using System;
using System.ComponentModel;
using System.Globalization;
 
namespace Microsoft.Maui.Converters
{
	/// <inheritdoc/>
	public class CornerRadiusTypeConverter : TypeConverter
	{
		public override bool CanConvertFrom(ITypeDescriptorContext? context, Type sourceType)
			=> sourceType == typeof(string) || PrimitiveTypeConversions.IsImplicitlyConvertibleToDouble(sourceType);
 
		public override bool CanConvertTo(ITypeDescriptorContext? context, Type? destinationType)
			=> destinationType == typeof(string);
 
		public override object ConvertFrom(ITypeDescriptorContext? context, CultureInfo? culture, object? value)
		{
			if (PrimitiveTypeConversions.TryGetDouble(value, out double d))
			{
				return (CornerRadius)d;
			}
 
			// IMPORTANT! Update CornerRadiusDesignTypeConverter.IsValid if making changes here
			var strValue = value?.ToString();
 
			if (strValue != null)
			{
				strValue = strValue.Trim();
				if (strValue.ContainsChar(','))
				{ //Xaml
					var cornerRadius = strValue.Split(',');
					if (cornerRadius.Length == 4
						&& double.TryParse(cornerRadius[0], NumberStyles.Number, CultureInfo.InvariantCulture, out double tl)
						&& double.TryParse(cornerRadius[1], NumberStyles.Number, CultureInfo.InvariantCulture, out double tr)
						&& double.TryParse(cornerRadius[2], NumberStyles.Number, CultureInfo.InvariantCulture, out double bl)
						&& double.TryParse(cornerRadius[3], NumberStyles.Number, CultureInfo.InvariantCulture, out double br))
						return new CornerRadius(tl, tr, bl, br);
					if (cornerRadius.Length > 1
						&& cornerRadius.Length < 4
						&& double.TryParse(cornerRadius[0], NumberStyles.Number, CultureInfo.InvariantCulture, out double l))
						return new CornerRadius(l);
				}
				else if (strValue.ContainsChar(' '))
				{ //CSS
					var cornerRadius = strValue.Split(' ');
					if (cornerRadius.Length == 2
						&& double.TryParse(cornerRadius[0], NumberStyles.Number, CultureInfo.InvariantCulture, out double t)
						&& double.TryParse(cornerRadius[1], NumberStyles.Number, CultureInfo.InvariantCulture, out double b))
						return new CornerRadius(t, b, b, t);
					if (cornerRadius.Length == 3
						&& double.TryParse(cornerRadius[0], NumberStyles.Number, CultureInfo.InvariantCulture, out double tl)
						&& double.TryParse(cornerRadius[1], NumberStyles.Number, CultureInfo.InvariantCulture, out double trbl)
						&& double.TryParse(cornerRadius[2], NumberStyles.Number, CultureInfo.InvariantCulture, out double br))
						return new CornerRadius(tl, trbl, trbl, br);
					if (cornerRadius.Length == 4
						&& double.TryParse(cornerRadius[0], NumberStyles.Number, CultureInfo.InvariantCulture, out tl)
						&& double.TryParse(cornerRadius[1], NumberStyles.Number, CultureInfo.InvariantCulture, out double tr)
						&& double.TryParse(cornerRadius[2], NumberStyles.Number, CultureInfo.InvariantCulture, out double bl)
						&& double.TryParse(cornerRadius[3], NumberStyles.Number, CultureInfo.InvariantCulture, out br))
						return new CornerRadius(tl, tr, bl, br);
				}
				else
				{ //single uniform CornerRadius
					if (double.TryParse(strValue, NumberStyles.Number, CultureInfo.InvariantCulture, out double l))
						return new CornerRadius(l);
				}
			}
 
			throw new InvalidOperationException($"Cannot convert \"{strValue}\" into {typeof(CornerRadius)}");
		}
 
		public override object ConvertTo(ITypeDescriptorContext? context, CultureInfo? culture, object? value, Type destinationType)
		{
			if (value is not CornerRadius cr)
				throw new NotSupportedException();
 
			return $"{cr.TopLeft.ToString(CultureInfo.InvariantCulture)}, {cr.TopRight.ToString(CultureInfo.InvariantCulture)}, " +
				$"{cr.BottomLeft.ToString(CultureInfo.InvariantCulture)}, {cr.BottomRight.ToString(CultureInfo.InvariantCulture)}";
 
		}
	}
}