@inherits DComponentBase

@* daisyUI Tab: https://daisyui.com/components/tab/ . Each DTab child registers itself through the cascading value;
   DTabs renders the tab buttons and the active tab's content. The active tab is an index (@bind-Active). *@
<CascadingValue Value="this" IsFixed="true">
	@ChildContent
</CascadingValue>

<div @attributes="AdditionalAttributes" role="tablist" class="@CssClass">
	@for (var i = 0; i < tabs.Count; i++)
	{
		var index = i;
		var tab = tabs[i];
		<button type="button" role="tab" aria-selected="@(index == Active ? "true" : "false")" disabled="@tab.Disabled"
				class="@Cx("tab", index == Active ? "tab-active" : null, tab.Disabled ? "tab-disabled" : null, tab.Class)"
				@onclick="() => Select(index)">
			@tab.Header
		</button>
	}
</div>

@if (Active >= 0 && Active < tabs.Count)
{
	<div role="tabpanel" class="@ContentClass">
		@tabs[Active].ChildContent
	</div>
}

@code {
	[Parameter] public RenderFragment ChildContent { get; set; }
	[Parameter] public int Active { get; set; }
	[Parameter] public EventCallback<int> ActiveChanged { get; set; }
	[Parameter] public DTabsVariant Variant { get; set; }
	[Parameter] public DSize Size { get; set; }
	[Parameter] public bool Bottom { get; set; }
	[Parameter] public string ContentClass { get; set; } = "pt-4";

	readonly List<DTab> tabs = new();

	string CssClass => Cx("tabs", VariantClass, SizeClass, Bottom ? "tabs-bottom" : null, Class);

	string VariantClass => Variant switch
	{
		DTabsVariant.Box => "tabs-box",
		DTabsVariant.Border => "tabs-border",
		DTabsVariant.Lift => "tabs-lift",
		_ => null
	};

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

	internal void Add(DTab tab)
	{
		tabs.Add(tab);
		StateHasChanged();
	}

	internal void Remove(DTab tab)
	{
		tabs.Remove(tab);
		StateHasChanged();
	}

	async Task Select(int index)
	{
		Active = index;
		await ActiveChanged.InvokeAsync(index);
	}
}