import streamlit as st
import sqlite3
import plotly.express as px
import pandas as pd
from PIL import Image
import re
import secrets
import bcrypt
import smtplib
from email.mime.text import MIMEText
import logging
from datetime import datetime

# Logging setup
logging.basicConfig(
    filename='app.log',
    level=logging.INFO,
    format='%(asctime)s - %(levelname)s - %(message)s'
)
logger = logging.getLogger()

# Database setup
def init_db():
    try:
        conn = sqlite3.connect('users.db')
        c = conn.cursor()
        c.execute('''CREATE TABLE IF NOT EXISTS users 
                     (id INTEGER PRIMARY KEY, name TEXT, username TEXT UNIQUE, email TEXT UNIQUE, password BLOB, reset_token TEXT)''')
        conn.commit()
    except sqlite3.Error as e:
        logger.error(f"Database initialization failed: {str(e)}")
        st.error("An error occurred while setting up the database.")
    finally:
        conn.close()

# Hash password
def hash_password(password):
    return bcrypt.hashpw(password.encode('utf-8'), bcrypt.gensalt())

# Check password
def check_password(password, hashed):
    return bcrypt.checkpw(password.encode('utf-8'), hashed)

# Login function
def login(username_email, password):
    try:
        conn = sqlite3.connect('users.db')
        c = conn.cursor()
        c.execute("SELECT * FROM users WHERE (username=? OR email=?)", (username_email, username_email))
        user = c.fetchone()
        if user and check_password(password, user[4]):  # user[4] is password column (BLOB)
            logger.info(f"User {username_email} logged in successfully.")
            return user
        logger.warning(f"Login failed for {username_email}: Invalid credentials.")
        return None
    except sqlite3.Error as e:
        logger.error(f"Login database error: {str(e)}")
        st.error("A database error occurred during login.")
        return None
    finally:
        conn.close()

# Create account function
def create_account(name, username, email, password):
    try:
        hashed_password = hash_password(password)  # Returns bytes
        conn = sqlite3.connect('users.db')
        c = conn.cursor()
        c.execute("INSERT INTO users (name, username, email, password) VALUES (?, ?, ?, ?)",
                  (name, username, email, hashed_password))
        conn.commit()
        logger.info(f"New account created: {username} ({email})")
        return True
    except sqlite3.IntegrityError as e:
        conn.close()
        if "username" in str(e):
            st.error("Username already exists!")
        elif "email" in str(e):
            st.error("Email already exists!")
        logger.warning(f"Account creation failed: {str(e)}")
        return False
    except sqlite3.Error as e:
        logger.error(f"Account creation database error: {str(e)}")
        st.error("A database error occurred during account creation.")
        return False
    finally:
        conn.close()

# Update profile function
def update_profile(user_id, name, username, email):
    try:
        conn = sqlite3.connect('users.db')
        c = conn.cursor()
        c.execute("UPDATE users SET name=?, username=?, email=? WHERE id=?",
                  (name, username, email, user_id))
        conn.commit()
        logger.info(f"Profile updated for user ID {user_id}")
        return True
    except sqlite3.IntegrityError as e:
        conn.close()
        if "username" in str(e):
            st.error("Username already taken!")
        elif "email" in str(e):
            st.error("Email already in use!")
        logger.warning(f"Profile update failed: {str(e)}")
        return False
    except sqlite3.Error as e:
        logger.error(f"Profile update database error: {str(e)}")
        st.error("A database error occurred during profile update.")
        return False
    finally:
        conn.close()

# Send reset email
def send_reset_email(email, token):
    sender_email = "your_email@example.com"  # Replace with your email
    sender_password = "your_password"       # Replace with your email password/app-specific password
    subject = "Password Reset Request"
    body = f"Your password reset token is: {token}\n\nThis token is valid for 15 minutes."
    msg = MIMEText(body)
    msg['Subject'] = subject
    msg['From'] = sender_email
    msg['To'] = email

    try:
        with smtplib.SMTP('smtp.gmail.com', 587) as server:  # Example for Gmail
            server.starttls()
            server.login(sender_email, sender_password)  # Fixed argument order
            server.send_message(msg)
        logger.info(f"Reset email sent to {email}")
        return True
    except Exception as e:
        logger.error(f"Failed to send reset email to {email}: {str(e)}")
        st.error("Failed to send reset email. Please try again later.")
        return False

# Generate reset token
def generate_reset_token(email):
    try:
        token = secrets.token_urlsafe(16)
        conn = sqlite3.connect('users.db')
        c = conn.cursor()
        c.execute("UPDATE users SET reset_token=? WHERE email=?", (token, email))
        affected = conn.total_changes
        conn.commit()
        if affected > 0 and send_reset_email(email, token):
            return token
        logger.warning(f"No user found with email {email} for reset token")
        return None
    except sqlite3.Error as e:
        logger.error(f"Reset token database error: {str(e)}")
        st.error("A database error occurred during token generation.")
        return None
    finally:
        conn.close()

