# post-install / post-upgrade hook for daedalus-v4l2-dkms.
#
# pacman + the dkms-helpers alpm hook will already attempt
# `dkms install` on its own.  This script's job is to emit a
# loud, actionable warning when the module didn't actually
# build for the running kernel — most commonly because the
# kernel headers package isn't installed yet.
#
# Without this you get a silent failure: the package looks
# installed but `modprobe daedalus_v4l2` returns ENOENT.

_check_dkms_built() {
    local name=daedalus_v4l2
    local ver=$1
    local kernelver=$(uname -r)

    if ! command -v dkms >/dev/null 2>&1; then
        return 1  # the hard-dep should have caught this
    fi

    local status
    status=$(dkms status -m "$name" -v "$ver" -k "$kernelver" 2>/dev/null || true)
    if printf '%s\n' "$status" | grep -q -E 'installed|loaded'; then
        return 0  # all good
    fi

    cat >&2 <<EOF
==> daedalus-v4l2-dkms: DKMS build did NOT land for kernel $kernelver.
==>   dkms status -m $name -v $ver -k $kernelver:
==>     $(printf '%s' "$status" | head -1)
==>
==> Most likely cause: kernel headers package is missing.
==>   Arch / ALARM:     pacman -S linux-rpi-headers (or linux-rpi5-headers)
==>   Raspberry Pi OS:  apt install linux-headers-rpi-2712
==>
==> After installing headers, finish the install with:
==>   sudo dkms autoinstall $name/$ver
==>   sudo modprobe daedalus_v4l2
==>
==> Until then daedalus_v4l2 will NOT be loadable and the
==> userspace daedalus-v4l2 daemon will have nothing to talk to.
EOF
    return 1
}

post_install() {
    _check_dkms_built "$1" || true
}

post_upgrade() {
    # New version pinned by the bump may have built fine, but if
    # a kernel-headers package was uninstalled / pruned since the
    # last upgrade we'd silently regress.  Re-check.
    _check_dkms_built "$1" || true
}

pre_remove() {
    # The dkms alpm hook handles dkms remove on its own; nothing
    # we need to add here.
    :
}