#!/bin/sh

set -x

LOG_FILE=/var/log/netbird/client_pre_install.log
AGENT=/usr/local/bin/netbird
UI_PROCESS=netbird-ui

mkdir -p /var/log/netbird/

# wait_for_ui_exit polls for up to $1 seconds, returning 0 as soon as no UI
# process is left and 1 if one is still running when the time is up.
wait_for_ui_exit() {
    waited=0
    while [ "$waited" -lt "$1" ]; do
        pgrep -x "$UI_PROCESS" > /dev/null 2>&1 || return 0
        sleep 1
        waited=$((waited + 1))
    done
    return 1
}

# request_ui_quit asks the UI to quit from inside the console user's session and
# reports whether the request could be sent at all. The installer runs as root
# outside that session, so a quit Apple event sent straight from here always
# fails with -600.
request_ui_quit() {
    console_user=$(stat -f%Su /dev/console 2>/dev/null)
    case "$console_user" in
        ""|root|loginwindow|_mbsetupuser)
            echo "No active GUI user session (console user: '${console_user:-none}'); skipping the quit request."
            return 1
            ;;
    esac

    uid=$(id -u "$console_user" 2>/dev/null)
    if [ -z "$uid" ]; then
        echo "Could not resolve uid for console user '$console_user'; skipping the quit request."
        return 1
    fi

    echo "Asking the NetBird UI to quit as console user $console_user (uid $uid)."
    launchctl asuser "$uid" sudo -u "$console_user" -H osascript -e 'quit app "NetBird"' || true
}

# quit_ui stops a running UI so the app bundle can be replaced underneath it. A
# UI process that survives the install keeps serving the old binary until it is
# quit by hand, so anything still running once the quit request is out of the
# way is signalled. Waiting for a graceful exit only makes sense when a quit
# request was actually sent.
quit_ui() {
    if request_ui_quit && wait_for_ui_exit 10; then
        return 0
    fi

    pgrep -x "$UI_PROCESS" > /dev/null 2>&1 || return 0

    echo "NetBird UI still running; terminating it."
    pkill -x "$UI_PROCESS" || true
    if wait_for_ui_exit 3; then
        return 0
    fi

    echo "NetBird UI ignored SIGTERM; killing it."
    pkill -KILL -x "$UI_PROCESS" || true
}

{
    # check if it was installed with brew
    brew list --formula | grep netbird
    if [ $? -eq 0 ]
    then
        echo "NetBird has been installed with Brew. Please use Brew to update the package."
        exit 1
    fi
    quit_ui
    $AGENT service stop || true

    echo "Preinstall complete"
    exit 0 # all good
} &> $LOG_FILE