// Copyright (c) The Geekeey Authors
// SPDX-License-Identifier: EUPL-1.2

using System.Linq.Expressions;

namespace Geekeey.Request.Persistence;

/// <summary>
/// Provides extension methods for <see cref="OrderedSpecificationBuilder{T}"/>.
/// </summary>
public static class OrderedBuilderExtensions
{
	/// <summary>
	/// Adds a ThenBy expression for secondary ordering.
	/// </summary>
	/// <param name="builder">The ordered builder.</param>
	/// <param name="expression">The expression.</param>
	/// <typeparam name="T">The entity type.</typeparam>
	/// <returns>The ordered builder.</returns>
	public static OrderedSpecificationBuilder<T> ThenBy<T>(this OrderedSpecificationBuilder<T> builder, Expression<Func<T, object?>> expression)
	{
		return ThenBy(builder, expression, condition: true);
	}

	/// <summary>
	/// Adds a ThenBy expression when <paramref name="condition"/> is <see langword="true"/>.
	/// </summary>
	/// <param name="builder">The ordered builder.</param>
	/// <param name="expression">The expression.</param>
	/// <param name="condition">Whether to apply the ThenBy.</param>
	/// <typeparam name="T">The entity type.</typeparam>
	/// <returns>The ordered builder.</returns>
	public static OrderedSpecificationBuilder<T> ThenBy<T>(this OrderedSpecificationBuilder<T> builder, Expression<Func<T, object?>> expression, bool condition)
	{
		if (condition && !builder.IsChainDiscarded)
		{
			builder.Builder.OrderExpressions.Add(new OrderExpressionInfo<T>(expression, OrderType.ThenBy));
		}
		else
		{
			builder.IsChainDiscarded = true;
		}

		return builder;
	}

	/// <summary>
	/// Adds a ThenByDescending expression for secondary ordering.
	/// </summary>
	/// <param name="builder">The ordered builder.</param>
	/// <param name="expression">The expression.</param>
	/// <typeparam name="T">The entity type.</typeparam>
	/// <returns>The ordered builder.</returns>
	public static OrderedSpecificationBuilder<T> ThenByDescending<T>(this OrderedSpecificationBuilder<T> builder, Expression<Func<T, object?>> expression)
	{
		return ThenByDescending(builder, expression, condition: true);
	}

	/// <summary>
	/// Adds a ThenByDescending expression when <paramref name="condition"/> is <see langword="true"/>.
	/// </summary>
	/// <param name="builder">The ordered builder.</param>
	/// <param name="expression">The expression.</param>
	/// <param name="condition">Whether to apply the ThenByDescending.</param>
	/// <typeparam name="T">The entity type.</typeparam>
	/// <returns>The ordered builder.</returns>
	public static OrderedSpecificationBuilder<T> ThenByDescending<T>(this OrderedSpecificationBuilder<T> builder, Expression<Func<T, object?>> expression, bool condition)
	{
		if (condition && !builder.IsChainDiscarded)
		{
			builder.Builder.OrderExpressions.Add(new OrderExpressionInfo<T>(expression, OrderType.ThenByDescending));
		}
		else
		{
			builder.IsChainDiscarded = true;
		}

		return builder;
	}
}