/* SPDX-License-Identifier: Apache-2.0
*
* The OpenSearch Contributors require contributions made to
* this file be licensed under the Apache-2.0 license or a
* compatible open source license.
*/
/*
* Modifications Copyright OpenSearch Contributors. See
* GitHub history for details.
*
*  Licensed to Elasticsearch B.V. under one or more contributor
*  license agreements. See the NOTICE file distributed with
*  this work for additional information regarding copyright
*  ownership. Elasticsearch B.V. licenses this file to you under
*  the Apache License, Version 2.0 (the "License"); you may
*  not use this file except in compliance with the License.
*  You may obtain a copy of the License at
*
* 	http://www.apache.org/licenses/LICENSE-2.0
*
*  Unless required by applicable law or agreed to in writing,
*  software distributed under the License is distributed on an
*  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
*  KIND, either express or implied.  See the License for the
*  specific language governing permissions and limitations
*  under the License.
*/

using System.Globalization;
using System.IO;
using System.Text;
using OpenSearch.Net.Utf8Json;
using OpenSearch.Net.Utf8Json.Internal;

namespace OpenSearch.Client
{
	internal class GeoLocationFormatter : IJsonFormatter<GeoLocation>
	{
		private static readonly AutomataDictionary Fields = new AutomataDictionary
		{
			{ "lat", 0 },
			{ "lon", 1 }
		};

		public GeoLocation Deserialize(ref JsonReader reader, IJsonFormatterResolver formatterResolver)
		{
			switch (reader.GetCurrentJsonToken())
			{
				case JsonToken.Null:
					reader.ReadNext();
					return null;
				case JsonToken.String:
					var wkt = reader.ReadString();
					using (var tokenizer = new WellKnownTextTokenizer(new StringReader(wkt)))
					{
						var token = tokenizer.NextToken();
						if (token != TokenType.Word)
							throw new GeoWKTException(
								$"Expected word but found {tokenizer.TokenString()}", tokenizer.LineNumber, tokenizer.Position);

						var type = tokenizer.TokenValue.ToUpperInvariant();
						if (type != GeoShapeType.Point)
							throw new GeoWKTException(
								$"Expected {GeoShapeType.Point} but found {type}", tokenizer.LineNumber, tokenizer.Position);

						if (GeoWKTReader.NextEmptyOrOpen(tokenizer) == TokenType.Word)
							return null;

						var lon = GeoWKTReader.NextNumber(tokenizer);
						var lat = GeoWKTReader.NextNumber(tokenizer);
						return new GeoLocation(lat, lon) { Format = GeoFormat.WellKnownText };
					}
				default:
				{
					var count = 0;
					double lat = 0;
					double lon = 0;
					while (reader.ReadIsInObject(ref count))
					{
						var propertyName = reader.ReadPropertyNameSegmentRaw();
						if (Fields.TryGetValue(propertyName, out var value))
						{
							switch (value)
							{
								case 0:
									lat = reader.ReadDouble();
									break;
								case 1:
									lon = reader.ReadDouble();
									break;
							}
						}
						else
							reader.ReadNextBlock();
					}

					return new GeoLocation(lat, lon) { Format = GeoFormat.GeoJson };
				}
			}
		}

		public void Serialize(ref JsonWriter writer, GeoLocation value, IJsonFormatterResolver formatterResolver)
		{
			if (value == null)
			{
				writer.WriteNull();
				return;
			}

			switch (value.Format)
			{
				case GeoFormat.GeoJson:
					writer.WriteBeginObject();
					writer.WritePropertyName("lat");
					writer.WriteDouble(value.Latitude);
					writer.WriteValueSeparator();
					writer.WritePropertyName("lon");
					writer.WriteDouble(value.Longitude);
					writer.WriteEndObject();
					break;
				case GeoFormat.WellKnownText:
					var lon = value.Longitude.ToString(CultureInfo.InvariantCulture);
					var lat = value.Latitude.ToString(CultureInfo.InvariantCulture);
					var length = GeoShapeType.Point.Length + lon.Length + lat.Length + 4;
					var builder = new StringBuilder(length)
						.Append(GeoShapeType.Point)
						.Append(" (")
						.Append(lon)
						.Append(" ")
						.Append(lat)
						.Append(")");
					writer.WriteString(builder.ToString());
					break;
			}
		}
	}
}