// Utilities.cs
//
//  Copyright (C) 2008 Amr Hassan
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// 
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
//
//

using System;
using System.Collections.Generic;
using System.Collections.Specialized;
using System.Text;
using System.Security.Cryptography;
using System.Net;
using System.Web;
using Lastfm.Services;

namespace Lastfm
{
	/// <summary>
	/// General utility functions
	/// </summary>
	public static class Utilities
	{
		internal static string UserAgent
		{
			get { return "lastfm-sharp/" + Lastfm.Lib.Version.ToString(); }
		}
		
		/// <summary>
		/// Returns the md5 hash of a string.
		/// </summary>
		/// <param name="text">
		/// A <see cref="System.String"/>
		/// </param>
		/// <returns>
		/// A <see cref="System.String"/>
		/// </returns>
		public static string md5(string text)
		{
			byte[] buffer = Encoding.UTF8.GetBytes(text);
			
			MD5CryptoServiceProvider c = new MD5CryptoServiceProvider();
			buffer = c.ComputeHash(buffer);
			
			StringBuilder builder = new StringBuilder();
			foreach(byte b in buffer)
				builder.Append(b.ToString("x2").ToLower());
			
			return builder.ToString();
		}
		
		public static DateTime TimestampToDateTime(long timestamp, DateTimeKind kind)
		{
			return new DateTime(1970, 1, 1, 0, 0, 0, 0, kind).AddSeconds(timestamp).ToLocalTime();
		}
		
		public static long DateTimeToUTCTimestamp(DateTime dateTime)
		{
			DateTime baseDate = new DateTime(1970, 1, 1, 0, 0, 0, 0, DateTimeKind.Utc);
			
			TimeSpan span = dateTime.ToUniversalTime() - baseDate;
			
			return (long)span.TotalSeconds;
		}
	}
}