# Reset password function
def reset_password(token, new_password):
    try:
        hashed_password = hash_password(new_password)  # Returns bytes
        conn = sqlite3.connect('users.db')
        c = conn.cursor()
        c.execute("UPDATE users SET password=?, reset_token=NULL WHERE reset_token=?", 
                  (hashed_password, token))
        affected = conn.total_changes
        conn.commit()
        if affected > 0:
            logger.info(f"Password reset successfully with token {token}")
        else:
            logger.warning(f"Password reset failed: Invalid token {token}")
        return affected > 0
    except sqlite3.Error as e:
        logger.error(f"Reset password database error: {str(e)}")
        st.error("A database error occurred during password reset.")
        return False
    finally:
        conn.close()

# Input validation
def validate_email(email):
    pattern = r'^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$'
    return re.match(pattern, email) is not None

def validate_password(password):
    return len(password) >= 8 and any(c.isupper() for c in password) and any(c.isdigit() for c in password)

# Enhanced Custom CSS
def load_css():
    st.markdown("""
    <style>
    .stApp {
        background: linear-gradient(135deg, #e0eafc, #cfdef3);
        font-family: 'Arial', sans-serif;
    }
    .stButton>button {
        background-color: #4CAF50;
        color: white;
        border-radius: 8px;
        padding: 10px 20px;
        transition: background-color 0.3s;
    }
    .stButton>button:hover {
        background-color: #45a049;
    }
    .stTextInput>input {
        border-radius: 8px;
        border: 2px solid #ccc;
        padding: 8px;
        transition: border-color 0.3s;
    }
    .stTextInput>input:focus {
        border-color: #4CAF50;
    }
    .title {
        color: #2c3e50;
        font-size: 2.8em;
        text-align: center;
        font-weight: bold;
        margin-bottom: 20px;
    }
    .sidebar .sidebar-content {
        background-color: #ffffff;
        border-radius: 10px;
        padding: 15px;
        box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
    }
    .stSelectbox {
        border-radius: 8px;
    }
    </style>
    """, unsafe_allow_html=True)

# Main application
def main():
    init_db()
    load_css()
    
    if 'page' not in st.session_state:
        st.session_state.page = 'login'
    if 'logged_in' not in st.session_state:
        st.session_state.logged_in = False

    # Sidebar
    with st.sidebar:
        st.image("https://via.placeholder.com/100", caption="App Logo")  # Placeholder logo
        st.title("Navigation")
        if st.session_state.logged_in:
            st.write(f"Welcome, {st.session_state.username}!")
            st.progress(100)  # Example of interactive element
            menu = ["Profile", "Data Visualization", "Emotion Analysis", "Logout"]
            choice = st.selectbox("Menu", menu, key="sidebar_menu")
            if choice == "Logout" and st.button("Confirm Logout", key="logout"):
                st.session_state.logged_in = False
                st.session_state.page = 'login'
                logger.info(f"User {st.session_state.username} logged out.")
                st.rerun()
            elif choice == "Profile":
                st.session_state.page = 'profile'
            elif choice == "Data Visualization":
                st.session_state.page = 'data_visualization'
            elif choice == "Emotion Analysis":
                st.session_state.page = 'main'
        else:
            col1, col2 = st.columns(2)
            with col1:
                if st.button("Create Account", key="create_account_btn"):
                    st.session_state.page = 'create_account'
            with col2:
                if st.button("Reset Password", key="reset_pass_btn"):
                    st.session_state.page = 'reset_password'

    # Page routing
    if st.session_state.page == 'login' and not st.session_state.logged_in:
        st.markdown('<p class="title">Login</p>', unsafe_allow_html=True)
        with st.form(key='login_form'):
            username_email = st.text_input("Username or Email", placeholder="Enter username or email")
            password = st.text_input("Password", type="password", placeholder="Enter password")
            submit_button = st.form_submit_button(label="Login")
        
        if submit_button:
            if not username_email or not password:
                st.error("Please fill in all fields!")
            else:
                user = login(username_email, password)
                if user:
                    st.session_state.logged_in = True
                    st.session_state.user_id = user[0]
                    st.session_state.username = user[2]
                    st.session_state.page = 'data_visualization'
                    st.success("Logged in successfully!")
                    st.balloons()  # Interactive UI element
                    st.rerun()
                else:
                    st.error("Invalid username/email or password!")

