def calculate_bmi(weight, height):
    """
    Calculate BMI from weight (kg) and height (cm)
    """
    height_m = height / 100
    return weight / (height_m ** 2)

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

def build_prompt(name, age, gender, height, weight, goal, fitness_level, equipment):
    """
    Build a prompt for the Llama model including all user parameters
    Optimized for Llama's instruction-following capabilities
    """
    bmi = calculate_bmi(weight, height)
    bmi_status = bmi_category(bmi)

    equipment_list = ", ".join(equipment) if equipment else "No Equipment"
    
    # Age-specific considerations
    age_considerations = ""
    if age < 18:
        age_considerations = "\nImportant: User is under 18. Focus on proper form and bodyweight exercises. Avoid heavy lifting."
    elif age > 50:
        age_considerations = "\nImportant: User is over 50. Focus on joint-friendly exercises, mobility work, and lower impact activities."
    
    # Goal-specific instructions
    goal_instructions = {
        "Weight Loss": "Focus on compound exercises and include cardio intervals. Higher reps (12-15) with moderate weight.",
        "Build Muscle": "Focus on hypertrophy with moderate weights (8-12 reps). Include progressive overload and mind-muscle connection.",
        "Strength Gain": "Focus on lower reps (5-8) with heavier weights. Include compound lifts like squats, deadlifts, bench press.",
        "Abs Building": "Include core-specific exercises along with full-body compound movements. Focus on controlled movements.",
        "Flexibility": "Include dynamic stretching, yoga poses, and mobility work. Hold stretches for 20-30 seconds."
    }
    
    specific_instruction = goal_instructions.get(goal, "Balance cardio and strength training.")

    # Llama-optimized prompt structure
    prompt = f"""<s>[INST] <<SYS>>
You are a certified professional fitness trainer. Create a detailed, safe, and effective 5-day workout plan based on the user's profile below.
<</SYS>>

USER PROFILE:
- Name: {name}
- Age: {age} years
- Gender: {gender}
- Height: {height} cm
- Weight: {weight} kg
- BMI: {bmi:.2f} ({bmi_status})
- Primary Goal: {goal}
- Fitness Level: {fitness_level}
- Available Equipment: {equipment_list}
{age_considerations}

SPECIFIC FOCUS: {specific_instruction}

REQUIREMENTS:
1. Create a COMPLETE 5-day workout plan with clear "DAY 1", "DAY 2", "DAY 3", "DAY 4", and "DAY 5" headers
2. For each day, include:
   - A warm-up section (5-10 minutes)
   - 4-6 main exercises
   - A cool-down/stretch section
3. For EACH exercise, specify:
   - Exercise name
   - Sets x Reps (e.g., "3 x 12")
   - Rest period between sets
4. Adjust intensity based on BMI category ({bmi_status}) and fitness level ({fitness_level})
5. Ensure all exercises are safe and can be done with available equipment: {equipment_list}
6. If equipment is limited, provide bodyweight alternatives

Please provide a well-structured, easy-to-follow 5-day workout plan. [/INST]

Here is a comprehensive 5-day workout plan for {name}:</s>
"""
    return prompt, bmi, bmi_status

def build_fitness_assistant_prompt(name, age, gender, height, weight, goal, fitness_level, equipment):
    """
    Alternative prompt optimized for the fitness-specific fine-tuned model
    """
    bmi = calculate_bmi(weight, height)
    bmi_status = bmi_category(bmi)
    equipment_list = ", ".join(equipment) if equipment else "No Equipment"
    
    prompt = f"""Create a 5-day workout plan for:

Name: {name}
Age: {age}
Gender: {gender}
Height: {height}cm
Weight: {weight}kg
BMI: {bmi:.1f} ({bmi_status})
Goal: {goal}
Level: {fitness_level}
Equipment: {equipment_list}

Requirements:
- 5 days (Day 1 to Day 5)
- Each day: warm-up, 4-6 exercises, cool-down
- Each exercise: name, sets, reps, rest
- Safe for {fitness_level} level
- Use available equipment only

Plan:"""
    return prompt, bmi, bmi_status