import streamlit as st
import sqlite3
from passlib.hash import bcrypt
import pandas as pd
import re
import warnings
warnings.filterwarnings("ignore", message="module 'bcrypt' has no attribute '__about__'")
if "is_starting" not in st.session_state:
    st.session_state["is_starting"] = True

if "authenticated" not in st.session_state:
    st.session_state["authenticated"] = False

from pages.About import show_about
from pages.Text_prompt import show_text_prompt
from pages.Multimodal import show_multimodal
from pages.Settings import show_settings


if "authenticated" not in st.session_state:
    st.session_state["authenticated"] = False

def create_usertable():
    conn = sqlite3.connect('users.db')
    c = conn.cursor()
    c.execute('CREATE TABLE IF NOT EXISTS userstable(username TEXT, password TEXT)')
    c.execute('CREATE TABLE IF NOT EXISTS system_instructions(username TEXT PRIMARY KEY, instruction TEXT)')
    c.execute('CREATE TABLE IF NOT EXISTS user_prompts(id INTEGER PRIMARY KEY AUTOINCREMENT, username TEXT, prompt_time TEXT, prompt_type TEXT)')
    conn.commit()
    conn.close()

def add_userdata(username, password):
    conn = sqlite3.connect('users.db')
    c = conn.cursor()
    c.execute('INSERT INTO userstable(username, password) VALUES (?,?)', (username, password))
    conn.commit()
    conn.close()

def login_user(username, password):
    conn = sqlite3.connect('users.db')
    c = conn.cursor()
    c.execute('SELECT password FROM userstable WHERE username =?', (username,))
    stored_hash = c.fetchone()
    conn.close()
    
    if stored_hash:
        stored_hash = stored_hash[0]
        return check_hashes(password, stored_hash)
    else:
        return False

def view_all_users():
    conn = sqlite3.connect('users.db')
    c = conn.cursor()
    c.execute('SELECT * FROM userstable')
    data = c.fetchall()
    conn.close()
    return data

# --- Hashing ---
def make_hashes(password):
    return bcrypt.hash(password)

def check_hashes(password, hashed_text):
    return bcrypt.verify(password, hashed_text)

# --- Authentication ---
def authenticate(username, password):
    return login_user(username, password)

def logout():
    del st.session_state["authenticated"]
    del st.session_state["username"]
    del st.session_state["page"]

# --- Initialize session state ---
if "authenticated" not in st.session_state:
    st.session_state["authenticated"] = False
if "username" not in st.session_state:
    st.session_state["username"] = None
if "page" not in st.session_state:
    st.session_state["page"] = "login"

# --- Login page ---
def login_page():
    st.title("User Authentication System")
    st.subheader("Login Section")
    username = st.text_input("User Name")
    password = st.text_input("Password", type='password')
    if st.button("Login"):
        result = authenticate(username.lower(), password)
        if result:
            st.session_state["authenticated"] = True
            st.session_state["username"] = username
            st.success("Logged In as {}".format(username))
            st.session_state["page"] = "main"
            st.session_state["is_starting"] = False
            st.rerun()
        else:
            st.warning("Incorrect Username/Password")

    st.write("Don't have an account? Click Signup.")
    # --- Signup button ---
    if st.button("Signup"):
        st.session_state["page"] = "signup"
        st.rerun()

# --- Signup page ---
def signup_page():
    st.subheader("Create New Account")
    new_user = st.text_input("Username")
    new_password = st.text_input("Password", type='password')
    
    # Display password requirements
    st.write("Password Requirements:")
    st.write("* Minimum length: 8 characters")
    st.write("* Mix of uppercase and lowercase letters")
    st.write("* At least one number")
    st.write("* At least one special character")
    
    # Validate password strength
    col1, col2 = st.columns([1, 1])
    if col1.button("Signup"):
        password_strength = validate_password(new_password)
        if password_strength:
            # Check if username already exists
            conn = sqlite3.connect('users.db')
            c = conn.cursor()
            c.execute('SELECT * FROM userstable WHERE username=?', (new_user,))
            existing_user = c.fetchone()
            conn.close()
            
            if existing_user:
                st.error("Username already exists. Please choose a different username.")
            else:
                hashed_new_password = make_hashes(new_password)
                add_userdata(new_user, hashed_new_password)
                st.success("You have successfully created a valid Account")
                st.info("Go to Login Menu to login")
                st.session_state["page"] = "login"
                st.rerun()
        else:
            st.error("Password does not meet the requirements.")
    if col2.button("Cancel"):
        st.session_state["page"] = "login"
        st.rerun()

# --- Validate password strength ---
def validate_password(password):
    # Define password requirements
    min_length = 8
    has_uppercase = re.search(r"[A-Z]", password)
    has_lowercase = re.search(r"[a-z]", password)
    has_number = re.search(r"\d", password)
    has_symbol = re.search(r"[!@#$%^&*()_+=-{};:'<>,./?]", password)
    
    # Check if password meets all requirements
    if (len(password) >= min_length and 
        has_uppercase and 
        has_lowercase and 
        has_number and 
        has_symbol):
        return True
    else:
        return False

# --- Manage users page ---
def manage_users_page():
    st.subheader("User Management")
    user_result = view_all_users()
    clean_db = pd.DataFrame(user_result, columns=["Username", "Password"])
    st.dataframe(clean_db)

# --- Main app ---
def main():
    create_usertable()

    if st.session_state["page"] == "login":
        login_page()
    elif st.session_state["page"] == "signup":
        signup_page()
    else:

        st.title("Welcome")
        st.write("This is the Welcome page.")
    
        # Display username and logout button on every page
        st.sidebar.write(f"Welcome, {st.session_state['username']}")
        if st.sidebar.button("Logout"):
            logout()
            st.rerun()

 
if __name__ == "__main__":
    main()