src/streamlit_app.py

import streamlit as st
from transformers import pipeline
# -------------------------
# PAGE CONFIG
# -------------------------
st.set_page_config(page_title="FitPlan-AI", page_icon="💪")

# -------------------------
# BMI FUNCTIONS
# -------------------------
def calculate_bmi(weight, height_cm):
    height_m = height_cm / 100
    return round(weight / (height_m ** 2), 2)

def get_category(bmi):
    if bmi < 18.5:
        return "Underweight"
    elif bmi < 24.9:
        return "Normal"
    elif bmi < 29.9:
        return "Overweight"
    else:
        return "Obese"

# -------------------------
# LOAD FLAN-T5 MODEL
# -------------------------
@st.cache_resource
def load_model():
    return pipeline(
        "text-generation",
        model="gpt2"
    )

generator = load_model()

# -------------------------
# UI STARTS
# -------------------------
st.title("💪 FitPlan-AI: Personalized Fitness Profile")

with st.form("fitness_form"):

    st.subheader("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=1.0, step=0.1)
    with col2:
        weight = st.number_input("Weight (kg)*", min_value=1.0, step=0.1)

    st.subheader("Fitness Details")

    goal = st.selectbox(
        "Fitness Goal",
        ["Build Muscle", "Weight Loss", "Strength Gain", "Abs Building", "Flexibility"]
    )

    level = st.radio(
        "Fitness Level",
        ["Beginner", "Intermediate", "Advanced"]
    )

    equipment = st.multiselect(
        "Available Equipment",
        ["Dumbbells", "Resistance Band", "Yoga Mat", "No Equipment", "Kettlebell", "Pull-up Bar"]
    )

    submit = st.form_submit_button("Submit Profile")
# -------------------------
# HANDLE SUBMISSION
# -------------------------
if submit:

    if not name.strip():
        st.error("Please enter your name.")

    elif height <= 0 or weight <= 0:
        st.error("Height and Weight must be positive values.")

    elif not equipment:
        st.error("Please select at least one equipment option.")

    else:
        # Calculate BMI
        user_bmi = calculate_bmi(weight, height)
        bmi_status = get_category(user_bmi)

        st.success(f"✅ Profile Created Successfully for {name}!")
        st.metric("Your BMI", user_bmi)
        st.info(f"Health Category: **{bmi_status}**")

        equipment_list = ", ".join(equipment)

        # FLAN-T5 works best with instruction-style prompts
        prompt = f"""
        Create a structured 5-day workout plan.

        User Details:
        Name: {name}
        BMI: {user_bmi} ({bmi_status})
        Goal: {goal}
        Fitness Level: {level}
        Equipment: {equipment_list}

        Include:
        - Warm-up
        - Exercises with sets and reps
        - Rest time
        - Day-wise breakdown
        - Safety advice
        """

        with st.spinner("Generating your AI workout plan..."):
            result = generator(
                prompt,
                max_new_tokens=400,
                do_sample=True,
                temperature=0.7
            )[0]["generated_text"]

        st.subheader("🏋️ Your Personalized Workout Plan")
        st.write(result)