chore: initialize public repository

app/services/calculations.py

@@ -0,0 +1,126 @@
+from collections import defaultdict
+from datetime import date, datetime, timedelta
+import re
+
+
+def parse_time_to_minutes(value: str) -> int:
+    if not re.fullmatch(r"([01]\d|2[0-3]):[0-5]\d", value):
+        raise ValueError("Uhrzeit muss im Format HH:MM sein")
+    try:
+        parsed = datetime.strptime(value, "%H:%M")
+    except ValueError as exc:
+        raise ValueError("Uhrzeit muss im Format HH:MM sein") from exc
+    return parsed.hour * 60 + parsed.minute
+
+
+def minutes_to_hhmm(minutes: int) -> str:
+    sign = "-" if minutes < 0 else ""
+    minutes_abs = abs(minutes)
+    hours = minutes_abs // 60
+    mins = minutes_abs % 60
+    return f"{sign}{hours:02d}:{mins:02d}"
+
+
+def validate_entry(start_minutes: int, end_minutes: int, break_minutes: int) -> None:
+    if end_minutes <= start_minutes:
+        raise ValueError("Arbeitsende muss nach Arbeitsbeginn liegen")
+
+    if break_minutes < 0:
+        raise ValueError("Pause darf nicht negativ sein")
+
+    gross_minutes = end_minutes - start_minutes
+    if break_minutes > gross_minutes:
+        raise ValueError("Pause darf nicht laenger als die Arbeitszeit sein")
+
+
+def required_break_minutes_for_span(work_span_minutes: int) -> int:
+    if work_span_minutes > 9 * 60:
+        return 45
+    if work_span_minutes > 6 * 60:
+        return 30
+    return 0
+
+
+def automatic_break_minutes(start_minutes: int, end_minutes: int) -> int:
+    if end_minutes <= start_minutes:
+        raise ValueError("Arbeitsende muss nach Arbeitsbeginn liegen")
+    return required_break_minutes_for_span(end_minutes - start_minutes)
+
+
+def automatic_break_minutes_for_net_minutes(net_minutes: int) -> int:
+    if net_minutes < 0:
+        raise ValueError("Nettoarbeitszeit darf nicht negativ sein")
+    if net_minutes > (9 * 60 - 45):
+        return 45
+    if net_minutes > (6 * 60 - 30):
+        return 30
+    return 0
+
+
+def compute_net_minutes(start_minutes: int, end_minutes: int, break_minutes: int) -> int:
+    validate_entry(start_minutes, end_minutes, break_minutes)
+    return (end_minutes - start_minutes) - break_minutes
+
+
+def iso_week_bounds(day: date) -> tuple[date, date]:
+    week_start = day - timedelta(days=day.weekday())
+    week_end = week_start + timedelta(days=6)
+    return week_start, week_end
+
+
+def daterange(start: date, end: date):
+    current = start
+    while current <= end:
+        yield current
+        current += timedelta(days=1)
+
+
+def aggregate_week(entries: list, week_start: date, weekly_target_minutes: int) -> dict:
+    week_end = week_start + timedelta(days=6)
+    entries_by_date = {entry.date: entry for entry in entries}
+
+    days = []
+    weekly_ist = 0
+    for day in daterange(week_start, week_end):
+        entry = entries_by_date.get(day)
+        if entry is None:
+            days.append({"date": day, "entry": None, "net_minutes": 0})
+            continue
+
+        net_minutes = compute_net_minutes(entry.start_minutes, entry.end_minutes, entry.break_minutes)
+        weekly_ist += net_minutes
+        days.append({"date": day, "entry": entry, "net_minutes": net_minutes})
+
+    weekly_delta = weekly_ist - weekly_target_minutes
+
+    return {
+        "week_start": week_start,
+        "week_end": week_end,
+        "days": days,
+        "weekly_ist": weekly_ist,
+        "weekly_soll": weekly_target_minutes,
+        "weekly_delta": weekly_delta,
+    }
+
+
+def cumulative_delta(entries: list, selected_week_start: date, weekly_target_minutes: int) -> int:
+    if not entries:
+        return 0
+
+    earliest_entry_date = min(entry.date for entry in entries)
+    current_week_start = earliest_entry_date - timedelta(days=earliest_entry_date.weekday())
+
+    net_by_week_start = defaultdict(int)
+    for entry in entries:
+        week_start, _ = iso_week_bounds(entry.date)
+        net_by_week_start[week_start] += compute_net_minutes(
+            entry.start_minutes, entry.end_minutes, entry.break_minutes
+        )
+
+    running = 0
+    while current_week_start <= selected_week_start:
+        weekly_ist = net_by_week_start[current_week_start]
+        running += weekly_ist - weekly_target_minutes
+        current_week_start += timedelta(days=7)
+
+    return running