import streamlit as st

from database import create_tables, save_weight, get_weight_history, save_otp
from auth import signup_user, login_user, verify_user_otp, generate_otp
from email_utils import send_otp_email
from model_api import query_model
from prompt_builder import build_prompt


# -------------------------
# DATABASE INIT
# -------------------------

create_tables()

st.set_page_config(
    page_title="FitPlan AI",
    layout="centered"
)

st.title("🏋️ FitPlan AI - Personalized Fitness Planner")


# -------------------------
# SESSION STATE
# -------------------------

if "user" not in st.session_state:
    st.session_state.user = None

if "email" not in st.session_state:
    st.session_state.email = None

if "credentials_verified" not in st.session_state:
    st.session_state.credentials_verified = False

if "otp_sent" not in st.session_state:
    st.session_state.otp_sent = False


# -------------------------
# SIDEBAR MENU
# -------------------------

menu = st.sidebar.selectbox(
    "Menu",
    ["Signup", "Login"]
)


# -------------------------
# SIGNUP PAGE
# -------------------------

if menu == "Signup":

    st.header("Create Account")

    email = st.text_input("Email")
    password = st.text_input("Password", type="password")

    if st.button("Signup"):

        success = signup_user(email, password)

        if success:
            st.success("Account created successfully. Please login.")
        else:
            st.error("User already exists")


# -------------------------
# LOGIN PAGE
# -------------------------

if menu == "Login" and st.session_state.user is None:

    st.header("Login")

    email = st.text_input("Email")
    password = st.text_input("Password", type="password")

    if st.button("Login"):

        user = login_user(email, password)

        if user:

            st.session_state.email = email
            st.session_state.credentials_verified = True

            st.success("Credentials verified. Click Send OTP.")

        else:
            st.error("Invalid email or password")


# -------------------------
# SEND OTP
# -------------------------

if st.session_state.credentials_verified and not st.session_state.otp_sent:

    if st.button("Send OTP"):

        otp = generate_otp()

        save_otp(st.session_state.email, otp)

        send_otp_email(st.session_state.email, otp)

        st.session_state.otp_sent = True

        st.success("OTP sent to your email")


# -------------------------
# VERIFY OTP
# -------------------------

if st.session_state.otp_sent:

    st.subheader("Enter OTP")

    otp_input = st.text_input("OTP")

    col1, col2 = st.columns(2)

    with col1:

        if st.button("Verify OTP"):

            verified = verify_user_otp(
                st.session_state.email,
                otp_input
            )

            if verified:

                st.session_state.user = st.session_state.email
                st.session_state.credentials_verified = False
                st.session_state.otp_sent = False

                st.success("Login successful")

                st.rerun()

            else:

                st.error("Invalid OTP")

    with col2:

        if st.button("Resend OTP"):

            otp = generate_otp()

            save_otp(st.session_state.email, otp)

            send_otp_email(st.session_state.email, otp)

            st.success("New OTP sent")


# -------------------------
# MAIN APPLICATION
# -------------------------

if st.session_state.user:

    st.sidebar.success(f"Logged in as {st.session_state.user}")

    tabs = st.tabs(
        [
            "Dashboard",
            "Profile",
            "Workout Plan",
            "Weight Tracker",
            "Logout"
        ]
    )


# -------------------------
# DASHBOARD
# -------------------------

    with tabs[0]:

        st.header("Dashboard")

        st.write(
            "Welcome to FitPlan AI. Generate personalized workout plans and track your fitness progress."
        )


# -------------------------
# PROFILE
# -------------------------

    with tabs[1]:

        st.header("User Profile")

        name = st.text_input("Name")

        age = st.number_input(
            "Age",
            10,
            80
        )

        gender = st.selectbox(
            "Gender",
            ["Male", "Female", "Other"]
        )

        height = st.number_input(
            "Height (cm)",
            100,
            220
        )


# -------------------------
# WORKOUT PLAN GENERATOR
# -------------------------

    with tabs[2]:

        st.header("Generate Personalized Workout Plan")

        weight = st.number_input(
            "Weight (kg)",
            30,
            150
        )

        goal = st.selectbox(
            "Fitness Goal",
            [
                "Lose Weight",
                "Build Muscle",
                "Maintain Fitness"
            ]
        )

        fitness_level = st.selectbox(
            "Fitness Level",
            [
                "Beginner",
                "Intermediate",
                "Advanced"
            ]
        )

        equipment = st.multiselect(
            "Available Equipment",
            [
                "Dumbbells",
                "Barbell",
                "Resistance Bands",
                "Bodyweight",
                "None"
            ]
        )

        if st.button("Generate AI Plan"):

            prompt, bmi, bmi_status = build_prompt(
                name,
                age,
                gender,
                height,
                weight,
                goal,
                fitness_level,
                equipment
            )

            st.write(f"BMI: {bmi:.2f} ({bmi_status})")

            with st.spinner("Generating workout plan..."):

                result = query_model(prompt)

            st.subheader("Your AI Workout Plan")

            st.write(result)


# -------------------------
# WEIGHT TRACKER
# -------------------------

    with tabs[3]:

        st.header("Weight Tracker")

        today_weight = st.number_input(
            "Enter today's weight",
            min_value=30.0
        )

        if st.button("Save Weight"):

            save_weight(
                st.session_state.user,
                today_weight
            )

            st.success("Weight saved")

        st.subheader("Weight History")

        history = get_weight_history(
            st.session_state.user
        )

        if history:

            st.table(history)

        else:

            st.info("No weight records found")


# -------------------------
# LOGOUT
# -------------------------

    with tabs[4]:

        st.header("Logout")

        if st.button("Logout"):

            st.session_state.user = None
            st.session_state.email = None
            st.session_state.credentials_verified = False
            st.session_state.otp_sent = False

            st.rerun()