Refactor codebase

app/__init__.py

@@ -1,10 +1,7 @@
-from datetime import datetime, timezone, timedelta
 from flask import Flask
-from app.config import Config
+from app.config import Config, SYDNEY_TZ
 from app.db import init_db, close_db
 
-SYDNEY_TZ = timezone(timedelta(hours=11))
-
 
 def create_app():
     app = Flask(__name__)
@@ -17,12 +14,17 @@ def create_app():
     # Jinja2 filter: convert UTC to Sydney time
     @app.template_filter('sydney')
     def sydney_time_filter(dt, fmt='%d %b %Y, %H:%M'):
+        from datetime import timezone
         if dt is None:
             return ''
         if dt.tzinfo is None:
             dt = dt.replace(tzinfo=timezone.utc)
         return dt.astimezone(SYDNEY_TZ).strftime(fmt)
 
+    # Make milestone labels available to all templates
+    from app.utils import MILESTONE_LABELS
+    app.jinja_env.globals['MILESTONE_LABELS'] = MILESTONE_LABELS
+
     # Register blueprints
     from app.routes.auth import bp as auth_bp
     from app.routes.dashboard import bp as dashboard_bp

app/auth.py

@@ -1,5 +1,5 @@
 from functools import wraps
-from flask import session, redirect, url_for, request
+from flask import session, redirect, url_for, request, jsonify
 from app.db import query_one
 
 
@@ -19,3 +19,19 @@ def get_current_user():
     if user_id is None:
         return None
     return query_one("SELECT * FROM users WHERE id = %s", (user_id,))
+
+
+def privacy_guard(f):
+    """Decorator for API endpoints that take a user_id parameter.
+
+    If the requested user is private and is not the current session user,
+    returns an empty JSON response instead of the actual data.
+    """
+    @wraps(f)
+    def decorated_function(user_id, *args, **kwargs):
+        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({})
+        return f(user_id, *args, **kwargs)
+    return decorated_function

app/config.py

@@ -1,8 +1,12 @@
 import os
+from datetime import timezone, timedelta
 from dotenv import load_dotenv
 
 load_dotenv()
 
+# Application-wide timezone for display formatting
+SYDNEY_TZ = timezone(timedelta(hours=11))
+
 
 class Config:
     DATABASE_URL = os.environ.get("DATABASE_URL")

app/routes/api.py

@@ -1,9 +1,12 @@
-from flask import Blueprint, jsonify, request, session
+from collections import OrderedDict
-from app import SYDNEY_TZ
-from app.auth import login_required
-from app.db import query, query_one
 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, pct = calculate_weight_change(start_w, current_w)
-            lost = start_w - current_w
-            pct = round((lost / start_w) * 100, 1)
-        else:
-            lost = 0
-            pct = 0
         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

app/routes/auth.py

@@ -1,6 +1,7 @@
 from flask import Blueprint, render_template, request, redirect, url_for, session, flash
 from werkzeug.security import generate_password_hash, check_password_hash
-from app.db import query_one, execute_returning, execute
+from app.db import query_one, execute_returning
+from app.utils import parse_profile_fields
 
 bp = Blueprint("auth", __name__)
 
@@ -10,13 +11,7 @@ def signup():
     if request.method == "POST":
         username = request.form.get("username", "").strip()
         password = request.form.get("password", "")
-        display_name = request.form.get("display_name", "").strip()
+        fields = parse_profile_fields(request.form)
-        height_cm = request.form.get("height_cm") or None
-        age = request.form.get("age") or None
-        gender = request.form.get("gender") or None
-        goal_weight_kg = request.form.get("goal_weight_kg") or None
-        starting_weight_kg = request.form.get("starting_weight_kg") or None
-        is_private = request.form.get("is_private") == "on"
 
         # Validation
         if not username or not password:
@@ -38,7 +33,11 @@ def signup():
         user = execute_returning(
             """INSERT INTO users (username, password_hash, display_name, height_cm, age, gender, goal_weight_kg, starting_weight_kg, is_private)
                VALUES (%s, %s, %s, %s, %s, %s, %s, %s, %s) RETURNING id""",
-            (username, password_hash, display_name or username, height_cm, age, gender, goal_weight_kg, starting_weight_kg, is_private),
+            (username, password_hash,
+             fields["display_name"] or username,
+             fields["height_cm"], fields["age"], fields["gender"],
+             fields["goal_weight_kg"], fields["starting_weight_kg"],
+             fields["is_private"]),
         )
 
         session["user_id"] = user["id"]

app/routes/checkin.py

@@ -1,57 +1,11 @@
-import math
 from flask import Blueprint, render_template, request, redirect, url_for, flash
 from app.auth import login_required, get_current_user
 from app.db import query, query_one, execute, execute_returning
+from app.utils import calculate_bmi, check_milestones
 
 bp = Blueprint("checkin", __name__)
 
