subcommand_last.bash

_my-app() {
    local i cur prev opts cmd
    COMPREPLY=()
    cur="${COMP_WORDS[COMP_CWORD]}"
    prev="${COMP_WORDS[COMP_CWORD-1]}"
    cmd=""
    opts=""

    for i in ${COMP_WORDS[@]}
    do
        case "${cmd},${i}" in
            ",$1")
                cmd="my__app"
                ;;
            my__app,bar)
                cmd="my__app__bar"
                ;;
            my__app,foo)
                cmd="my__app__foo"
                ;;
            my__app,help)
                cmd="my__app__help"
                ;;
            my__app__help,bar)
                cmd="my__app__help__bar"
                ;;
            my__app__help,foo)
                cmd="my__app__help__foo"
                ;;
            my__app__help,help)
                cmd="my__app__help__help"
                ;;
            *)
                ;;
        esac
    done

    case "${cmd}" in
        my__app)
            opts="-h --help [free] foo bar help"
            if [[ ${cur} == -* || ${COMP_CWORD} -eq 1 ]] ; then
                COMPREPLY=( $(compgen -W "${opts}" -- "${cur}") )
                return 0
            fi
            case "${prev}" in
                *)
                    COMPREPLY=()
                    ;;
            esac
            COMPREPLY=( $(compgen -W "${opts}" -- "${cur}") )
            return 0
            ;;
        my__app__bar)
            opts="-h --help"
            if [[ ${cur} == -* || ${COMP_CWORD} -eq 2 ]] ; then
                COMPREPLY=( $(compgen -W "${opts}" -- "${cur}") )
                return 0
            fi
            case "${prev}" in
                *)
                    COMPREPLY=()
                    ;;
            esac
            COMPREPLY=( $(compgen -W "${opts}" -- "${cur}") )
            return 0
            ;;
        my__app__foo)
            opts="-h --help"
            if [[ ${cur} == -* || ${COMP_CWORD} -eq 2 ]] ; then
                COMPREPLY=( $(compgen -W "${opts}" -- "${cur}") )
                return 0
            fi
            case "${prev}" in
                *)
                    COMPREPLY=()
                    ;;
            esac
            COMPREPLY=( $(compgen -W "${opts}" -- "${cur}") )
            return 0
            ;;
        my__app__help)
            opts="foo bar help"
            if [[ ${cur} == -* || ${COMP_CWORD} -eq 2 ]] ; then
                COMPREPLY=( $(compgen -W "${opts}" -- "${cur}") )
                return 0
            fi
            case "${prev}" in
                *)
                    COMPREPLY=()
                    ;;
            esac
            COMPREPLY=( $(compgen -W "${opts}" -- "${cur}") )
            return 0
            ;;
        my__app__help__bar)
            opts=""
            if [[ ${cur} == -* || ${COMP_CWORD} -eq 3 ]] ; then
                COMPREPLY=( $(compgen -W "${opts}" -- "${cur}") )
                return 0
            fi
            case "${prev}" in
                *)
                    COMPREPLY=()
                    ;;
            esac
            COMPREPLY=( $(compgen -W "${opts}" -- "${cur}") )
            return 0
            ;;
        my__app__help__foo)
            opts=""
            if [[ ${cur} == -* || ${COMP_CWORD} -eq 3 ]] ; then
                COMPREPLY=( $(compgen -W "${opts}" -- "${cur}") )
                return 0
            fi
            case "${prev}" in
                *)
                    COMPREPLY=()
                    ;;
            esac
            COMPREPLY=( $(compgen -W "${opts}" -- "${cur}") )
            return 0
            ;;
        my__app__help__help)
            opts=""
            if [[ ${cur} == -* || ${COMP_CWORD} -eq 3 ]] ; then
                COMPREPLY=( $(compgen -W "${opts}" -- "${cur}") )
                return 0
            fi
            case "${prev}" in
                *)
                    COMPREPLY=()
                    ;;
            esac
            COMPREPLY=( $(compgen -W "${opts}" -- "${cur}") )
            return 0
            ;;
    esac
}

if [[ "${BASH_VERSINFO[0]}" -eq 4 && "${BASH_VERSINFO[1]}" -ge 4 || "${BASH_VERSINFO[0]}" -gt 4 ]]; then
    complete -F _my-app -o nosort -o bashdefault -o default my-app
else
    complete -F _my-app -o bashdefault -o default my-app
fi