DocSpace-client/common/ASC.Core.Common/EF/LinqExtensions.cs

namespace ASC.Core.Common.EF;

public static class LinqExtensions
{
    public static IOrderedQueryable<T> OrderBy<T>(this IQueryable<T> query, string name, bool sortOrderAsc)
    {
        var propInfo = GetPropertyInfo(typeof(T), name);
        var expr = GetOrderExpression(typeof(T), propInfo);

        var method = typeof(Queryable).GetMethods().FirstOrDefault(m => m.Name == (sortOrderAsc ? "OrderBy" : "OrderByDescending") && m.GetParameters().Length == 2);
        var genericMethod = method.MakeGenericMethod(typeof(T), propInfo.PropertyType);

        return (IOrderedQueryable<T>)genericMethod.Invoke(null, new object[] { query, expr });
    }

    public static IOrderedQueryable<T> ThenBy<T>(this IOrderedQueryable<T> query, string name, bool sortOrderAsc)
    {
        var propInfo = GetPropertyInfo(typeof(T), name);
        var expr = GetOrderExpression(typeof(T), propInfo);

        var method = typeof(Queryable).GetMethods().FirstOrDefault(m => m.Name == (sortOrderAsc ? "ThenBy" : "ThenByDescending") && m.GetParameters().Length == 2);
        var genericMethod = method.MakeGenericMethod(typeof(T), propInfo.PropertyType);

        return (IOrderedQueryable<T>)genericMethod.Invoke(null, new object[] { query, expr });
    }


    private static PropertyInfo GetPropertyInfo(Type objType, string name)
    {
        var properties = objType.GetProperties();
        var matchedProperty = properties.FirstOrDefault(p => p.Name.Equals(name, StringComparison.OrdinalIgnoreCase));
        if (matchedProperty == null)
        {
            throw new ArgumentException(nameof(name));
        }

        return matchedProperty;
    }
    private static LambdaExpression GetOrderExpression(Type objType, PropertyInfo pi)
    {
        var paramExpr = Expression.Parameter(objType);
        var propAccess = Expression.PropertyOrField(paramExpr, pi.Name);
        var expr = Expression.Lambda(propAccess, paramExpr);

        return expr;
    }
}