namespace TrackCenter.Domain;

public static class ExpressionExtensions
{
    public static Expression<Func<T, bool>> And<T>(this Expression<Func<T, bool>> expr1, Expression<Func<T, bool>> expr2)
    {
        Expression right = new RebindParameterVisitor(expr2.Parameters[0], expr1.Parameters[0]).Visit(expr2.Body);
        return Expression.Lambda<Func<T, bool>>((Expression) Expression.AndAlso(expr1.Body, right), (IEnumerable<ParameterExpression>) expr1.Parameters);
    }
    public static Expression<Func<T, bool>> Or<T>(this Expression<Func<T, bool>> expr1,
        Expression<Func<T, bool>> expr2)
    {
        var expr2Body = new RebindParameterVisitor(expr2.Parameters[0], expr1.Parameters[0]).Visit(expr2.Body);
        return Expression.Lambda<Func<T, bool>>(Expression.OrElse(expr1.Body, expr2Body), expr1.Parameters);
    }

    private class RebindParameterVisitor : ExpressionVisitor
    {
        private readonly ParameterExpression _oldParameter;
        private readonly ParameterExpression _newParameter;

        public RebindParameterVisitor(ParameterExpression oldParameter, ParameterExpression newParameter)
        {
            _oldParameter = oldParameter;
            _newParameter = newParameter;
        }

        protected override Expression VisitParameter(ParameterExpression node)
        {
            return node == _oldParameter ? _newParameter : base.VisitParameter(node);
        }
    }
}