using System;
using System.Text;

namespace BetterUI;

/// <summary>
/// A builder for CSS classes.
/// </summary>
public sealed class CssBuilder
{
	private readonly StringBuilder _builder = new();

	/// <summary>
	/// Adds a CSS class to the builder.
	/// </summary>
	/// <param name="name">The name of the class to add.</param>
	/// <returns>The builder.</returns>
	public CssBuilder AddClass( string name )
	{
		Append( name );
		return this;
	}

	/// <summary>
	/// Adds a CSS class to the builder if the condition is true.
	/// </summary>
	/// <param name="name">The name of the class to add.</param>
	/// <param name="condition">The condition to check.</param>
	/// <returns>The builder.</returns>
	public CssBuilder AddClass( string name, bool condition )
	{
		if ( condition )
			Append( name );

		return this;
	}

	/// <summary>
	/// Adds a CSS class to the builder if the condition is true.
	/// </summary>
	/// <param name="name">The name of the class to add.</param>
	/// <param name="condition">The condition to check.</param>
	/// <returns>The builder.</returns>
	public CssBuilder AddClass( string name, Func<bool> condition )
	{
		if ( condition.Invoke() )
			Append( name );

		return this;
	}

	/// <summary>
	/// Appends a CSS class to the builder.
	/// </summary>
	/// <param name="name">The name of the class to append.</param>
	private void Append( string name )
	{
		if ( _builder.Length is 0 ) _builder.Append( name );
		else _builder.Append( ' ' ).Append( name );
	}

	/// <summary>
	/// Builds the CSS classes.
	/// </summary>
	/// <returns>The CSS classes as a string.</returns>
	public string Build() => _builder.ToString();

	public override string ToString() => _builder.ToString();
}