// 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.
//
// Copyright (c) 2007 Novell, Inc. (http://www.novell.com)
//
// Authors:
//	Chris Toshok (toshok@novell.com)
//

using System;
using System.ComponentModel;
using System.Globalization;
using System.Windows.Converters;
using System.Windows.Markup;

namespace System.Windows {

	[Serializable]
	[ValueSerializer (typeof (SizeValueSerializer))]
	[TypeConverter (typeof (SizeConverter))]
	public struct Size : IFormattable
	{
		public Size (double width, double height)
		{
			if (width < 0 || height < 0)
				throw new ArgumentException ("Width and Height must be non-negative.");

			this._width = width;
			this._height = height;
		}

		public bool Equals (Size value)
		{
			return _width == value.Width && _height == value.Height;
		}

		public override bool Equals (object o)
		{
			if (!(o is Size))
				return false;

			return Equals ((Size)o);
		}

		public static bool Equals (Size size1, Size size2)
		{
			return size1.Equals (size2);
		}

		public override int GetHashCode ()
		{
			unchecked
			{
				return (_width.GetHashCode () * 397) ^ _height.GetHashCode ();
			}
		}

		public static Size Parse (string source)
		{
			if (source == null)
				throw new ArgumentNullException ("source");

			if (source.Trim () == "Empty")
			{
				return Empty;
			}
			var tokenizer = new NumericListTokenizer (source, CultureInfo.InvariantCulture);
			double width;
			double height;
			if (!double.TryParse (tokenizer.GetNextToken (), NumberStyles.Float, CultureInfo.InvariantCulture, out width) ||
			    !double.TryParse (tokenizer.GetNextToken (), NumberStyles.Float, CultureInfo.InvariantCulture, out height))
			{
				throw new FormatException (string.Format ("Invalid Size format: {0}", source));
			}
			if (!tokenizer.HasNoMoreTokens ())
			{
				throw new InvalidOperationException ("Invalid Size format: " + source);
			}
			return new Size(width, height);
		}

		public override string ToString ()
		{
			return ConvertToString (null, null);
		}

		public string ToString (IFormatProvider provider)
		{
			return ConvertToString (null, provider);
		}

		string IFormattable.ToString (string format, IFormatProvider provider)
		{
			return ConvertToString (format, provider);
		}

		private string ConvertToString (string format, IFormatProvider provider)
		{
			if (IsEmpty)
				return "Empty";

			if (provider == null)
				provider = CultureInfo.CurrentCulture;
			if (format == null)
				format = string.Empty;
			var separator = NumericListTokenizer.GetSeparator (provider);
			var vectorFormat  = string.Format ("{{0:{0}}}{1}{{1:{0}}}", format, separator);
			return string.Format (provider, vectorFormat, _width, _height);
		}

		public bool IsEmpty {
			get {
				return (_width == Double.NegativeInfinity &&
					_height == Double.NegativeInfinity);
			}
		}

		public double Height {
			get { return _height; }
			set {
				if (IsEmpty)
					throw new InvalidOperationException ("Cannot modify this property on the Empty Size.");

				if (value < 0)
					throw new ArgumentException ("height must be non-negative.");

				_height = value;
			}
		}

		public double Width {
			get { return _width; }
			set {
				if (IsEmpty)
					throw new InvalidOperationException ("Cannot modify this property on the Empty Size.");

				if (value < 0)
					throw new ArgumentException ("width must be non-negative.");

				_width = value;
			}
		}

		public static Size Empty {
			get {
				Size s = new Size ();
				s._width = s._height = Double.NegativeInfinity;
				return s;
			}
		}

		/* operators */
		public static explicit operator Point (Size size)
		{
			return new Point (size.Width, size.Height);
		}

		public static explicit operator Vector (Size size)
		{
			return new Vector (size.Width, size.Height);
		}

		public static bool operator ==(Size size1, Size size2)
		{
			return size1.Equals (size2);
		}

		public static bool operator !=(Size size1, Size size2)
		{
			return !size1.Equals (size2);
		}

		double _width;
		double _height;
	}
}
