import logging
import os
from typing import Optional

import gradio as gr
import pandas as pd

from buster.completers import Completion

import cfg
from cfg import setup_buster

buster = setup_buster(cfg.buster_cfg)

#  suppress httpx logs they are spammy and uninformative
logging.getLogger("httpx").setLevel(logging.WARNING)

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

AVAILABLE_SOURCES = ["towardsai", "wikipedia", "langchain_course"]


def format_sources(matched_documents: pd.DataFrame) -> str:
    if len(matched_documents) == 0:
        return ""

    documents_answer_template: str = "📝 Here are the sources I used to answer your question:\n\n{documents}\n\n{footnote}"
    document_template: str = "[🔗 {document.title}]({document.url}), relevance: {document.similarity_to_answer:2.1f} %"

    matched_documents.similarity_to_answer = (
        matched_documents.similarity_to_answer * 100
    )

    # drop duplicates, keep highest ranking ones
    matched_documents = matched_documents.sort_values(
        "similarity_to_answer", ascending=False
    ).drop_duplicates("title", keep="first")

    documents = "\n".join(
        [
            document_template.format(document=document)
            for _, document in matched_documents.iterrows()
        ]
    )
    footnote: str = "I'm a bot 🤖 and not always perfect."

    return documents_answer_template.format(documents=documents, footnote=footnote)


def add_sources(history, completion):
    if completion.answer_relevant:
        formatted_sources = format_sources(completion.matched_documents)
        history.append([None, formatted_sources])

    return history


def user(user_input, history):
    """Adds user's question immediately to the chat."""
    return "", history + [[user_input, None]]


def get_empty_source_completion(user_input):
    return Completion(
        user_input=user_input,
        answer_text="You have to select at least one source from the dropdown menu.",
        matched_documents=pd.DataFrame(),
        error=False,
    )


def get_answer(history, sources: Optional[list[str]] = None):
    user_input = history[-1][0]

    if len(sources) == 0:
        completion = get_empty_source_completion(user_input)

    else:
        completion = buster.process_input(user_input, sources=sources)

    history[-1][1] = ""

    for token in completion.answer_generator:
        history[-1][1] += token

        yield history, completion


block = gr.Blocks()

with block:
    with gr.Row():
        gr.Markdown(
            "<h3><center>Buster 🤖: A Question-Answering Bot for your documentation</center></h3>"
        )

    source_selection = gr.Dropdown(
        choices=AVAILABLE_SOURCES,
        label="Select Sources",
        value=AVAILABLE_SOURCES,
        multiselect=True,
    )

    chatbot = gr.Chatbot()

    with gr.Row():
        question = gr.Textbox(
            label="What's your question?",
            placeholder="Ask a question to AI stackoverflow here...",
            lines=1,
        )
        submit = gr.Button(value="Send", variant="secondary")

    examples = gr.Examples(
        examples=cfg.example_questions,
        inputs=question,
    )

    gr.Markdown(
        "This application uses ChatGPT to search the docs for relevant info and answer questions. "
        "\n\n### Powered by [Buster 🤖](www.github.com/jerpint/buster)"
    )

    response = gr.State()

    submit.click(user, [question, chatbot], [question, chatbot], queue=False).then(
        get_answer, inputs=[chatbot, source_selection], outputs=[chatbot, response]
    ).then(add_sources, inputs=[chatbot, response], outputs=[chatbot])
    question.submit(user, [question, chatbot], [question, chatbot], queue=False).then(
        get_answer, inputs=[chatbot, source_selection], outputs=[chatbot, response]
    ).then(add_sources, inputs=[chatbot, response], outputs=[chatbot])


block.queue(concurrency_count=16)
block.launch(debug=True, share=False)