using MediatR;
using System;
using System.Collections.Generic;

namespace IdentityServer.Application.Commands
{
    public abstract class Command<TResponse> : ICommand, IRequest<TResponse>
    {
        public Metadata Metadata { get; }

        protected Command()
        {
            Metadata = new Metadata() { CorrelationId = Guid.NewGuid() };
        }

        protected Command(Metadata metadata)
        {
            Metadata = metadata;
        }
    }

    public interface ICommand
    {
    }

    public class Metadata : Dictionary<string, string>
    {
        public const string CorrelationIdKey = "CorrelationId";

        public Guid CorrelationId
        {
            get
            {
                return Guid.Parse(this[CorrelationIdKey]);
            }
            set
            {
                if (ContainsKey(CorrelationIdKey))
                    this[CorrelationIdKey] = value.ToString();
                else
                    Add(CorrelationIdKey, value.ToString());
            }
        }
    }
}