Initial commit v1

lib/handicap.ts

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+/**
+ * Returns the number of handicap strokes a player receives on a given hole.
+ * WHS allocation: distribute course_handicap strokes across holes by stroke index.
+ */
+export function strokesReceived(
+  courseHandicap: number,
+  strokeIndex: number,
+  holesCount: number,
+): number {
+  if (courseHandicap <= 0) return 0
+  const fullStrokes = Math.floor(courseHandicap / holesCount)
+  const extraStrokes = courseHandicap % holesCount
+  return fullStrokes + (strokeIndex <= extraStrokes ? 1 : 0)
+}
+
+/**
+ * Net score on a hole (gross strokes minus strokes received).
+ */
+export function netStrokes(
+  gross: number,
+  courseHandicap: number,
+  strokeIndex: number,
+  holesCount: number,
+): number {
+  return gross - strokesReceived(courseHandicap, strokeIndex, holesCount)
+}
+
+/**
+ * Score vs par as a display string: "−2", "E", "+1", "+3"
+ */
+export function formatVsPar(diff: number): string {
+  if (diff === 0) return 'E'
+  return diff > 0 ? `+${diff}` : `${diff}`
+}
+
+/**
+ * CSS class for a gross score vs par (standard golf scorecard conventions).
+ */
+export function scoreColorClass(vsPar: number | null): string {
+  if (vsPar === null) return ''
+  if (vsPar <= -2) return 'bg-yellow-300 text-yellow-900 rounded-full'   // Eagle or better
+  if (vsPar === -1) return 'bg-red-500 text-white rounded-full'           // Birdie
+  if (vsPar === 0) return ''                                               // Par
+  if (vsPar === 1) return 'border border-border rounded-sm'               // Bogey
+  if (vsPar === 2) return 'border-2 border-border rounded-sm'             // Double
+  return 'border-2 border-destructive rounded-sm text-destructive'        // Triple+
+}