"""
Main script to run the LLM chatbot using the Zigistry framework

This script performs the following tasks:
    1. Perform pre-requisites check
    2. Configure LLM and embedding model
    3. Data ingestion
    4. Query handling
    5. Launch the chatbot interface
"""

# --- Importing required libraries ---
from zigistry import constants
from llama_index.llms.openrouter import OpenRouter
from llama_index.core.llms import ChatMessage
from zigistry import pre_requisite
import gradio as gr
from llama_index.core import (
    StorageContext,
    load_index_from_storage,
    VectorStoreIndex,
    SimpleDirectoryReader,
    ChatPromptTemplate,
    Settings,
)
from llama_index.llms.huggingface_api import HuggingFaceInferenceAPI
from llama_index.embeddings.huggingface import HuggingFaceEmbedding

# -------------------------------------


# --- Perform pre-requisites and pre-requisite check ---
pre_requisite.performPreRequisites()

if not pre_requisite.CorrectlyCompletedPreRequisites():
    exit(1)
# ------------------------------------------------------


# --- Configure LLM and embedding model ---
Settings.llm = OpenRouter(
    model_name=constants.LLM,
    api_key=constants.OR_TOKEN,
    context_window=3000,
    max_tokens=512,
    temperature=constants.TEMPERATURE,
)

Settings.embed_model = HuggingFaceEmbedding(model_name=constants.EMBEDDER)
# -----------------------------------------


def data_ingestion():
    """
    Ingest data from the input files and create an index
    """
    documents = SimpleDirectoryReader(input_files=constants.FILES).load_data()
    index = VectorStoreIndex.from_documents(documents)
    index.storage_context.persist(persist_dir=constants.PERSIST_DIR)


def handle_query(query):
    """
    Handle the query and return the response
    """
    storage_context = StorageContext.from_defaults(persist_dir=constants.PERSIST_DIR)
    index = load_index_from_storage(storage_context)
    text_qa_template = ChatPromptTemplate.from_messages(constants.LLM_RESPONSE_FORMAT)
    query_engine = index.as_query_engine(text_qa_template=text_qa_template)

    answer = query_engine.query(query)
    if hasattr(answer, "response"):
        return answer.response
    if isinstance(answer, dict) and "response" in answer:
        return answer["response"]
    return "Sorry, I couldn't find an answer."


if __name__ == "__main__":
    data_ingestion()

    # --- Launch the chatbot interface ---
    demo = gr.Interface(
        fn=handle_query,
        inputs="text",
        outputs="text",
        title="LLM Chatbot",
        flagging_mode="never",
    )
    demo.launch()
    # -------------------------------------