From 3d5308a6e5f2b3bbfc307716292d1cc98e424edb Mon Sep 17 00:00:00 2001
From: Andrew Dolgov <fox@fakecake.org>
Date: Tue, 24 Oct 2023 17:50:00 +0300
Subject: [PATCH] add stub opentelemetry classes in case it is disabled

---
 .vscode/tasks.json       |   2 +-
 classes/tracer.php       | 206 ++++++++++++++++++++++++++++++---------
 utils/phpstan-watcher.sh |   0
 3 files changed, 162 insertions(+), 46 deletions(-)
 mode change 100644 => 100755 utils/phpstan-watcher.sh

diff --git a/.vscode/tasks.json b/.vscode/tasks.json
index 69fd3f3f4..d59e3ff10 100644
--- a/.vscode/tasks.json
+++ b/.vscode/tasks.json
@@ -21,7 +21,7 @@
 
 				}
 		  },
-			"command": "${workspaceRoot}/utils/phpstan-watcher.sh",
+			"command": "chmod +x ${workspaceRoot}/utils/phpstan-watcher.sh && ${workspaceRoot}/utils/phpstan-watcher.sh",
 		},
 		{
 			"type": "gulp",
diff --git a/classes/tracer.php b/classes/tracer.php
index 034d85619..7163adb90 100644
--- a/classes/tracer.php
+++ b/classes/tracer.php
@@ -1,8 +1,16 @@
 <?php
 
-
 use OpenTelemetry\API\Trace\Propagation\TraceContextPropagator;
+use OpenTelemetry\API\Trace\SpanContextInterface;
+use OpenTelemetry\API\Trace\SpanInterface;
 use OpenTelemetry\API\Trace\SpanKind;
+use OpenTelemetry\API\Trace\TraceFlags;
+use OpenTelemetry\API\Trace\TraceStateInterface;
+use OpenTelemetry\Context\ContextInterface;
+use OpenTelemetry\Context\ContextKey;
+use OpenTelemetry\Context\ContextKeyInterface;
+use OpenTelemetry\Context\ImplicitContextKeyedInterface;
+use OpenTelemetry\Context\ScopeInterface;
 use OpenTelemetry\Contrib\Otlp\OtlpHttpTransportFactory;
 use OpenTelemetry\Contrib\Otlp\SpanExporter;
 use OpenTelemetry\SDK\Common\Attribute\Attributes;
@@ -10,20 +18,126 @@ use OpenTelemetry\SDK\Resource\ResourceInfo;
 use OpenTelemetry\SDK\Resource\ResourceInfoFactory;
 use OpenTelemetry\SDK\Trace\Sampler\AlwaysOnSampler;
 use OpenTelemetry\SDK\Trace\Sampler\ParentBased;
-use OpenTelemetry\SDK\Trace\SpanExporter\InMemoryExporter;
 use OpenTelemetry\SDK\Trace\SpanProcessor\SimpleSpanProcessor;
 use OpenTelemetry\SDK\Trace\TracerProvider;
 use OpenTelemetry\SemConv\ResourceAttributes;
 
-class Tracer {
-	/** @var Tracer $instance */
+class DummyContextInterface implements ContextInterface {
+
+	/** @var DummyContextInterface */
 	private static $instance;
 
+	public function __construct() {
+		self::$instance = $this;
+	}
+
+	/** @phpstan-ignore-next-line */
+	public static function createKey(string $key): ContextKeyInterface { return new ContextKey(); }
+
+	public static function getCurrent(): ContextInterface { return self::$instance; }
+
+	public function activate(): ScopeInterface { return new DummyScopeInterface(); }
+
+	public function with(ContextKeyInterface $key, $value): ContextInterface { return $this; }
+
+	public function withContextValue(ImplicitContextKeyedInterface $value): ContextInterface { return $this; }
+
+	public function get(ContextKeyInterface $key) { return new ContextKey(); }
+
+}
+
+class DummySpanContextInterface implements SpanContextInterface {
+
+	/** @var DummySpanContextInterface $instance */
+	private static $instance;
+
+	public function __construct() {
+		self::$instance = $this;
+	}
+
+	public static function createFromRemoteParent(string $traceId, string $spanId, int $traceFlags = TraceFlags::DEFAULT, ?TraceStateInterface $traceState = null): SpanContextInterface { return self::$instance; }
+
+	public static function getInvalid(): SpanContextInterface { return self::$instance; }
+
+	public static function create(string $traceId, string $spanId, int $traceFlags = TraceFlags::DEFAULT, ?TraceStateInterface $traceState = null): SpanContextInterface { return self::$instance; }
+
+	public function getTraceId(): string { return ""; }
+
+	public function getTraceIdBinary(): string { return ""; }
+
+	public function getSpanId(): string { return ""; }
+
+	public function getSpanIdBinary(): string { return ""; }
+
+	public function getTraceFlags(): int { return 0; }
+
+	public function getTraceState(): ?TraceStateInterface { return null; }
+
+	public function isValid(): bool { return false; }
+
+	public function isRemote(): bool { return false; }
+
+	public function isSampled(): bool { return false; }
+}
+
+class DummyScopeInterface implements ScopeInterface {
+	public function detach(): int { return 0; }
+}
+
+class DummySpanInterface implements SpanInterface {
+
+	/** @var DummySpanInterface $instance */
+	private static $instance;
+
+	public function __construct() {
+		self::$instance = $this;
+	}
+
+	public static function fromContext(ContextInterface $context): SpanInterface { return self::$instance; }
+
+	public static function getCurrent(): SpanInterface { return self::$instance; }
+
+	public static function getInvalid(): SpanInterface { return self::$instance; }
+
+	public static function wrap(SpanContextInterface $spanContext): SpanInterface { return self::$instance; }
+
+	public function getContext(): SpanContextInterface { return new DummySpanContextInterface(); }
+
+	public function isRecording(): bool { return false; }
+
+	/** @phpstan-ignore-next-line */
+	public function setAttribute(string $key, $value): SpanInterface { return self::$instance; }
+
+	/** @phpstan-ignore-next-line */
+	public function setAttributes(iterable $attributes): SpanInterface { return self::$instance; }
+
+	/** @phpstan-ignore-next-line */
+	public function addEvent(string $name, iterable $attributes = [], ?int $timestamp = null): SpanInterface { return $this; }
+
+	/** @phpstan-ignore-next-line */
+	public function recordException(Throwable $exception, iterable $attributes = []): SpanInterface { return $this; }
+
+	public function updateName(string $name): SpanInterface { return $this; }
+
+	public function setStatus(string $code, ?string $description = null): SpanInterface { return $this; }
+
+	public function end(?int $endEpochNanos = null): void { }
+
+	public function activate(): ScopeInterface { return new DummyScopeInterface(); }
+
+	public function storeInContext(ContextInterface $context): ContextInterface { return new DummyContextInterface(); }
+
+}
+
+class Tracer {
+	/** @var Tracer $instance */
+	private static $instance = null;
+
 	/** @var OpenTelemetry\SDK\Trace\TracerProviderInterface $tracerProvider */
-	private $tracerProvider;
+	private $tracerProvider = null;
 
