Neue Funktion Schüler austragen statt aus Kurs löschen.

2026-08-15 23:38:42 +02:00
parent 52bb9c2c2f
commit da8d2bb1da
19 changed files with 473 additions and 114 deletions
@@ -0,0 +1,64 @@
+using LehrerApp.Core.Models;
+
+namespace LehrerApp.Core.Services;
+
+public enum SchoolYearPeriodKind { FullYear, H1, H2 }
+
+/// <summary>
+/// Gemeinsame Regeln für zeitlich begrenzte Gruppenzugehörigkeiten.
+/// Eintritt und Austritt gelten unabhängig vom gewählten Halbjahresmodus.
+/// </summary>
+public static class GroupMembershipService
+{
+    public static bool IsActiveOn(GroupMembership membership, DateOnly date)
+    {
+        if (membership.JoinedAt is { } joinedAt && date < joinedAt) return false;
+        if (membership.LeftAt is { } leftAt && date > leftAt) return false;
+
+        return membership.Period switch
+        {
+            MembershipPeriod.H1Only => IsFirstSemester(date),
+            MembershipPeriod.H2Only => !IsFirstSemester(date),
+            _ => true,
+        };
+    }
+
+    public static bool Overlaps(GroupMembership membership, DateOnly from, DateOnly to)
+    {
+        if (to < from) return false;
+
+        var effectiveFrom = membership.JoinedAt is { } joinedAt && joinedAt > from ? joinedAt : from;
+        var effectiveTo = membership.LeftAt is { } leftAt && leftAt < to ? leftAt : to;
+        if (effectiveTo < effectiveFrom) return false;
+
+        if (membership.Period is MembershipPeriod.FullYear or MembershipPeriod.Custom) return true;
+
+        for (var month = new DateOnly(effectiveFrom.Year, effectiveFrom.Month, 1);
+             month <= effectiveTo;
+             month = month.AddMonths(1))
+        {
+            if (membership.Period == MembershipPeriod.H1Only && IsFirstSemester(month)) return true;
+            if (membership.Period == MembershipPeriod.H2Only && !IsFirstSemester(month)) return true;
+        }
+
+        return false;
+    }
+
+    public static (DateOnly From, DateOnly To) SchoolYearPeriod(
+        string schoolYear, SchoolYearPeriodKind period)
+    {
+        var slash = schoolYear.IndexOf('/');
+        var startText = slash >= 0 ? schoolYear[..slash] : schoolYear;
+        if (!int.TryParse(startText, out var startYear))
+            throw new ArgumentException("Ungültiges Schuljahr.", nameof(schoolYear));
+
+        return period switch
+        {
+            SchoolYearPeriodKind.H1 => (new DateOnly(startYear, 8, 1), new DateOnly(startYear + 1, 1, 31)),
+            SchoolYearPeriodKind.H2 => (new DateOnly(startYear + 1, 2, 1), new DateOnly(startYear + 1, 7, 31)),
+            _ => (new DateOnly(startYear, 8, 1), new DateOnly(startYear + 1, 7, 31)),
+        };
+    }
+
+    private static bool IsFirstSemester(DateOnly date) => date.Month >= 8 || date.Month <= 1;
+}