//
// MediaTypeHeaderValue.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.Collections.Generic;

namespace System.Net.Http.Headers
{
	public class MediaTypeHeaderValue : ICloneable
	{
		internal List<NameValueHeaderValue> parameters;
		string media_type;

		public MediaTypeHeaderValue (string mediaType)
		{
			MediaType = mediaType;
		}

		protected MediaTypeHeaderValue (MediaTypeHeaderValue source)
		{
			if (source == null)
				throw new ArgumentNullException ("source");

			media_type = source.media_type;
			if (source.parameters != null) {
				foreach (var item in source.parameters)
					Parameters.Add (new NameValueHeaderValue (item));
			}
		}

		internal MediaTypeHeaderValue ()
		{
		}

		public string CharSet {
			get {
				if (parameters == null)
					return null;

				var found = parameters.Find (l => string.Equals (l.Name, "charset", StringComparison.OrdinalIgnoreCase));
				if (found == null)
					return null;

				return found.Value;
			}

			set {
				if (parameters == null)
					parameters = new List<NameValueHeaderValue> ();

				parameters.SetValue ("charset", value);
			}
		}

		public string MediaType {
			get {
				return media_type;
			}
			set {
				if (value == null)
					throw new ArgumentNullException ("MediaType");

				string temp;
				var token = TryParseMediaType (new Lexer (value), out temp);
				if (token == null || token.Value.Kind != Token.Type.End)
					throw new FormatException ();

				media_type = temp;
			}
		}

		public ICollection<NameValueHeaderValue> Parameters {
			get {
				return parameters ?? (parameters = new List<NameValueHeaderValue> ());
			}
		}

		object ICloneable.Clone ()
		{
			return new MediaTypeHeaderValue (this);
		}

		public override bool Equals (object obj)
		{
			var source = obj as MediaTypeHeaderValue;
			if (source == null)
				return false;

			return string.Equals (source.media_type, media_type, StringComparison.OrdinalIgnoreCase) &&
				source.parameters.SequenceEqual (parameters);
		}

		public override int GetHashCode ()
		{
			return media_type.ToLowerInvariant ().GetHashCode () ^ HashCodeCalculator.Calculate (parameters);
		}

		public static MediaTypeHeaderValue Parse (string input)
		{
			MediaTypeHeaderValue value;
			if (TryParse (input, out value))
				return value;

			throw new FormatException (input);
		}

		public override string ToString ()
		{
			if (parameters == null)
				return media_type;

			return media_type + CollectionExtensions.ToString (parameters);
		}
		
		public static bool TryParse (string input, out MediaTypeHeaderValue parsedValue)
		{
			parsedValue = null;

			var lexer = new Lexer (input);

			string media;
			List<NameValueHeaderValue> parameters = null;
			var token = TryParseMediaType (lexer, out media);
			if (token == null)
				return false;

			switch (token.Value.Kind) {
			case Token.Type.SeparatorSemicolon:
				if (!NameValueHeaderValue.TryParseParameters (lexer, out parameters))
					return false;
				break;
			case Token.Type.End:
				break;
			default:
				return false;
			}

			parsedValue = new MediaTypeHeaderValue () {
				media_type = media,
				parameters = parameters
			};

			return true;
		}

		internal static bool TryParse<T> (string input, out T parsedValue, Func<T> factory) where T : MediaTypeHeaderValue
		{
			parsedValue = null;

			var lexer = new Lexer (input);

			string media;
			List<NameValueHeaderValue> parameters = null;
			var token = TryParseMediaType (lexer, out media);
			if (token == null)
				return false;

			switch (token.Value.Kind) {
			case Token.Type.SeparatorSemicolon:
				if (!NameValueHeaderValue.TryParseParameters (lexer, out parameters))
					return false;
				break;
			case Token.Type.End:
				break;
			default:
				return false;
			}

			parsedValue = factory ();
			parsedValue.media_type = media;
			parsedValue.parameters = parameters;

			return true;
		}

		static Token? TryParseMediaType (Lexer lexer, out string media)
		{
			media = null;

			var token = lexer.Scan ();
			if (token != Token.Type.Token)
				return null;

			if (lexer.Scan () != Token.Type.SeparatorSlash)
				return null;

			var token2 = lexer.Scan ();
			if (token2 != Token.Type.Token)
				return null;

			media = lexer.GetStringValue (token) + "/" + lexer.GetStringValue (token2);

			return lexer.Scan ();
		}
	}
}