refactor: route all log writes through a single LogWriter

lib/Http/Client/Middleware/CountingStream.php

@@ -195,12 +195,7 @@ private function writeLog(bool $complete): void {
 
 			[$jsonFile, $plainFile] = LogPathHelper::getPathsFromMeta($this->meta, $this->logBaseDir, $this->reqId);
 
-			if (in_array($this->logFormat, ['json', 'both'], true)) {
-				@file_put_contents($jsonFile, json_encode($merged, JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE) . PHP_EOL, FILE_APPEND | LOCK_EX);
-			}
-			if (in_array($this->logFormat, ['plain', 'both'], true)) {
-				@file_put_contents($plainFile, $plain, FILE_APPEND | LOCK_EX);
-			}
+			LogWriter::write($this->logFormat, $jsonFile, $merged, $plainFile, $plain, $this->logger);
 
 			TransferStatsStore::clear($this->reqId);
 		} catch (\Throwable $e) {

lib/Http/Client/Middleware/HttpClientLoggerMiddleware.php

@@ -195,7 +195,7 @@ function (ResponseInterface $response) use ($request, $reqHeaders, $reqId) {
 
 						if ($immediate) {
 							if ($this->shouldLog($intStatus)) {
-								$this->writeImmediate($reqId, $meta, $respHeaders, $handlerStats);
+								$this->writeImmediate($reqId, $meta, $handlerStats);
 							}
 							TransferStatsStore::clear($reqId);
 						} else {
@@ -250,12 +250,7 @@ function ($reason) use ($request, $reqHeaders, $reqId) {
 						];
 						[$jsonFile, $plainFile] = LogPathHelper::getPathsFromMeta($metaForPaths, $this->logBaseDir, $reqId);
 
-						if (in_array($this->logFormat, ['json', 'both'], true)) {
-							@file_put_contents($jsonFile, json_encode($entry, JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE) . PHP_EOL, FILE_APPEND | LOCK_EX);
-						}
-						if (in_array($this->logFormat, ['plain', 'both'], true)) {
-							@file_put_contents($plainFile, $plain, FILE_APPEND | LOCK_EX);
-						}
+						LogWriter::write($this->logFormat, $jsonFile, $entry, $plainFile, $plain, $this->logger);
 
 						TransferStatsStore::clear($reqId);
 					} catch (\Throwable $e) {
@@ -271,7 +266,7 @@ function ($reason) use ($request, $reqHeaders, $reqId) {
 		};
 	}
 
-	private function writeImmediate(string $reqId, array $meta, array $respHeaders, ?array $handlerStats): void {
+	private function writeImmediate(string $reqId, array $meta, ?array $handlerStats): void {
 		try {
 			$compressed = null;
 			$encoding = 'none';
@@ -280,7 +275,7 @@ private function writeImmediate(string $reqId, array $meta, array $respHeaders,
 				$compressed = (int)round($handlerStats['size_download']);
 			}
 
-			$compact = $this->compactHeaders($respHeaders);
+			$compact = $meta['responseHeaders'];
 
 			foreach ($compact as $k => $v) {
 				$lk = strtolower($k);
@@ -358,12 +353,7 @@ private function writeImmediate(string $reqId, array $meta, array $respHeaders,
 
 			[$jsonFile, $plainFile] = LogPathHelper::getPathsFromMeta($meta, $this->logBaseDir, $reqId);
 
-			if (in_array($this->logFormat, ['json', 'both'], true)) {
-				@file_put_contents($jsonFile, json_encode($merged, JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE) . PHP_EOL, FILE_APPEND | LOCK_EX);
-			}
-			if (in_array($this->logFormat, ['plain', 'both'], true)) {
-				@file_put_contents($plainFile, $plain, FILE_APPEND | LOCK_EX);
-			}
+			LogWriter::write($this->logFormat, $jsonFile, $merged, $plainFile, $plain, $this->logger);
 		} catch (\Throwable $e) {
 			$this->logger->debug('HttpClientLoggerMiddleware: writeImmediate failed: ' . $e->getMessage());
 		}

