# app.py
# Simple BMI Calculator - Hugging Face Space (Gradio)
# No pip installs here — just define your Gradio app.

import gradio as gr

def weight_to_kg(weight, unit):
    if unit == "kg":
        return weight
    elif unit == "lb":
        return weight * 0.45359237
    else:
        return None

def height_to_m(height, unit):
    if unit == "m":
        return height
    elif unit == "cm":
        return height / 100.0
    elif unit == "in":
        return height * 0.0254
    elif unit == "ft":
        return height * 0.3048
    else:
        return None

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

def calculate_bmi(weight, weight_unit, height, height_unit, decimals):
    # Basic validation
    if weight is None or height is None:
        return "⚠️ Please enter both weight and height."
    try:
        weight = float(weight)
        height = float(height)
    except:
        return "⚠️ Please enter numeric values for weight and height."
    if weight <= 0:
        return "⚠️ Weight must be greater than zero."
    if height <= 0:
        return "⚠️ Height must be greater than zero."

    kg = weight_to_kg(weight, weight_unit)
    m = height_to_m(height, height_unit)
    if kg is None or m is None:
        return "⚠️ Invalid unit selected."
    if m <= 0:
        return "⚠️ Converted height must be greater than zero."

    bmi = kg / (m * m)
    try:
        decimals = int(decimals)
    except:
        decimals = 2
    bmi_str = f"{bmi:.{decimals}f}"
    category = bmi_category(bmi)
    note = (
        "ℹ️ Note: BMI is a rough estimate and may be inaccurate for athletes, "
        "children, elderly people, or pregnant individuals. For medical advice, consult a professional."
    )
    return f"✅ BMI = {bmi_str} kg/m² — {category}\n\n{note}"

with gr.Blocks(title="Simple BMI Calculator") as demo:
    gr.Markdown("# 🧮 Simple BMI Calculator\nEnter weight and height, choose units, and click **Calculate**.")
    with gr.Row():
        weight = gr.Number(label="Weight", value=70)
        weight_unit = gr.Dropdown(["kg", "lb"], value="kg", label="Weight unit")
    with gr.Row():
        height = gr.Number(label="Height", value=170)
        height_unit = gr.Dropdown(["cm", "m", "in", "ft"], value="cm", label="Height unit")
    decimals = gr.Slider(0, 5, value=2, step=1, label="Decimal precision")
    calc_btn = gr.Button("Calculate BMI")
    output = gr.Textbox(label="Result", lines=6)
    calc_btn.click(fn=calculate_bmi, inputs=[weight, weight_unit, height, height_unit, decimals], outputs=output)
    gr.Examples(
        examples=[
            [70, "kg", 170, "cm", 2],
            [50, "kg", 160, "cm", 2],
            [200, "lb", 72, "in", 2],
            [90, "kg", 1.8, "m", 2],
        ],
        inputs=[weight, weight_unit, height, height_unit, decimals],
        label="Examples (click to fill)"
    )

# When Spaces runs this file it will serve the Gradio app automatically.
if __name__ == "__main__":
    demo.launch()