#region License

// The MIT License
//
// Copyright (c) 2006-2008 DevDefined Limited.
// 
// 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, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.

#endregion

using System;
using System.Linq;
using System.Text;
using DevDefined.OAuth.Framework;

namespace DevDefined.OAuth
{
	/// <summary>
	/// Generates unique nonces (via Guids) to let the server detect duplicated requests.
	/// </summary>
	public class GuidNonceGenerator : INonceGenerator
	{
		protected Random random = new Random();

		public string GenerateNonce(IOAuthContext context)
		{
			return Guid.NewGuid().ToString();
		}
	}

	public class Char40NonceGenerator : INonceGenerator
	{
		protected Random random = new Random();
		protected string selectFrom = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";

		public string GenerateNonce(IOAuthContext context) =>
			Enumerable
				.Range(1, 40)
				.Aggregate(new StringBuilder(), (sb, i) => sb.Append(selectFrom[random.Next(0, selectFrom.Length)]))
				.ToString();
	}
}