# app.py
# Advanced AI R&D Assistant for Hugging Face Spaces
#
# This app leverages LangGraph, DeepSeek-R1 via text-based function calling, and Agentic RAG.
# API keys are securely loaded via environment variables.
#
# To deploy:
# 1. Add your API key to Hugging Face Space secrets with the key DEEP_SEEK_API.
# 2. Ensure your requirements.txt includes langchain-community.
# 3. Run the app with Streamlit.

import os
import re
import logging
import streamlit as st
import requests
from typing import Sequence
from typing_extensions import TypedDict, Annotated

# Updated imports for LangChain
from langchain.embeddings.openai import OpenAIEmbeddings
from langchain.vectorstores import Chroma
from langchain.schema import HumanMessage, AIMessage
from langchain.text_splitter import RecursiveCharacterTextSplitter
from langchain.tools.retriever import create_retriever_tool

# Imports for LangGraph remain the same
from langgraph.graph import END, StateGraph, START
from langgraph.prebuilt import ToolNode
from langgraph.graph.message import add_messages

# Configure logging
logging.basicConfig(level=logging.INFO)
logger = logging.getLogger(__name__)

# --- Dummy Data Setup ---
research_texts = [
    "Research Report: Results of a New AI Model Improving Image Recognition Accuracy to 98%",
    "Academic Paper Summary: Why Transformers Became the Mainstream Architecture in Natural Language Processing",
    "Latest Trends in Machine Learning Methods Using Quantum Computing"
]

development_texts = [
    "Project A: UI Design Completed, API Integration in Progress",
    "Project B: Testing New Feature X, Bug Fixes Needed",
    "Product Y: In the Performance Optimization Stage Before Release"
]

# --- Preprocessing & Embeddings ---
splitter = RecursiveCharacterTextSplitter(chunk_size=100, chunk_overlap=10)
research_docs = splitter.create_documents(research_texts)
development_docs = splitter.create_documents(development_texts)

embeddings = OpenAIEmbeddings(model="text-embedding-3-large")

research_vectorstore = Chroma.from_documents(
    documents=research_docs,
    embedding=embeddings,
    collection_name="research_collection"
)
development_vectorstore = Chroma.from_documents(
    documents=development_docs,
    embedding=embeddings,
    collection_name="development_collection"
)

research_retriever = research_vectorstore.as_retriever()
development_retriever = development_vectorstore.as_retriever()

research_tool = create_retriever_tool(
    research_retriever,
    "research_db_tool",
    "Search information from the research database."
)
development_tool = create_retriever_tool(
    development_retriever,
    "development_db_tool",
    "Search information from the development database."
)
tools = [research_tool, development_tool]

# --- Agent and Workflow Functions ---
# Note: We are using only AIMessage and HumanMessage for our message types.
class AgentState(TypedDict):
    messages: Annotated[Sequence[AIMessage | HumanMessage], add_messages]

def agent(state: AgentState):
    logger.info("Agent invoked")
    messages = state["messages"]
    user_message = messages[0][1] if isinstance(messages[0], tuple) else messages[0].content

    prompt = f"""Given this user question: "{user_message}"
If it's about research or academic topics, respond EXACTLY in this format:
SEARCH_RESEARCH: <search terms>

If it's about development status, respond EXACTLY in this format:
SEARCH_DEV: <search terms>

Otherwise, just answer directly.
"""
    headers = {
        "Accept": "application/json",
        "Authorization": f"Bearer {os.environ.get('DEEP_SEEK_API')}",
        "Content-Type": "application/json"
    }
    data = {
        "model": "deepseek-chat",
        "messages": [{"role": "user", "content": prompt}],
        "temperature": 0.7,
        "max_tokens": 1024
    }
    response = requests.post(
        "https://api.deepseek.com/v1/chat/completions",
        headers=headers,
        json=data,
        verify=False
    )
    if response.status_code == 200:
        response_text = response.json()['choices'][0]['message']['content']
        logger.info(f"DeepSeek response: {response_text}")
        if "SEARCH_RESEARCH:" in response_text:
            query = response_text.split("SEARCH_RESEARCH:")[1].strip()
            results = research_retriever.invoke(query)
            return {"messages": [AIMessage(content=f'Action: research_db_tool\n{{"query": "{query}"}}\n\nResults: {str(results)}')]}
        elif "SEARCH_DEV:" in response_text:
            query = response_text.split("SEARCH_DEV:")[1].strip()
            results = development_retriever.invoke(query)
            return {"messages": [AIMessage(content=f'Action: development_db_tool\n{{"query": "{query}"}}\n\nResults: {str(results)}')]}
        else:
            return {"messages": [AIMessage(content=response_text)]}
    else:
        error_msg = f"DeepSeek API call failed: {response.text}"
        logger.error(error_msg)
        raise Exception(error_msg)

def simple_grade_documents(state: AgentState):
    last_message = state["messages"][-1]
    logger.info(f"Grading message: {last_message.content}")
    if "Results: [Document" in last_message.content:
        return "generate"
    else:
        return "rewrite"

