using System.Reflection;
using static System.Reflection.BindingFlags;

namespace InnovEnergy.Lib.Utils.Reflection
{
    public class Property : DataMember
    {
        private readonly Object?      _Instance;
        private readonly PropertyInfo _PropertyInfo;

        internal Property(Object? instance, PropertyInfo propertyInfo)
        {
            _Instance     = instance;
            _PropertyInfo = propertyInfo;
        }

        public override Boolean IsWriteable => _PropertyInfo.CanWrite;
        public override Boolean IsReadable  => _PropertyInfo.CanRead;
        public override String  Name        => _PropertyInfo.Name;
        public override Type    Type        => _PropertyInfo.PropertyType;

        public override Boolean IsPublic  => _PropertyInfo.IsPublic();
        public override Boolean IsPrivate => _PropertyInfo.IsPrivate();
        public override Boolean IsStatic  => _PropertyInfo.IsStatic();

        public override IEnumerable<Attribute> Attributes => GetAttributes<Attribute>();

        public override Object? Get() => _PropertyInfo.GetValue(_Instance);
        public override void    Set(Object value) => _PropertyInfo.SetValue(_Instance, value);

        public IEnumerable<T> GetAttributes<T> () where T : Attribute => _PropertyInfo
                                                                         .GetCustomAttributes(inherit: false)
                                                                         .OfType<T>();

        public Boolean HasAttribute<T> () where T : Attribute => GetAttributes<T>().Any();
    }

    
    public static class Properties
    {
        public static IEnumerable<Property> GetProperties<T>(this T instance) where T : notnull
        {
            return instance
                  .GetType()
                  .GetProperties(Instance | Static | Public | NonPublic)
                  .Where(p => p.GetIndexParameters().Length == 0)  // no indexers please
                  .Select(pi => new Property(pi.IsStatic() ? null : instance, pi));
        }
        
        public static IEnumerable<Property> OfInstance<T>(T instance) where T : notnull
        {
            return instance.GetProperties();
        }
    }

 
    internal static class PropertyInfoExtensions
    {
        public static Boolean IsStatic(this PropertyInfo i)
        {
            var getter = i.GetMethod;
            var setter = i.SetMethod;

            return (getter is not null && getter.IsStatic)
                || (setter is not null && setter.IsStatic);
        }

        public static Boolean IsPublic(this PropertyInfo i)
        {
            var getter = i.GetMethod;
            var setter = i.SetMethod;

            return (getter is not null && getter.IsPublic)
                || (setter is not null && setter.IsPublic);
        }

        public static Boolean IsPrivate(this PropertyInfo i)
        {
            var getter = i.GetMethod;
            var setter = i.SetMethod;

            return (getter is not null && getter.IsPrivate)
                || (setter is not null && setter.IsPrivate);
        }
    }

}