# Arch Linux install script for YAMS.
# The package ships a systemd *user* unit (/usr/lib/systemd/user/yams-daemon.service)
# and a user preset that enables it for every user; it starts with each user's
# next session. Releases up to 0.20.x shipped a *system* unit, which pre_upgrade
# stops and disables while its file is still installed.

UNIT=yams-daemon.service

# Run `systemctl --user <args>` in every running user manager (no-op without
# systemd, runuser or logged-in users). Used for daemon-reload, try-restart and
# stop; the scripts never start per-user instances.
yams_user_managers() {
    command -v runuser >/dev/null 2>&1 || return 0
    command -v systemctl >/dev/null 2>&1 || return 0
    for d in /run/user/*; do
        # A running user manager always has its private socket; the D-Bus user
        # bus is optional (Debian/Ubuntu without dbus-user-session).
        [ -S "$d/systemd/private" ] || continue
        uid="${d##*/}"
        user="$(getent passwd "$uid" | cut -d: -f1)"
        [ -n "$user" ] || continue
        runuser -u "$user" -- env XDG_RUNTIME_DIR="$d" \
            systemctl --user "$@" >/dev/null 2>&1 || true
    done
}

post_install() {
    systemctl --global preset "${UNIT}" >/dev/null 2>&1 || true
    yams_user_managers daemon-reload
    echo ">>> The per-user YAMS daemon starts with your next login session."
    echo ">>> Start it now with: systemctl --user enable --now ${UNIT}"
}

pre_upgrade() {
    if [ -f "/usr/lib/systemd/system/${UNIT}" ]; then
        systemctl --system disable --now "${UNIT}" >/dev/null 2>&1 || true
    fi
}

post_upgrade() {
    # From a release with the system unit ($2 = old version): enable per preset.
    if [ "$(vercmp "$2" 0.20.4)" -lt 0 ]; then
        systemctl --global preset "${UNIT}" >/dev/null 2>&1 || true
    fi
    systemctl --system daemon-reload >/dev/null 2>&1 || true
    yams_user_managers daemon-reload
    yams_user_managers try-restart "${UNIT}"
}

pre_remove() {
    yams_user_managers stop "${UNIT}"
    systemctl --global disable "${UNIT}" >/dev/null 2>&1 || true
}

post_remove() {
    yams_user_managers daemon-reload
    echo ">>> ~/.local/share/yams (each user's corpus) was kept."
}