feat: WM2026 Tippspiel - Initial Backend + Frontend

backend/src/services/pointsService.ts

@@ -0,0 +1,87 @@
+import { PointsCalculation, POINTS } from '../types';
+
+interface Score {
+  home: number;
+  away: number;
+}
+
+/**
+ * Berechnet die Punkte für einen Tipp.
+ *
+ * Punkteregeln:
+ * - Exaktes Ergebnis:   3 Punkte
+ * - Richtige Tendenz:   1 Punkt (Sieg/Unentschieden/Niederlage korrekt)
+ * - Falsche Tendenz:    0 Punkte
+ *
+ * @param tip - Der abgegebene Tipp
+ * @param actual - Das tatsächliche Ergebnis
+ */
+export const calculatePoints = (
+  tip: Score,
+  actual: Score
+): PointsCalculation => {
+  // Exaktes Ergebnis
+  if (tip.home === actual.home && tip.away === actual.away) {
+    return { result: 'exact', points: POINTS.EXACT };
+  }
+
+  // Tendenz prüfen (Sieg Heim / Unentschieden / Sieg Auswärts)
+  const tipTendency = getTendency(tip.home, tip.away);
+  const actualTendency = getTendency(actual.home, actual.away);
+
+  if (tipTendency === actualTendency) {
+    return { result: 'tendency', points: POINTS.TENDENCY };
+  }
+
+  return { result: 'wrong', points: POINTS.WRONG };
+};
+
+type Tendency = 'home' | 'draw' | 'away';
+
+const getTendency = (home: number, away: number): Tendency => {
+  if (home > away) return 'home';
+  if (home < away) return 'away';
+  return 'draw';
+};
+
+/**
+ * Berechnet Punkte für die gesamte Tipp-History eines Users.
+ * Nützlich für Statistiken.
+ */
+export const calculateUserStats = (
+  tips: Array<{
+    tipHome: number;
+    tipAway: number;
+    actualHome: number | null;
+    actualAway: number | null;
+    points: number | null;
+  }>
+) => {
+  const evaluated = tips.filter(
+    (t) => t.actualHome !== null && t.actualAway !== null
+  );
+
+  const exactCount = evaluated.filter((t) => t.points === POINTS.EXACT).length;
+  const tendencyCount = evaluated.filter(
+    (t) => t.points === POINTS.TENDENCY
+  ).length;
+  const wrongCount = evaluated.filter((t) => t.points === POINTS.WRONG).length;
+  const totalPoints = evaluated.reduce((sum, t) => sum + (t.points ?? 0), 0);
+
+  const accuracy =
+    evaluated.length > 0
+      ? Math.round(
+          ((exactCount + tendencyCount) / evaluated.length) * 100
+        )
+      : 0;
+
+  return {
+    totalPoints,
+    exactCount,
+    tendencyCount,
+    wrongCount,
+    accuracy,
+    evaluatedCount: evaluated.length,
+    pendingCount: tips.length - evaluated.length,
+  };
+};