#!/bin/bash
#
# ScoutFS kernel install/remove hook for DKMS
#
# Installed to:
#   /etc/kernel/postinst.d/scoutfs  (Debian/Ubuntu)
#   /etc/kernel/postrm.d/scoutfs    (Debian/Ubuntu)
#
# On postinst: attempts to build and install the scoutfs module for the
# newly installed kernel via DKMS. On failure, logs a warning but NEVER
# blocks kernel installation.
#
# On postrm: removes the scoutfs DKMS module for the removed kernel.
#
# Usage: Called by the kernel package system with the kernel version as $1
#

KVER="${1:-}"
LOGFILE="/var/log/scoutfs-dkms.log"

if [ -z "$KVER" ]; then
    exit 0
fi

# Determine if we're in postinst or postrm context
HOOK_DIR="$(basename "$(dirname "$0")")"

# Find the installed scoutfs DKMS version
get_scoutfs_version() {
    dkms status scoutfs 2>/dev/null | head -1 | sed -n 's/^scoutfs[, ]*\([^,: ]*\).*/\1/p'
}

log() {
    local msg="$(date '+%Y-%m-%d %H:%M:%S') scoutfs-dkms: $*"
    echo "$msg" >> "$LOGFILE" 2>/dev/null || true
    logger -t scoutfs-dkms "$*" 2>/dev/null || true
}

SCOUTFS_VERSION="$(get_scoutfs_version)"

if [ -z "$SCOUTFS_VERSION" ]; then
    # scoutfs-dkms not installed, nothing to do
    exit 0
fi

case "$HOOK_DIR" in
    postinst.d)
        log "New kernel ${KVER} detected, attempting DKMS build..."

        if dkms build -m scoutfs -v "$SCOUTFS_VERSION" -k "$KVER" >> "$LOGFILE" 2>&1; then
            if dkms install -m scoutfs -v "$SCOUTFS_VERSION" -k "$KVER" >> "$LOGFILE" 2>&1; then
                log "SUCCESS: ScoutFS module ${SCOUTFS_VERSION} built and installed for kernel ${KVER}"
            else
                log "WARNING: ScoutFS module ${SCOUTFS_VERSION} built but failed to install for kernel ${KVER}"
            fi
        else
            log "WARNING: ScoutFS module ${SCOUTFS_VERSION} failed to build for kernel ${KVER}. The scoutfs filesystem will not be available with this kernel."
        fi
        ;;

    postrm.d)
        if dkms status scoutfs/"$SCOUTFS_VERSION" -k "$KVER" 2>/dev/null | grep -q "$KVER"; then
            dkms remove -m scoutfs -v "$SCOUTFS_VERSION" -k "$KVER" >> "$LOGFILE" 2>&1 || true
            log "Removed ScoutFS module ${SCOUTFS_VERSION} for kernel ${KVER}"
        fi
        ;;
esac

# NEVER block kernel installation/removal
exit 0