bugfix ASCReader (#1257)

Author: zariiii9003

can/io/asc.py

@@ -34,8 +34,6 @@ class ASCReader(MessageReader):
 
     file: TextIO
 
-    FORMAT_START_OF_FILE_DATE = "%a %b %d %I:%M:%S.%f %p %Y"
-
     def __init__(
         self,
         file: Union[StringPathLike, TextIO],
@@ -60,51 +58,95 @@ def __init__(
         self.base = base
         self._converted_base = self._check_base(base)
         self.relative_timestamp = relative_timestamp
-        self.date = None
+        self.date: Optional[str] = None
+        self.start_time = 0.0
         # TODO - what is this used for? The ASC Writer only prints `absolute`
-        self.timestamps_format = None
-        self.internal_events_logged = None
+        self.timestamps_format: Optional[str] = None
+        self.internal_events_logged = False
 
-    def _extract_header(self):
+    def _extract_header(self) -> None:
         for line in self.file:
             line = line.strip()
-            lower_case = line.lower()
-            if lower_case.startswith("date"):
-                self.date = line[5:]
-            elif lower_case.startswith("base"):
-                try:
-                    _, base, _, timestamp_format = line.split()
-                except ValueError as exception:
-                    raise Exception(
-                        f"Unsupported header string format: {line}"
-                    ) from exception
+
+            datetime_match = re.match(
+                r"date\s+\w+\s+(?P<datetime_string>.+)", line, re.IGNORECASE
+            )
+            base_match = re.match(
+                r"base\s+(?P<base>hex|dec)(?:\s+timestamps\s+"
+                r"(?P<timestamp_format>absolute|relative))?",
+                line,
+                re.IGNORECASE,
+            )
+            comment_match = re.match(r"//.*", line)
+            events_match = re.match(
+                r"(?P<no_events>no)?\s*internal\s+events\s+logged", line, re.IGNORECASE
+            )
+
+            if datetime_match:
+                self.date = datetime_match.group("datetime_string")
+                self.start_time = (
+                    0.0
+                    if self.relative_timestamp
+                    else self._datetime_to_timestamp(self.date)
+                )
+                continue
+
+            elif base_match:
+                base = base_match.group("base")
+                timestamp_format = base_match.group("timestamp_format")
                 self.base = base
                 self._converted_base = self._check_base(self.base)
-                self.timestamps_format = timestamp_format
-            elif lower_case.endswith("internal events logged"):
-                self.internal_events_logged = not lower_case.startswith("no")
-            elif lower_case.startswith("//"):
-                # ignore comments
+                self.timestamps_format = timestamp_format or "absolute"
                 continue
-            # grab absolute timestamp
-            elif lower_case.startswith("begin triggerblock"):
-                if self.relative_timestamp:
-                    self.start_time = 0.0
-                else:
-                    try:
-                        _, _, start_time = lower_case.split(None, 2)
-                        start_time = datetime.strptime(
-                            start_time, self.FORMAT_START_OF_FILE_DATE
-                        ).timestamp()
-                    except (ValueError, OSError):
-                        # `OSError` to handle non-POSIX capable timestamps
-                        start_time = 0.0
-                    self.start_time = start_time
-                # Currently the last line in the header which is parsed
+
+            elif comment_match:
+                continue
+
+            elif events_match:
+                self.internal_events_logged = events_match.group("no_events") is None
                 break
+
             else:
                 break
 
+    @staticmethod
+    def _datetime_to_timestamp(datetime_string: str) -> float:
+        # ugly locale independent solution
+        month_map = {
+            "Jan": 1,
+            "Feb": 2,
+            "Mar": 3,
+            "Apr": 4,
+            "May": 5,
+            "Jun": 6,
+            "Jul": 7,
+            "Aug": 8,
+            "Sep": 9,
+            "Oct": 10,
+            "Nov": 11,
+            "Dec": 12,
+            "Mär": 3,
+            "Mai": 5,
+            "Okt": 10,
+            "Dez": 12,
+        }
+        for name, number in month_map.items():
+            datetime_string = datetime_string.replace(name, str(number).zfill(2))
+
+        datetime_formats = (
+            "%m %d %I:%M:%S.%f %p %Y",
+            "%m %d %I:%M:%S %p %Y",
+            "%m %d %H:%M:%S.%f %Y",
+            "%m %d %H:%M:%S %Y",
+        )
+        for format_str in datetime_formats:
+            try:
+                return datetime.strptime(datetime_string, format_str).timestamp()
+            except ValueError:
+                continue
+
+        raise ValueError(f"Incompatible datetime string {datetime_string}")
+
     def _extract_can_id(self, str_can_id: str, msg_kwargs: Dict[str, Any]) -> None:
         if str_can_id[-1:].lower() == "x":
             msg_kwargs["is_extended_id"] = True
@@ -219,6 +261,20 @@ def __iter__(self) -> Generator[Message, None, None]:
         for line in self.file:
             line = line.strip()
 
+            trigger_match = re.match(
+                r"begin\s+triggerblock\s+\w+\s+(?P<datetime_string>.+)",
+                line,
+                re.IGNORECASE,
+            )
+            if trigger_match:
+                datetime_str = trigger_match.group("datetime_string")
+                self.start_time = (
+                    0.0
+                    if self.relative_timestamp
+                    else self._datetime_to_timestamp(datetime_str)
+                )
+                continue
+
             if not re.match(
                 r"\d+\.\d+\s+(\d+\s+(\w+\s+(Tx|Rx)|ErrorFrame)|CANFD)",
                 line,