Initial commit

backend/app/utils/time_utils.py

@@ -0,0 +1,64 @@
+from datetime import datetime, time, timedelta
+from typing import List
+
+
+def get_day_night_splits(
+    session_start: datetime,
+    session_end: datetime,
+    day_start_boundary: time,
+    day_end_boundary: time,
+) -> List[dict]:
+    """
+    Splits a sleep session into day and night segments based on boundaries.
+    A segment is defined by [segment_start, segment_end] and its type (day/night).
+    """
+    segments = []
+    points = [session_start, session_end]
+
+    for offset in [0, 1]:
+        base_date = session_start.date() + timedelta(days=offset)
+        try:
+            b1 = datetime.combine(base_date, day_start_boundary).replace(
+                tzinfo=session_start.tzinfo
+            )
+            b2 = datetime.combine(base_date, day_end_boundary).replace(
+                tzinfo=session_start.tzinfo
+            )
+            if session_start < b1 < session_end:
+                points.append(b1)
+            if session_start < b2 < session_end:
+                points.append(b2)
+        except (ValueError, AttributeError):
+            continue
+
+    sorted_points = sorted(list(set(points)))
+
+    for i in range(len(sorted_points) - 1):
+        seg_start = sorted_points[i]
+        seg_end = sorted_points[i + 1]
+        midpoint = seg_start + (seg_end - seg_start) / 2
+        is_day = day_start_pattern(
+            midpoint.time(), day_start_boundary, day_end_boundary
+        )
+        segments.append(
+            {"start": seg_start, "end": seg_end, "type": "day" if is_day else "night"}
+        )
+
+    return segments
+
+
+def day_start_pattern(current_time: time, start: time, end: time) -> bool:
+    if start <= end:
+        return start <= current_time < end
+    else:  # Spans midnight
+        return current_time >= start or current_time < end
+
+
+from datetime import datetime, time, timedelta
+
+
+def minutes_after(dt: datetime, reference: time) -> float:
+    """Returns minutes after a reference time."""
+    ref_delta = timedelta(hours=reference.hour, minutes=reference.minute)
+    dt_delta = timedelta(hours=dt.hour, minutes=dt.minute)
+    return (dt_delta - ref_delta).total_seconds() / 60.0