#!/bin/bash
# ./vm_control.sh [start|stop]

# der Pfad im Web-Verzeichnis von vm_control.php ist anzupassen:
vm_control_php_path="/volume1/web/vm_control.php"

################################################################################
#                       ab hier nichts mehr ändern
# ------------------------------------------------------------------------------

saved_IFS=$IFS
vm_state_path="$(dirname "$vm_control_php_path")/vm_state.php"

if [ ! $(which inotifywait) ]; then
    echo "inotify-tools nicht installiert"
    exit 1
elif [ $(whoami) != "root" ]; then
    echo "ERROR: you are not root!"
    exit 1
fi

inotify_start() {
    PROZESSID=$(ps aux | grep -v "grep" | grep -E "inotifywait.*vm_state.php" | awk -F' ' '{print $2}')
    echo "..."
    if [[ -z $PROZESSID ]];then
        echo "Überwachung von ${vm_state_path} wird gestartet"

        # initial Web-Status auslesen:
        web_state=$(cat "$vm_state_path" | grep "=>" "$vm_state_path" | grep -v "letzter Zugriff")
        declare -A vm_states
        while read line ; do
            vm=$(awk -F\' '{print $2}' <<<"$line")
            vms+=( "$vm" )
            vm_states[$vm]=$(echo "$line" | grep "$vm" | awk -F\' '{print $4}')
        done <<<"$web_state"

        inotifywait "${vm_state_path}" --monitor --event modify --timeout -1 --format %e | 
            while read line ; do 

                unset vm_states_saved
                declare -A vm_states_saved

            # associative array umschreiben / umbenennen:
                for key in "${!vm_states[@]}"; do  # make sure you include the quotes there
                    vm_states_saved+=( ["$key"]="${vm_states["$key"]}" )
                    # or: 
                    # vm_states_saved["$key"]="${vm_states["$key"]}"
                done

                unset vm_states
                unset vms

            # neu einlesen:
                web_state=$(cat "$vm_state_path" | grep "=>" "$vm_state_path" | grep -v "letzter Zugriff")
                declare -A vm_states
                while read line ; do
                    vm=$(awk -F\' '{print $2}' <<<"$line")
                    vms+=( "$vm" )
                    vm_states[$vm]=$(echo "$line" | grep "$vm" | awk -F\' '{print $4}')
                    echo "Name: $vm     Status: $(echo "$line" | grep "$vm" | awk -F\' '{print $4}')"
                done <<<"$web_state"

                for vm in "${vms[@]}"; do
                    vm_host_status=$(synowebapi --exec api=SYNO.Virtualization.API.Guest version=1 method=get runner=admin guest_name="$vm" 2>/dev/null | jq -r .data.status )

                    if [ "${vm_states[$vm]}" = "${vm_states_saved[$vm]}" ]; then
                        echo "keine Änderung für $vm (web_state online: ${vm_states[$vm]} / web_state saved: ${vm_states_saved[$vm]})"
                        continue
                    else
                        echo "Änderung für $vm (web_state online: ${vm_states[$vm]} / web_state saved: ${vm_states_saved[$vm]})"
                    fi

                    # wenn Änderung gefunden wurde:
                    case "${vm_states[$vm]}" in
                        on)
                            if [ "$vm_host_status" = "shutdown" ]; then
                                echo "starte $vm ..."
                                synowebapi --exec api=SYNO.Virtualization.API.Guest.Action version=1 method=poweron runner=admin guest_name="$vm" 2>/dev/null 
                            else
                                echo "VM $vm hat folgenden Status und kann nicht gestartet werden: $vm_host_status"
                            fi
                            ;;
                        off)
                            if [ "$vm_host_status" = "running" ]; then
                                echo "beende $vm ..."
                                synowebapi --exec api=SYNO.Virtualization.API.Guest.Action version=1 method=shutdown runner=admin guest_name="$vm" 2>/dev/null 
                            else
                                echo "VM $vm hat folgenden Status und kann nicht beendet werden: $vm_host_status"
                            fi
                            ;;
                    esac
                done
        #    done >/dev/null 2>&1 &
            done &
    else
        echo "läuft bereits …"
    fi

}

inotify_stop() 
{
# Überwachung stoppem:
# --------------------------------------------------------------
    PROZESSID=$(ps aux | grep -v "grep" | grep -E "inotifywait.*vm_state.php" | awk -F' ' '{print $2}')

    if [[ ! -z $PROZESSID ]];then
        kill $PROZESSID
        if [ $? = 0 ]; then
            echo "Überwachung beendet"
            exit 0
        else
            echo "FEHLER beim Beenden der Überwachung!"
            exit 1
        fi
    else
        echo "läuft nicht … "
    fi

}

# start-stop-Überwachung:
    case "$1" in
        start)
            inotify_start
            echo "läuft … "
            exit 0
            ;;
        stop)
            inotify_stop
            exit 0
            ;;
    esac

exit 0