language.py

from __future__ import annotations

import json
import os
from pathlib import Path

from source_config import LANGUAGE_BUCKETS

LANGUAGE_GROUPS = {group: cfg["langs"] for group, cfg in LANGUAGE_BUCKETS.items()}
LANGUAGE_GROUP_WEIGHTS = {group: float(cfg["weight"]) for group, cfg in LANGUAGE_BUCKETS.items()}
LANGUAGE_GROUP_MIN_CHARS = {group: int(cfg["min_chars"]) for group, cfg in LANGUAGE_BUCKETS.items()}
LATIN_GROUPS = {group for group, cfg in LANGUAGE_BUCKETS.items() if cfg.get("latin")}
LANG_ALIASES = {
    "nn": "no",
}

LANGS_JSON = Path(__file__).with_name("all_langs.json")

# Read from file to load the key-value pairs. JSON key order is canonical.
LANG_ISO2_TO_ISO3 = {}
with open(LANGS_JSON) as f:
    # Parse the file as a json string
    LANG_ISO2_TO_ISO3 = json.load(f)

ALL_LANGS = list(LANG_ISO2_TO_ISO3.keys())
LANG_TO_GROUP = {lang: group for group, langs in LANGUAGE_GROUPS.items() for lang in langs}


def canonical_lang(lang: str) -> str:
    return LANG_ALIASES.get(lang, lang)


def write_all_langs_json(path: str | os.PathLike[str] = LANGS_JSON) -> None:
    """Write the canonical ALL_LANGS list to JSON if it is missing."""
    path = Path(path)
    if path.exists():
        return
    with path.open("w", encoding="utf-8") as f:
        json.dump(ALL_LANGS, f, ensure_ascii=False, indent=2)


def load_all_langs(path: str | os.PathLike[str] = LANGS_JSON) -> list[str]:
    """Load ALL_LANGS from JSON, falling back to the in-repo constant."""
    path = Path(path)
    if path.exists():
        with path.open(encoding="utf-8") as f:
            langs = json.load(f)
        if isinstance(langs, list) and all(isinstance(lang, str) for lang in langs):
            return langs
    write_all_langs_json(path)
    return ALL_LANGS[:]