implement ping/pong dataclasses

vban_cmd/packet/headers.py

@@ -8,11 +8,15 @@ VBAN_PROTOCOL_SERVICE = 0x60
 
 VBAN_SERVICE_RTPACKETREGISTER = 32
 VBAN_SERVICE_RTPACKET = 33
+VBAN_SERVICE_PING = 0
+VBAN_SERVICE_PONG = 0  # PONG uses same service type as PING
 VBAN_SERVICE_MASK = 0xE0
 VBAN_PROTOCOL_MASK = 0xE0
 VBAN_SERVICE_REQUESTREPLY = 0x02
 VBAN_SERVICE_FNCT_REPLY = 0x02
 
+PINGPONG_PACKET_SIZE = 704  # Size of the PING/PONG header + payload in bytes
+
 MAX_PACKET_SIZE = 1436
 HEADER_SIZE = 4 + 1 + 1 + 1 + 1 + 16
 
@@ -207,6 +211,92 @@ class VbanMatrixResponseHeader:
         return header, payload
 
 
+@dataclass
+class VbanPingHeader:
+    """Represents the header of a PING packet"""
+
+    name: str = 'PING0'
+    format_sr: int = VBAN_PROTOCOL_SERVICE
+    format_nbs: int = 0
+    format_nbc: int = VBAN_SERVICE_PING
+    format_bit: int = 0
+    framecounter: int = 0
+
+    @property
+    def vban(self) -> bytes:
+        return b'VBAN'
+
+    @property
+    def streamname(self) -> bytes:
+        return self.name.encode('ascii')[:16].ljust(16, b'\x00')
+
+    @classmethod
+    def to_bytes(cls, framecounter: int = 0) -> bytes:
+        """Creates the PING header bytes only."""
+        header = cls(framecounter=framecounter)
+
+        data = bytearray()
+        data.extend(header.vban)
+        data.extend(header.format_sr.to_bytes(1, 'little'))
+        data.extend(header.format_nbs.to_bytes(1, 'little'))
+        data.extend(header.format_nbc.to_bytes(1, 'little'))
+        data.extend(header.format_bit.to_bytes(1, 'little'))
+        data.extend(header.streamname)
+        data.extend(header.framecounter.to_bytes(4, 'little'))
+        return bytes(data)
+
+
+@dataclass
+class VbanPongHeader:
+    """Represents the header of a PONG response packet"""
+
+    name: str = 'PING0'
+    format_sr: int = VBAN_PROTOCOL_SERVICE
+    format_nbs: int = 0
+    format_nbc: int = VBAN_SERVICE_PONG
+    format_bit: int = 0
+    framecounter: int = 0
+
+    @property
+    def vban(self) -> bytes:
+        return b'VBAN'
+
+    @property
+    def streamname(self) -> bytes:
+        return self.name.encode('ascii')[:16].ljust(16, b'\x00')
+
+    @classmethod
+    def from_bytes(cls, data: bytes):
+        """Parse a PONG response packet from bytes."""
+        parsed = _parse_vban_service_header(data)
+
+        # PONG responses use the same service type as PING (0x00)
+        # and are identified by having payload data
+        if parsed['format_nbc'] != VBAN_SERVICE_PONG:
+            raise ValueError(f'Not a PONG response packet: {parsed["format_nbc"]:02x}')
+
+        return cls(**parsed)
+
+    @classmethod
+    def is_pong_response(cls, data: bytes) -> bool:
+        """Check if packet is a PONG response by analyzing the actual response format."""
+        try:
+            parsed = _parse_vban_service_header(data)
+
+            # Validate this is a service protocol packet with PING/PONG service type
+            if parsed['format_nbc'] != VBAN_SERVICE_PONG:
+                return False
+
+            if parsed['name'] not in ['PING0', 'VBAN Service']:
+                return False
+
+            # PONG should have payload data (same size as PING)
+            return len(data) >= PINGPONG_PACKET_SIZE
+
+        except (ValueError, Exception):
+            return False
+
+
 @dataclass
 class VbanRequestHeader:
     """Represents the header of a request packet"""
@@ -238,7 +328,7 @@ class VbanRequestHeader:
 
     @property
     def streamname(self) -> bytes:
-        return self.name.encode() + bytes(16 - len(self.name))
+        return self.name.encode()[:16].ljust(16, b'\x00')
 
     @classmethod
     def to_bytes(