# The CUDA trellis kernels live in the qtip_kernels extension. If it can't be
# imported (ABI mismatch after a torch upgrade, not built, no nvcc to rebuild),
# every shape must use the torch decode fallback — force has_kernel False.
try:
    import torch  # ensure libc10 is loaded before the qtip_kernels .so
    import qtip_kernels as _qtip_kernels  # noqa: F401
    _QTIP_KERNELS_OK = True
except Exception:
    _QTIP_KERNELS_OK = False


def has_kernel(decode_mode, L, K, V, tlut_bits, td_x, td_y):
    if not _QTIP_KERNELS_OK:
        return False
    if decode_mode != 'quantlut_sym':
        return False
    if L != 16:
        return False
    if V != 2:
        return False
    if K < 2 or K > 4:
        return False
    if tlut_bits != 9:
        return False
    if td_x != 16 or td_y != 16:
        return False
    return True