#!/bin/sh

## Container configuration
SOCAT_LINK=${SOCAT_LINK:-false}
RUN_CROND=${RUN_CROND:-false}

## Container utils
cleanup() {
    # Cleanup SOCAT services and s6 event folder
    # On start and on shutdown in case container has been killed
    rm -rf $(find /app/gogs/docker/s6/ -name 'event')
    rm -rf /app/gogs/docker/s6/SOCAT_*
}

create_volume_subfolder() {
    # Create VOLUME subfolder
    for f in /data/gogs/data /data/gogs/conf /data/gogs/log /data/git /data/ssh; do
        if ! test -d $f; then
            mkdir -p $f
        fi
    done
}

## Container option activators
create_socat_links() {
    # Bind linked docker container to localhost socket using socat
    USED_PORT="3000:22"
    echo "init:socat  | Socat links will be created (requested via SOCAT_LINK)" 1>&2
    while read NAME ADDR PORT; do
        if test -z "$NAME$ADDR$PORT"; then
            continue
        elif echo $USED_PORT | grep -E "(^|:)$PORT($|:)" > /dev/null; then
            echo "init:socat  | ! Can't bind linked container ${NAME} to localhost, port ${PORT} already in use" 1>&2
        else
            SERV_FOLDER=/app/gogs/docker/s6/SOCAT_${NAME}_${PORT}
            mkdir -p ${SERV_FOLDER}
            CMD="socat -ls TCP4-LISTEN:${PORT},fork,reuseaddr TCP4:${ADDR}:${PORT}"
            echo -e "#!/bin/sh\nexec $CMD" > ${SERV_FOLDER}/run
            chmod +x ${SERV_FOLDER}/run
            USED_PORT="${USED_PORT}:${PORT}"
            echo "init:socat  | + Linked container ${NAME} will be binded to localhost on port ${PORT}" 1>&2
        fi
    done << EOT
    $(env | sed -En 's|(.*)_PORT_([0-9]+)_TCP=tcp://(.*):([0-9]+)|\1 \3 \4|p')
EOT
}

activate_crond () {
    # Request s6 to run crond
    echo "init:crond  | Cron Daemon (crond) will be run as requested by s6" 1>&2
    rm -f /app/gogs/docker/s6/crond/down
}

deactivate_crond () {
    # Tell s6 not to run the crond service
    touch /app/gogs/docker/s6/crond/down
}

## Environment variable parser
parse_container_options () {
    # Parse opt-in / opt-out container optionss based on environment variable
    # SOCAT_LINK: bind linked containers to localhost via socat
    case $(echo "$SOCAT_LINK" | tr '[:upper:]' '[:lower:]') in
      true|1) create_socat_links;;
    esac
    # RUN_CROND: request crond to be run inside the container
    case $(echo "$RUN_CROND" | tr '[:upper:]' '[:lower:]') in
      true|1) activate_crond;;
      *)      deactivate_crond;;
    esac
}

## Main
cleanup
create_volume_subfolder
parse_container_options

## End of initialization: exec CMD or s6 by default
if [ $# -gt 0 ];then
    exec "$@"
else
    exec /bin/s6-svscan /app/gogs/docker/s6/
fi