 	/** @var OpenTelemetry\API\Trace\TracerInterface $tracer */
-	private $tracer;
+	private $tracer = null;
 
 	public function __construct() {
 		$OPENTELEMETRY_ENDPOINT = Config::get(Config::OPENTELEMETRY_ENDPOINT);
@@ -31,41 +145,39 @@ class Tracer {
 		if ($OPENTELEMETRY_ENDPOINT) {
 			$transport = (new OtlpHttpTransportFactory())->create($OPENTELEMETRY_ENDPOINT, 'application/x-protobuf');
 			$exporter = new SpanExporter($transport);
-		} else {
-			$exporter = new InMemoryExporter();
+
+			$resource = ResourceInfoFactory::emptyResource()->merge(
+				ResourceInfo::create(Attributes::create(
+					[ResourceAttributes::SERVICE_NAME => Config::get(Config::OPENTELEMETRY_SERVICE)]
+				), ResourceAttributes::SCHEMA_URL),
+			);
+
+			$this->tracerProvider = TracerProvider::builder()
+				->addSpanProcessor(new SimpleSpanProcessor($exporter))
+				->setResource($resource)
+				->setSampler(new ParentBased(new AlwaysOnSampler()))
+				->build();
+
+			$this->tracer = $this->tracerProvider->getTracer('io.opentelemetry.contrib.php');
+
+			$context = TraceContextPropagator::getInstance()->extract(getallheaders());
+
+			$span = $this->tracer->spanBuilder($_SESSION['name'] ?? 'not logged in')
+				->setParent($context)
+				->setSpanKind(SpanKind::KIND_SERVER)
+				->setAttribute('php.request', json_encode($_REQUEST))
+				->setAttribute('php.server', json_encode($_SERVER))
+				->setAttribute('php.session', json_encode($_SESSION ?? []))
+				->startSpan();
+
+			$scope = $span->activate();
+
+			register_shutdown_function(function() use ($span, $scope) {
+				$span->end();
+				$scope->detach();
+				$this->tracerProvider->shutdown();
+			});
 		}
-
-		$resource = ResourceInfoFactory::emptyResource()->merge(
-			ResourceInfo::create(Attributes::create(
-				[ResourceAttributes::SERVICE_NAME => Config::get(Config::OPENTELEMETRY_SERVICE)]
-			), ResourceAttributes::SCHEMA_URL),
-		);
-
-		$this->tracerProvider = TracerProvider::builder()
-			->addSpanProcessor(new SimpleSpanProcessor($exporter))
-			->setResource($resource)
-			->setSampler(new ParentBased(new AlwaysOnSampler()))
-			->build();
-
-		$this->tracer = $this->tracerProvider->getTracer('io.opentelemetry.contrib.php');
-
-		$context = TraceContextPropagator::getInstance()->extract(getallheaders());
-
-		$span = $this->tracer->spanBuilder($_SESSION['name'] ?? 'not logged in')
-			->setParent($context)
-			->setSpanKind(SpanKind::KIND_SERVER)
-			->setAttribute('php.request', json_encode($_REQUEST))
-			->setAttribute('php.server', json_encode($_SERVER))
-			->setAttribute('php.session', json_encode($_SESSION ?? []))
-			->startSpan();
-
-		$scope = $span->activate();
-
-		register_shutdown_function(function() use ($span, $scope) {
-			$span->end();
-			$scope->detach();
-			$this->tracerProvider->shutdown();
-		});
 	}
 
 	/**
@@ -73,12 +185,16 @@ class Tracer {
 	 * @return OpenTelemetry\API\Trace\SpanInterface
 	 */
 	private function _start(string $name) {
-		$span = $this->tracer
-			->spanBuilder($name)
-			->setSpanKind(SpanKind::KIND_SERVER)
-			->startSpan();
+		if ($this->tracer != null) {
+			$span = $this->tracer
+				->spanBuilder($name)
+				->setSpanKind(SpanKind::KIND_SERVER)
+				->startSpan();
 
-		$span->activate();
+			$span->activate();
+		} else {
+			$span = new DummySpanInterface();
+		}
 
 		return $span;
 	}
diff --git a/utils/phpstan-watcher.sh b/utils/phpstan-watcher.sh
old mode 100644
new mode 100755