<?php
// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: Apache-2.0

// snippet-start:[cloudwatch.php.get_metric_stats.complete]
// snippet-start:[cloudwatch.php.get_metric_stats.import]
require 'vendor/autoload.php';

use Aws\CloudWatch\CloudWatchClient;
use Aws\Exception\AwsException;

// snippet-end:[cloudwatch.php.get_metric_stats.import]

/* ////////////////////////////////////////////////////////////////////////////
 * Purpose: Provides statistical information for a specified metric
 * in Amazon CloudWatch.
 *
 * Inputs:
 * - $cloudWatchClient: An initialized CloudWatch client.
 * - $namespace: The metric's namespace.
 * - $metricName: The metric's name.
 * - $dimensions: Any required dimensions for the specified metric.
 * - $startTime: The datapoints' start time.
 * - $endTime: The datapoints' end time.
 * - $period: The time period to report datapoints for.
 * - $statistics: The datapoints' measurement type.
 * - $unit: The datapoints' unit of measurement.
 *
 * Returns: Statistical information for the specific metric;
 * otherwise, the error message.
 * ///////////////////////////////////////////////////////////////////////// */

// snippet-start:[cloudwatch.php.get_metric_stats.main]
function getMetricStatistics(
    $cloudWatchClient,
    $namespace,
    $metricName,
    $dimensions,
    $startTime,
    $endTime,
    $period,
    $statistics,
    $unit
) {
    try {
        $result = $cloudWatchClient->getMetricStatistics([
            'Namespace' => $namespace,
            'MetricName' => $metricName,
            'Dimensions' => $dimensions,
            'StartTime' => $startTime,
            'EndTime' => $endTime,
            'Period' => $period,
            'Statistics' => $statistics,
            'Unit' => $unit
        ]);

        $message = '';

        if (isset($result['@metadata']['effectiveUri'])) {
            $message .= 'For the effective URI at ' .
                $result['@metadata']['effectiveUri'] . "\n\n";

            if (
                (isset($result['Datapoints'])) and
                (count($result['Datapoints']) > 0)
            ) {
                $message .= "Datapoints found:\n\n";

                foreach ($result['Datapoints'] as $datapoint) {
                    foreach ($datapoint as $key => $value) {
                        $message .= $key . ' = ' . $value . "\n";
                    }

                    $message .= "\n";
                }
            } else {
                $message .= 'No datapoints found.';
            }
        } else {
            $message .= 'No datapoints found.';
        }

        return $message;
    } catch (AwsException $e) {
        return 'Error: ' . $e->getAwsErrorMessage();
    }
}

function getTheMetricStatistics()
{
    // Average number of Amazon EC2 vCPUs every 5 minutes within
    // the past 3 hours.
    $namespace = 'AWS/Usage';
    $metricName = 'ResourceCount';
    $dimensions = [
        [
            'Name' => 'Service',
            'Value' => 'EC2'
        ],
        [
            'Name' => 'Resource',
            'Value' => 'vCPU'
        ],
        [
            'Name' => 'Type',
            'Value' => 'Resource'
        ],
        [
            'Name' => 'Class',
            'Value' => 'Standard/OnDemand'
        ]
    ];
    $startTime = strtotime('-3 hours');
    $endTime = strtotime('now');
    $period = 300; // Seconds. (5 minutes = 300 seconds.)
    $statistics = ['Average'];
    $unit = 'None';

    $cloudWatchClient = new CloudWatchClient([
        'profile' => 'default',
        'region' => 'us-east-1',
        'version' => '2010-08-01'
    ]);

    echo getMetricStatistics(
        $cloudWatchClient,
        $namespace,
        $metricName,
        $dimensions,
        $startTime,
        $endTime,
        $period,
        $statistics,
        $unit
    );

    // Another example: average number of bytes of standard storage in the
    // specified Amazon S3 bucket each day for the past 3 days.

    /*
    $namespace = 'AWS/S3';
    $metricName = 'BucketSizeBytes';
    $dimensions = [
        [
            'Name' => 'StorageType',
            'Value'=> 'StandardStorage'
        ],
        [
            'Name' => 'BucketName',
            'Value' => 'amzn-s3-demo-bucket'
        ]
    ];
    $startTime = strtotime('-3 days');
    $endTime = strtotime('now');
    $period = 86400; // Seconds. (1 day = 86400 seconds.)
    $statistics = array('Average');
    $unit = 'Bytes';

    $cloudWatchClient = new CloudWatchClient([
        'profile' => 'default',
        'region' => 'us-east-1',
        'version' => '2010-08-01'
    ]);

    echo getMetricStatistics($cloudWatchClient, $namespace, $metricName,
    $dimensions, $startTime, $endTime, $period, $statistics, $unit);
    */
}

// Uncomment the following line to run this code in an AWS account.
// getTheMetricStatistics();
// snippet-end:[cloudwatch.php.get_metric_stats.main]
// snippet-end:[cloudwatch.php.get_metric_stats.complete]