 
-def calculate_bmi(weight_kg, height_cm):
-    """Calculate BMI from weight (kg) and height (cm)."""
-    if not weight_kg or not height_cm or float(height_cm) == 0:
-        return None
-    h_m = float(height_cm) / 100.0
-    return round(float(weight_kg) / (h_m * h_m), 1)
-
-
-def check_milestones(user_id, user):
-    """Check and award any new milestones after a check-in."""
-    checkins = query(
-        "SELECT weight_kg, checked_in_at FROM checkins WHERE user_id = %s ORDER BY checked_in_at ASC",
-        (user_id,),
-    )
-    if not checkins:
-        return
-
-    starting = float(user.get("starting_weight_kg") or checkins[0]["weight_kg"])
-    current = float(checkins[-1]["weight_kg"])
-    total_lost = starting - current
-    count = len(checkins)
-
-    milestone_checks = [
-        ("first_checkin", count >= 1),
-        ("5_checkins", count >= 5),
-        ("10_checkins", count >= 10),
-        ("25_checkins", count >= 25),
-        ("lost_1kg", total_lost >= 1),
-        ("lost_2kg", total_lost >= 2),
-        ("lost_5kg", total_lost >= 5),
-        ("lost_10kg", total_lost >= 10),
-        ("lost_15kg", total_lost >= 15),
-        ("lost_20kg", total_lost >= 20),
-    ]
-
-    for key, achieved in milestone_checks:
-        if achieved:
-            try:
-                execute(
-                    "INSERT INTO milestones (user_id, milestone_key) VALUES (%s, %s) ON CONFLICT DO NOTHING",
-                    (user_id, key),
-                )
-            except Exception:
-                pass
-
-
 @bp.route("/checkin", methods=["GET"])
 @login_required
 def index():
@@ -88,7 +42,6 @@ def create():
         (user["id"], weight_kg, bmi, notes or None),
     )
 
-    # Check milestones
     check_milestones(user["id"], user)
 
     # If HTMX request, return just the new row

app/routes/dashboard.py

@@ -1,7 +1,7 @@
 from flask import Blueprint, render_template
 from app.auth import login_required, get_current_user
 from app.db import query, query_one
-from app.utils import calculate_streak
+from app.utils import calculate_streak, calculate_weight_change
 
 bp = Blueprint("dashboard", __name__)
 
@@ -32,11 +32,11 @@ def index():
     weight_change = None
     weight_change_pct = None
     if latest and first_checkin:
-        start_w = float(first_checkin["weight_kg"])
+        kg_lost, pct_lost = calculate_weight_change(
-        current_w = float(latest["weight_kg"])
+            first_checkin["weight_kg"], latest["weight_kg"]
-        weight_change = round(current_w - start_w, 1)
+        )
-        if start_w > 0:
+        weight_change = round(-kg_lost, 1)       # negative = gained, positive = lost
-            weight_change_pct = round((weight_change / start_w) * 100, 1)
+        weight_change_pct = round(-pct_lost, 1)
 
     # Recent check-ins (last 5)
     recent_checkins = query(
@@ -75,4 +75,3 @@ def index():
         milestones=milestones,
         streak=streak,
     )
-

app/routes/leaderboard.py

@@ -1,8 +1,8 @@
 from flask import Blueprint, render_template
 from app.auth import login_required
 from app.db import query, query_one
-from app import SYDNEY_TZ
+from app.config import SYDNEY_TZ
-from app.utils import calculate_streak
+from app.utils import calculate_streak, calculate_weight_change
 from datetime import timezone
 
 bp = Blueprint("leaderboard", __name__)
@@ -33,13 +33,7 @@ def index():
     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)
-
+        weight_lost, pct_lost = calculate_weight_change(start_w, current_w)
-        if start_w > 0:
-            weight_lost = start_w - current_w
-            pct_lost = round((weight_lost / start_w) * 100, 1)
-        else:
-            weight_lost = 0
-            pct_lost = 0
 
