prompt_builder.py

def calculate_bmi(weight, height):
    height_m = height / 100
    return weight / (height_m ** 2)

def bmi_category(bmi):
    if bmi < 18.5:
        return "Underweight"
    elif bmi < 25:
        return "Normal Weight"
    elif bmi < 30:
        return "Overweight"
    else:
        return "Obese"

def build_prompt(name, gender, height, weight, goal, fitness_level, equipment):
    bmi = calculate_bmi(weight, height)
    bmi_status = bmi_category(bmi)
    equipment_list = ", ".join(equipment) if equipment else "No Equipment"

    prompt = f"""You are a certified professional fitness trainer.
Create a structured 5-day personalized workout plan.
User Profile:
- Name: {name}
- Gender: {gender}
- Height: {height} cm
- Weight: {weight} kg
- BMI: {bmi:.2f} ({bmi_status})
- Goal: {goal}
- Fitness Level: {fitness_level}
- Available Equipment: {equipment_list}
Instructions:
1. Divide clearly into Day 1 to Day 5 with headers like "## Day 1 - [Focus Area]"
2. For each day list 5-6 exercises.
3. Include sets x reps for each exercise.
4. Include rest period between sets.
5. Adjust intensity based on BMI category and fitness level.
6. Avoid unsafe exercises for beginners.
7. End with a brief motivational note for {name}.
8. Keep the plan professional, structured and easy to follow.
"""
    return prompt, bmi, bmi_status