"""Which languages a documented checkout declares, and which it translates."""

from __future__ import annotations

from babel.messages.pofile import read_po

from utils.cache.yaml import load_yaml_str


def translated_languages(src):
    """Return the languages of ``src`` and those its ``docs`` catalogs translate.

    Args:
        src: checkout of the version to document.

    Returns:
        ``(known, translated)``: every language of ``meta/languages.yml``
        mapped to its native name, and the codes whose ``docs.po`` holds at
        least one translation.
    """
    languages_file = src / "meta" / "languages.yml"
    if not languages_file.is_file():
        return {}, []
    known = {
        str(code): str((entry or {}).get("native", code))
        for code, entry in (
            load_yaml_str(languages_file.read_text(encoding="utf-8")) or {}
        ).items()
    }
    translated = []
    for code in sorted(known):
        catalog = src / "locale" / code / "LC_MESSAGES" / "docs.po"
        if not catalog.is_file():
            continue
        with catalog.open("rb") as handle:
            if any(m.id and m.string and not m.fuzzy for m in read_po(handle)):
                translated.append(code)
    return known, translated