = value;
            CollectionChanged?.Invoke(this,
                new NotifyCollectionChangedEventArgs(action, dictionary[key]));
            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(Count)));
            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(Keys)));
            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(Values)));
        }
    }

    public ICollection<TKey> Keys => dictionary.Keys;
    public ICollection<TValue> Values => dictionary.Values;
}