from genericpath import isdir
import logging
import os
import subprocess
from typing import Optional
import re

from tempfile import NamedTemporaryFile

from telegram import Update, ForceReply
from telegram.ext import (
    Updater,
    CommandHandler,
    DictPersistence,
    CallbackContext,
)


def start(update: Update, context: CallbackContext) -> None:
    """Send a message when the command /start is issued."""
    user = update.effective_user
    update.message.reply_markdown_v2(
        fr"Hi {user.mention_markdown_v2()}\!",
        reply_markup=ForceReply(selective=True),
    )


class KollagenBot:
    def __init__(
        self, tg_token: str, kollagen_path: str, base_dir: Optional[str]
    ) -> None:
        self.logger = logging.getLogger("kollagen")
        self.kollagen_path = kollagen_path
        self.base_dir = base_dir

        self.updater = Updater(tg_token, persistence=DictPersistence())

        dispatcher = self.updater.dispatcher

        dispatcher.add_handler(CommandHandler("start", start))
        dispatcher.add_handler(CommandHandler("list_modes", self.tg_list_modes))
        dispatcher.add_handler(CommandHandler("generate", self.tg_generate))
        dispatcher.add_handler(CommandHandler("g", self.tg_generate))
        dispatcher.add_handler(CommandHandler("regenerate", self.tg_regenerate))
        dispatcher.add_handler(CommandHandler("r", self.tg_regenerate))
        dispatcher.add_error_handler(self.tg_error)

    def tg_generate(self, update: Update, context: CallbackContext):
        cmd_line = update.message.text.split(" ")[1:]
        self._process(cmd_line, update)
        if context.user_data:
            context.user_data["last_cmd_line"] = cmd_line

    def tg_regenerate(self, update: Update, context: CallbackContext):
        if context.user_data and context.user_data.get("last_cmd_line"):
            self._process(context.user_data["last_cmd_line"], update)
        else:
            update.message.reply_text("No previous command to regenerate!")

    def _process(self, cmd_line: str, update: Update):
        self.logger.info(f"Generating from {update.effective_user}, with cmd_line: `{cmd_line}`")
        directories = [
            os.path.join(self.base_dir or "./", re.sub(r"[^a-zA-Z0-9]", "", arg))
            for arg in cmd_line
        ]
        directories = [dir for dir in directories if os.path.isdir(dir)]
        if len(directories) == 0 and self.base_dir:
            directories = [self.base_dir]
        with NamedTemporaryFile(suffix=".png") as ntf:
            subprocess.run(
                [self.kollagen_path, "-r", *directories, "-o", ntf.name],
                check=True,
                capture_output=True,
            )
            ntf.seek(0)
            update.message.reply_photo(ntf)

    def tg_list_modes(self, update: Update, context: CallbackContext):
        modes = subprocess.run(
            [self.kollagen_path, "-m"], check=True, capture_output=True
        )
        update.message.reply_text(f"Available modes: {modes.stdout.decode('utf-8')}")

    def tg_error(self, update: object, context: CallbackContext) -> None:
        self.logger.error(
            msg="Exception while handling an update:", exc_info=context.error
        )

        if isinstance(update, Update):
            if isinstance(context.error, subprocess.CalledProcessError):
                update.message.reply_text(f"Something is fucked!\n{context.error.stderr.decode('utf-8')}")
            else:
                update.message.reply_text(f"Something is fucked!\n{context.error}")

    def start_idle(self):
        self.updater.start_polling()
        self.updater.idle()


def main() -> None:
    logging.basicConfig(
        format="%(asctime)s - %(name)s - %(levelname)s - %(message)s",
        level=logging.INFO,
    )

    tg_token = os.getenv("TG_TOKEN")
    if not tg_token:
        logging.error("TG_TOKEN is required.")
        exit(1)

    if env_kollagen_path := os.getenv("KOLLAGEN_PATH"):
        if os.path.exists(env_kollagen_path):
            kollagen_path = env_kollagen_path
        else:
            logging.error(f"kollagen not found! {env_kollagen_path} does not exist.")
            exit(1)
    else:
        which = subprocess.run(["which", "kollagen"], capture_output=True)
        try:
            which.check_returncode()
            kollagen_path = which.stdout.decode("utf-8").strip()
        except subprocess.CalledProcessError:
            logging.error(
                "kollagen not found! KOLLAGEN_PATH not specified and `kollagen` isn't in $PATH."
            )
            exit(1)

    bot = KollagenBot(tg_token, kollagen_path, os.getenv("BASE_DIR"))
    bot.start_idle()


if __name__ == "__main__":
    main()