using System;
using System.Globalization;
using DPumpHydr.WinFrmUI.WenSkin.Json.Bson;
using DPumpHydr.WinFrmUI.WenSkin.Json.Utilities;

namespace DPumpHydr.WinFrmUI.WenSkin.Json.Converters
{
	/// <summary>
	/// Converts a <see cref="T:Newtonsoft.Json.Bson.BsonObjectId" /> to and from JSON and BSON.
	/// </summary>
	public class BsonObjectIdConverter : JsonConverter
	{
		/// <summary>
		/// Writes the JSON representation of the object.
		/// </summary>
		/// <param name="writer">The <see cref="T:Newtonsoft.Json.JsonWriter" /> to write to.</param>
		/// <param name="value">The value.</param>
		/// <param name="serializer">The calling serializer.</param>
		public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
		{
			BsonObjectId bsonObjectId = (BsonObjectId)value;
			BsonWriter bsonWriter = writer as BsonWriter;
			if (bsonWriter != null)
			{
				bsonWriter.WriteObjectId(bsonObjectId.Value);
			}
			else
			{
				writer.WriteValue(bsonObjectId.Value);
			}
		}

		/// <summary>
		/// Reads the JSON representation of the object.
		/// </summary>
		/// <param name="reader">The <see cref="T:Newtonsoft.Json.JsonReader" /> to read from.</param>
		/// <param name="objectType">Type of the object.</param>
		/// <param name="existingValue">The existing value of object being read.</param>
		/// <param name="serializer">The calling serializer.</param>
		/// <returns>The object value.</returns>
		public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
		{
			if (reader.TokenType != JsonToken.Bytes)
			{
				throw new JsonSerializationException("Expected Bytes but got {0}.".FormatWith(CultureInfo.InvariantCulture, reader.TokenType));
			}
			return new BsonObjectId((byte[])reader.Value);
		}

		/// <summary>
		/// Determines whether this instance can convert the specified object type.
		/// </summary>
		/// <param name="objectType">Type of the object.</param>
		/// <returns>
		/// 	<c>true</c> if this instance can convert the specified object type; otherwise, <c>false</c>.
		/// </returns>
		public override bool CanConvert(Type objectType)
		{
			return objectType == typeof(BsonObjectId);
		}
	}
}