﻿// This software is part of the Autofac IoC container
// Copyright (c) 2007 - 2008 Autofac Contributors
// http://autofac.org
//
// Permission is hereby granted, free of charge, to any person
// obtaining a copy of this software and associated documentation
// files (the "Software"), to deal in the Software without
// restriction, including without limitation the rights to use,
// copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following
// conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
// OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
// HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
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// OTHER DEALINGS IN THE SOFTWARE.

using System;
using Revenj.Extensibility.Autofac.Core;

namespace Revenj.Extensibility.Autofac.Integration.Mef
{
	/// <summary>
	/// Identifies a service by the MEF contract name it supports.
	/// </summary>
	public class ContractBasedService : Service
	{
		readonly string _exportTypeIdentity;
		readonly string _contractName;

		/// <summary>
		/// Initializes a new instance of the <see cref="ContractBasedService"/> class.
		/// </summary>
		/// <param name="contractName">The contract name.</param>
		/// <param name="exportTypeIdentity">Type identity of the objects exported under the contract.</param>
		public ContractBasedService(string contractName, string exportTypeIdentity)
		{
			if (exportTypeIdentity == null) throw new ArgumentNullException("exportTypeIdentity");

			if (string.IsNullOrEmpty(contractName))
				throw new ArgumentOutOfRangeException("contractName");

			_exportTypeIdentity = exportTypeIdentity;

			_contractName = contractName;
		}

		/// <summary>
		/// Type identity of the objects exported under the contract.
		/// </summary>
		public string ExportTypeIdentity
		{
			get { return _exportTypeIdentity; }
		}

		/// <summary>
		/// Gets or sets the name of the contract.
		/// </summary>
		/// <value>The name of the contract.</value>
		public string ContractName
		{
			get { return _contractName; }
		}

		/// <summary>
		/// Gets a human-readable description of the service.
		/// </summary>
		/// <value>The description.</value>
		public override string Description
		{
			get
			{
				return string.Format(ContractBasedServiceResources.DescriptionFormat, ContractName);
			}
		}

		/// <summary>
		/// Determines whether the specified <see cref="T:System.Object"/> is equal to the current <see cref="T:System.Object"/>.
		/// </summary>
		/// <param name="obj">The <see cref="T:System.Object"/> to compare with the current <see cref="T:System.Object"/>.</param>
		/// <returns>
		/// true if the specified <see cref="T:System.Object"/> is equal to the current <see cref="T:System.Object"/>; otherwise, false.
		/// </returns>
		/// <exception cref="T:System.NullReferenceException">The <paramref name="obj"/> parameter is null.</exception>
		public override bool Equals(object obj)
		{
			var that = obj as ContractBasedService;

			if (that == null)
				return false;

			return ContractName == that.ContractName && ExportTypeIdentity == that.ExportTypeIdentity;
		}

		/// <summary>
		/// Serves as a hash function for a particular ExportDefinition.
		/// </summary>
		/// <returns>
		/// A hash code for the current <see cref="T:System.Object"/>.
		/// </returns>
		public override int GetHashCode()
		{
			return ContractName.GetHashCode() ^ ExportTypeIdentity.GetHashCode();
		}
	}
}
