/* 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 System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Linq.Expressions;
using System.Runtime.Serialization;
using OpenSearch.Net.Utf8Json;

namespace OpenSearch.Client
{
	/// <summary>
	/// Returns any documents that match with at least one or more of the provided terms.
	/// The terms are not analyzed and thus must match exactly.
	/// The number of terms that must match varies per document and is either controlled by a minimum should match
	/// field or computed per document in a minimum should match script.
	/// </summary>
	[InterfaceDataContract]
	[JsonFormatter(typeof(FieldNameQueryFormatter<TermsSetQuery, ITermsSetQuery>))]
	public interface ITermsSetQuery : IFieldNameQuery
	{
		/// <summary>
		/// A field containing the number of required terms that must match
		/// </summary>
		[DataMember(Name = "minimum_should_match_field")]
		Field MinimumShouldMatchField { get; set; }

		/// <summary>
		/// A script to control how many terms are required to match
		/// </summary>
		[DataMember(Name = "minimum_should_match_script")]
		IScript MinimumShouldMatchScript { get; set; }

		/// <summary>
		/// The required terms to match
		/// </summary>
		[DataMember(Name = "terms")]
		[JsonFormatter(typeof(SourceWriteFormatter<IEnumerable<object>>))]
		IEnumerable<object> Terms { get; set; }
	}

	/// <inheritdoc cref="ITermsSetQuery" />
	public class TermsSetQuery : FieldNameQueryBase, ITermsSetQuery
	{
		/// <inheritdoc />
		public Field MinimumShouldMatchField { get; set; }

		/// <inheritdoc />
		public IScript MinimumShouldMatchScript { get; set; }

		/// <inheritdoc />
		public IEnumerable<object> Terms { get; set; }

		protected override bool Conditionless => IsConditionless(this);

		internal override void InternalWrapInContainer(IQueryContainer c) => c.TermsSet = this;

		internal static bool IsConditionless(ITermsSetQuery q) =>
			q.Field.IsConditionless() ||
			q.Terms == null ||
			!q.Terms.HasAny() ||
			q.Terms.All(t => t == null || ((t as string)?.IsNullOrEmpty()).GetValueOrDefault(false)) ||
			q.MinimumShouldMatchField.IsConditionless() && q.MinimumShouldMatchScript == null;
	}

	/// <summary>
	/// Returns any documents that match with at least one or more of the provided terms.
	/// The terms are not analyzed and thus must match exactly.
	/// The number of terms that must match varies per document and is either controlled by a minimum should match
	/// field or computed per document in a minimum should match script.
	/// </summary>
	/// <typeparam name="T">The type that represents the expected hit type</typeparam>
	public class TermsSetQueryDescriptor<T>
		: FieldNameQueryDescriptorBase<TermsSetQueryDescriptor<T>, ITermsSetQuery, T>
			, ITermsSetQuery where T : class
	{
		protected override bool Conditionless => TermsSetQuery.IsConditionless(this);
		Field ITermsSetQuery.MinimumShouldMatchField { get; set; }
		IScript ITermsSetQuery.MinimumShouldMatchScript { get; set; }
		IEnumerable<object> ITermsSetQuery.Terms { get; set; }

		/// <summary>
		/// The required terms to match
		/// </summary>
		public TermsSetQueryDescriptor<T> Terms<TValue>(IEnumerable<TValue> terms) => Assign(terms?.Cast<object>(), (a, v) => a.Terms = v);

		/// <summary>
		/// The required terms to match
		/// </summary>
		public TermsSetQueryDescriptor<T> Terms<TValue>(params TValue[] terms) => Assign(terms, (a, v) =>
		{
			if (v?.Length == 1 && typeof(IEnumerable).IsAssignableFrom(typeof(TValue)) && typeof(TValue) != typeof(string))
				a.Terms = (v.First() as IEnumerable)?.Cast<object>();
			else a.Terms = v?.Cast<object>();
		});

		/// <summary>
		/// A field containing the number of required terms that must match
		/// </summary>
		public TermsSetQueryDescriptor<T> MinimumShouldMatchField(Field field) => Assign(field, (a, v) => a.MinimumShouldMatchField = v);

		/// <summary>
		/// A field containing the number of required terms that must match
		/// </summary>
		public TermsSetQueryDescriptor<T> MinimumShouldMatchField<TValue>(Expression<Func<T, TValue>> objectPath) =>
			Assign(objectPath, (a, v) => a.MinimumShouldMatchField = v);

		/// <summary>
		/// A script to control how many terms are required to match
		/// </summary>
		public TermsSetQueryDescriptor<T> MinimumShouldMatchScript(Func<ScriptDescriptor, IScript> scriptSelector) =>
			Assign(scriptSelector, (a, v) => a.MinimumShouldMatchScript = v?.Invoke(new ScriptDescriptor()));
	}
}