<?php

declare(strict_types=1);

namespace App\CloudFormation;

use Aws\CloudFormation\CloudFormationClient;

class Client
{
	protected $cfn;

	public function __construct(?string $region = null, ?string $profile = null)
	{
		$this->cfn = new CloudFormationClient([
			'version' => 'latest',
			'region' => $region ?? env('AWS_REGION'),
			'profile' => $profile ?? env('AWS_PROFILE')
		]);
	}

	public function getStack(string $stack): ?Stack
	{
		try
		{
			$stack_description = $this->cfn->describeStacks([
				'StackName' => $stack
			]);
		}
		catch (\Aws\Exception\AwsException $ex)
		{
			if ($ex->getAwsErrorMessage() == 'Stack with id '.$stack.' does not exist')
			{
				return null;
			}
			throw new \Exception($ex->getAwsErrorMessage(), $ex->getAwsErrorCode());
		}
		return new Stack($stack_description['Stacks'][0]);
	}

	public function createStack(string $stack_name, string $template_body, array $parameters = []): Stack
	{
		$response = $this->cfn->createStack($this->buildStackRequest($stack_name, $template_body, $parameters));
		return $this->getStack($response['StackId']);
	}

	public function updateStack(string $stack_name, string $template_body, array $parameters = []): Stack
	{
		$response = $this->cfn->updateStack($this->buildStackRequest($stack_name, $template_body, $parameters));
		return $this->getStack($response['StackId']);
	}

	protected function buildStackRequest(string $stack_name, string $template_body, array $parameters = []): array
	{
		$request = [
			'StackName' => $stack_name,
			'TemplateBody' => $template_body,
			'Capabilities' => ['CAPABILITY_IAM', 'CAPABILITY_NAMED_IAM'],
			'TimeoutInMinutes' => 5
		];
		if (sizeof($parameters))
		{
			$request['Parameters'] = [];
			foreach ($parameters as $k => $v)
			{
				$request['Parameters'][] = [
					'ParameterKey' => $k,
					'ParameterValue' => $v
				];
			}
		}
		return $request;
	}
}