using System;
using System.Linq;

// ReSharper disable once CheckNamespace
namespace DTS.Slice.Users.UserSettings
{
    /// <summary>
    /// this PropertyId attribute is a little more complex than some of the other attributes
    /// it can be associated with an enum or an integer, in the db obviously properties are keyed by
    /// property id as an integer, but for convenience in code we use the enum form
    /// this attribute lets you store the property id for a property and get either the id or enum value
    /// </summary>
    public class PropertyIdAttribute : Attribute
    {
        private readonly PropertyEnums.PropertyIds _propertyId;
        /// <summary>
        /// returns the property id from a property
        /// </summary>
        /// <param name="o"></param>
        /// <returns></returns>
        public static int GetPropertyId(System.Reflection.PropertyInfo o)
        {
            if (o == null) throw new NullReferenceException("GetPropertyId called on a null reference");

            var attr = o.GetCustomAttributes(typeof(PropertyIdAttribute), false);
            if (null == attr || 0 == attr.Length)
            {
                throw new NullReferenceException("GetPropertyId called on an object with no PropertyIdAttribute, object: " + o);
            }
            return (int)((PropertyIdAttribute)attr.First())._propertyId;
        }
        /// <summary>
        /// returns the propertyid (as an enum) from a property
        /// </summary>
        /// <param name="o"></param>
        /// <returns></returns>
        public static PropertyEnums.PropertyIds GetPropertyIdEnum(System.Reflection.PropertyInfo o)
        {
            if (o == null) throw new NullReferenceException();

            var attr = o.GetCustomAttributes(typeof(PropertyIdAttribute), false);
            if (null == attr || 0 == attr.Length)
            {
                throw new NullReferenceException();
            }
            return ((PropertyIdAttribute)attr.First())._propertyId;
        }
        public PropertyIdAttribute(PropertyEnums.PropertyIds propertyId)
        {
            _propertyId = propertyId;
        }
    }
}