         goal = float(u["goal_weight_kg"]) if u["goal_weight_kg"] else None
         goal_progress = None
@@ -50,7 +44,7 @@ def index():
         streak = calculate_streak(u["id"])
         ranked.append({
             **u,
-            "weight_lost": round(weight_lost, 1),
+            "weight_lost": weight_lost,
             "pct_lost": pct_lost,
             "goal_progress": goal_progress,
             "streak": streak["current"],

app/routes/profile.py

@@ -1,6 +1,7 @@
 from flask import Blueprint, render_template, request, redirect, url_for, flash
 from app.auth import login_required, get_current_user
 from app.db import execute
+from app.utils import parse_profile_fields
 
 bp = Blueprint("profile", __name__)
 
@@ -16,21 +17,17 @@ def index():
 @login_required
 def update():
     user = get_current_user()
-    display_name = request.form.get("display_name", "").strip()
+    fields = parse_profile_fields(request.form)
-    height_cm = request.form.get("height_cm") or None
-    age = request.form.get("age") or None
-    gender = request.form.get("gender") or None
-    goal_weight_kg = request.form.get("goal_weight_kg") or None
-    starting_weight_kg = request.form.get("starting_weight_kg") or None
-    is_private = request.form.get("is_private") == "on"
 
     execute(
         """UPDATE users
            SET display_name = %s, height_cm = %s, age = %s, gender = %s,
                goal_weight_kg = %s, starting_weight_kg = %s, is_private = %s
            WHERE id = %s""",
-        (display_name or user["username"], height_cm, age, gender,
+        (fields["display_name"] or user["username"],
-         goal_weight_kg, starting_weight_kg, is_private, user["id"]),
+         fields["height_cm"], fields["age"], fields["gender"],
+         fields["goal_weight_kg"], fields["starting_weight_kg"],
+         fields["is_private"], user["id"]),
     )
 
     if request.headers.get("HX-Request"):

app/templates/dashboard.html

@@ -103,18 +103,7 @@
             <div class="milestones-grid">
                 {% for m in milestones %}
                 <span class="milestone-badge {{ 'gold' if 'lost' in m.milestone_key else '' }}">
-                    {% if m.milestone_key == 'first_checkin' %}✅ First Check-in
+                    {{ MILESTONE_LABELS.get(m.milestone_key, m.milestone_key) }}
-                    {% elif m.milestone_key == '5_checkins' %}🔥 5 Check-ins
-                    {% elif m.milestone_key == '10_checkins' %}💪 10 Check-ins
-                    {% elif m.milestone_key == '25_checkins' %}🎯 25 Check-ins
-                    {% elif m.milestone_key == 'lost_1kg' %}⭐ 1kg Lost
-                    {% elif m.milestone_key == 'lost_2kg' %}⭐ 2kg Lost
-                    {% elif m.milestone_key == 'lost_5kg' %}🌟 5kg Lost
-                    {% elif m.milestone_key == 'lost_10kg' %}💎 10kg Lost
-                    {% elif m.milestone_key == 'lost_15kg' %}👑 15kg Lost
-                    {% elif m.milestone_key == 'lost_20kg' %}🏆 20kg Lost
-                    {% else %}{{ m.milestone_key }}
-                    {% endif %}
                 </span>
                 {% endfor %}
             </div>

app/utils.py

@@ -1,8 +1,71 @@
-from app.db import query
+"""
-from app import SYDNEY_TZ
+Shared business-logic helpers.
+
+Keep route handlers thin — calculation logic lives here.
+"""
+
+from app.db import query, execute
+from app.config import SYDNEY_TZ
 from datetime import datetime, timedelta
 