    elif st.session_state.page == 'create_account' and not st.session_state.logged_in:
        st.markdown('<p class="title">Create Account</p>', unsafe_allow_html=True)
        with st.form(key='create_account_form'):
            name = st.text_input("Full Name", placeholder="Enter your full name")
            username = st.text_input("Username", placeholder="Choose a username")
            email = st.text_input("Email", placeholder="Enter your email")
            password = st.text_input("Password", type="password", placeholder="Create a password")
            submit_button = st.form_submit_button(label="Submit")
        
        if submit_button:
            if not all([name, username, email, password]):
                st.error("All fields are required!")
            elif not validate_email(email):
                st.error("Invalid email format!")
            elif not validate_password(password):
                st.error("Password must be 8+ characters with uppercase and numbers!")
            elif create_account(name, username, email, password):
                st.success("Account created successfully!")
                st.session_state.page = 'login'
                st.rerun()

    elif st.session_state.page == 'reset_password' and not st.session_state.logged_in:
        st.markdown('<p class="title">Reset Password</p>', unsafe_allow_html=True)
        step = st.session_state.get('reset_step', 'request')
        
        if step == 'request':
            with st.form(key='reset_request_form'):
                email = st.text_input("Email", placeholder="Enter your email")
                submit_button = st.form_submit_button(label="Request Reset")
            if submit_button:
                if not validate_email(email):
                    st.error("Invalid email format!")
                else:
                    token = generate_reset_token(email)
                    if token:
                        st.success("A reset token has been sent to your email!")
                        st.session_state.reset_step = 'reset'
                        st.session_state.reset_email = email
                        st.rerun()
                    else:
                        st.error("Email not found or email sending failed!")

        elif step == 'reset':
            with st.form(key='reset_form'):
                token = st.text_input("Reset Token", placeholder="Enter the token from your email")
                new_password = st.text_input("New Password", type="password", placeholder="Enter new password")
                submit_button = st.form_submit_button(label="Reset Password")
            if submit_button:
                if not validate_password(new_password):
                    st.error("Password must be 8+ characters with uppercase and numbers!")
                elif reset_password(token, new_password):
                    st.success("Password reset successfully!")
                    st.session_state.page = 'login'
                    del st.session_state['reset_step']
                    st.rerun()
                else:
                    st.error("Invalid or expired token!")

    elif st.session_state.logged_in and st.session_state.page == 'profile':
        st.markdown('<p class="title">User Profile</p>', unsafe_allow_html=True)
        conn = sqlite3.connect('users.db')
        c = conn.cursor()
        c.execute("SELECT name, username, email FROM users WHERE id=?", (st.session_state.user_id,))
        user = c.fetchone()
        conn.close()
        
        with st.form(key='profile_form'):
            name = st.text_input("Full Name", value=user[0], placeholder="Update your name")
            username = st.text_input("Username", value=user[1], placeholder="Update your username")
            email = st.text_input("Email", value=user[2], placeholder="Update your email")
            submit_button = st.form_submit_button(label="Update Profile")
        
        if submit_button:
            if not all([name, username, email]):
                st.error("All fields are required!")
            elif not validate_email(email):
                st.error("Invalid email format!")
            elif update_profile(st.session_state.user_id, name, username, email):
                st.session_state.username = username
                st.success("Profile updated successfully!")
                st.rerun()

    elif st.session_state.logged_in and st.session_state.page == 'data_visualization':
        st.markdown('<p class="title">Data Visualization</p>', unsafe_allow_html=True)
        st.write("""
        ### Models Overview
        - **Custom CNN**: Custom-built Convolutional Neural Network designed for emotion recognition
        - **MobileNetV2**: Lightweight deep learning model optimized for mobile devices
        - **VGG19**: Deep 19-layer convolutional neural network for image classification
        """)
        emotions = ['Happiness', 'Neutral', 'Sadness', 'Anger', 'Surprise', 'Disgust', 'Fear']
        counts = [5000, 6000, 5500, 4500, 4000, 3500, 4200]
        df = pd.DataFrame({'Emotion': emotions, 'Count': counts})
        fig = px.bar(df, x='Emotion', y='Count', title='Emotion Distribution in Dataset', color='Emotion')
        st.plotly_chart(fig)
        if st.button("Next Page", key="next_page"):
            st.session_state.page = 'main'
            st.rerun()

    elif st.session_state.logged_in and st.session_state.page == 'main':
        st.markdown('<p class="title">Emotion Recognition & Analysis</p>', unsafe_allow_html=True)
        model = st.selectbox("Select Model", ["Custom CNN", "MobileNetV2", "VGG19"], key="model_select")
        if model:
            uploaded_file = st.file_uploader("Upload an image", type=['jpg', 'png', 'jpeg'], key="file_uploader")
            if uploaded_file is not None:
                image = Image.open(uploaded_file)
                st.image(image, caption='Uploaded Image', use_container_width=True)
                with st.spinner(f"Processing with {model}..."):
                    # Placeholder for model prediction
                    st.write("Analysis complete (placeholder).")

if __name__ == "__main__":
    main()