using System;

using System.Collections.Generic;

using System.IO;

using System.Net;

using System.Net.Http;

using System.Net.Http.Formatting;

using System.Net.Http.Headers;

using System.Threading.Tasks;

using System.Web.Http;

using JSONAPI.Documents;

using JSONAPI.Documents.Builders;

using Newtonsoft.Json;

namespace JSONAPI.Json

{

/// <summary>

/// MediaTypeFormatter for JSON API

/// </summary>

public class JsonApiFormatter : JsonMediaTypeFormatter

{

private readonly ISingleResourceDocumentFormatter _singleResourceDocumentFormatter;

private readonly IResourceCollectionDocumentFormatter _resourceCollectionDocumentFormatter;

private readonly IErrorDocumentFormatter _errorDocumentFormatter;

private readonly IErrorDocumentBuilder _errorDocumentBuilder;

/// <summary>

/// Creates a new JsonApiFormatter

/// </summary>

public JsonApiFormatter(ISingleResourceDocumentFormatter singleResourceDocumentFormatter,

IResourceCollectionDocumentFormatter resourceCollectionDocumentFormatter,

IErrorDocumentFormatter errorDocumentFormatter,

IErrorDocumentBuilder errorDocumentBuilder)

{

_singleResourceDocumentFormatter = singleResourceDocumentFormatter;

_resourceCollectionDocumentFormatter = resourceCollectionDocumentFormatter;

_errorDocumentFormatter = errorDocumentFormatter;

_errorDocumentBuilder = errorDocumentBuilder;

SupportedMediaTypes.Clear();

SupportedMediaTypes.Add(new MediaTypeHeaderValue("application/vnd.api+json"));

}

public override bool CanReadType(Type t)

{

return true;

}

public override bool CanWriteType(Type t)

{

return true;

}

public override async Task WriteToStreamAsync(Type type, object value, Stream writeStream, HttpContent content, TransportContext transportContext)

{

if (type == typeof(IJsonApiDocument) && value == null)

return;

var contentHeaders = content == null ? null : content.Headers;

var effectiveEncoding = SelectCharacterEncoding(contentHeaders);

var writer = CreateJsonWriter(typeof(object), writeStream, effectiveEncoding);

var singleResourceDocument = value as ISingleResourceDocument;

var resourceCollectionDocument = value as IResourceCollectionDocument;

var errorDocument = value as IErrorDocument;

if (singleResourceDocument != null)

{

await _singleResourceDocumentFormatter.Serialize(singleResourceDocument, writer);

}

else if (resourceCollectionDocument != null)

{

await _resourceCollectionDocumentFormatter.Serialize(resourceCollectionDocument, writer);

}

else if (errorDocument != null)

{

await _errorDocumentFormatter.Serialize(errorDocument, writer);

}

else

{

var error = value as HttpError;

if (error != null)

{

var httpErrorDocument = _errorDocumentBuilder.BuildFromHttpError(error, HttpStatusCode.InternalServerError);

await _errorDocumentFormatter.Serialize(httpErrorDocument, writer);

}

else

{

WriteErrorForUnsupportedType(value, writer);

}

}

writer.Flush();

}

public override async Task<object> ReadFromStreamAsync(Type type, Stream readStream, HttpContent content, IFormatterLogger formatterLogger)

{

var contentHeaders = content == null ? null : content.Headers;

var effectiveEncoding = SelectCharacterEncoding(contentHeaders);

var reader = CreateJsonReader(typeof(IDictionary<string, object>), readStream,

effectiveEncoding);

reader.DateParseHandling = DateParseHandling.None; // We will decide whether to parse as a DateTime or DateTimeOffset according to the attribute type

reader.Read();

if (typeof(ISingleResourceDocument).IsAssignableFrom(type))

return await _singleResourceDocumentFormatter.Deserialize(reader, "");

if (typeof(IResourceCollectionDocument).IsAssignableFrom(type))

return await _resourceCollectionDocumentFormatter.Deserialize(reader, "");

throw new Exception(string.Format("The type {0} is not supported for deserialization.", type.Name));

}

private void WriteErrorForUnsupportedType(object obj, JsonWriter writer)

{

writer.WriteStartObject();

writer.WritePropertyName("title");

writer.WriteValue("Unexpected Content");

writer.WritePropertyName("detail");

writer.WriteValue("The JsonApiFormatter was asked to serialize an unsupported object.");

writer.WritePropertyName("meta");

writer.WriteStartObject();

writer.WritePropertyName("objectTypeName");

writer.WriteValue(obj.GetType().Name);

writer.WriteEndObject();

writer.WriteEndObject();

}

}

}