Fix APRS parser for direwolf bracket-prefixed frames

intercept_agent.py

@@ -2860,11 +2860,22 @@ class ModeManager:
                     pass
             logger.info("APRS reader stopped")
 
-    def _parse_aprs_packet(self, line: str) -> dict | None:
-        """Parse APRS packet from direwolf or multimon-ng."""
-        match = re.match(r'([A-Z0-9-]+)>([^:]+):(.+)', line)
-        if not match:
-            return None
+    def _parse_aprs_packet(self, line: str) -> dict | None:
+        """Parse APRS packet from direwolf or multimon-ng."""
+        if not line:
+            return None
+
+        # Normalize common decoder prefixes before parsing.
+        # multimon-ng: "AFSK1200: ..."
+        # direwolf: "[0.4] ...", "[0L] ..."
+        line = line.strip()
+        if line.startswith('AFSK1200:'):
+            line = line[9:].strip()
+        line = re.sub(r'^(?:\[[^\]]+\]\s*)+', '', line)
+
+        match = re.match(r'([A-Z0-9-]+)>([^:]+):(.+)', line)
+        if not match:
+            return None
 
         callsign = match.group(1)
         path = match.group(2)

routes/aprs.py

@@ -94,7 +94,7 @@ def find_rtl_power() -> Optional[str]:
 DIREWOLF_CONFIG_PATH = os.path.join(tempfile.gettempdir(), 'intercept_direwolf.conf')
 
 
-def create_direwolf_config() -> str:
+def create_direwolf_config() -> str:
     """Create a minimal direwolf config for receive-only operation."""
     config = """# Minimal direwolf config for INTERCEPT (receive-only)
 # Audio input is handled via stdin
@@ -104,12 +104,32 @@ CHANNEL 0
 MYCALL N0CALL
 MODEM 1200
 """
-    with open(DIREWOLF_CONFIG_PATH, 'w') as f:
-        f.write(config)
-    return DIREWOLF_CONFIG_PATH
-
-
-def parse_aprs_packet(raw_packet: str) -> Optional[dict]:
+    with open(DIREWOLF_CONFIG_PATH, 'w') as f:
+        f.write(config)
+    return DIREWOLF_CONFIG_PATH
+
+
+def normalize_aprs_output_line(line: str) -> str:
+    """Normalize a decoder output line to raw APRS packet format.
+
+    Handles common decoder prefixes:
+    - multimon-ng: ``AFSK1200: ...``
+    - direwolf tags: ``[0.4] ...``, ``[0L] ...``, etc.
+    """
+    if not line:
+        return ''
+
+    normalized = line.strip()
+    if normalized.startswith('AFSK1200:'):
+        normalized = normalized[9:].strip()
+
+    # Strip one or more leading bracket tags emitted by decoders.
+    # Examples: [0.4], [0L], [NONE]
+    normalized = re.sub(r'^(?:\[[^\]]+\]\s*)+', '', normalized)
+    return normalized
+
+
+def parse_aprs_packet(raw_packet: str) -> Optional[dict]:
     """Parse APRS packet into structured data.
 
     Supports all major APRS packet types:
@@ -123,13 +143,17 @@ def parse_aprs_packet(raw_packet: str) -> Optional[dict]:
     - Third-party traffic
     - Raw GPS/NMEA data
     - User-defined formats
-    """
-    try:
-        # Basic APRS packet format: CALLSIGN>PATH:DATA
-        # Example: N0CALL-9>APRS,TCPIP*:@092345z4903.50N/07201.75W_090/000g005t077
-
-        match = re.match(r'^([A-Z0-9-]+)>([^:]+):(.+)$', raw_packet, re.IGNORECASE)
-        if not match:
+    """
+    try:
+        raw_packet = normalize_aprs_output_line(raw_packet)
+        if not raw_packet:
+            return None
+
+        # Basic APRS packet format: CALLSIGN>PATH:DATA
+        # Example: N0CALL-9>APRS,TCPIP*:@092345z4903.50N/07201.75W_090/000g005t077
+
+        match = re.match(r'^([A-Z0-9-]+)>([^:]+):(.+)$', raw_packet, re.IGNORECASE)
+        if not match:
             return None
 
         callsign = match.group(1).upper()
@@ -1348,17 +1372,12 @@ def stream_aprs_output(rtl_process: subprocess.Popen, decoder_process: subproces
                     app_module.aprs_queue.put(meter_msg)
                 continue  # Audio level lines are not packets
 
-            # multimon-ng prefixes decoded packets with "AFSK1200: "
-            if line.startswith('AFSK1200:'):
-                line = line[9:].strip()
-
-            # direwolf often prefixes packets with "[0.4] " or similar audio level indicator
-            # Strip any leading bracket prefix like "[0.4] " before parsing
-            line = re.sub(r'^\[\d+\.\d+\]\s*', '', line)
-
-            # Skip non-packet lines (APRS format: CALL>PATH:DATA)
-            if '>' not in line or ':' not in line:
-                continue
+            # Normalize decoder prefixes (multimon/direwolf) before parsing.
+            line = normalize_aprs_output_line(line)
+
+            # Skip non-packet lines (APRS format: CALL>PATH:DATA)
+            if '>' not in line or ':' not in line:
+                continue
 
             packet = parse_aprs_packet(line)
             if packet:

tests/test_aprs_parser.py

@@ -0,0 +1,27 @@
+"""APRS packet parser regression tests."""
+
+from __future__ import annotations
+
+import pytest
+
+from routes.aprs import parse_aprs_packet
+
+
+_BASE_PACKET = "N0CALL-9>APRS,TCPIP*:@092345z4903.50N/07201.75W_090/000g005t077"
+
+
+@pytest.mark.parametrize(
+    "line",
+    [
+        _BASE_PACKET,
+        f"[0.4] {_BASE_PACKET}",
+        f"[0L] {_BASE_PACKET}",
+        f"AFSK1200: {_BASE_PACKET}",
+        f"AFSK1200: [0L] {_BASE_PACKET}",
+    ],
+)
+def test_parse_aprs_packet_accepts_decoder_prefix_variants(line: str) -> None:
+    packet = parse_aprs_packet(line)
+    assert packet is not None
+    assert packet["callsign"] == "N0CALL-9"
+    assert packet["type"] == "aprs"