#!/bin/sh
set -eu

# Re-exec outside of apparmor confinement
if [ -d /sys/kernel/security/apparmor ] && [ "$(cat /proc/self/attr/current)" != "unconfined" ]; then
    exec aa-exec -p unconfined -- "$0" "$@"
fi

export LXD_DIR="${SNAP_COMMON}/lxd/"
PID=$(cat "${SNAP_COMMON}/lxd.pid" || true)

# FIXME: Detect stop reason
#        This should be exposed by snapd directly
STATUS=$(snap-query /run/snapd.socket lxd 2>/dev/null || true)

reason="host shutdown"
if [ -s "${SNAP_COMMON}/state" ]; then
    reason="$(cat "${SNAP_COMMON}/state")"
elif [ "${STATUS}" = "auto-refresh" ]; then
    reason="snap refresh"
elif [ "${STATUS}" = "refresh-snap" ]; then
    reason="snap refresh"
elif [ "${STATUS}" = "install-snap" ]; then
    reason="snap refresh"
elif [ "${STATUS}" = "remove-snap" ]; then
    reason="snap removal"
fi

echo "=> Stop reason is: ${reason}"

# Handle lxd shutdown
if [ "${reason}" = "shutdown" ]; then
    exit 0
fi

# Handle reloads and crashes
if [ "${reason}" = "reload" ] || [ "${reason}" = "crashed" ]; then
    exit 0
fi

# Handle refreshes
if [ "${reason}" = "snap refresh" ]; then
    echo "=> Stopping LXD"
    if [ -n "${PID}" ] && kill -0 "${PID}" 2>/dev/null; then
        if ! kill "${PID}"; then
            echo "==> Failed to signal LXD to exit"
        fi

        DEAD=0
        for _ in $(seq 320); do
            if ! kill -0 "${PID}" 2>/dev/null; then
                DEAD=1
                echo "==> Stopped LXD"
                break
            fi
            sleep 1
        done

        if [ "${DEAD}" = "0" ]; then
            echo "==> Forcefully stopping LXD after 5 minutes wait"
            if kill -9 "${PID}" 2>/dev/null; then
                echo "==> Stopped LXD"
            else
                echo "==> Failed to stop LXD"
            fi
        fi
    fi

    exit 0
fi

# Shutdown the daemons
## LXD
echo "=> Stopping LXD (with container shutdown)"

echo host-shutdown > "${SNAP_COMMON}/state"
if [ -n "${PID}" ] && kill -0 "${PID}" 2>/dev/null; then
    if ! kill -30 "${PID}"; then
        echo "==> Failed to signal LXD to shutdown"
    fi

    DEAD=0
    for _ in $(seq 540); do
        if ! kill -0 "${PID}" 2>/dev/null; then
            DEAD=1
            echo "==> Stopped LXD"
            break
        fi
        sleep 1
    done

    if [ "${DEAD}" = "0" ]; then
        echo "==> Forcefully stopping LXD after 9 minutes wait"
        if kill -9 "${PID}" 2>/dev/null; then
            echo "==> Stopped LXD"
        else
            echo "==> Failed to stop LXD"
        fi
    fi
fi

## OpenVswitch
if [ -e "${SNAP_COMMON}/openvswitch/run/ovs-vswitchd.pid" ]; then
    PID=$(cat "${SNAP_COMMON}/openvswitch/run/ovs-vswitchd.pid")
    if [ -n "${PID}" ] && kill -0 "${PID}" 2>/dev/null; then
        (
            echo "=> Stopping Open vSwitch"

            set -e
            export OVS_LOGDIR="${SNAP_COMMON}/openvswitch/logs/"
            export OVS_RUNDIR="${SNAP_COMMON}/openvswitch/run/"
            export OVS_DBDIR="${SNAP_COMMON}/openvswitch/db/"
            export OVS_SYSCONFDIR="${SNAP_COMMON}/openvswitch/conf/"
            export OVS_PKGDATADIR="${SNAP}/share/openvswitch/"
            export OVS_BINDIR="${SNAP}/bin/"
            export OVS_SBINDIR="${SNAP}/bin/"

            if "${SNAP}/share/openvswitch/scripts/ovs-ctl" stop; then
                echo "==> Stopped Open vSwitch"
            else
                echo "==> Failed to stop Open vSwitch"
            fi
        )
    fi
fi

## LXCFS
if [ -e "${SNAP_COMMON}/lxcfs.pid" ]; then
    echo "=> Stopping LXCFS"

    PID=$(cat "${SNAP_COMMON}/lxcfs.pid")
    if [ -n "${PID}" ] && kill -0 "${PID}" 2>/dev/null; then
        if ! kill "$PID"; then
            echo "==> Failed to signal LXCFS to stop"
        fi

        DEAD=0
        for _ in $(seq 30); do
            if ! kill -0 "${PID}" 2>/dev/null; then
                DEAD=1
                echo "==> Stopped LXCFS"
                break
            fi
            sleep 1
        done

        if [ "${DEAD}" = "0" ]; then
            echo "==> Forcefully stopping LXCFS after 30 seconds wait"
            if kill -9 "${PID}" 2>/dev/null; then
                echo "==> Stopped LXCFS"
            else
                echo "==> Failed to stop LXCFS"
            fi
        fi

        fusermount -u "${SNAP_COMMON}/var/lib/lxcfs" >/dev/null 2>&1 || true
    fi
fi

## Cleanup
echo "=> Cleaning up PID files"
rm -f "${SNAP_COMMON}/lxcfs.pid" "${SNAP_COMMON}/lxd.pid"

## Flush our shared namespace from the host
echo "=> Cleaning up namespaces"
nsenter -t 1 -m umount -l /var/snap/lxd/common/ns 2>/dev/null || true

echo "=> All done"
exit 0