#!/bin/bash

cleanup_and_exit()
{
    trap EXIT
    exit "${1:-0}"
}

fail_exit()
{
    echo "$@"
    cleanup_and_exit 1
}

job_lock() {
    [ -z "$1" ] && fail_exit "Lock file is not specified"
    local LOCKFILE=$1
    shift
    local fd=1000
    eval "exec $fd>>$LOCKFILE"
    case $1 in
        "set")
            flock -x -n "$fd" \
                || fail_exit "Process already running. Lockfile: $LOCKFILE"
            ;;
        "unset")
            flock -u "$fd"
            [ -f "$LOCKFILE" ] && rm -f "$LOCKFILE"
            ;;
        "wait")
            local TIMEOUT=${2:-3600}
            [ "$IS_VERBOSE" == "true" ] \
                && echo "[INFO] Waiting of concurrent process (lockfile: $LOCKFILE, timeout = $TIMEOUT seconds) ..."
            flock -x -w "$TIMEOUT" "$fd" \
                || fail_exit "Timeout error (lockfile: $LOCKFILE)"
            [ "${IS_VERBOSE}" == "true" ] && echo "[INFO] Done"
            ;;
    esac
}

trap fail_exit EXIT