#!/bin/bash

VERSION="1.1.0"

cmd="$1"
group="$2"

add_service_to_group() {
    service="$1"
    group="$2"

    if [[ ! -f "/etc/systemd/system/${group}.target" ]]; then
        sudo tee "/etc/systemd/system/${group}.target" > /dev/null <<EOF
[Unit]
Description=Group 1 Target
PartOf=killswitch.target

[Install]
WantedBy=multi-user.target
EOF
    fi

    sudo mkdir -p "/etc/systemd/system/${group}.target.wants"
    
    sudo ln -sf "/etc/systemd/system/${service}.service" "/etc/systemd/system/${group}.target.wants/${service}.service"
    
    echo "Added service '$service' to group '$group'."
    
    sudo systemctl daemon-reload
    sudo systemctl enable ${group}.target
}

case "$cmd" in
    stop)
        if [[ -n "$group" ]]; then
            systemctl stop "$group".target
            echo "Killswitch activated: stopped group '$group'."
        else
            systemctl stop killswitch.target
            echo "Killswitch activated: all linked services have been stopped."
        fi
        ;;
    start)
        if [[ -n "$group" ]]; then
            systemctl start "$group".target
            echo "Killswitch deactivated: started group '$group'."
        else
            systemctl start killswitch.target
            echo "Killswitch deactivated: all linked services have been started."
        fi
        ;;
    status)
        if [[ -n "$group" ]]; then
            systemctl status "$group".target
        else
            systemctl status killswitch.target
        fi
        ;;
    add)
        if [[ -n "$2" && "$3" == "to" && -n "$4" ]]; then
            add_service_to_group "$2" "$4"
        else
            echo "Usage: killsw add [service] to [group]"
        fi
        ;;
    help|-h|--help)
        cat << EOF
KillSwitch CLI Tool - v$VERSION

USAGE:
    killsw <command> [group]

COMMANDS:
    stop                                Stop all services linked to killswitch.target, or a specific group
    start                               Start all services linked to killswitch.target, or a specific group
    status                              Show the current status of killswitch.target or a group
    add [service] to [group]            Add a service to a group (creates group-target if needed)
    -h, --help                          Show this help message
    -v, --version                       Show version information

ABOUT KILLSWITCH:
    What it does:
        Stops or starts services linked to 'killswitch.target'. Supports groups for partial control.

    How to link services:
        1) Edit your systemd service and add:
            PartOf=<group>.target
        2) Enable the service for boot:
            sudo systemctl enable <your-service>.service
        3) Use killsw script to manage:
            killsw start [group]
            killsw stop [group]
EOF
        ;;
    -v|--version)
        echo "KillSwitch CLI Tool version $VERSION"
        ;;
    *)
        echo "Ahoy, matey! No command provided. Check --help for guidance."
        ;;
esac