// Copyright Epic Games, Inc. All Rights Reserved.

using AutomationTool;
using EpicGames.Core;
using System;
using System.Collections.Generic;
using System.IO;
using System.Text;
using System.Text.Json;
using System.Xml;
using UnrealBuildBase;

namespace BuildGraph.Tasks
{
	/// <summary>
	/// Parameters for a AWS ECS deploy task
	/// </summary>
	public class AwsEcsDeployTaskParameters
	{
		/// <summary>
		/// Task definition file to use
		/// </summary>
		[TaskParameter(Optional = false)]
		public string TaskDefinitionFile;

		/// <summary>
		/// Docker image to set in new task definition (will replace %%DOCKER_PATTERN%% with this value)
		/// </summary>
		[TaskParameter(Optional = false)]
		public string DockerImage;

		/// <summary>
		/// App version to set in new task definition (will replace %%VERSION%% with this value)
		/// </summary>
		[TaskParameter(Optional = true)]
		public string Version;

		/// <summary>
		/// Cluster ARN representing AWS ECS cluster to operate on
		/// </summary>
		[TaskParameter(Optional = false)]
		public string Cluster;

		/// <summary>
		/// Service name to update and deploy to
		/// </summary>
		[TaskParameter(Optional = false)]
		public string Service;

		/// <summary>
		/// Environment variables
		/// </summary>
		[TaskParameter(Optional = true)]
		public string Environment;

		/// <summary>
		/// File to read environment from
		/// </summary>
		[TaskParameter(Optional = true)]
		public string EnvironmentFile;

		/// <summary>
		/// Write output to the log
		/// </summary>
		[TaskParameter(Optional = true)]
		public bool LogOutput = false;
	}

	/// <summary>
	/// Creates a new AWS ECS task definition and updates the ECS service to use this new revision of the task def
	/// </summary>
	[TaskElement("Aws-EcsDeploy", typeof(AwsEcsDeployTaskParameters))]
	public class AwsEcsDeployTask : SpawnTaskBase
	{
		/// <summary>
		/// Parameters for this task
		/// </summary>
		AwsEcsDeployTaskParameters Parameters;

		/// <summary>
		/// Construct an AWS ECS deploy task
		/// </summary>
		/// <param name="InParameters">Parameters for the task</param>
		public AwsEcsDeployTask(AwsEcsDeployTaskParameters InParameters)
		{
			Parameters = InParameters;
		}

		/// <summary>
		/// Execute the task.
		/// </summary>
		/// <param name="Job">Information about the current job</param>
		/// <param name="BuildProducts">Set of build products produced by this node.</param>
		/// <param name="TagNameToFileSet">Mapping from tag names to the set of files they include</param>
		public override void Execute(JobContext Job, HashSet<FileReference> BuildProducts, Dictionary<string, HashSet<FileReference>> TagNameToFileSet)
		{
			string TaskDefTemplate = File.ReadAllText(ResolveFile(Parameters.TaskDefinitionFile).FullName);
			string TaskDefRendered = TaskDefTemplate.Replace("%%DOCKER_IMAGE%%", Parameters.DockerImage);
			if (Parameters.Version != null)
			{
				TaskDefRendered = TaskDefRendered.Replace("%%VERSION%%", Parameters.Version);
			}

			FileReference TempTaskDefFile = FileReference.Combine(Unreal.RootDirectory, "Engine", "Intermediate", "Build", "AwsEcsDeployTaskTemp.json");
			DirectoryReference.CreateDirectory(TempTaskDefFile.Directory);
			File.WriteAllText(TempTaskDefFile.FullName, TaskDefRendered, new UTF8Encoding(encoderShouldEmitUTF8Identifier: false));
			
			IProcessResult CreateTaskDefResult = SpawnTaskBase.Execute("aws", $"ecs register-task-definition --cli-input-json \"file://{TempTaskDefFile.FullName}\"", EnvVars: ParseEnvVars(Parameters.Environment, Parameters.EnvironmentFile), LogOutput: Parameters.LogOutput);

			JsonDocument TaskDefJson = JsonDocument.Parse(CreateTaskDefResult.Output);
			string TaskDefFamily = TaskDefJson.RootElement.GetProperty("taskDefinition").GetProperty("family").GetString();
			string TaskDefRevision = TaskDefJson.RootElement.GetProperty("taskDefinition").GetProperty("revision").ToString();

			string Params = $"ecs update-service --cluster {Parameters.Cluster} --service {Parameters.Service} --task-definition {TaskDefFamily}:{TaskDefRevision}";
			SpawnTaskBase.Execute("aws", Params, EnvVars: ParseEnvVars(Parameters.Environment, Parameters.EnvironmentFile), LogOutput: Parameters.LogOutput);

			Log.TraceInformation($"Service {Parameters.Service} updated to use new task def {TaskDefFamily}:{TaskDefRevision}");
		}

		/// <summary>
		/// Output this task out to an XML writer.
		/// </summary>
		public override void Write(XmlWriter Writer)
		{
			Write(Writer, Parameters);
		}

		/// <summary>
		/// Find all the tags which are used as inputs to this task
		/// </summary>
		/// <returns>The tag names which are read by this task</returns>
		public override IEnumerable<string> FindConsumedTagNames()
		{
			yield break;
		}

		/// <summary>
		/// Find all the tags which are modified by this task
		/// </summary>
		/// <returns>The tag names which are modified by this task</returns>
		public override IEnumerable<string> FindProducedTagNames()
		{
			yield break;
		}
	}
}