src/streamlit_app.py

import streamlit as st

# Page Configuration
st.set_page_config(page_title="FitPlan AI", page_icon="💪", layout="centered")

# Custom Styling
st.markdown("""
    <style>
    .main {
        background-color: #f5f7f9;
    }
    .stButton>button {
        width: 100%;
        border-radius: 5px;
        height: 3em;
        background-color: #FF4B4B;
        color: white;
    }
    </style>
    """, unsafe_allow_html=True)

st.title("💪 FitPlan AI")
st.subheader("Milestone 1: Fitness Profile & BMI Analysis")
st.write("Complete the form below to begin your personalized fitness journey.")

# --- Form Section ---
with st.form("fitness_form"):
    st.header("1. Personal Information")
    name = st.text_input("Full Name*", placeholder="Enter your name")
    
    col1, col2 = st.columns(2)
    with col1:
        height = st.number_input("Height (cm)*", min_value=0.0, step=0.1, help="e.g., 175")
    with col2:
        weight = st.number_input("Weight (kg)*", min_value=0.0, step=0.1, help="e.g., 70")

    st.divider()
    
    st.header("2. Fitness Details")
    goal = st.selectbox("Fitness Goal", 
                        ["Build Muscle", "Weight Loss", "Strength Gain", "Abs Building", "Flexible"])
    
    level = st.select_slider("Fitness Level", 
                             options=["Beginner", "Intermediate", "Advanced"])
    
    equipment = st.multiselect("Available Equipment", 
                               ["Dumbbells", "Resistance Band", "Yoga Mat", "Kettlebell", "Pull-up Bar", "No Equipment"],
                               default=["No Equipment"])

    submit_button = st.form_submit_button("Generate Profile")

# --- Logic & Results ---
if submit_button:
    # 5. Input Validation
    if not name.strip():
        st.error("Please enter your name.")
    elif height <= 0 or weight <= 0:
        st.error("Height and weight must be greater than zero.")
    else:
        # 3. Functional Requirements
        height_m = height / 100  # Convert cm to meters
        bmi = weight / (height_m ** 2)
        bmi_rounded = round(bmi, 2)

        # Classify BMI
        if bmi < 18.5:
            category = "Underweight"
            color = "blue"
        elif 18.5 <= bmi < 24.9:
            category = "Normal"
            color = "green"
        elif 25.0 <= bmi < 29.9:
            category = "Overweight"
            color = "orange"
        else:
            category = "Obese"
            color = "red"

        # 4. Display Results
        st.success(f"Profile Created Successfully for **{name}**!")
        
        res_col1, res_col2 = st.columns(2)
        with res_col1:
            st.metric("Your BMI", bmi_rounded)
        with res_col2:
            st.markdown(f"**Category:** :{color}[{category}]")
        
        st.info(f"**Goal:** {goal} | **Level:** {level}")
        st.write(f"**Equipment:** {', '.join(equipment)}")