#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.Collections.Generic;
using System.Collections.Specialized;
using System.Linq;
using System.Text;
using System.Web;

namespace DevDefined.OAuth.Framework
{
	[Serializable]
	public class OAuthProblemReport
	{
		public OAuthProblemReport()
		{
			ParametersRejected = new List<string>();
			ParametersAbsent = new List<string>();
		}

		public OAuthProblemReport(NameValueCollection parameters)
		{
			Problem = parameters[Parameters.OAuth_Problem];

			ProblemAdvice = parameters[Parameters.OAuth_Problem_Advice];

			ParametersAbsent = parameters.AllKeys.Any(key => key == Parameters.OAuth_Parameters_Absent)
			                   	? ParseFormattedParameters(parameters[Parameters.OAuth_Parameters_Absent])
			                   	: new List<string>();

			ParametersRejected = parameters.AllKeys.Any(key => key == Parameters.OAuth_Parameters_Rejected)
			                     	? ParseFormattedParameters(parameters[Parameters.OAuth_Parameters_Rejected])
			                     	: new List<string>();

			if (parameters.AllKeys.Any(key => key == Parameters.OAuth_Acceptable_Timestamps))
			{
				string[] timeStamps = parameters[Parameters.OAuth_Acceptable_Timestamps].Split(new[] {'-'});
				AcceptableTimeStampsFrom = DateTimeUtility.FromEpoch(Convert.ToInt64(timeStamps[0]));
				AcceptableTimeStampsTo = DateTimeUtility.FromEpoch(Convert.ToInt64(timeStamps[1]));
			}

			if (parameters.AllKeys.Any(key => key == Parameters.OAuth_Acceptable_Versions))
			{
				string[] versions = parameters[Parameters.OAuth_Acceptable_Versions].Split(new[] {'-'});
				AcceptableVersionFrom = versions[0];
				AcceptableVersionTo = versions[1];
			}
		}

		public OAuthProblemReport(string formattedReport)
			: this(HttpUtility.ParseQueryString(formattedReport))
		{
		}

		public string AcceptableVersionTo { get; set; }
		public string AcceptableVersionFrom { get; set; }
		public List<string> ParametersRejected { get; set; }
		public List<string> ParametersAbsent { get; set; }
		public string ProblemAdvice { get; set; }
		public string Problem { get; set; }
		public DateTime? AcceptableTimeStampsTo { get; set; }
		public DateTime? AcceptableTimeStampsFrom { get; set; }

		public override string ToString()
		{
			if (string.IsNullOrEmpty(Problem)) throw Error.CantBuildProblemReportWhenProblemEmpty();

			var response = new NameValueCollection();

			response[Parameters.OAuth_Problem] = Problem;

			if (!string.IsNullOrEmpty(ProblemAdvice))
			{
				response[Parameters.OAuth_Problem_Advice] = ProblemAdvice.Replace("\r\n", "\n").Replace("\r", "\n");
			}

			if (ParametersAbsent.Count > 0)
			{
				response[Parameters.OAuth_Parameters_Absent] = FormatParameterNames(ParametersAbsent);
			}

			if (ParametersRejected.Count > 0)
			{
				response[Parameters.OAuth_Parameters_Rejected] = FormatParameterNames(ParametersRejected);
			}

			if (AcceptableTimeStampsFrom.HasValue && AcceptableTimeStampsTo.HasValue)
			{
				response[Parameters.OAuth_Acceptable_Timestamps] = string.Format("{0}-{1}",
				                                                                 AcceptableTimeStampsFrom.Value.Epoch(),
				                                                                 AcceptableTimeStampsTo.Value.Epoch());
			}

			if (!(string.IsNullOrEmpty(AcceptableVersionFrom) || string.IsNullOrEmpty(AcceptableVersionTo)))
			{
				response[Parameters.OAuth_Acceptable_Versions] = string.Format("{0}-{1}", AcceptableVersionFrom,
				                                                               AcceptableVersionTo);
			}

			return UriUtility.FormatQueryString(response);
		}

		static string FormatParameterNames(IEnumerable<string> names)
		{
			var builder = new StringBuilder();

			foreach (string name in names)
			{
				if (builder.Length > 0) builder.Append("&");
				builder.Append(UriUtility.UrlEncode(name));
			}

			return builder.ToString();
		}

		static List<string> ParseFormattedParameters(string formattedList)
		{
			return formattedList.Split(new[] {'&'}, StringSplitOptions.RemoveEmptyEntries).ToList();
		}
	}
}