Add barcode-based meal logging workflow

Introduces a new add_meal blueprint with routes and templates for scanning barcodes, adding new food items, and logging meals. Updates FoodItemForm and FoodLogForm validation, changes FoodLog.amount to float, and integrates the new workflow into the daily log UI. Refactors user routes and templates to support the new meal logging process.

application/add_meal/routes.py

@@ -0,0 +1,131 @@
+from flask import (
+    Blueprint,
+    redirect,
+    url_for,
+    render_template,
+    session,
+)
+from flask_login import current_user
+from forms import FoodItemForm, FoodLogForm
+from application import db
+from models import FoodItem, FoodLog
+
+bp = Blueprint(
+    "add_meal",
+    __name__,
+    url_prefix="/add_meal",
+    template_folder="templates",
+)
+
+
+@bp.before_request
+def login_required():
+    if not current_user.is_authenticated:
+        return redirect(url_for("login"))
+
+
+@bp.route("/select_meal/<int:meal_type>", methods=["GET"])
+def step1(meal_type: int):
+    assert type(meal_type) is int
+    assert 0 <= meal_type <= 3
+    session["meal_type"] = meal_type
+    return redirect(url_for("add_meal.step2"))
+
+
+@bp.route("/get_barcode", methods=["GET"])
+def step2():
+    return render_template("scan_barcode.html")
+
+
+@bp.route("/step3/<barcode>", methods=["GET"])
+def step3(barcode: str):
+    if "meal_type" not in session:
+        return redirect("/")
+    assert barcode.isdigit()
+    item = current_user.food_items.filter_by(barcode=barcode).first()
+    if item is None:
+        # Does not exist, add item
+        return redirect(url_for("add_meal.step3_alt1", barcode=barcode))
+    else:
+        session["item_id"] = item.id
+        return redirect(url_for("add_meal.step4"))
+
+
+@bp.route("/step3_alt1/<barcode>", methods=["GET", "POST"])
+def step3_alt1(barcode: str):
+    form = FoodItemForm()
+    if form.validate_on_submit():
+        print("[DEBUG] Valid form")
+        if (
+            current_user.food_items.filter_by(
+                barcode=form.barcode.data
+            ).first()
+            is None
+        ):
+            assert form.name.data is not None
+            assert form.energy.data is not None
+            assert form.protein.data is not None
+            assert form.carbs.data is not None
+            assert form.fat.data is not None
+            assert form.barcode.data is not None
+            db.session.add(
+                FoodItem(
+                    name=form.name.data,
+                    owner_id=current_user.id,
+                    energy=form.energy.data,
+                    protein=form.protein.data,
+                    carbs=form.carbs.data,
+                    fat=form.fat.data,
+                    barcode=(
+                        form.barcode.data
+                        if form.barcode.data.isdigit()
+                        else None
+                    ),
+                    saturated_fat=form.saturated_fat.data,
+                    sugar=form.sugar.data,
+                )
+            )
+            db.session.commit()
+            print("[DEBUG] New item added")
+        return redirect(url_for("add_meal.step3", barcode=form.barcode.data))
+    print("[DEBUG] Invalid form")
+    if barcode.isdigit():
+        form.barcode.data = barcode
+    return render_template("add_item.html", form=form)
+
+
+@bp.route("/step4", methods=["GET", "POST"])
+def step4():
+    if "item_id" not in session:
+        return redirect(url_for("add_meal.step2"))
+    form = FoodLogForm()
+    item = db.session.get(FoodItem, session["item_id"])
+
+    assert item
+    if form.validate_on_submit():
+        assert form.amount.data
+        db.session.add(
+            FoodLog(
+                food_item_id=item.id,
+                user_id=current_user.id,
+                amount=form.amount.data,
+                part_of_day=session["meal_type"],
+            )
+        )
+        db.session.commit()
+        session.pop("meal_type")
+        session.pop("item_id")
+        return redirect("/")
+
+    match session["meal_type"]:
+        case 0:
+            tod = "Breakfast"
+        case 1:
+            tod = "Lunch"
+        case 2:
+            tod = "Dinner"
+        case 3:
+            tod = "Snack"
+        case _:
+            tod = "Unknown"
+    return render_template("step4.html", tod=tod, item=item, form=form)