/* 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.Generic;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Security.Cryptography;
using System.Text;
using OpenSearch.OpenSearch.Managed;
using OpenSearch.Stack.ArtifactsApi;

namespace OpenSearch.OpenSearch.Ephemeral
{
	public class EphemeralCluster : EphemeralCluster<EphemeralClusterConfiguration>
	{
		public EphemeralCluster(OpenSearchVersion version, int numberOfNodes = 1)
			: base(new EphemeralClusterConfiguration(version, ServerType.DEFAULT, ClusterFeatures.None, numberOfNodes: numberOfNodes))
		{
		}

		public EphemeralCluster(EphemeralClusterConfiguration clusterConfiguration) : base(clusterConfiguration)
		{
		}
	}

	public abstract class EphemeralCluster<TConfiguration> : ClusterBase<TConfiguration>,
		IEphemeralCluster<TConfiguration>
		where TConfiguration : EphemeralClusterConfiguration
	{
		protected EphemeralCluster(TConfiguration clusterConfiguration) : base(clusterConfiguration) =>
			Composer = new EphemeralClusterComposer<TConfiguration>(this);

		protected EphemeralClusterComposer<TConfiguration> Composer { get; }

		public virtual ICollection<Uri> NodesUris(string hostName = null)
		{
			hostName = hostName ?? (ClusterConfiguration.HttpFiddlerAware && Process.GetProcessesByName("fiddler").Any()
				? "ipv4.fiddler"
				: "localhost");
			var ssl = ClusterConfiguration.EnableSsl ? "s" : "";
			return Nodes
				.Select(n => $"http{ssl}://{hostName}:{n.Port ?? 9200}")
				.Distinct()
				.Select(n => new Uri(n))
				.ToList();
		}

		public bool CachingAndCachedHomeExists()
		{
			if (!ClusterConfiguration.CacheOpenSearchHomeInstallation) return false;
			var cachedOpenSearchHomeFolder = Path.Combine(FileSystem.LocalFolder, GetCacheFolderName());
			return Directory.Exists(cachedOpenSearchHomeFolder);
		}

		public virtual string GetCacheFolderName()
		{
			var config = ClusterConfiguration;

			var sb = new StringBuilder();
			sb.Append(EphemeralClusterComposerBase.InstallationTasks.Count());
			sb.Append("-");
			if (config.EnableSsl) sb.Append("ssl");
			if (config.Plugins != null && config.Plugins.Count > 0)
			{
				sb.Append("-");
				foreach (var p in config.Plugins.OrderBy(p => p.SubProductName))
					sb.Append(p.SubProductName.ToLowerInvariant());
			}

			var name = sb.ToString();

			return CalculateSha1(name, Encoding.UTF8);
		}

		protected override void OnBeforeStart()
		{
			Composer.Install();
			Composer.OnBeforeStart();
		}

		protected override void OnDispose() => Composer.OnStop();

		protected override void OnAfterStarted() => Composer.OnAfterStart();

		protected override string SeeLogsMessage(string message)
		{
			var log = Path.Combine(FileSystem.LogsPath, $"{ClusterConfiguration.ClusterName}.log");
			if (!File.Exists(log) || ClusterConfiguration.ShowOpenSearchOutputAfterStarted) return message;
			if (!Started) return message;
			using (var fileStream = new FileStream(log, FileMode.Open, FileAccess.Read, FileShare.ReadWrite))
			using (var textReader = new StreamReader(fileStream))
			{
				var logContents = textReader.ReadToEnd();
				return message + $" contents of {log}:{Environment.NewLine}" + logContents;
			}
		}

		public static string CalculateSha1(string text, Encoding enc)
		{
			var buffer = enc.GetBytes(text);
			var cryptoTransformSha1 = new SHA1CryptoServiceProvider();
			return BitConverter.ToString(cryptoTransformSha1.ComputeHash(buffer))
				.Replace("-", "").ToLowerInvariant().Substring(0, 12);
		}
	}
}