//
// Parser.cs
//
// Authors:
//	Marek Safar  <marek.safar@gmail.com>
//
// Copyright (C) 2011 Xamarin Inc (http://www.xamarin.com)
//
// 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.
//

using System.Net.Mail;
using System.Globalization;

namespace System.Net.Http.Headers
{
	static class Parser
	{
		public static class Token
		{
			public static bool TryParse (string input, out string result)
			{
				if (input != null && Lexer.IsValidToken (input)) {
					result = input;
					return true;
				}

				result = null;
				return false;
			}

			public static void Check (string s)
			{
				if (s == null)
					throw new ArgumentNullException ();

				if (!Lexer.IsValidToken (s)) {
					if (s.Length == 0)
						throw new ArgumentException ();

					throw new FormatException (s);
				}
			}

			public static bool TryCheck (string s)
			{
				if (s == null)
					return false;

				if (!Lexer.IsValidToken (s)) {
					if (s.Length == 0)
						return false;

					return false;
				}

				return true;
			}

			public static void CheckQuotedString (string s)
			{
				if (s == null)
					throw new ArgumentNullException ();

				var lexer = new Lexer (s);
				if (lexer.Scan () == Headers.Token.Type.QuotedString && lexer.Scan () == Headers.Token.Type.End)
					return;

				if (s.Length == 0)
					throw new ArgumentException ();

				throw new FormatException (s);
			}

			public static void CheckComment (string s)
			{
				if (s == null)
					throw new ArgumentNullException ();

				var lexer = new Lexer (s);

				string temp;
				if (!lexer.ScanCommentOptional (out temp)) {
					if (s.Length == 0)
						throw new ArgumentException ();

					throw new FormatException (s);
				}
			}
		}

		public static class DateTime
		{
			public new static readonly Func<object, string> ToString = l => ((DateTimeOffset) l).ToString ("r", CultureInfo.InvariantCulture);
			
			public static bool TryParse (string input, out DateTimeOffset result)
			{
				return Lexer.TryGetDateValue (input, out result);
			}
		}

		public static class EmailAddress
		{
			public static bool TryParse (string input, out string result)
			{
				try {
					new MailAddress (input);
					result = input;
					return true;
				} catch {
					result = null;
					return false;
				}
			}
		}

		public static class Int
		{
			public static bool TryParse (string input, out int result)
			{
				return int.TryParse (input, NumberStyles.None, CultureInfo.InvariantCulture, out result);
			}
		}

		public static class Long
		{
			public static bool TryParse (string input, out long result)
			{
				return long.TryParse (input, NumberStyles.None, CultureInfo.InvariantCulture, out result);
			}
		}

		public static class MD5
		{
			public static bool TryParse (string input, out byte[] result)
			{
				try {
					result = Convert.FromBase64String (input);
					return true;
				} catch {
					result = null;
					return false;
				}
			}
		}

		public static class TimeSpanSeconds
		{
			public static bool TryParse (string input, out TimeSpan result)
			{
				int value;
				if (Int.TryParse (input, out value)) {
					result = TimeSpan.FromSeconds (value);
					return true;
				}

				result = TimeSpan.Zero;
				return false;
			}
		}

		public static class Uri
		{
			public static bool TryParse (string input, out System.Uri result)
			{
				return System.Uri.TryCreate (input, UriKind.RelativeOrAbsolute, out result);
			}

			public static void Check (string s)
			{
				if (s == null)
					throw new ArgumentNullException ();

				System.Uri uri;
				if (!TryParse (s, out uri)) {
					if (s.Length == 0)
						throw new ArgumentException ();

					throw new FormatException (s);
				}
			}
		}
	}
}