using System.Linq;
using Chernobyl.Values;

namespace Chernobyl.Collections.Generic.Graph
{
    /// <summary>
    /// An interface for a type that is single vertex in a larger network with
    /// each vertex holding data.
    /// </summary>
    /// <typeparam name="T">The type of the data contained by <c>this</c>.</typeparam>
    public interface IDataNode<T> : INode
    {
        /// <summary>
        /// The data held by this vertex.
        /// </summary>
        IValue<T> Data { get; }
    }

    /// <summary>
    /// Utility and extension methods for <see cref="IDataNode{T}"/>.
    /// </summary>
    public static class DataNodeExtensions
    {
        /// <summary>
        /// Returns a <see cref="IDynamicContainer{T}"/> holding the data on
        /// the <see cref="INode"/> provided.
        /// </summary>
        /// <param name="node">The instance whose data is to be retrieved.</param>
        /// <returns>The data of the node.</returns>
        public static IDynamicContainer<T> GetDynamicContainer<T>(this INode node)
        {
            IDataNode<T> dataNode = node.Connections.OfType<IDataNode<T>>().First();
            return (IDynamicContainer<T>) dataNode.Data;
        }
    }
}