 
+# ---------------------------------------------------------------------------
+# Milestones — single source of truth for keys, thresholds, and labels
+# ---------------------------------------------------------------------------
+
+MILESTONES = [
+    # (key, check_fn_or_description, emoji + display label)
+    ("first_checkin", "count >= 1", "✅ First Check-in"),
+    ("5_checkins",    "count >= 5", "🔥 5 Check-ins"),
+    ("10_checkins",   "count >= 10", "💪 10 Check-ins"),
+    ("25_checkins",   "count >= 25", "🎯 25 Check-ins"),
+    ("lost_1kg",      "lost >= 1",  "⭐ 1kg Lost"),
+    ("lost_2kg",      "lost >= 2",  "⭐ 2kg Lost"),
+    ("lost_5kg",      "lost >= 5",  "🌟 5kg Lost"),
+    ("lost_10kg",     "lost >= 10", "💎 10kg Lost"),
+    ("lost_15kg",     "lost >= 15", "👑 15kg Lost"),
+    ("lost_20kg",     "lost >= 20", "🏆 20kg Lost"),
+]
+
+# Quick lookup: milestone_key → display label (used in templates)
+MILESTONE_LABELS = {key: label for key, _, label in MILESTONES}
+
+
+# ---------------------------------------------------------------------------
+# Weight calculations
+# ---------------------------------------------------------------------------
+
+def calculate_bmi(weight_kg, height_cm):
+    """Calculate BMI from weight (kg) and height (cm)."""
+    if not weight_kg or not height_cm or float(height_cm) == 0:
+        return None
+    h_m = float(height_cm) / 100.0
+    return round(float(weight_kg) / (h_m * h_m), 1)
+
+
+def calculate_weight_change(start_w, current_w):
+    """Return (kg_lost, pct_lost) from a start and current weight.
+
+    kg_lost is positive when weight decreased.
+    pct_lost is the percentage of start weight that was lost.
+    """
+    start_w = float(start_w or 0)
+    current_w = float(current_w or start_w)
+
+    if start_w > 0:
+        kg_lost = round(start_w - current_w, 1)
+        pct_lost = round((kg_lost / start_w) * 100, 1)
+    else:
+        kg_lost = 0.0
+        pct_lost = 0.0
+
+    return kg_lost, pct_lost
+
+
+# ---------------------------------------------------------------------------
+# Streaks
+# ---------------------------------------------------------------------------
+
 def calculate_streak(user_id):
     """Calculate current and best consecutive-day check-in streaks."""
     rows = query(
@@ -40,3 +103,65 @@ def calculate_streak(user_id):
 
     best = max(best, current)
     return {"current": current, "best": best}
+
+
+# ---------------------------------------------------------------------------
+# Milestone checker
+# ---------------------------------------------------------------------------
+
+def check_milestones(user_id, user):
+    """Check and award any new milestones after a check-in."""
+    checkins = query(
+        "SELECT weight_kg, checked_in_at FROM checkins WHERE user_id = %s ORDER BY checked_in_at ASC",
+        (user_id,),
+    )
+    if not checkins:
+        return
+
+    starting = float(user.get("starting_weight_kg") or checkins[0]["weight_kg"])
+    current = float(checkins[-1]["weight_kg"])
+    total_lost = starting - current
+    count = len(checkins)
+
+    milestone_checks = [
+        ("first_checkin", count >= 1),
+        ("5_checkins",    count >= 5),
+        ("10_checkins",   count >= 10),
+        ("25_checkins",   count >= 25),
+        ("lost_1kg",      total_lost >= 1),
+        ("lost_2kg",      total_lost >= 2),
+        ("lost_5kg",      total_lost >= 5),
+        ("lost_10kg",     total_lost >= 10),
+        ("lost_15kg",     total_lost >= 15),
+        ("lost_20kg",     total_lost >= 20),
+    ]
+
+    for key, achieved in milestone_checks:
+        if achieved:
+            try:
+                execute(
+                    "INSERT INTO milestones (user_id, milestone_key) VALUES (%s, %s) ON CONFLICT DO NOTHING",
+                    (user_id, key),
+                )
+            except Exception:
+                pass
+
+
+# ---------------------------------------------------------------------------
+# Form helpers
+# ---------------------------------------------------------------------------
+
+def parse_profile_fields(form):
+    """Extract the common profile fields from a request form.
+
+    Returns a dict suitable for both signup and profile-update flows.
+    """
+    return {
+        "display_name": form.get("display_name", "").strip(),
+        "height_cm":    form.get("height_cm") or None,
+        "age":          form.get("age") or None,
+        "gender":       form.get("gender") or None,
+        "goal_weight_kg":     form.get("goal_weight_kg") or None,
+        "starting_weight_kg": form.get("starting_weight_kg") or None,
+        "is_private":   form.get("is_private") == "on",
+    }