psi-pipe

_psi-pipe()
{
    local cur prev
    COMPREPLY=()
    cur="${COMP_WORDS[COMP_CWORD]}"
    prev="${COMP_WORDS[COMP_CWORD-1]}"

    # result of: psi-pipe --help 2> /dev/null | grep -oP '(?=(\[| )) --[a-z\-]+'
    local pipe_opts="--help --version --line-by-line --processors --aliases --list-encodings --from-encoding --log-level --log-file"

    local procs=$( psi-pipe --processors 2> /dev/null | tail -n +2 )
    local aliases=$( psi-pipe --aliases 2> /dev/null | grep -oP '.+(?= -> )' )
    local all_procs="${procs} ${aliases}"

    if [[ ${cur} == -* ]] ; then
        case "${all_procs}" in
            *${prev}*)
                local proc_opts=$( psi-pipe --help ${prev} 2> /dev/null | grep -oP '(?=(\[| )) --[a-z\-]+' | sort -u )
                COMPREPLY=( $(compgen -W "${proc_opts}" -- ${cur}) )
                return 0
                ;;
            *)
                COMPREPLY=( $(compgen -W "${pipe_opts}" -- ${cur}) )
                return 0
            ;;
        esac
    fi

    case "${prev}" in
        # show only readers and annotators
        psi-pipe)
            local procs=$( echo "${all_procs}" | grep -vP 'write|get\-|draw|show' )
            COMPREPLY=( $(compgen -W "${pipe_opts} ${procs}" -- ${cur}) )
            return 0
            ;;
        --from-encoding)
            local encodings=$( psi-pipe --list-encodings 2> /dev/null | tail -n +2 )
            COMPREPLY=( $(compgen -W "${encodings}" -- ${cur}) )
            return 0
            ;;
        --log-level)
            local levels="TRACE DEBUG INFO WARN ERROR FATAL"
            COMPREPLY=( $(compgen -W "${levels}" -- ${cur}) )
            return 0
            ;;
        # show only annotators and writers
        !)
            local procs=$( echo "${all_procs}" | grep -vP '\-reader|read-' )
            COMPREPLY=( $(compgen -W "${procs}" -- ${cur}) )
            return 0
            ;;
        --help)
            COMPREPLY=( $(compgen -W "${all_procs}" -- ${cur}) )
            return 0
            ;;
        *)
        ;;
    esac

    _filedir
}
complete -F _psi-pipe psi-pipe