import os
base = r"F:\steam\steamapps\common\The I of the Dragon\Data\Misc"
out  = r"C:\Users\29452\AppData\Local\Temp\opencode\decoded"
os.makedirs(out, exist_ok=True)
key = b"GBDFYTNE"
for f in ["Fonts.dat", "UnitDescription.dat", "AIDescription.dat"]:
    d = open(os.path.join(base, f), "rb").read()
    assert d[:2] == b"==", d[:2]
    body = d[2:]
    dec = bytes(body[i] ^ key[i % len(key)] for i in range(len(body)))
    fp = os.path.join(out, f + ".txt")
    open(fp, "wb").write(dec)
    print(f, "->", fp, len(dec), "bytes")

# also prove re-encode round trips
def enc(text_bytes):
    return b"==" + bytes(text_bytes[i] ^ key[i % len(key)] for i in range(len(text_bytes)))
for f in ["Fonts.dat", "UnitDescription.dat", "AIDescription.dat"]:
    d = open(os.path.join(base, f), "rb").read()
    body = d[2:]
    dec = bytes(body[i] ^ key[i % len(key)] for i in range(len(body)))
    assert enc(dec) == d, f
print("round-trip OK")