feat: initial project scaffold with Watch companion app

src/features/workout-builder/hooks/useWorkoutBuilder.ts

@@ -0,0 +1,83 @@
+import { useState, useCallback } from "react";
+import type { WorkoutSet, StrokeType, RestType } from "@types/workout";
+import { saveWorkout, saveTemplate } from "@db/operations";
+
+const DEFAULT_SET: WorkoutSet = {
+  stroke: "Freestyle",
+  distancePerRep: 200,
+  repCount: 1,
+  restType: "fixed_rest",
+  restDuration: 30,
+};
+
+export function useWorkoutBuilder(initialSets?: WorkoutSet[]) {
+  const [sets, setSets] = useState<WorkoutSet[]>(initialSets ?? [{ ...DEFAULT_SET }]);
+  const [workoutName, setWorkoutName] = useState("");
+  const [isSaving, setIsSaving] = useState(false);
+
+  const addSet = useCallback(() => {
+    setSets((prev) => [...prev, { ...DEFAULT_SET }]);
+  }, []);
+
+  const updateSet = useCallback((index: number, updates: Partial<WorkoutSet>) => {
+    setSets((prev) => prev.map((s, i) => (i === index ? { ...s, ...updates } : s)));
+  }, []);
+
+  const removeSet = useCallback((index: number) => {
+    setSets((prev) => prev.filter((_, i) => i !== index));
+  }, []);
+
+  const totalDistance = sets.reduce((acc, s) => acc + s.distancePerRep * s.repCount, 0);
+
+  const save = useCallback(
+    async (poolLength: number, templateId?: string) => {
+      setIsSaving(true);
+      try {
+        const name = workoutName.trim() || `Workout ${new Date().toLocaleDateString()}`;
+        const id = await saveWorkout(name, poolLength, sets, templateId);
+        return id;
+      } finally {
+        setIsSaving(false);
+      }
+    },
+    [workoutName, sets]
+  );
+
+  const saveAsTemplate = useCallback(
+    async (templateName: string, poolLength: number) => {
+      setIsSaving(true);
+      try {
+        const id = await saveTemplate(templateName, poolLength, sets);
+        return id;
+      } finally {
+        setIsSaving(false);
+      }
+    },
+    [sets]
+  );
+
+  const loadTemplate = useCallback((templateSets: WorkoutSet[], name?: string) => {
+    setSets(templateSets);
+    if (name) setWorkoutName(name);
+  }, []);
+
+  const reset = useCallback(() => {
+    setSets([{ ...DEFAULT_SET }]);
+    setWorkoutName("");
+  }, []);
+
+  return {
+    sets,
+    workoutName,
+    setWorkoutName,
+    totalDistance,
+    isSaving,
+    addSet,
+    updateSet,
+    removeSet,
+    save,
+    saveAsTemplate,
+    loadTemplate,
+    reset,
+  };
+}