// Copyright (c) Microsoft Open Technologies, Inc. All rights reserved.
// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.

using System.IO;
using Newtonsoft.Json;

namespace Microsoft.AspNet.Mvc
{
    public class JsonOutputFormatter
    {
        private readonly JsonSerializerSettings _settings;
        private readonly bool _indent;

        public JsonOutputFormatter([NotNull] JsonSerializerSettings settings, bool indent)
        {
            _settings = settings;
            _indent = indent;
        }

        public static JsonSerializerSettings CreateDefaultSettings()
        {
            return new JsonSerializerSettings()
            {
                MissingMemberHandling = MissingMemberHandling.Ignore,

                // Do not change this setting
                // Setting this to None prevents Json.NET from loading malicious, unsafe, or security-sensitive types.
                TypeNameHandling = TypeNameHandling.None
            };
        }

        public void WriteObject([NotNull] TextWriter writer, object value)
        {
            using (var jsonWriter = CreateJsonWriter(writer))
            {
                var jsonSerializer = CreateJsonSerializer();
                jsonSerializer.Serialize(jsonWriter, value);

                // We're explicitly calling flush here to simplify the debugging experience because the
                // underlying TextWriter might be long-lived. If this method ends up being called repeatedly
                // for a request, we should revisit.
                jsonWriter.Flush();
            }
        }

        private JsonWriter CreateJsonWriter([NotNull] TextWriter writer)
        {
            var jsonWriter = new JsonTextWriter(writer);
            if (_indent)
            {
                jsonWriter.Formatting = Formatting.Indented;
            }

            jsonWriter.CloseOutput = false;

            return jsonWriter;
        }

        private JsonSerializer CreateJsonSerializer()
        {
            var jsonSerializer = JsonSerializer.Create(_settings);
            return jsonSerializer;
        }
    }
}