using Newtonsoft.Json;
using Newtonsoft.Json.Serialization;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net;
using System.Net.Http;
using System.Net.Http.Formatting;
using System.Net.Http.Headers;
using System.Reflection;
using System.Text;
using System.Threading.Tasks;
using System.Web;
using Tango.BL;

namespace Tango.Web.Formatters
{
    public class JsonNetFormatter : MediaTypeFormatter
    {
        private class JsonIgnoreAttributeIgnorerContractResolver : DefaultContractResolver
        {
            protected override JsonProperty CreateProperty(MemberInfo member, MemberSerialization memberSerialization)
            {
                var property = base.CreateProperty(member, memberSerialization);

                if (typeof(IObservableEntity).IsAssignableFrom(property.PropertyType))
                {
                    property.Ignored = false;
                }
                return property;
            }
        }

        private JsonSerializerSettings _jsonSerializerSettings;

        public JsonNetFormatter(JsonSerializerSettings jsonSerializerSettings)
        {
            _jsonSerializerSettings = jsonSerializerSettings ?? new JsonSerializerSettings();
            _jsonSerializerSettings.ContractResolver = new JsonIgnoreAttributeIgnorerContractResolver();

            SupportedMediaTypes.Add(new MediaTypeHeaderValue("application/json"));
        }

        public override bool CanReadType(Type type)
        {
            return true;
        }

        public override bool CanWriteType(Type type)
        {
            return true;
        }

        public override Task<object> ReadFromStreamAsync(Type type, Stream readStream, HttpContent content, IFormatterLogger formatterLogger)
        {
            // Create a serializer
            JsonSerializer serializer = JsonSerializer.Create(_jsonSerializerSettings);

            // Create task reading the content
            return Task.Factory.StartNew(() =>
            {
                using (StreamReader streamReader = new StreamReader(readStream))
                {
                    using (JsonTextReader jsonTextReader = new JsonTextReader(streamReader))
                    {
                        return serializer.Deserialize(jsonTextReader, type);
                    }
                }
            });
        }

        public override Task WriteToStreamAsync(Type type, object value, Stream writeStream, HttpContent content, TransportContext transportContext)
        {
            // Create a serializer
            JsonSerializer serializer = JsonSerializer.Create(_jsonSerializerSettings);

            // Create task writing the serialized content
            return Task.Factory.StartNew(() =>
            {
                using (JsonTextWriter jsonTextWriter = new JsonTextWriter(new StreamWriter(writeStream)) { CloseOutput = false })
                {
                    serializer.Serialize(jsonTextWriter, value);
                    jsonTextWriter.Flush();
                }
            });
        }
    }
}