#!/usr/bin/env python

import asyncio
import logging
from dataclasses import dataclass
from http import HTTPStatus
from config import BOT_TOKEN, TELEGRAM_WEBHOOK_URL, HEALTHCHECK_URL, FEDI_LOGIN_CALLBACK_URL, BOT_DOMAIN, BOT_PORT

import uvicorn
from starlette.applications import Starlette
from starlette.requests import Request
from starlette.responses import PlainTextResponse, Response
from starlette.routing import Route


from telegram import Update
from telegram.ext import (
    Application,
    CallbackContext,
    ContextTypes,
    ExtBot,
    TypeHandler,
)

from telegram.ext import (
    Application,
    CallbackQueryHandler,
    CommandHandler,
    MessageHandler,
    filters,
    ConversationHandler
)

from callback import (
    callback_generate_fedi_login_url,
    callback_skip_media,
    callback_location_sharing,
    callback_manual_location,
    callback_location_confirmation,
    callback_location_keyword_search,
    callback_skip_location_keyword_search,
    callback_add_comment,
    callback_skip_comment,
    callback_add_media
)
from command import (
    start_command,
    fedi_login_command,
    cancel_command,
    help_command
)
from config import (
    FEDI_LOGIN,
    WAIT_LOCATION,
    LOCATION_SEARCH_KEYWORD,
    LOCATION_CONFIRMATION,
    ADD_MEDIA,
    ADD_COMMENT,
    BOT_TOKEN,
    BOT_SCOPE
)
from mastodon import Mastodon


# Enable logging
logging.basicConfig(
    format="%(asctime)s - %(name)s - %(levelname)s - %(message)s", level=logging.INFO
)
logger = logging.getLogger(__name__)


@dataclass
class FediLoginCallbackUpdate:
    code: str
    state: int


class FediLoginCallbackContext(CallbackContext[ExtBot, dict, dict, dict]):
    @classmethod
    def from_update(
            cls,
            update: object,
            application: "Application",
    ) -> "FediLoginCallbackContext":
        if isinstance(update, FediLoginCallbackUpdate):
            return cls(application=application, user_id=update.state)
        return super().from_update(update, application)


async def process_oauth_login_callback(update: FediLoginCallbackUpdate, context: FediLoginCallbackContext) -> None:
    # query client_id and client_secret from in memory database
    client_id = ""
    client_secret = ""
    home_instance = ""

    mastodon_client = Mastodon(client_id=client_id, client_secret=client_secret, api_base_url=home_instance)
    access_token = mastodon_client.log_in(
        code=update.code,
        redirect_uri="{}{}".format(BOT_DOMAIN, FEDI_LOGIN_CALLBACK_URL),
        scopes=BOT_SCOPE
    )

    # TODO
    # save access_token to database

    text = "You have successfully logged in to your Mastodon account!"
    await context.bot.send_message(chat_id=update.state, text=text)


async def main() -> None:
    context_types = ContextTypes(context=FediLoginCallbackContext)
    # Here we set updater to None because we want our custom webhook server to handle the updates
    # and hence we don't need an Updater instance
    application = (
        Application.builder().token(BOT_TOKEN).context_types(context_types).build()
    )

    checkin_handler = ConversationHandler(
        entry_points=[
            CommandHandler("start", start_command),
            CommandHandler("login", fedi_login_command),
            MessageHandler(filters.LOCATION, callback_location_sharing),
        ],
        states={
            FEDI_LOGIN: [
                MessageHandler(filters.TEXT & ~filters.COMMAND, callback_generate_fedi_login_url),
            ],
            WAIT_LOCATION: [
                MessageHandler(filters.LOCATION, callback_location_sharing),
            ],
            LOCATION_SEARCH_KEYWORD: [
                MessageHandler(filters.TEXT & ~filters.COMMAND, callback_location_keyword_search),
                CallbackQueryHandler(callback_skip_location_keyword_search),
            ],
            LOCATION_CONFIRMATION: [
                CallbackQueryHandler(callback_location_confirmation),
                MessageHandler(filters.TEXT & ~filters.COMMAND, callback_manual_location)
            ],
            ADD_COMMENT: [
                MessageHandler(filters.TEXT & ~filters.COMMAND, callback_add_comment),
                CallbackQueryHandler(callback_skip_comment),
            ],
            ADD_MEDIA: [MessageHandler(filters.PHOTO, callback_add_media),
                        CallbackQueryHandler(callback_skip_media)],
        },
        fallbacks=[CommandHandler("cancel", cancel_command)],
        per_message=False,
        allow_reentry=True,
    )

    # register handlers
    application.add_handler(CommandHandler("help", help_command))
    application.add_handler(checkin_handler)
    application.add_handler(TypeHandler(type=FediLoginCallbackUpdate, callback=process_oauth_login_callback))

    # Pass webhook settings to telegram
    await application.bot.set_webhook(url=f"{BOT_DOMAIN}{TELEGRAM_WEBHOOK_URL}")

    # Set up webserver
    async def telegram_webhook(request: Request) -> Response:
        """Handle incoming Telegram updates by putting them into the `update_queue`"""
        await application.update_queue.put(
            Update.de_json(data=await request.json(), bot=application.bot)
        )
        return Response()

    async def fedi_oauth_login_callback(request: Request) -> PlainTextResponse:
        """
        Handle incoming webhook updates by also putting them into the `update_queue` if
        the required parameters were passed correctly.
        """
        try:
            code = request.query_params["code"]
            state = int(request.query_params.get("state"))
        except KeyError:
            return PlainTextResponse(
                status_code=HTTPStatus.BAD_REQUEST,
                content="Mastodon callback request doesn't contain a valid OAuth code",
            )

        await application.update_queue.put(FediLoginCallbackUpdate(state=state, code=code))
        return PlainTextResponse("Thank you for login! Now you can close the browser")

    async def healthcheck(_: Request) -> PlainTextResponse:
        return PlainTextResponse(content="OK")

    starlette_app = Starlette(
        routes=[
            Route(TELEGRAM_WEBHOOK_URL, telegram_webhook, methods=["POST"]),
            Route(HEALTHCHECK_URL, healthcheck, methods=["GET"]),
            Route(FEDI_LOGIN_CALLBACK_URL, fedi_oauth_login_callback, methods=["POST", "GET"]),
        ]
    )
    webserver = uvicorn.Server(
        config=uvicorn.Config(
            app=starlette_app,
            port=BOT_PORT,
            use_colors=False,
            host="127.0.0.1",
        )
    )

    # Run application and webserver together
    async with application:
        await application.start()
        await webserver.serve()
        await application.stop()


if __name__ == "__main__":
    asyncio.run(main())