v2: Updates

* Simplifies & beautifies everything
* Introduces a new Class system.
* Errors are defaulted to AWS's handler.
* New function names & more efficient handling.
* Should fix a majority of the errors.

Please read the README for more!

aws/Aws/ClientSideMonitoring/ApiCallMonitoringMiddleware.php

@@ -0,0 +1,176 @@
+<?php
+
+namespace Aws\ClientSideMonitoring;
+
+use Aws\CommandInterface;
+use Aws\Exception\AwsException;
+use Aws\MonitoringEventsInterface;
+use Aws\ResultInterface;
+use Psr\Http\Message\RequestInterface;
+
+/**
+ * @internal
+ */
+class ApiCallMonitoringMiddleware extends AbstractMonitoringMiddleware
+{
+
+    /**
+     * Api Call Attempt event keys for each Api Call event key
+     *
+     * @var array
+     */
+    private static $eventKeys = [
+        'FinalAwsException' => 'AwsException',
+        'FinalAwsExceptionMessage' => 'AwsExceptionMessage',
+        'FinalSdkException' => 'SdkException',
+        'FinalSdkExceptionMessage' => 'SdkExceptionMessage',
+        'FinalHttpStatusCode' => 'HttpStatusCode',
+    ];
+
+    /**
+     * Standard middleware wrapper function with CSM options passed in.
+     *
+     * @param callable $credentialProvider
+     * @param mixed  $options
+     * @param string $region
+     * @param string $service
+     * @return callable
+     */
+    public static function wrap(
+        callable $credentialProvider,
+        $options,
+        $region,
+        $service
+    ) {
+        return function (callable $handler) use (
+            $credentialProvider,
+            $options,
+            $region,
+            $service
+        ) {
+            return new static(
+                $handler,
+                $credentialProvider,
+                $options,
+                $region,
+                $service
+            );
+        };
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public static function getRequestData(RequestInterface $request)
+    {
+        return [];
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public static function getResponseData($klass)
+    {
+        if ($klass instanceof ResultInterface) {
+            $data = [
+                'AttemptCount' => self::getResultAttemptCount($klass),
+                'MaxRetriesExceeded' => 0,
+            ];
+        } elseif ($klass instanceof \Exception) {
+            $data = [
+                'AttemptCount' => self::getExceptionAttemptCount($klass),
+                'MaxRetriesExceeded' => self::getMaxRetriesExceeded($klass),
+            ];
+        } else {
+            throw new \InvalidArgumentException('Parameter must be an instance of ResultInterface or Exception.');
+        }
+
+        return $data + self::getFinalAttemptData($klass);
+    }
+
+    private static function getResultAttemptCount(ResultInterface $result) {
+        if (isset($result['@metadata']['transferStats']['http'])) {
+            return count($result['@metadata']['transferStats']['http']);
+        }
+        return 1;
+    }
+
+    private static function getExceptionAttemptCount(\Exception $e) {
+        $attemptCount = 0;
+        if ($e instanceof MonitoringEventsInterface) {
+            foreach ($e->getMonitoringEvents() as $event) {
+                if (isset($event['Type']) &&
+                    $event['Type'] === 'ApiCallAttempt') {
+                    $attemptCount++;
+                }
+            }
+
+        }
+        return $attemptCount;
+    }
+
+    private static function getFinalAttemptData($klass)
+    {
+        $data = [];
+        if ($klass instanceof MonitoringEventsInterface) {
+            $finalAttempt = self::getFinalAttempt($klass->getMonitoringEvents());
+
+            if (!empty($finalAttempt)) {
+                foreach (self::$eventKeys as $callKey => $attemptKey) {
+                    if (isset($finalAttempt[$attemptKey])) {
+                        $data[$callKey] = $finalAttempt[$attemptKey];
+                    }
+                }
+            }
+        }
+
+        return $data;
+    }
+
+    private static function getFinalAttempt(array $events)
+    {
+        for (end($events); key($events) !== null; prev($events)) {
+            $current = current($events);
+            if (isset($current['Type'])
+                && $current['Type'] === 'ApiCallAttempt'
+            ) {
+                return $current;
+            }
+        }
+
+        return null;
+    }
+
+    private static function getMaxRetriesExceeded($klass)
+    {
+        if ($klass instanceof AwsException && $klass->isMaxRetriesExceeded()) {
+            return 1;
+        }
+        return 0;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    protected function populateRequestEventData(
+        CommandInterface $cmd,
+        RequestInterface $request,
+        array $event
+    ) {
+        $event = parent::populateRequestEventData($cmd, $request, $event);
+        $event['Type'] = 'ApiCall';
+        return $event;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    protected function populateResultEventData(
+        $result,
+        array $event
+    ) {
+        $event = parent::populateResultEventData($result, $event);
+        $event['Latency'] = (int) (floor(microtime(true) * 1000) - $event['Timestamp']);
+        return $event;
+    }
+}