import streamlit as st
import random
import time
import hmac
import bcrypt
import os

st.header(" Scientific Claim Verification ")

def check_password():
    """Returns `True` if the user had a correct password."""

    def login_form():
        """Form with widgets to collect user information"""
        with st.form("Credentials"):
            st.text_input("Username", key="username")
            st.text_input("Password", type="password", key="password")
            st.form_submit_button("Log in", on_click=password_entered)

    def password_entered():
        """Checks whether a password entered by the user is correct."""

        stored_password = os.getenv(st.session_state["username"])
        if stored_password == st.session_state["password"]:
            st.session_state["password_correct"] = True
            del st.session_state["password"]  # Remove credentials from session
            del st.session_state["username"]
            return
        
        # if st.session_state["username"] in st.secrets["passwords"]:
        #     stored_hashed_password = st.secrets["passwords"][st.session_state["username"]]  # Retrieved as a string

        #     # Convert hashed password back to bytes if it's stored as a string
        #     if isinstance(stored_hashed_password, str):
        #         stored_hashed_password = stored_hashed_password.encode()

        #     # Compare user-entered password (encoded) with stored hash
        #     if bcrypt.checkpw(st.session_state["password"].encode(), stored_hashed_password):
        #         st.session_state["password_correct"] = True
        #         del st.session_state["password"]  # Remove credentials from session
        #         del st.session_state["username"]
        #         return

          # If authentication fails
        st.session_state["password_correct"] = False

    # Return True if the username + password is validated.
    if st.session_state.get("password_correct", False):
        return True

    # Show inputs for username + password.
    login_form()
    if "password_correct" in st.session_state:
        st.error("😕 User not known or password incorrect")
    return False


if not check_password():
    st.stop()

#Start of the Agentic Demo

st.caption("Team UMBC-SBU-UT")

# Initialize chat history
if "messages" not in st.session_state:
    st.session_state.messages = [{"role": "assistant", "content": "Let's start verifying the claims here! 👇"}]

# Display chat messages from history on app rerun
for message in st.session_state.messages:
    with st.chat_message(message["role"]):
        st.markdown(message["content"])

def retriever(query: str):
    """Simulate a 'retriever' step, searching for relevant information."""
    with st.chat_message("assistant"):
        placeholder = st.empty()
        text=""
        message = "Retrieving the documents related to the claim..."
        for chunk in message.split():
            text += chunk + " "
            time.sleep(0.05)
            # Add a blinking cursor to simulate typing
            placeholder.markdown(text + "▌")
        placeholder.markdown(text)
    # You could return retrieved info here.
    return message

def reasoner(info: list[str]):
    """Simulate a 'reasoner' step, thinking about how to answer."""
    with st.chat_message("assistant"):
        placeholder = st.empty()
        text=""
        message = "Reasoning and verifying the claim..."
        for chunk in message.split():
            text += chunk + " "
            time.sleep(0.05)
            # Add a blinking cursor to simulate typing
            placeholder.markdown(text + "▌")
        placeholder.markdown(text)
    # You could return reasoning info here.
    return message

# Accept user input
if prompt := st.chat_input("Type here"):
    # Add user message to chat history
    st.session_state.messages.append({"role": "user", "content": prompt})
    # Display user message in chat message container
    with st.chat_message("user"):
        st.markdown(prompt)


    retrieved_documents=retriever(prompt)

   
    reasoning = reasoner(retrieved_documents)

    # Display assistant response in chat message container
    with st.chat_message("assistant"):
        message_placeholder = st.empty()
        full_response = ""
        assistant_response = random.choice(
            [
                "The claim is correct.",
                "The claim is incorrect.",
            ]
        )

        # Simulate stream of response with milliseconds delay
        for chunk in assistant_response.split():
            full_response += chunk + " "
            time.sleep(0.05)
            # Add a blinking cursor to simulate typing
            message_placeholder.markdown(full_response + "▌")
        message_placeholder.markdown(full_response)
    # Add assistant response to chat history
    st.session_state.messages.append({"role": "assistant", "content": full_response})