import streamlit as st

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

# --------------------------------------------------
# Custom CSS (HF Compatible + Visible UI)
# --------------------------------------------------
st.markdown("""
<style>

/* Page background */
.stApp {
    background-color: #f4f7fb;
}

/* Main container */
.block-container {
    background-color: #ffffff;
    padding: 2.5rem;
    border-radius: 18px;
    max-width: 900px;
}

/* Headings */
h1, h2, h3 {
    color: #0f172a !important;
}

/* Labels */
label {
    color: #1e293b !important;
    font-weight: 600;
}

/* Inputs */
input, textarea {
    background-color: #ffffff !important;
    color: #0f172a !important;
    border-radius: 10px !important;
    border: 1px solid #cbd5e1 !important;
}

/* Selectbox & Multiselect */
div[data-baseweb="select"] {
    background-color: #ffffff !important;
    border-radius: 10px;
}

/* Form card */
div[data-testid="stForm"] {
    background-color: #f8fafc;
    padding: 2rem;
    border-radius: 14px;
    box-shadow: 0 10px 25px rgba(0,0,0,0.08);
}

/* Main button */
.stButton > button {
    width: 100%;
    height: 3.2em;
    border-radius: 10px;
    background: linear-gradient(90deg, #2563eb, #1d4ed8);
    color: white !important;
    font-size: 17px;
    font-weight: 600;
    border: none;
}

</style>
""", unsafe_allow_html=True)

# --------------------------------------------------
# Title Section
# --------------------------------------------------
st.title("💪 FitPlan AI")
st.subheader("Milestone 1: Fitness Profile & BMI Analysis")
st.write("Enter your details to calculate BMI and generate your fitness profile.")

# --------------------------------------------------
# Fitness Profile Form
# --------------------------------------------------
with st.form("fitness_form"):

    # -------- Section 1 --------
    st.header("🧍‍♂️ 1. Personal Information")

    name = st.text_input("Full Name *")

    col1, col2 = st.columns(2)
    with col1:
        height = st.number_input("Height (cm) *", min_value=0.0, step=0.1)
    with col2:
        weight = st.number_input("Weight (kg) *", min_value=0.0, step=0.1)

    st.divider()

    # -------- Section 2 --------
    st.header("🏋️ 2. Fitness Details")

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

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

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

    submit = st.form_submit_button("Generate Profile")

# --------------------------------------------------
# Processing & Output
# --------------------------------------------------
if submit:

    # -------- 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:
        # -------- BMI Calculation --------
        height_m = height / 100
        bmi = round(weight / (height_m ** 2), 2)

        # -------- BMI Classification --------
        if bmi < 18.5:
            category = "Underweight"
            color = "blue"
            progress = bmi / 18.5
        elif 18.5 <= bmi < 24.9:
            category = "Normal"
            color = "green"
            progress = bmi / 24.9
        elif 25 <= bmi < 29.9:
            category = "Overweight"
            color = "orange"
            progress = bmi / 29.9
        else:
            category = "Obese"
            color = "red"
            progress = 1.0

        # -------- Results Section --------
        st.success(f"✅ Profile created successfully for **{name}**")

        colA, colB = st.columns(2)
        with colA:
            st.metric("Your BMI", bmi)
        with colB:
            st.markdown(f"**BMI Category:** :{color}[{category}]")

        # -------- BMI Progress Bar --------
        st.markdown("### 📊 BMI Progress Indicator")
        st.progress(min(progress, 1.0))

        # -------- Summary --------
        st.info(f"🎯 Goal: {goal} | 📈 Level: {level}")

        if equipment:
            st.write("🧰 Equipment:", ", ".join(equipment))
        else:
            st.write("🧰 Equipment: No equipment selected")