def generate(state: AgentState):
    logger.info("Generating final answer")
    messages = state["messages"]
    question = messages[0].content if not isinstance(messages[0], tuple) else messages[0][1]
    last_message = messages[-1]
    docs = ""
    if "Results: [" in last_message.content:
        docs = last_message.content[last_message.content.find("Results: ["):]
    headers = {
        "Accept": "application/json",
        "Authorization": f"Bearer {os.environ.get('DEEP_SEEK_API')}",
        "Content-Type": "application/json"
    }
    prompt = f"""Based on these research documents, summarize the latest advancements in AI:
Question: {question}
Documents: {docs}
Focus on extracting and synthesizing the key findings from the research papers.
"""
    data = {
        "model": "deepseek-chat",
        "messages": [{"role": "user", "content": prompt}],
        "temperature": 0.7,
        "max_tokens": 1024
    }
    response = requests.post(
        "https://api.deepseek.com/v1/chat/completions",
        headers=headers,
        json=data,
        verify=False
    )
    if response.status_code == 200:
        response_text = response.json()['choices'][0]['message']['content']
        return {"messages": [AIMessage(content=response_text)]}
    else:
        error_msg = f"DeepSeek API generate call failed: {response.text}"
        logger.error(error_msg)
        raise Exception(error_msg)

def rewrite(state: AgentState):
    logger.info("Rewriting question")
    original_question = state["messages"][0].content if state["messages"] else "N/A"
    headers = {
        "Accept": "application/json",
        "Authorization": f"Bearer {os.environ.get('DEEP_SEEK_API')}",
        "Content-Type": "application/json"
    }
    data = {
        "model": "deepseek-chat",
        "messages": [{"role": "user", "content": f"Rewrite this question to be more specific and clearer: {original_question}"}],
        "temperature": 0.7,
        "max_tokens": 1024
    }
    response = requests.post(
        "https://api.deepseek.com/v1/chat/completions",
        headers=headers,
        json=data,
        verify=False
    )
    if response.status_code == 200:
        response_text = response.json()['choices'][0]['message']['content']
        return {"messages": [AIMessage(content=response_text)]}
    else:
        error_msg = f"DeepSeek API rewrite call failed: {response.text}"
        logger.error(error_msg)
        raise Exception(error_msg)

tools_pattern = re.compile(r"Action: .*")
def custom_tools_condition(state: AgentState):
    last_message = state["messages"][-1]
    if tools_pattern.match(last_message.content):
        return "tools"
    return END

# Build the workflow with LangGraph's StateGraph
workflow = StateGraph(AgentState)
workflow.add_node("agent", agent)
retrieve_node = ToolNode(tools)
workflow.add_node("retrieve", retrieve_node)
workflow.add_node("rewrite", rewrite)
workflow.add_node("generate", generate)
workflow.add_edge(START, "agent")
workflow.add_conditional_edges("agent", custom_tools_condition, {"tools": "retrieve", END: END})
workflow.add_conditional_edges("retrieve", simple_grade_documents)
workflow.add_edge("generate", END)
workflow.add_edge("rewrite", "agent")
app_workflow = workflow.compile()

def process_question(user_question, app, config):
    events = []
    for event in app.stream({"messages": [("user", user_question)]}, config):
        events.append(event)
    return events

# --- Streamlit UI ---
def main():
    st.set_page_config(page_title="Advanced AI R&D Assistant", layout="wide", initial_sidebar_state="expanded")
    st.markdown(
        """
        <style>
        .stApp { background-color: #f8f9fa; }
        .stButton > button { width: 100%; margin-top: 20px; }
        .data-box { padding: 20px; border-radius: 10px; margin: 10px 0; }
        .research-box { background-color: #e3f2fd; border-left: 5px solid #1976d2; }
        .dev-box { background-color: #e8f5e9; border-left: 5px solid #43a047; }
        </style>
        """, unsafe_allow_html=True
    )

    # Sidebar: Display available data
    with st.sidebar:
        st.header("📚 Available Data")
        st.subheader("Research Database")
        for text in research_texts:
            st.markdown(f'<div class="data-box research-box">{text}</div>', unsafe_allow_html=True)
        st.subheader("Development Database")
        for text in development_texts:
            st.markdown(f'<div class="data-box dev-box">{text}</div>', unsafe_allow_html=True)

    st.title("🤖 Advanced AI R&D Assistant")
    st.markdown("---")
    query = st.text_area("Enter your question:", height=100, placeholder="e.g., What is the latest advancement in AI research?")

    col1, col2 = st.columns([1, 2])
    with col1:
        if st.button("🔍 Get Answer", use_container_width=True):
            if query:
                with st.spinner('Processing your question...'):
                    events = process_question(query, app_workflow, {"configurable": {"thread_id": "1"}})
                    for event in events:
                        if 'agent' in event:
                            with st.expander("🔄 Processing Step", expanded=True):
                                content = event['agent']['messages'][0].content
                                if "Results:" in content:
                                    st.markdown("### 📑 Retrieved Documents:")
                                    docs = content[content.find("Results:"):]
                                    st.info(docs)
                        elif 'generate' in event:
                            st.markdown("### ✨ Final Answer:")
                            st.success(event['generate']['messages'][0].content)
            else:
                st.warning("⚠️ Please enter a question first!")
    with col2:
        st.markdown(
            """
            ### 🎯 How to Use
            1. Type your question in the text box.
            2. Click "Get Answer" to process.
            3. View retrieved documents and the final answer.
            
            ### 💡 Example Questions
            - What are the latest advancements in AI research?
            - What is the status of Project A?
            - What are the current trends in machine learning?
            """
        )

if __name__ == "__main__":
    main()