SMARTCART

public GeminiMealPlanDto generateMealPlan(...) {
    // Auto-rotate: sample subset for variety
    preferredProteins = sampleFromList(preferredProteins, 3);
    preferredVegetables = sampleFromList(preferredVegetables, 5);

    Set<MealSlot> requestedSlots = expectedSlots(mealSchedule);
    LinkedHashMap<MealSlot, MealEntry> acceptedMeals = new LinkedHashMap<>();
    List<MealSlot> remainingSlots = new ArrayList<>(requestedSlots);

    // Retry loop: up to 3 attempts for incomplete plans
    for (int attempt = 1; attempt <= 3 && !remainingSlots.isEmpty(); attempt++) {
        String prompt = buildFullMealPlanPrompt(
            pantryIngredients, servingSize, dietaryRestrictions,
            allergies, preferredCuisines, remainingSlotSet, ...);

        lastRaw = generateContent(prompt);
        GeminiMealPlanDto dto = parseJson(lastRaw, GeminiMealPlanDto.class);
        ExtractedMeals extracted = extractValidMeals(dto, remainingSlotSet);

        acceptedMeals.putAll(extracted.acceptedMeals());
        remainingSlots = extracted.missingSlots();
    }
    return buildMealPlan(acceptedMeals);
}

static UnitInfo from(String rawUnit) {
    String unit = normalizeUnitText(rawUnit);
    return switch (unit) {
        case "tsp", "teaspoon"     -> new UnitInfo("volume", "tsp",  4.929);
        case "tbsp", "tablespoon"  -> new UnitInfo("volume", "tbsp", 14.787);
        case "cup"               -> new UnitInfo("volume", "cup", 236.588);
        case "ml"                -> new UnitInfo("volume", "ml",  1.0);
        case "oz", "ounce"      -> new UnitInfo("weight", "oz", 28.350);
        case "lb", "pound"      -> new UnitInfo("weight", "lb", 453.592);
        case "g", "gram"        -> new UnitInfo("weight", "g",  1.0);
        default -> new UnitInfo("exact:" + unit, unit, 1.0);
    };
}

double convertTo(double quantity, UnitInfo target) {
    double baseQuantity = quantity * baseFactor;
    return baseQuantity / target.baseFactor;
}

// Post-generation allergy verification with auto-regeneration
Set<String> allergenSet = parseAllergenSet(effectiveAllergies);

for (MealEntry entry : mealPlan.meals()) {
    if (!allergenSet.isEmpty()
        && recipeContainsAllergen(entry.recipe(), allergenSet)) {

        log.warn("Allergy detected in {} {} — re-generating",
                entry.dayOfWeek(), entry.mealType());

        // Re-generate this single slot with stronger allergy prompt
        GeminiRecipeDto replacement = geminiService
            .generateSingleMeal(entry.dayOfWeek(), entry.mealType(),
                effectiveAllergies, dietaryRestrictions, cuisines);

        if (replacement != null
            && !recipeContainsAllergen(replacement, allergenSet)) {
            Recipe recipe = persistRecipe(replacement, servingSize);
            plan.getRecipes().add(new MealPlanRecipe(plan, recipe, day, meal));
        } else {
            removedMeals.add(entry.dayOfWeek() + " " + entry.mealType());
            log.warn("Still unsafe — slot removed");
        }
    }
}