cleanup framing/deframing of beesure

[loctrkd.git] / loctrkd / beesure.py

diff --git a/loctrkd/beesure.py b/loctrkd/beesure.py
index 9b0255c2401a7d65f817afcb7363d9190122f073..a0d802bb1df306e888e87218028241210ffd5695 100755 (executable)
--- a/loctrkd/beesure.py
+++ b/loctrkd/beesure.py
@@ -24,6 +24,7 @@ from typing import (
 __all__ = (
     "Stream",
     "class_by_prefix",
+    "enframe",
     "inline_response",
     "parse_message",
     "probe_buffer",
@@ -67,11 +68,6 @@ class Stream:
         self.imei: Optional[str] = None
         self.datalen: int = 0
 
-    @staticmethod
-    def enframe(buffer: bytes, imei: Optional[str] = None) -> bytes:
-        assert imei is not None and len(imei) == 10
-        return f"[LT*{imei:10s}*{len(buffer):04X}*".encode() + buffer + b"]"
-
     def recv(self, segment: bytes) -> List[Union[bytes, str]]:
         """
         Process next segment of the stream. Return successfully deframed
@@ -96,12 +92,13 @@ class Stream:
                     )
                     self.buffer = self.buffer[toskip:]
                     # From this point, buffer starts with a packet header
-                if self.imei is not None and self.imei != imei:
+                if self.imei is None:
+                    self.imei = imei
+                if self.imei != imei:
                     msgs.append(
                         f"Packet's imei {imei} mismatches"
-                        f" previous value {self.imei}"
+                        f" previous value {self.imei}, old value kept"
                     )
-                self.imei = imei
                 self.datalen = datalen
             if len(self.buffer) < self.datalen + 21:  # Incomplete packet
                 break
@@ -125,6 +122,13 @@ class Stream:
         return ret
 
 
+def enframe(buffer: bytes, imei: Optional[str] = None) -> bytes:
+    assert imei is not None and len(imei) == 10
+    off, vid, _, dlen = _framestart(buffer)
+    assert off == 0
+    return f"[{vid:2s}*{imei:10s}*{dlen:04X}*".encode() + buffer[20:]
+
+
 ### Parser/Constructor ###
 
 
@@ -289,7 +293,8 @@ class BeeSurePkt(metaclass=MetaPkt):
 
     @property
     def packed(self) -> bytes:
-        return self.encode().encode()  # first is object's, second str's
+        buffer = self.encode().encode()
+        return f"[LT*0000000000*{len(buffer):04X}*".encode() + buffer + b"]"
 
 
 class UNKNOWN(BeeSurePkt):
@@ -411,7 +416,7 @@ def proto_by_name(name: str) -> str:
 
 
 def proto_of_message(packet: bytes) -> str:
-    return PROTO_PREFIX + packet.split(b",")[0].decode()
+    return PROTO_PREFIX + packet[20:-1].split(b",")[0].decode()
 
 
 def imei_from_packet(packet: bytes) -> Optional[str]: