#!/usr/bin/env python3
"""Set the emulated console's language by editing canary's own persisted XConfig.

There is no `--user_language` flag in this tree: the cvar is DECLARE_int32 at
four call sites with no DEFINE, and it is absent from xenia-canary.config.toml.
⚠ Do NOT pass it anyway -- xenia calls ShowSimpleMessageBox from
ParseLaunchArguments BEFORE logging starts, so an unknown flag blocks forever
with an empty log (see run-canary's header).

The supported route is the file. kernel_state.cc builds XConfig over
`<storage_root>/xconfig.settings`; SetDefaults() hard-codes language = kEnglish,
and whatever is in the file wins.

The offset is NOT hard-coded here -- it is located from struct landmarks every
run, so this keeps working if the layout moves:

    music_volume = 0.7f  at User+449      -> gives the User base
    language     = u32   at User+44       -> must currently read a valid XLanguage
    country      = u8    at User+64       -> sanity check

    set_console_language.py ja        # or: en, or a raw integer
    set_console_language.py --restore # put back the .bak this wrote

XLanguage (xbox.h): 1 en, 2 ja, 3 de, 4 fr, 5 es, 6 it, 7 ko, 8 zh-TW, 9 pt.
Restore when you are done: other captures in this corpus assume English.
"""
import struct, sys, shutil, pathlib

PATH = pathlib.Path("/sylph-home/re/.local/share/Xenia/xconfig.settings")
BAK = PATH.with_suffix(".settings.agent-bak")
LANGS = {"en": 1, "ja": 2, "de": 3, "fr": 4, "es": 5, "it": 6, "ko": 7, "zh": 8, "pt": 9}

def find_language_offset(d):
    """User base from the music_volume landmark; language sits 405 bytes before."""
    for o in range(len(d) - 4):
        if abs(struct.unpack_from(">f", d, o)[0] - 0.7) < 1e-6:
            user = o - 449
            if user < 0:
                continue
            lang = user + 44
            cur = struct.unpack_from(">I", d, lang)[0]
            if 1 <= cur <= 12:                      # a plausible XLanguage
                return lang, cur, d[user + 64]
    raise SystemExit("could not locate the User block -- layout changed?")

def main():
    arg = sys.argv[1] if len(sys.argv) > 1 else "--show"
    if arg == "--restore":
        if not BAK.exists():
            raise SystemExit("no backup to restore")
        shutil.copy2(BAK, PATH)
        d = PATH.read_bytes()
        off, cur, _ = find_language_offset(d)
        print(f"restored; language at 0x{off:x} is now {cur}")
        return
    d = bytearray(PATH.read_bytes())
    off, cur, country = find_language_offset(bytes(d))
    print(f"language at 0x{off:x} = {cur}   (country byte = {country})")
    if arg == "--show":
        return
    want = LANGS.get(arg, None)
    if want is None:
        want = int(arg)
    if not BAK.exists():
        shutil.copy2(PATH, BAK)
        print(f"backed up -> {BAK}")
    struct.pack_into(">I", d, off, want)
    PATH.write_bytes(bytes(d))
    print(f"language {cur} -> {want}")

if __name__ == "__main__":
    main()