Refactor codebase

app/routes/api.py

@@ -1,9 +1,12 @@
-from flask import Blueprint, jsonify, request, session
-from app import SYDNEY_TZ
-from app.auth import login_required
-from app.db import query, query_one
+from collections import OrderedDict
 from datetime import datetime, timezone
 
+from flask import Blueprint, jsonify, request, session
+from app.config import SYDNEY_TZ
+from app.auth import login_required, privacy_guard
+from app.db import query
+from app.utils import calculate_weight_change
+
 bp = Blueprint("api", __name__, url_prefix="/api")
 
 # Distinct hues for up to 12 users; cycles if more
@@ -58,7 +61,6 @@ def progress_over_time():
     """, params)
 
     # Group rows by user
-    from collections import OrderedDict
     users_map = OrderedDict()
     for r in rows:
         uid = r["user_id"]
@@ -90,7 +92,6 @@ def progress_over_time():
         points = entry["data"]
         best_fit = {"slope": 0, "intercept": 0}
         if len(points) >= 2:
-            # Convert dates to day offsets from first point
             base = datetime.strptime(points[0]["date"], "%Y-%m-%d")
             xs = [(datetime.strptime(p["date"], "%Y-%m-%d") - base).days for p in points]
             ys = [p["weight"] for p in points]
@@ -118,14 +119,9 @@ def progress_over_time():
 
 @bp.route("/chart-data/<int:user_id>")
 @login_required
+@privacy_guard
 def chart_data(user_id):
     """Return weight & BMI over time for Chart.js."""
-    # Privacy guard: don't expose private user data to others
-    if user_id != session.get("user_id"):
-        target = query_one("SELECT is_private FROM users WHERE id = %s", (user_id,))
-        if target and target["is_private"]:
-            return jsonify({"labels": [], "weights": [], "bmis": []})
-
     checkins = query(
         """SELECT weight_kg, bmi, checked_in_at
            FROM checkins WHERE user_id = %s
@@ -169,15 +165,10 @@ def comparison():
     for u in users:
         start_w = float(u["starting_weight_kg"] or u["first_weight"] or 0)
         current_w = float(u["current_weight"] or start_w)
-        if start_w > 0:
-            lost = start_w - current_w
-            pct = round((lost / start_w) * 100, 1)
-        else:
-            lost = 0
-            pct = 0
+        lost, pct = calculate_weight_change(start_w, current_w)
         names.append(u["display_name"] or u["username"])
         pct_lost.append(pct)
-        kg_lost.append(round(lost, 1))
+        kg_lost.append(lost)
 
     return jsonify({
         "names": names,
@@ -188,14 +179,9 @@ def comparison():
 
 @bp.route("/weekly-change/<int:user_id>")
 @login_required
+@privacy_guard
 def weekly_change(user_id):
     """Return weekly weight changes for bar chart."""
-    # Privacy guard: don't expose private user data to others
-    if user_id != session.get("user_id"):
-        target = query_one("SELECT is_private FROM users WHERE id = %s", (user_id,))
-        if target and target["is_private"]:
-            return jsonify({"labels": [], "changes": []})
-
     checkins = query(
         """SELECT weight_kg, checked_in_at
            FROM checkins WHERE user_id = %s