def print_welcome_message():
    print("=" * 100)
    print("Welcome to the Comprehensive BMI Calculator!".center(100))
    print("=" * 100)


def get_user_input():
    while True:
        try:
            height = float(input("Enter your height in meters: "))
            if height <= 0:
                raise ValueError("Height must be a positive number.")

            weight = float(input("Enter your weight in kilograms: "))
            if weight <= 0:
                raise ValueError("Weight must be a positive number.")

            return height, weight
        except ValueError as e:
            print(f"Invalid input: {e}. Please try again.")


def calculate_bmi(height, weight):
    return round(weight / (height ** 2), 2)


def interpret_bmi(bmi):
    if bmi < 18.5:
        return "Underweight"
    elif 18.5 <= bmi < 24.9:
        return "Normal weight"
    elif 25 <= bmi < 29.9:
        return "Overweight"
    else:
        return "Obese"


def print_bmi_result(bmi, category):
    print("=" * 100)
    print(f"Your BMI is: {bmi}")
    print(f"Category: {category}")
    print("=" * 100)


def offer_recommendations(category):
    print("Recommendations:")
    if category == "Underweight":
        print("- Consider a balanced diet with more calories.")
        print("- Include protein-rich foods like nuts, dairy, and legumes.")
        print("- Consult a healthcare provider if needed.")
        print("- Track your progress regularly.")
        print("- Eat at regular intervals.")
    elif category == "Normal weight":
        print("- Great job! Maintain your healthy lifestyle.")
        print("- Stay active and eat a balanced diet.")
        print("- Regular health check-ups are beneficial.")
        print("- Stay hydrated and get enough sleep.")
    elif category == "Overweight":
        print("- Consider regular physical activity.")
        print("- Focus on a diet with fruits, vegetables, and lean proteins.")
        print("- Avoid excessive sugars and saturated fats.")
        print("- Try incorporating walking or cycling into your routine.")
        print("- Monitor your calorie intake.")
    elif category == "Obese":
        print("- Consult with a healthcare provider.")
        print("- Engage in regular exercise.")
        print("- Follow a structured diet plan.")
    print("=" * 50)


def ask_for_retry():
    while True:
        retry = input("Would you like to calculate another BMI? (yes/no): ").strip().lower()
        if retry in ["yes", "y"]:
            return True
        elif retry in ["no", "n"]:
            return False
        else:
            print("Please enter 'yes' or 'no'.")


def main():
    print_welcome_message()
    while True:
        height, weight = get_user_input()
        bmi = calculate_bmi(height, weight)
        category = interpret_bmi(bmi)
        print_bmi_result(bmi, category)
        offer_recommendations(category)

        if not ask_for_retry():
            print("Thank you for using the BMI Calculator. Stay healthy!")
            break


if __name__ == "__main__":
    main()