using ln.json;
using ln.json.mapping;
using ln.logging;
using System;
using System.Collections.Generic;
using System.Reflection;
using System.Text;

namespace ln.objects.serialization.json
{
    public class JSONDeserializer : Deserializer
    {
        ObjectStore ObjectStore;
        public JSONMapper Mapper { get; }

        public JSONDeserializer(ObjectStore objectStore)
        {
            ObjectStore = objectStore;
            Mapper = new JSONMapper() { DefaultBindingFlags = BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic, DefaultMappingFlags = JSONObjectMappingFlags.FIELDS };
            Mapper.OnRequestCustomUnserialization += Mapper_OnRequestCustomUnserialization;

            Mapper.AddMappingFactory(
                typeof(IList<>),
                (Type targetType, out JSONMapping mapping) =>
                {
                    mapping = (JSONMapping)Activator.CreateInstance(typeof(LazyListMapping<>).MakeGenericType(targetType.GetGenericArguments()),objectStore);
                    return false;
                });

        }

        private bool Mapper_OnRequestCustomUnserialization(JSONValue json, Type targetType, out object o)
        {
            if (!(json is JSONNull) && !targetType.IsValueType && !targetType.IsInterface && Mapper.GetOrBuildMapping(targetType, out JSONMapping mapping) && mapping is JSONObjectMapping)
            {
                Guid uid = new Guid(Convert.FromBase64String((json as JSONString).Value));
                return TryLookupObject(uid, targetType, out o);
            }
            o = null;
            return false;
        }

        public override bool DeserializeObject(byte[] serializedBytes, ref object o)
        {
            throw new NotImplementedException();
            /*
            if (ObjectStore.DEBUG)
                Logging.Log(LogLevel.DEBUG, "Deserializing: {0}", Encoding.UTF8.GetString(serializedBytes));

            if (serializedBytes.Length == 0)
            {
                o = null;
                return true;
            }

            if (Mapper.GetOrBuildMapping(targetType, out JSONMapping mapping))
            {
                JSONValue json = JSONParser.Parse(Encoding.UTF8.GetString(serializedBytes));
                if (mapping is JSONObjectMapping objectMapping)
                {
                    objectMapping.Apply(Mapper, json as JSONObject, o);
                }
                else
                {
                    o = mapping.FromJson(Mapper, json);
                }

                return true;
            }

            throw new NotSupportedException();
            */
        }
    }
}