import gradio as gr

# Function to calculate BMI
def calculate_bmi(weight, height, unit, precision):
    try:
        if weight <= 0 or height <= 0:
            return "❌ Please enter positive numbers."

        # Convert height and weight depending on unit system
        if unit == "Metric (kg, cm)":
            weight_kg = weight
            height_m = height / 100  # convert cm → m
        else:  # Imperial (lbs, inches)
            weight_kg = weight * 0.45359237
            height_m = height * 0.0254

        bmi = weight_kg / (height_m ** 2)
        bmi = round(bmi, precision)

        # WHO classification
        if bmi < 18.5:
            category = "Underweight 🟡"
            advice = "You may need to gain some healthy weight."
        elif 18.5 <= bmi < 25:
            category = "Normal ✅"
            advice = "Great! Maintain your healthy lifestyle."
        elif 25 <= bmi < 30:
            category = "Overweight 🟠"
            advice = "Consider balanced diet and exercise."
        else:
            category = "Obese 🔴"
            advice = "Seek medical advice for weight management."

        return f"📊 BMI: {bmi}\n📌 Category: {category}\n💡 Advice: {advice}"

    except Exception as e:
        return f"Error: {str(e)}"

# Gradio UI
with gr.Blocks() as demo:
    gr.Markdown("# 🧮 BMI Calculator")

    with gr.Row():
        unit = gr.Radio(["Metric (kg, cm)", "Imperial (lbs, inches)"], value="Metric (kg, cm)", label="Unit System")

    with gr.Row():
        weight = gr.Number(label="Weight (kg or lbs)")
        height = gr.Number(label="Height (cm or inches)")

    precision = gr.Slider(0, 4, value=2, step=1, label="Decimal Precision")

    calc_btn = gr.Button("Calculate BMI")
    result = gr.Textbox(label="Result", lines=4)

    calc_btn.click(calculate_bmi, [weight, height, unit, precision], result)

# Run
demo.launch()