"""
This script is a simple web demo based on Streamlit, showcasing the use of the ChatGLM3-6B model. For a more comprehensive web demo,
it is recommended to use 'composite_demo'.

Usage:
- Run the script using Streamlit: `streamlit run web_demo_streamlit.py`
- Adjust the model parameters from the sidebar.
- Enter questions in the chat input box and interact with the ChatGLM3-6B model.

Note: Ensure 'streamlit' and 'transformers' libraries are installed and the required model checkpoints are available.
"""

import os
import streamlit as st
import torch
from transformers import AutoModel, AutoTokenizer

MODEL_PATH = os.environ.get('MODEL_PATH', 'THUDM/chatglm3-6b')
TOKENIZER_PATH = os.environ.get("TOKENIZER_PATH", MODEL_PATH)

st.set_page_config(
    page_title="ChatGLM3-6B Streamlit Simple Demo",
    page_icon=":robot:",
    layout="wide"
)


@st.cache_resource
def get_model():

    tokenizer = AutoTokenizer.from_pretrained(TOKENIZER_PATH, trust_remote_code=True)
    model = AutoModel.from_pretrained(MODEL_PATH, trust_remote_code=True, device_map="auto").eval()
    return tokenizer, model


# 加载Chatglm3的model和tokenizer
tokenizer, model = get_model()

if "history" not in st.session_state:
    st.session_state.history = []
if "past_key_values" not in st.session_state:
    st.session_state.past_key_values = None

max_length = st.sidebar.slider("max_length", 0, 32768, 8192, step=1)
top_p = st.sidebar.slider("top_p", 0.0, 1.0, 0.8, step=0.01)
temperature = st.sidebar.slider("temperature", 0.0, 1.0, 0.6, step=0.01)

buttonClean = st.sidebar.button("清理会话历史", key="clean")
if buttonClean:
    st.session_state.history = []
    st.session_state.past_key_values = None
    if torch.cuda.is_available():
        torch.cuda.empty_cache()
    st.rerun()

for i, message in enumerate(st.session_state.history):
    if message["role"] == "user":
        with st.chat_message(name="user", avatar="user"):
            st.markdown(message["content"])
    else:
        with st.chat_message(name="assistant", avatar="assistant"):
            st.markdown(message["content"])

with st.chat_message(name="user", avatar="user"):
    input_placeholder = st.empty()
with st.chat_message(name="assistant", avatar="assistant"):
    message_placeholder = st.empty()

prompt_text = st.chat_input("请输入您的问题")
if prompt_text:
    input_placeholder.markdown(prompt_text)
    history = st.session_state.history
    past_key_values = st.session_state.past_key_values
    for response, history, past_key_values in model.stream_chat(
            tokenizer,
            prompt_text,
            history,
            past_key_values=past_key_values,
            max_length=max_length,
            top_p=top_p,
            temperature=temperature,
            return_past_key_values=True,
    ):
        message_placeholder.markdown(response)
    st.session_state.history = history
    st.session_state.past_key_values = past_key_values