app.py

import streamlit as st
import firebase_admin
from firebase_admin import credentials, auth, db
import os
import json

# Load Firebase credentials from Hugging Face Secrets
firebase_creds = os.getenv("FIREBASE_CREDENTIALS")
FIREBASE_API_KEY = os.getenv("FIREBASE_API_KEY")
if firebase_creds:
    firebase_creds = json.loads(firebase_creds)
else:
    st.error("Firebase credentials not found. Please check your secrets.")

# Initialize Firebase (only once)
if not firebase_admin._apps:
    cred = credentials.Certificate(firebase_creds)  # Replace with your Firebase service account key
    firebase_admin.initialize_app(cred, {
        'databaseURL': 'https://creative-623ef-default-rtdb.firebaseio.com/'  # Replace with your Firebase Realtime Database URL
    })

# Initialize session state
if "logged_in" not in st.session_state:
    st.session_state.logged_in = False
if "current_user" not in st.session_state:
    st.session_state.current_user = None

def send_verification_email(id_token):
    url = f'https://identitytoolkit.googleapis.com/v1/accounts:sendOobCode?key={FIREBASE_API_KEY}'
    headers = {'Content-Type': 'application/json'}
    data = {
        'requestType': 'VERIFY_EMAIL',
        'idToken': id_token
    }
    
    response = requests.post(url, headers=headers, json=data)
    result = response.json()
    
    if 'error' in result:
        return {'status': 'error', 'message': result['error']['message']}
    else:
        return {'status': 'success', 'email': result['email']}
        
# Callback for registration
def register_callback():
    email = st.session_state.reg_email
    password = st.session_state.reg_password
    try:
        # Step 1: Create a new user in Firebase
        user = auth.create_user(email=email, password=password)
        st.success("Registration successful! Sending verification email...")

        # Step 2: Sign in the user programmatically to get the id_token
        url = f'https://identitytoolkit.googleapis.com/v1/accounts:signInWithPassword?key={FIREBASE_API_KEY}'
        data = {
            'email': email,
            'password': password,
            'returnSecureToken': True
        }
        response = requests.post(url, json=data)
        result = response.json()

        if 'idToken' in result:
            id_token = result['idToken']  # Retrieve the id_token
            st.session_state.id_token = id_token  # Store the id_token in session state

            # Step 3: Send the verification email
            verification_result = send_verification_email(id_token)
            if verification_result['status'] == 'success':
                st.success(f"Verification email sent to {email}.")
            else:
                st.error(f"Failed to send verification email: {verification_result['message']}")
        else:
            st.error(f"Failed to retrieve id_token: {result['error']['message']}")
    except Exception as e:
        st.error(f"Registration failed: {e}")

# Callback for login
def login_callback():
    email = st.session_state.login_email
    password = st.session_state.login_password
    try:
        # Authenticate user with Firebase
        user = auth.get_user_by_email(email)
        st.session_state.logged_in = True
        st.session_state.current_user = user.uid  # Store the user UID in session state
        st.success("Logged in successfully!")
    except Exception as e:
        st.error(f"Login failed: {e}")

# Callback for logout
def logout_callback():
    st.session_state.logged_in = False
    st.session_state.current_user = None
    st.info("Logged out successfully!")

# Function to store text in Firebase Realtime Database
def store_text_in_db(user_id, text):
    try:
        ref = db.reference(f'users/{user_id}/texts')
        new_text_ref = ref.push()
        new_text_ref.set({
            'text': text,
            'timestamp': firebase_admin.db.ServerValue.TIMESTAMP
        })
        st.success("Text saved successfully!")
    except Exception as e:
        st.error(f"Failed to save text: {e}")

# Registration form
def registration_form():
    with st.form("Registration"):
        st.subheader("Register")
        email = st.text_input("Email", key="reg_email")
        password = st.text_input("Password (min 6 characters)", type="password", key="reg_password")
        submit_button = st.form_submit_button("Register", on_click=register_callback)

# Login form
def login_form():
    with st.form("Login"):
        st.subheader("Login")
        email = st.text_input("Email", key="login_email")
        password = st.text_input("Password", type="password", key="login_password")
        submit_button = st.form_submit_button("Login", on_click=login_callback)

# Main app screen (after login)
def main_app():
    st.subheader(f"Welcome, {st.session_state.current_user}!")
    st.write("Enter a name below to get a greeting.")

    # Input field for name
    name = st.text_input("Enter a name", key="name_input")

    # Display greeting in real-time
    if name:
        st.write(f"Hello {name}!")
        # Store the entered text in Firebase Realtime Database
        store_text_in_db(st.session_state.current_user, name)

    # Logout button
    if st.button("Logout", on_click=logout_callback):
        pass

# Render the appropriate screen based on login status
if st.session_state.logged_in:
    main_app()
else:
    registration_form()
    login_form()