feat: add scriptable housekeeper rule engine

src/ccma/rules/scripts/membership_anniversary.py

@@ -0,0 +1,50 @@
+from ccma.domain.dates import DateValidationError, parse_iso_date
+from ccma.rules.api import RuleContext, task
+from ccma.rules.scripts._shared import relative_title
+
+RULE_ID = "membership-anniversary"
+ORDER = 30
+
+
+def evaluate(context: RuleContext):
+    member = context.member
+    try:
+        started_at = parse_iso_date(member.membership_started_at, "Mitglied seit")
+    except DateValidationError:
+        return []
+    if not started_at:
+        return []
+    actions = []
+    for interval in context.settings.anniversary_intervals:
+        try:
+            target = interval.target_date(started_at)
+        except (OverflowError, ValueError):
+            continue
+        delta = (target - context.today).days
+        if (
+            delta > context.settings.anniversary_days_before
+            or delta < -context.settings.anniversary_days_after
+        ):
+            continue
+        occasion = _anniversary_name(interval)
+        actions.append(
+            task(
+                rule_id=RULE_ID,
+                member=member,
+                key_suffix=f"{interval.value}{interval.unit}",
+                severity="info",
+                title=relative_title(member.display_name, delta, occasion),
+                detail=f"Mitglied seit {started_at:%d.%m.%Y}.",
+                due_date=target,
+                code="membership_anniversary",
+            )
+        )
+    return actions
+
+
+def _anniversary_name(interval):
+    if interval.unit == "D":
+        return f"{interval.value}-Tage-Mitgliedsjubiläum"
+    if interval.unit == "M":
+        return f"{interval.value}-Monats-Mitgliedsjubiläum"
+    return f"{interval.value}-jähriges Mitgliedsjubiläum"