import random
from functools import partial
from typing import List, Tuple

import gradio as gr

from refresh_bots import BotCache


def middchat(bot_cache: BotCache, message: str, history: List[Tuple[str, str]]) -> str:
    """
    Generate a message given a message history and bots

    Args:
        bot_cache (BotCache): a bot cache to get bot classes from
        message (str): the message sent by the user
        history (List[Tuple[str, str]]): history of messages/responses

    Returns:
        str: bot's response
    """
    # get the bot options
    # for new chats, fetch new bots
    if message == "update bots" or len(history) <= 1:
        all_bots = bot_cache.update()
    else:
        all_bots = bot_cache.bots

    # check to see if the bot was set in the message history
    bot = None
    bot_set_id = None
    for i, (historical_message, _) in enumerate(history):
        # check if a bot has already been selected
        if historical_message.strip() in all_bots:
            # initialize the bot and store ID to start history of coversation
            # with the bot directly.
            bot = all_bots[historical_message.strip()]()
            bot_set_id = i

    # If the bot wasn't set before, check if the current message includes
    # a valid bot ID. If it does, tell the user that they are now successfully
    # chatting with the bot.
    # If it doesn't, tell the user about the options again.
    if bot is None:
        if message.strip() in all_bots:
            return f"You're now chatting with {message.strip()}! \
                If you aren't sure what to say, type \"examples\""
        else:
            bot_options = "Please choose one of the following bots:\n"
            bot_options += "\n".join(f"* {bot}" for bot in all_bots.keys())
            return bot_options

    # Unfortunately, the only way that the gradio chat interface keeps track
    # of individual user's sessions is through the chat history. This means
    # that there isn't a good way to create a bot that keeps track of state
    # for different users on the server with instance variables.
    # This is an inefficient workaround: re-initialize the bot and go through
    # the full set of replies each time...
    random.seed(457)
    for historical_message, _ in history[bot_set_id + 1:]:
        bot.make_reply(historical_message)

    if message.strip().lower() == "examples":
        return "Here are some things you might want to say to me:\n" + \
            "\n".join(f"* {ex}" for ex in bot.examples())

    return bot.make_reply(message)

cache = BotCache()
chat_partial = partial(middchat, cache)
initial_msg = "Welcome to MiddChat! Type anything to get a list of available bots.\nPlease note that if you want to reset your chat, you should refresh this page!\nIf you want to update the bot list, type \"update bots\""
chatbot = gr.Chatbot([(initial_msg, None)])
demo = gr.ChatInterface(
    fn=chat_partial,
    chatbot=chatbot,
    title="MiddChat")

demo.launch(share=True)