Rename project, part 2 (#42)

Reviewed-on: #42

common/time.py

@@ -0,0 +1,63 @@
+import re
+from datetime import datetime, timedelta
+from zoneinfo import ZoneInfo
+
+from django.conf import settings
+
+
+def now() -> datetime:
+    return datetime.now(ZoneInfo(settings.TIME_ZONE))
+
+
+def _safe_timedelta(duration: timedelta | int | None):
+    if duration == None:
+        return timedelta(0)
+    elif isinstance(duration, int):
+        return timedelta(seconds=duration)
+    elif isinstance(duration, timedelta):
+        return duration
+
+
+def format_duration(
+    duration: timedelta | int | None, format_string: str = "%H hours"
+) -> str:
+    """
+    Format timedelta into the specified format_string.
+    Valid format variables:
+    - %H hours
+    - %m minutes
+    - %s seconds
+    - %r total seconds
+    Values don't change into higher units if those units are missing
+    from the formatting string. For example:
+    - 61 seconds as "%s" = 61 seconds
+    - 61 seconds as "%m %s" = 1 minutes 1 seconds"
+    """
+    minute_seconds = 60
+    hour_seconds = 60 * minute_seconds
+    day_seconds = 24 * hour_seconds
+    duration = _safe_timedelta(duration)
+    # we don't need float
+    seconds_total = int(duration.total_seconds())
+    # timestamps where end is before start
+    if seconds_total < 0:
+        seconds_total = 0
+    days = hours = minutes = seconds = 0
+    remainder = seconds = seconds_total
+    if "%d" in format_string:
+        days, remainder = divmod(seconds_total, day_seconds)
+    if "%H" in format_string:
+        hours, remainder = divmod(remainder, hour_seconds)
+    if "%m" in format_string:
+        minutes, seconds = divmod(remainder, minute_seconds)
+    literals = {
+        "%d": str(days),
+        "%H": str(hours),
+        "%m": str(minutes),
+        "%s": str(seconds),
+        "%r": str(seconds_total),
+    }
+    formatted_string = format_string
+    for pattern, replacement in literals.items():
+        formatted_string = re.sub(pattern, replacement, formatted_string)
+    return formatted_string