#!/bin/bash

CONFIGFILE="/etc/default/dnscrypt-proxy"
DAEMON="/usr/sbin/dnscrypt-proxy"

. $CONFIGFILE

start_instance() {
    if [ ! -r ${DNSCRYPTCONFIG[$1]} ]; then
        echo "No configuration for instance $1 found!"
        return
    fi
    if [ -z ${PIDFILE[$1]} ]; then
        echo "No PID configuration for instance $1 found!"
        return
    fi
    if [ -z ${USER[$1]} ]; then
        echo "No user configuration for instance $1 found!"
        return
    fi
    if [ -r ${PIDFILE[$1]} ]; then
        echo "dnscrypt-proxy (instance $1) already running!"
        return
    fi

    mkdir -p $(dirname ${PIDFILE[$1]})
    # The child (unprivileged) process needs write access or the PID will not
    # be written.
    chmod 0700 $(dirname ${PIDFILE[$1]})
    chown ${USER[$1]} $(dirname ${PIDFILE[$1]})

    # The new Go-based dnscrypt-proxy no longer has the ability to daemonize.
    # In the absence of a standard Slackware daemon tool we'll use nohup. :(
    nohup $DAEMON -config ${DNSCRYPTCONFIG[$1]} -pidfile ${PIDFILE[$1]} >> /dev/null 2>&1 &
}

stop_instance() {
    if [ ! -r ${DNSCRYPTCONFIG[$1]} ]; then
        echo "No configuration for instance $1 found!"
        return
    fi
    if [ -z ${PIDFILE[$1]} ]; then
        echo "No PID configuration for instance $1 found!"
        return
    fi
    if [ ! -r ${PIDFILE[$1]} ]; then
        echo "dnscrypt-proxy (instance $1) is not running!"
        return
    fi
    echo "Stopping dnscrypt-proxy (instance $1)..."
    kill $(cat ${PIDFILE[$1]})
}

status_instance() {
    if [ ! -r ${DNSCRYPTCONFIG[$1]} ]; then
        echo "No configuration for instance $1 found!"
        return
    fi
    if [ -z ${PIDFILE[$1]} ]; then
        echo "No PID configuration for instance $1 found!"
        return
    fi
    if [ ! -r ${PIDFILE[$1]} ]; then
        echo "dnscrypt-proxy (instance $1) is not running."
        return
    fi
    PID=$(cat ${PIDFILE[$1]})
    if [ -z "$PID" ]; then
        echo "PID file is empty! dnscrypt-proxy (instance $1) does not appear to be running, but there is a stale PID file."
    elif kill -0 $PID ; then
        echo "dnscrypt-proxy (instance $1) is running."
    else
        echo "dnscrypt-proxy (instance $1) is not running, but there is a stale PID file."
    fi
}

start() {
    for i in `/usr/bin/seq 0 $((${#DNSCRYPTCONFIG[@]}-1))`
    do
        start_instance $i
    done
}

stop() {
    for i in `/usr/bin/seq 0 $((${#DNSCRYPTCONFIG[@]}-1))`
    do
        stop_instance $i
    done
}

status() {
    for i in `/usr/bin/seq 0 $((${#DNSCRYPTCONFIG[@]}-1))`
    do
        status_instance $i
    done
}

case "$1" in
    'start')
        start
        ;;
    'stop')
        stop
        ;;
    'restart')
        stop
        start
        ;;
    'status')
        status
        ;;
    *_start)
        INSTANCE=`echo $1 | /bin/cut -d '_' -f 1`
        start_instance $INSTANCE
        ;;
    *_stop)
        INSTANCE=`echo $1 | /bin/cut -d '_' -f 1`
        stop_instance $INSTANCE
        ;;
    *_restart)
        INSTANCE=`echo $1 | /bin/cut -d '_' -f 1`
        stop_instance $INSTANCE
        sleep 1
        start_instance $INSTANCE
        ;;
    *_status)
        INSTANCE=`echo $1 | /bin/cut -d '_' -f 1`
        status_instance $INSTANCE
        ;;
    *)
        echo "Usage: $0 {start|stop|restart|status|#_start|#_stop|#_restart}"
        exit 1
        ;;
esac