feat: extract date & time from tags

Signed-off-by: Konstantin Fickel <mail@konstantinfickel.de>

src/streamer/localize/extract_datetime.py

@@ -1,9 +1,9 @@
-from datetime import datetime
-import re
 import os
+import re
+from datetime import date, datetime, time
 
 
-def extract_date_from_file_name(file_name: str) -> datetime | None:
+def extract_datetime_from_file_name(file_name: str) -> datetime | None:
     FILE_NAME_REGEX = r"^(?P<date>\d{8})(?:-(?P<time>\d{4,6}))?.+.md$"
     base_name = os.path.basename(file_name)
     match = re.match(FILE_NAME_REGEX, base_name)
@@ -17,4 +17,76 @@ def extract_date_from_file_name(file_name: str) -> datetime | None:
     return None
 
 
-__all__ = ["extract_date_from_file_name"]
+def extract_datetime_from_marker(marker: str) -> datetime | None:
+    """
+    Extract a datetime from a marker string in the exact format: YYYYMMDDHHMMSS.
+
+    Returns:
+        Parsed datetime if the format is fulfilled and values are valid, else None.
+    """
+    if not re.fullmatch(r"\d{14}", marker or ""):
+        return None
+    try:
+        return datetime.strptime(marker, "%Y%m%d%H%M%S")
+    except ValueError:
+        return None
+
+
+def extract_date_from_marker(marker: str) -> date | None:
+    """
+    Extract a date from a marker string in the exact format: YYYYMMDD.
+
+    Returns:
+        Parsed date if the format is fulfilled and values are valid, else None.
+    """
+    if not re.fullmatch(r"\d{8}", marker or ""):
+        return None
+    try:
+        return datetime.strptime(marker, "%Y%m%d").date()
+    except ValueError:
+        return None
+
+
+def extract_time_from_marker(marker: str) -> time | None:  # noqa: F821
+    """
+    Extract a time from a marker string in the exact format: HHMMSS.
+
+    Returns:
+        Parsed time if the format is fulfilled and values are valid, else None.
+    """
+    if not re.fullmatch(r"\d{6}", marker or ""):
+        return None
+    try:
+        return datetime.strptime(marker, "%H%M%S").time()
+    except ValueError:
+        return None
+
+
+def extract_datetime_from_marker_list(markers: list[str], inherited_datetime: datetime):
+    shard_time: time | None = None
+    shard_date: date | None = None
+
+    for marker in markers[::-1]:
+        if parsed_time := extract_time_from_marker(marker):
+            shard_time = parsed_time
+        if parsed_date := extract_date_from_marker(marker):
+            shard_date = parsed_date
+        if parsed_datetime := extract_datetime_from_marker(marker):
+            shard_date = parsed_datetime.date()
+            shard_time = parsed_datetime.time()
+
+    if shard_date and not shard_time:
+        return datetime.combine(shard_date, time(0, 0, 0))
+
+    return datetime.combine(
+        shard_date or inherited_datetime.date(), shard_time or inherited_datetime.time()
+    )
+
+
+__all__ = [
+    "extract_datetime_from_file_name",
+    "extract_datetime_from_marker",
+    "extract_date_from_marker",
+    "extract_time_from_marker",
+    "extract_datetime_from_marker_list",
+]