using System;
using System.Collections;

namespace Org.BouncyCastle.Utilities.Collections;

public abstract class UnmodifiableDictionary : IDictionary, ICollection, IEnumerable
{
	public abstract int Count { get; }

	public abstract bool IsFixedSize { get; }

	public virtual bool IsReadOnly => true;

	public abstract bool IsSynchronized { get; }

	public abstract object SyncRoot { get; }

	public abstract ICollection Keys { get; }

	public abstract ICollection Values { get; }

	public virtual object this[object k]
	{
		get
		{
			return GetValue(k);
		}
		set
		{
			throw new NotSupportedException();
		}
	}

	public virtual void Add(object k, object v)
	{
		throw new NotSupportedException();
	}

	public virtual void Clear()
	{
		throw new NotSupportedException();
	}

	public abstract bool Contains(object k);

	public abstract void CopyTo(Array array, int index);

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

	public abstract IDictionaryEnumerator GetEnumerator();

	public virtual void Remove(object k)
	{
		throw new NotSupportedException();
	}

	protected abstract object GetValue(object k);
}