fix: message streaming

Signed-off-by: Sebastian Krupinski <krupinski01@gmail.com>

lib/Client/Command/FetchResponseParser.php

@@ -39,7 +39,7 @@ final class FetchResponseParser
     public function parseMany(ResponseStream $responses): Generator
     {
         foreach ($responses as $response) {
-            if ($response instanceof UntaggedResponse && MessageParser::isFetchMessage($response->payload())) {
+            if ($response instanceof UntaggedResponse && MessageParser::isFetchMessage($response->raw())) {
                 yield MessageParser::parse($response->raw());
                 continue;
             }
@@ -55,4 +55,4 @@ final class FetchResponseParser
 
         throw new ImapException('FETCH did not receive a tagged completion response.');
     }
-}
+}

lib/Client/MessageParser.php

@@ -8,19 +8,21 @@ use DateTimeInterface;
 
 final class MessageParser
 {
-    public static function isFetchMessage(string $payload): bool
+    public static function isFetchMessage(string $raw): bool
     {
-        return str_contains(strtoupper($payload), 'FETCH (');
+        return preg_match('/^\*\s+\d+\s+FETCH\s+\(/i', $raw) === 1;
     }
 
     public static function parse(string $raw): Message
     {
-        if (!preg_match('/^\*\s+(\d+)\s+FETCH\s+\((.*)\)$/is', $raw, $matches)) {
+        if (preg_match('/^\*\s+(\d+)\s+FETCH\s+\(/iA', $raw, $matches) !== 1
+            || !str_ends_with($raw, ')')) {
             throw new ImapException('Unable to parse FETCH response: ' . $raw);
         }
 
         $sequence = (int) $matches[1];
-        $attributes = self::parseAttributes($matches[2]);
+        $offset = strlen($matches[0]);
+        $attributes = self::parseAttributes($raw, $offset, strlen($raw) - 1);
         $uid = self::toInt($attributes['UID'] ?? null, 'FETCH response is missing UID: ' . $raw);
         $envelope = is_array($attributes['ENVELOPE'] ?? null) ? $attributes['ENVELOPE'] : null;
         $bodyStructure = isset($attributes['BODYSTRUCTURE']) ? self::parseBodyPart($attributes['BODYSTRUCTURE'], '') : null;
@@ -52,15 +54,13 @@ final class MessageParser
     /**
      * @return array<string, mixed>
      */
-    private static function parseAttributes(string $payload): array
+    private static function parseAttributes(string $payload, int &$offset, int $end): array
     {
         $attributes = [];
-        $offset = 0;
-        $length = strlen($payload);
 
-        while ($offset < $length) {
+        while ($offset < $end) {
             self::skipWhitespace($payload, $offset);
-            if ($offset >= $length) {
+            if ($offset >= $end) {
                 break;
             }
 
@@ -784,4 +784,4 @@ final class MessageParser
             $value,
         )));
     }
-}
+}

lib/Client/Protocol/ProtocolReader.php

@@ -56,16 +56,27 @@ final class ProtocolReader
         }
 
         if (str_starts_with($raw, '* ')) {
-            $parts = preg_split('/\s+/', substr($raw, 2), 2) ?: [];
-            $label = strtoupper($parts[0] ?? '');
+            // Keep the payload as a slice of the raw response. FETCH payloads can
+            // contain large message literals, so eagerly splitting here would keep
+            // a second full copy alive while the message is parsed.
+            $labelEnd = 2;
+            while (isset($raw[$labelEnd]) && !ctype_space($raw[$labelEnd])) {
+                $labelEnd++;
+            }
+            $label = strtoupper(substr($raw, 2, $labelEnd - 2));
+            $payloadOffset = $labelEnd;
+            while (isset($raw[$payloadOffset]) && ctype_space($raw[$payloadOffset])) {
+                $payloadOffset++;
+            }
             $this->logger?->debug('IMAP untagged response received: {raw}', [
                 'label' => $label,
                 'raw' => $raw,
             ]);
             return new UntaggedResponse(
                 $label,
-                $parts[1] ?? '',
+                '',
                 $raw,
+                $payloadOffset,
             );
         }
 
@@ -181,4 +192,4 @@ final class ProtocolReader
 
         return $raw;
     }
-}
+}

lib/Client/Protocol/Response/UntaggedResponse.php

@@ -10,6 +10,7 @@ final class UntaggedResponse implements ResponseInterface
         private readonly string $label,
         private readonly string $payload,
         private readonly string $raw,
+        private readonly ?int $payloadOffset = null,
     ) {}
 
     public function label(): string
@@ -19,6 +20,12 @@ final class UntaggedResponse implements ResponseInterface
 
     public function payload(): string
     {
+        // ProtocolReader records an offset for potentially large responses and
+        // only materializes the payload for command parsers that actually need it.
+        if ($this->payloadOffset !== null) {
+            return substr($this->raw, $this->payloadOffset);
+        }
+
         return $this->payload;
     }
 
@@ -27,7 +34,7 @@ final class UntaggedResponse implements ResponseInterface
      */
     public function payloadTokens(): array
     {
-        $payload = trim($this->payload);
+        $payload = trim($this->payload());
 
         if ($payload === '') {
             return [];
@@ -40,4 +47,4 @@ final class UntaggedResponse implements ResponseInterface
     {
         return $this->raw;
     }
-}
+}