convert_po_to_json.py

# Copyright (c) 2025 Walter Bender
# Copyright (c) 2025 Aman Chadha, DMP'25
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the The GNU Affero General Public
# License as published by the Free Software Foundation; either
# version 3 of the License, or (at your option) any later version.
#
# You should have received a copy of the GNU Affero General Public
# License along with this library; if not, write to the Free Software
# Foundation, 51 Franklin Street, Suite 500 Boston, MA 02110-1335 USA
#
# Note: This script converts .po translation files into JSON format,
# following the i18n infrastructure used in Music Blocks. -- Aman Chadha, July 2025

import os
import json
import re
import sys

SOLFEGE_KEY = "ti la sol fa mi re do"
SOLFEGE_TOKEN_COUNT = 7

def is_valid_solfege_translation(value):
    """Return True when a solfege translation has seven note labels."""
    return len(value.split()) == SOLFEGE_TOKEN_COUNT

def parse_po_file(po_file):
    """Parse a .po file and return a dict of {msgid: msgstr}."""
    data = {}
    current_msgid = None
    current_msgstr = None

    with open(po_file, "r", encoding="utf-8") as f:
        for line in f:
            line = line.strip()
            if line.startswith("msgid"):
                current_msgid = re.findall(r'"(.*)"', line)[0]
            elif line.startswith("msgstr"):
                current_msgstr = re.findall(r'"(.*)"', line)[0]
                if current_msgid is not None:
                    if (
                        current_msgid == SOLFEGE_KEY
                        and not is_valid_solfege_translation(current_msgstr)
                    ):
                        print(
                            f"Warning: invalid solfege translation in "
                            f"{po_file}: expected {SOLFEGE_TOKEN_COUNT} "
                            f"tokens, got {len(current_msgstr.split())}. "
                            f"Falling back to English.",
                            file=sys.stderr,
                        )
                        data[current_msgid] = current_msgid
                    else:
                        data[current_msgid] = current_msgstr or current_msgid
                    current_msgid = None
    return data

def convert_po_to_json(po_file, output_dir):
    """Convert a .po file to .json. Special case: ja.po + ja-kana.po -> merged ja.json."""

    lang_code = os.path.splitext(os.path.basename(po_file))[0]

    # Special handling for Japanese
    if lang_code in ["ja", "ja-kana"]:
        ja_file = os.path.join(os.path.dirname(po_file), "ja.po")
        kana_file = os.path.join(os.path.dirname(po_file), "ja-kana.po")

        if os.path.exists(ja_file) and os.path.exists(kana_file):
            ja_dict = parse_po_file(ja_file)
            kana_dict = parse_po_file(kana_file)

            combined = {}
            all_keys = list(ja_dict.keys())
            all_keys.extend(key for key in kana_dict.keys() if key not in ja_dict)
            for key in all_keys:
                combined[key] = {
                    "kanji": ja_dict.get(key, key),
                    "kana": kana_dict.get(key, key),
                }

            output_path = os.path.join(output_dir, "ja.json")
            os.makedirs(output_dir, exist_ok=True)
            with open(output_path, "w", encoding="utf-8") as f:
                json.dump(combined, f, indent=2, ensure_ascii=False)
            print(f"Combined ja.po + ja-kana.po -> {output_path}")
            return  # Don’t fall through to default case

    # Default for all other langs
    json_data = parse_po_file(po_file)
    output_path = os.path.join(output_dir, f"{lang_code}.json")
    os.makedirs(output_dir, exist_ok=True)
    with open(output_path, "w", encoding="utf-8") as f:
        json.dump(json_data, f, indent=2, ensure_ascii=False)
    print(f"Converted {po_file} -> {output_path}")

def convert_all_po_files(po_dir, output_dir):
    """Convert all .po files in the given directory to .json format."""
    for root, _, files in os.walk(po_dir):
        for file in files:
            if file.endswith(".po"):
                convert_po_to_json(os.path.join(root, file), output_dir)

if __name__ == "__main__":
    if len(sys.argv) == 3:
        convert_po_to_json(sys.argv[1], sys.argv[2])
    else:
        convert_all_po_files("./po", "./locales")