using System.Collections;
using System.Diagnostics.CodeAnalysis;

namespace Qrakhen.Qamp.Core.Collections;

/// <summary>
///     Dictionary wrapper implementing <see cref="IGetSet{TKey, TValue}"/>.
/// </summary>
public class Register<TKey, TValue> : 
    IGetSet<TKey, TValue>,
    IToArray<TValue>,
    IEnumerable<KeyValuePair<TKey, TValue>>
    where TKey : notnull
{
    private readonly Dictionary<TKey, TValue> _data = new();

    public int Length => _data.Count;

    public TValue this[TKey key] {
        get => Get(key);
        set => Set(key, value);
    }

    public TKey Add(TKey key, TValue value)
    {
        _data.Add(key, value);
        return key;
    }

    public bool TryGet(TKey key, [MaybeNullWhen(false)] out TValue value) => _data.TryGetValue(key, out value);
    public TValue Get(TKey key) => _data[key];
    public void Set(TKey key, TValue value) => _data[key] = value;
    public bool Has(TKey key) => _data.ContainsKey(key);

    public TValue[] ToArray() => _data.Values.ToArray();

    public IEnumerator<KeyValuePair<TKey, TValue>> GetEnumerator()
    {
        foreach (var item in _data)
            yield return item;
    }

    IEnumerator IEnumerable.GetEnumerator()
    {
        return GetEnumerator();
    }
}