/* 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;
using OpenSearch.Net.Extensions;
using OpenSearch.Net.Utf8Json;

namespace OpenSearch.Client
{
	[JsonFormatter(typeof(DateMathExpressionFormatter))]
	public class DateMathExpression : DateMath
	{
		public DateMathExpression(string anchor) => Anchor = anchor;

		public DateMathExpression(DateTime anchor) => Anchor = anchor;

		public DateMathExpression(Union<DateTime, string> anchor, DateMathTime range, DateMathOperation operation)
		{
			anchor.ThrowIfNull(nameof(anchor));
			range.ThrowIfNull(nameof(range));
			operation.ThrowIfNull(nameof(operation));
			Anchor = anchor;
			Self.Ranges.Add(Tuple.Create(operation, range));
		}

		public DateMathExpression Add(DateMathTime expression)
		{
			Self.Ranges.Add(Tuple.Create(DateMathOperation.Add, expression));
			return this;
		}

		public DateMathExpression Subtract(DateMathTime expression)
		{
			Self.Ranges.Add(Tuple.Create(DateMathOperation.Subtract, expression));
			return this;
		}

		public DateMathExpression Operation(DateMathTime expression, DateMathOperation operation)
		{
			Self.Ranges.Add(Tuple.Create(operation, expression));
			return this;
		}

		public DateMath RoundTo(DateMathTimeUnit round)
		{
			Round = round;
			return this;
		}
	}

	internal class DateMathExpressionFormatter : IJsonFormatter<DateMathExpression>
	{
		public DateMathExpression Deserialize(ref JsonReader reader, IJsonFormatterResolver formatterResolver)
		{
			var token = reader.GetCurrentJsonToken();
			if (token != JsonToken.String)
				return null;

			var segment = reader.ReadStringSegmentUnsafe();

			if (!segment.ContainsDateMathSeparator() && segment.IsDateTime(formatterResolver, out var dateTime))
				return new DateMathExpression(dateTime);

			var value = segment.Utf8String();
			return new DateMathExpression(value);
		}

		public void Serialize(ref JsonWriter writer, DateMathExpression value, IJsonFormatterResolver formatterResolver) =>
			writer.WriteString(value.ToString());
	}
}