Initial commit for Start9 packaging

workout-planner/lib/utils.ts

@@ -0,0 +1,74 @@
+import { ClassValue, clsx } from "clsx";
+import { twMerge } from "tailwind-merge";
+import { SetLog } from "@prisma/client";
+
+/**
+ * Merge classnames using clsx and tailwind-merge
+ */
+export function cn(...inputs: ClassValue[]): string {
+  return twMerge(clsx(inputs));
+}
+
+/**
+ * Format a date to a readable string (e.g., "Feb 16, 2026")
+ */
+export function formatDate(date: Date | string): string {
+  const dateObj = typeof date === "string" ? new Date(date) : date;
+  return dateObj.toLocaleDateString("en-US", {
+    year: "numeric",
+    month: "short",
+    day: "numeric",
+  });
+}
+
+/**
+ * Format weight with unit (e.g., "150 lbs")
+ */
+export function formatWeight(weight: number, unit: string): string {
+  return `${weight} ${unit}`;
+}
+
+/**
+ * Calculate total volume (sets * reps * weight)
+ */
+export function calculateVolume(sets: SetLog[]): number {
+  return sets.reduce((total, set) => {
+    const reps = set.reps || 0;
+    const weight = set.weight || 0;
+    return total + reps * weight;
+  }, 0);
+}
+
+/**
+ * Calculate estimated 1-rep max using Epley formula
+ * 1RM = weight * (1 + reps / 30)
+ */
+export function calculateE1RM(weight: number, reps: number): number {
+  if (reps === 1) return weight;
+  return Math.round(weight * (1 + reps / 30) * 100) / 100;
+}
+
+/**
+ * Get the start and end of a week for a given date
+ */
+export function getWeekRange(date: Date): { start: Date; end: Date } {
+  const d = new Date(date);
+  const day = d.getDay();
+  const diff = d.getDate() - day + (day === 0 ? -6 : 1); // Adjust to Monday
+
+  const start = new Date(d.setDate(diff));
+  start.setHours(0, 0, 0, 0);
+
+  const end = new Date(start);
+  end.setDate(end.getDate() + 6);
+  end.setHours(23, 59, 59, 999);
+
+  return { start, end };
+}
+
+/**
+ * Generate a random UUID
+ */
+export function generateId(): string {
+  return crypto.randomUUID();
+}