using System;
using System.Collections.Generic;

namespace EPS.Common.Repositories
{
	/// <summary>
	/// Responsible for maintaining active repositories through the life of an application.
	/// </summary>
	public static class RepoFactory
	{
		private static Dictionary<string, object> _repos = new Dictionary<string, object>();

		/// <summary>
		/// Deletes the repository for the type of TModel.
		/// </summary>
		/// <typeparam name="TModel">The type of the model.</typeparam>
		public static void Delete<TModel>() where TModel : IModel, new()
		{
			_repos.Remove(GetKey<TModel>());
        }

		/// <summary>
		/// Gets a repository for the type of TModel.  If one does not already exist, it will
		/// be created and returned, otherwise the existing one is returned.
		/// </summary>
		/// <typeparam name="TModel">The type of the model used as the type of the repository 
		/// to create or retrieve.</typeparam>
		/// <returns>A repository for the specified type.</returns>
		public static IRepository<TModel> Get<TModel>() where TModel : IModel, new()
		{
			string key = GetKey<TModel>();
			if (_repos.ContainsKey(key))
				return (IRepository<TModel>)_repos[key];

			IRepository<TModel> repo = new Repository<TModel>();
			_repos.Add(key, repo);
			return repo;
		}
		private static string GetKey<TModel>()
		{
			return typeof(TModel).Name;
		}
	}
}