#!/usr/bin/env python3
import ast
import struct
import sys
from pathlib import Path


def read_po(path):
    messages = {}
    current = None
    buffers = {"msgid": [], "msgstr": []}

    def flush():
        if buffers["msgid"] or buffers["msgstr"]:
            messages["".join(buffers["msgid"])] = "".join(buffers["msgstr"])
        buffers["msgid"] = []
        buffers["msgstr"] = []

    for raw_line in path.read_text(encoding="utf-8").splitlines():
        line = raw_line.strip()
        if not line or line.startswith("#"):
            continue
        if line.startswith("msgid "):
            flush()
            current = "msgid"
            buffers[current].append(ast.literal_eval(line[6:].strip()))
            continue
        if line.startswith("msgstr "):
            current = "msgstr"
            buffers[current].append(ast.literal_eval(line[7:].strip()))
            continue
        if line.startswith('"') and current:
            buffers[current].append(ast.literal_eval(line))
    flush()
    return messages


def write_mo(messages, path):
    keys = sorted(messages)
    ids = b"\x00".join(key.encode("utf-8") for key in keys) + b"\x00"
    strs = b"\x00".join(messages[key].encode("utf-8") for key in keys) + b"\x00"

    keystart = 7 * 4 + len(keys) * 16
    valuestart = keystart + len(ids)
    koffsets = []
    voffsets = []
    offset = keystart
    for key in keys:
        encoded = key.encode("utf-8")
        koffsets.append((len(encoded), offset))
        offset += len(encoded) + 1
    offset = valuestart
    for key in keys:
        encoded = messages[key].encode("utf-8")
        voffsets.append((len(encoded), offset))
        offset += len(encoded) + 1

    output = [
        struct.pack("Iiiiiii", 0x950412DE, 0, len(keys), 7 * 4, 7 * 4 + len(keys) * 8, 0, 0)
    ]
    output.extend(struct.pack("ii", length, offset) for length, offset in koffsets)
    output.extend(struct.pack("ii", length, offset) for length, offset in voffsets)
    output.append(ids)
    output.append(strs)
    path.write_bytes(b"".join(output))


def main():
    root = Path(sys.argv[1] if len(sys.argv) > 1 else "locale")
    for po in root.glob("*/LC_MESSAGES/*.po"):
        mo = po.with_suffix(".mo")
        write_mo(read_po(po), mo)
        print(mo)


if __name__ == "__main__":
    main()