lib/Http/Client/Middleware/LogWriter.php

@@ -0,0 +1,49 @@
+<?php
+
+/**
+ * SPDX-FileCopyrightText: 2026 [ernolf] Raphael Gradenwitz <raphael.gradenwitz@googlemail.com>
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+declare(strict_types=1);
+
+namespace OCA\AdminAuditHttpClient\Http\Client\Middleware;
+
+use Psr\Log\LoggerInterface;
+
+/**
+ * Single write path for all log sinks. Appends with an exclusive lock and
+ * reports the first failed write per process as a warning — without that, a
+ * full or unwritable log directory would go entirely unnoticed.
+ */
+class LogWriter {
+	private static bool $failureLogged = false;
+
+	public static function write(
+		string $format,
+		string $jsonFile,
+		array $entry,
+		string $plainFile,
+		string $plainLine,
+		LoggerInterface $logger,
+	): void {
+		if (in_array($format, ['json', 'both'], true)) {
+			self::append($jsonFile, json_encode($entry, JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE) . PHP_EOL, $logger);
+		}
+		if (in_array($format, ['plain', 'both'], true)) {
+			self::append($plainFile, $plainLine, $logger);
+		}
+	}
+
+	private static function append(string $file, string $line, LoggerInterface $logger): void {
+		if (@file_put_contents($file, $line, FILE_APPEND | LOCK_EX) !== false) {
+			return;
+		}
+		if (!self::$failureLogged) {
+			self::$failureLogged = true;
+			$logger->warning(
+				'admin_audit_http_client: could not write to ' . $file . ' - further write failures are not reported'
+			);
+		}
+	}
+}

tests/unit/Http/Client/Middleware/HttpClientLoggerMiddlewareTest.php

@@ -171,7 +171,7 @@ public function testWriteImmediateOmitsDecompressedBytesAndRatio(): void {
 		];
 
 		try {
-			$this->invokePrivate($mw, 'writeImmediate', ['req-wi-1', $meta, [], ['size_download' => 10]]);
+			$this->invokePrivate($mw, 'writeImmediate', ['req-wi-1', $meta, ['size_download' => 10]]);
 
 			$lines = file($dir . '/example.com.json', FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES);
 			$this->assertNotFalse($lines);

tests/unit/Http/Client/Middleware/LogWriterTest.php

@@ -0,0 +1,65 @@
+<?php
+
+declare(strict_types=1);
+
+/*
+ * SPDX-FileCopyrightText: 2026 [ernolf] Raphael Gradenwitz <raphael.gradenwitz@googlemail.com>
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OCA\AdminAuditHttpClient\Tests\Unit\Http\Client\Middleware;
+
+use OCA\AdminAuditHttpClient\Http\Client\Middleware\LogWriter;
+use PHPUnit\Framework\TestCase;
+use Psr\Log\LoggerInterface;
+use Psr\Log\NullLogger;
+
+class LogWriterTest extends TestCase {
+	private string $baseDir;
+
+	protected function setUp(): void {
+		parent::setUp();
+		$this->baseDir = sys_get_temp_dir() . '/aahc-writer-' . bin2hex(random_bytes(4));
+		mkdir($this->baseDir);
+	}
+
+	protected function tearDown(): void {
+		foreach (glob($this->baseDir . '/*') ?: [] as $file) {
+			@unlink($file);
+		}
+		@rmdir($this->baseDir);
+		parent::tearDown();
+	}
+
+	public function testWritesJsonAndPlainForFormatBoth(): void {
+		$json = $this->baseDir . '/host.json';
+		$plain = $this->baseDir . '/host.log';
+
+		LogWriter::write('both', $json, ['a' => 1], $plain, "plain line\n", new NullLogger());
+
+		$this->assertSame('{"a":1}' . PHP_EOL, file_get_contents($json));
+		$this->assertSame("plain line\n", file_get_contents($plain));
+	}
+
+	public function testRespectsFormatSelection(): void {
+		$json = $this->baseDir . '/host.json';
+		$plain = $this->baseDir . '/host.log';
+
+		LogWriter::write('json', $json, ['a' => 1], $plain, "plain line\n", new NullLogger());
+
+		$this->assertFileExists($json);
+		$this->assertFileDoesNotExist($plain);
+	}
+
+	public function testWarnsExactlyOnceOnWriteFailure(): void {
+		$blocker = $this->baseDir . '/blocker';
+		touch($blocker);
+
+		$logger = $this->createMock(LoggerInterface::class);
+		// Both appends fail (paths below a regular file); once() proves the
+		// second failure is suppressed.
+		$logger->expects($this->once())->method('warning');
+
+		LogWriter::write('both', $blocker . '/x.json', ['a' => 1], $blocker . '/x.log', "line\n", $logger);
+	}
+}