import yaml
import argparse


class FunctionTag:
    def __init__(self, value):
        self.value = value


def function_representer(dumper, data):
    return dumper.represent_scalar('!function', data.value, style='')


yaml.add_representer(FunctionTag, function_representer)


def gen_lang_yamls(output_dir: str, overwrite: bool) -> None:
    """
    Generate a yaml file for each language.

    :param output_dir: The directory to output the files to.
    :param overwrite: Whether to overwrite files if they already exist.
    """
    err = []
    languages = ['amh', 'ibo', 'fra', 'sna', 'lin', 'wol', 'ewe', 'lug', 'xho', 'kin', 'twi', 'zul', 'orm',
                 'yor', 'hau', 'sot', 'swa']
    for lang in languages:
        file_name = f"afrixnli_{lang}.yaml"
        try:
            with open(
                f"{output_dir}/{file_name}", "w" if overwrite else "x", encoding="utf8"
            ) as f:
                f.write("# Generated by utils.py\n")
                yaml.dump(
                    {
                        "include": "afrixnli_common_yaml",
                        "task": f"afrixnli_{lang}",
                        "dataset_name": lang,
                        "doc_to_target": "{{label}}", #FunctionTag('preprocess_wikitext.wikitext_detokenizer'),
                        "doc_to_text": "Premise: {{premise}} \nHypothesis: {{hypothesis}} \nIs it entailment, "
                                       "contradiction, or neutral?"
                    },
                    f,
                    allow_unicode=True,
                )
        except FileExistsError:
            err.append(file_name)

    if len(err) > 0:
        raise FileExistsError(
            "Files were not created because they already exist (use --overwrite flag):"
            f" {', '.join(err)}"
        )


def main() -> None:
    """Parse CLI args and generate language-specific yaml files."""
    parser = argparse.ArgumentParser()
    parser.add_argument(
        "--overwrite",
        default=True,
        action="store_true",
        help="Overwrite files if they already exist",
    )
    parser.add_argument(
        "--output-dir", default=".", help="Directory to write yaml files to"
    )
    args = parser.parse_args()

    gen_lang_yamls(output_dir=args.output_dir, overwrite=args.overwrite)


if __name__ == "__main__":
    main()