using System;
using System.Collections.Generic;
using System.Globalization;
 
namespace Microsoft.Maui.Graphics.Text
{
	public static class TextAttributesExtensions
	{
		public static string GetAttribute(
			this ITextAttributes attributes,
			TextAttribute type,
			string defaultValue = null)
		{
			if (attributes != null)
			{
				if (attributes.TryGetValue(type, out var value))
					return value;
			}
 
			return defaultValue;
		}
 
		public static void SetAttribute(
			this Dictionary<TextAttribute, string> attributes,
			TextAttribute type,
			string value)
		{
			if (attributes != null)
			{
				if (value == null)
					attributes.Remove(type);
				else
					attributes[type] = value;
			}
		}
 
		public static void RemoveAttribute(
			this Dictionary<TextAttribute, string> attributes,
			TextAttribute type)
		{
			attributes?.Remove(type);
		}
 
		public static int GetIntAttribute(
			this ITextAttributes attributes,
			TextAttribute type,
			int defaultValue)
		{
			var value = attributes.GetAttribute(type);
			if (value != null)
			{
				if (int.TryParse(value, out var intValue))
					return intValue;
			}
 
			return defaultValue;
		}
 
		public static void SetIntAttribute(
			this Dictionary<TextAttribute, string> attributes,
			TextAttribute type,
			int value,
			int defaultValue)
		{
			if (value == defaultValue)
				attributes.RemoveAttribute(type);
			else
				attributes.SetAttribute(type, value.ToString(CultureInfo.InvariantCulture));
		}
 
		public static float GetFloatAttribute(
			this ITextAttributes attributes,
			TextAttribute type,
			float defaultValue)
		{
			var value = attributes.GetAttribute(type);
			if (value != null)
			{
				if (float.TryParse(value, out var floatValue))
					return floatValue;
			}
 
			return defaultValue;
		}
 
		public static void SetFloatAttribute(
			this Dictionary<TextAttribute, string> attributes,
			TextAttribute type,
			float value,
			float defaultValue)
		{
#pragma warning disable RECS0018 // Comparison of floating point numbers with equality operator
			if (value == defaultValue)
#pragma warning restore RECS0018 // Comparison of floating point numbers with equality operator
				attributes.RemoveAttribute(type);
			else
				attributes.SetAttribute(type, value.ToString(CultureInfo.InvariantCulture));
		}
 
		public static bool GetBoolAttribute(
			this ITextAttributes attributes,
			TextAttribute type,
			bool defaultValue = false)
		{
			var value = attributes.GetAttribute(type);
			if (value != null)
			{
				if (bool.TryParse(value, out var boolValue))
					return boolValue;
			}
 
			return defaultValue;
		}
 
		public static void SetBoolAttribute(
			this Dictionary<TextAttribute, string> attributes,
			TextAttribute type,
			bool value,
			bool defaultValue = false)
		{
			if (value == defaultValue)
				attributes.RemoveAttribute(type);
			else
				attributes.SetAttribute(type, value.ToString());
		}
 
		public static T GetEnumAttribute<T>(
			this ITextAttributes attributes,
			TextAttribute type,
			T defaultValue) where T : struct
		{
			var value = attributes.GetAttribute(type);
			if (value != null)
			{
				if (Enum.TryParse(value, out T enumValue))
					return enumValue;
			}
 
			return defaultValue;
		}
 
		public static void SetEnumAttribute<T>(
			this Dictionary<TextAttribute, string> attributes,
			TextAttribute type,
			T value,
			T defaultValue) where T : struct
		{
			if (Equals(value, defaultValue))
				attributes.RemoveAttribute(type);
			else
				attributes.SetAttribute(type, value.ToString());
		}
	}
}