#compdef mach
_mach_complete()
{
    local com coms comsubs cur optkey opts state sub subs
    cur=${words[${#words[@]}]}
    typeset -A comsubs
    comsubs=( %(commands_subcommands)s )

    # lookup for command and subcommand
    for word in ${words[@]:1}; do
        if [[ $word == -* ]]; then
            continue
        fi

        if [[ -z $com ]]; then
            com=$word
        elif [[ ${comsubs[$com]} == *" $word "* ]]; then
            sub=$word
            break
        fi
    done

    # check for a subcommand
    if [[ $cur == $com ]]; then
        state="command"
        coms=(%(commands)s)
    elif [[ ${cur} == -* ]]; then
        state="option"
        if [[ -z $com ]]; then
            # no command, use global options
            opts=(%(globalopts)s)
        fi
    fi
    case $state in
        (command)
            _describe 'command' coms
        ;;
        (option)
            if [[ -n $sub ]]; then
                optkey="$com $sub"
            else
                optkey="$com"
            fi
            case $optkey in
%(case_options)s
            esac
            _describe 'option' opts
        ;;
        *)
            if [[ -z $sub ]]; then
                # if we're completing a command with subcommands, add them here
                case "$com" in
%(case_subcommands)s
                esac
                _describe 'subcommand' subs
            fi
            # also fallback to file completion
            _arguments '*:file:_files'
    esac
}
_mach_complete "$@"
compdef _mach_complete mach