import argparse
from pathlib import Path
from itertools import zip_longest
from .common import invert_input_tag_args, add_file_as_text
from ..configuration import Config
from ..message import MessageFilter, Message, Question
from ..chat import ChatDB, msg_location


class TranslationCmdError(Exception):
    pass


def create_message(chat: ChatDB, args: argparse.Namespace) -> Message:
    """
    Create a new message from the given arguments and write it
    to the cache directory.
    """
    text_parts = []
    if args.create is not None:
        text_list = args.create
    elif args.ask is not None:
        text_list = args.ask
    else:
        raise TranslationCmdError("No input text found")
    # NOTE: we currently support only one input document
    text_files = args.input_document if args.input_document is not None else []

    # create the full text to be translated by combining all text parts
    # from the arguments with the content of the document
    for text, text_file in zip_longest(text_list, text_files, fillvalue=None):
        if text is not None and len(text.strip()) > 0:
            text_parts.append(text)
        if text_file is not None and len(text_file) > 0:
            add_file_as_text(text_parts, text_file)
    full_text = '\n\n'.join([str(s) for s in text_parts])

    # FIXME: prepend translation prompt and glossaries (if given)
    message = Message(question=Question(full_text),
                      tags=args.output_tags,
                      ai=args.AI,
                      model=args.model)
    # only write the new message to the cache,
    # don't add it to the internal list
    chat.cache_write([message])
    return message


def translation_cmd(args: argparse.Namespace, config: Config) -> None:
    """
    Handler for the 'translation' command. Creates and executes translation
    requests based on the input and selected AI. Depending on the AI, the
    whole process may be significantly different (e.g. DeepL vs OpenAI).
    """
    invert_input_tag_args(args)
    mfilter = MessageFilter(tags_or=args.or_tags,
                            tags_and=args.and_tags,
                            tags_not=args.exclude_tags)
    chat = ChatDB.from_dir(cache_path=Path(config.cache),
                           db_path=Path(config.db),
                           mfilter=mfilter,
                           glob=args.glob,
                           loc=msg_location(args.location))
    # if it's a new translation, create and store it immediately
    if args.ask or args.create:
        # message = create_message(chat, args)
        create_message(chat, args)
    if args.create:
        return