from __future__ import annotations

import argparse
import sys

from argostranslate import translate


def main():
    """Run Argos Translate command line interface"""
    # Parse args
    parser = argparse.ArgumentParser(description="Open-source offline translation.\n")
    parser.add_argument(
        "text",
        nargs="?",
        metavar="TEXT",
        help="The text to translate. Read from standard input if missing.",
    )
    parser.add_argument(
        "--from-lang",
        "-f",
        help="The code for the language to translate from (ISO 639-1)",
    )
    parser.add_argument(
        "--to-lang", "-t", help="The code for the language to translate to (ISO 639-1)"
    )
    args = parser.parse_args()

    from_and_to_lang_provided = args.from_lang is not None and args.to_lang is not None

    # Get text to translate
    if args.text:
        # argos-translate-cli --from-lang en --to-lang es "Text to translate"
        text_to_translate = args.text
    elif from_and_to_lang_provided:
        # echo "Text to translate" | argos-translate-cli --from-lang en --to-lang es
        text_to_translate = "".join(sys.stdin)
    else:
        # argos-translate
        parser.print_help()
        return

    # Perform translation
    if from_and_to_lang_provided:
        installed_languages = {
            lang.code: lang for lang in translate.load_installed_languages()
        }
        if args.from_lang not in installed_languages:
            parser.error("{!r} is not an installed language.".format(args.from_lang))
        if args.to_lang not in installed_languages:
            parser.error("{!r} is not an installed language.".format(args.to_lang))
        from_lang = installed_languages[args.from_lang]
        to_lang = installed_languages[args.to_lang]
        translation = from_lang.get_translation(to_lang)
        if translation is None:
            parser.error(
                f"No translation installed from {args.from_name} to {args.to_name}"
            )
    else:
        translation = translate.IdentityTranslation("")

    # Print translation
    print(translation.translate(text_to_translate))