@typeparam TValue
@inherits DComponentBase

@* One radio of a DRadioGroup: checked while the group's value equals Value; choosing it sets the group's value. With
   LabelText it sits in a label.label followed by the text. *@
@if (LabelText is null)
{
	@Radio
}
else
{
	<label class="label">
		@Radio
		@LabelText
	</label>
}

@code {
	[CascadingParameter] DRadioGroup<TValue> Group { get; set; }
	[Parameter] public TValue Value { get; set; }
	[Parameter] public DColor Color { get; set; }
	[Parameter] public DSize Size { get; set; }
	[Parameter] public bool Disabled { get; set; }
	[Parameter] public string LabelText { get; set; }

	RenderFragment Radio =>
		@<input @attributes="AdditionalAttributes" type="radio" class="@CssClass" name="@Group.GroupName"
				checked="@Group.IsSelected(Value)" disabled="@Disabled" @onchange="() => Group.Select(Value)"
				aria-invalid="@(Group.GroupInvalid ? "true" : null)" />;

	string CssClass => Cx("radio", Group.GroupInvalid ? "radio-error" : ColorClass, SizeClass, Class);

	string ColorClass => Color switch
	{
		DColor.Neutral => "radio-neutral",
		DColor.Primary => "radio-primary",
		DColor.Secondary => "radio-secondary",
		DColor.Accent => "radio-accent",
		DColor.Info => "radio-info",
		DColor.Success => "radio-success",
		DColor.Warning => "radio-warning",
		DColor.Error => "radio-error",
		_ => null
	};

	string SizeClass => Size switch
	{
		DSize.Xs => "radio-xs",
		DSize.Sm => "radio-sm",
		DSize.Lg => "radio-lg",
		DSize.Xl => "radio-xl",
		_ => null
	};

	protected override void OnInitialized()
	{
		if (Group is null)
			throw new InvalidOperationException("DRadio must be inside a DRadioGroup of the same TValue.");
	}
}