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

using System.Linq.Expressions;

namespace Geekeey.Request.Persistence;

/// <summary>
/// Stores information about a where expression.
/// </summary>
/// <typeparam name="T">The entity type.</typeparam>
public sealed class WhereExpressionInfo<T>
{
	private readonly Lazy<Func<T, bool>> _filterFunc;

	/// <summary>
	/// Creates a new where expression info.
	/// </summary>
	/// <param name="filter">The filter expression.</param>
	public WhereExpressionInfo(Expression<Func<T, bool>> filter)
	{
		ArgumentNullException.ThrowIfNull(filter);

		Filter = filter;

		_filterFunc = new Lazy<Func<T, bool>>(Filter.Compile);
	}

	/// <summary>
	/// Gets the filter expression.
	/// </summary>
	public Expression<Func<T, bool>> Filter { get; }

	/// <summary>
	/// Gets the compiled filter function.
	/// </summary>
	public Func<T, bool> FilterFunc => _filterFunc.Value;
}