Perl6/Panda completion

# bash completion for (rakudo?) perl6
# Usefull looking things that may or may not exist
# _filedir

_panda_read_json_perl() {
perl <<'HEREPERL'
    use feature qw{say};
    use utf8;
    binmode STDOUT, q{:utf8};
    use Module::Load::Conditional qw[can_load]; # builtin, so safe?
    my $json;
    {
        local $/;
        # FIXME should check CompUnitRepo or something and compile the output into one.
        open my $fh, q{<}, $ENV{HOME} . q{/.perl6/panda/projects.json};
        $json = <$fh>;
        close $fh;
    }
    # NOTE! Module::Load::Conditional::can_load return false if it can load the module, and true if it cannot. (is this a bug?)
    unless ( can_load(modules => q{JSON}) ) {
        require JSON; JSON->import(qw{decode_json});

        foreach ( @{decode_json($json)} ){
                say $_->{name};
        }
    } else { # because requiring perl5 mods wont fly
        while ($json =~ m/ \" name \" \: \" ([^\"]*) \" /gx) {
                say $1;
        }
    }
HEREPERL
}

_panda_modules() { # TIMTOWTDI. (actualy, I think the container may change in future versions(or implimintations).. but feel free to try seding/greping/whatever instead)
    _panda_read_json_perl
}

_perl6_match() { # Succeeds if argument is repeated. Must be an EXACT MATCH.
        #usage,  _perl6_match 'str to match' a list of str #returns fale/1;
        #usage,  _perl6_match 'matched str' a 'matched str' was found  #returns true/0;
    repcur="$1"
    shift
    for val in "$@"; do
        [[ "${repcur}" == "${val}" ]] && return 0
    done
    return 1
}
_perl6_assoc() { # Removes associated arguments. usage, from _perl6_rem: _perl6_assoc $i -h --help
    asscur=$1; shift
    akv=($@)
    for (( k=0; k<$((${#akv[@]}-1)); k+=2)); do
        v=$(($k+1))
        [[ "$asscur" == "${akv[$k]}" ]] && {
            COMPREPLY=" ${COMPREPLY[@]} "
            COMPREPLY=(${COMPREPLY/ ${akv[$v]%% *} / })
        }
        [[ "$asscur" == "${akv[$v]}" ]] && {
            COMPREPLY=" ${COMPREPLY[@]} "
            COMPREPLY=(${COMPREPLY/ ${akv[$k]%% *} / })
        }
    done
    printf "%s\n" "${COMPREPLY[@]}"
}
_perl6_seper() { # Prints the arguments that are deliminated by 'cnt' number of 'sep's. ie:
        # _perl6_seper 1 '--' -a -1 -- -2 -b -- c 3 ; #yeilds -2 -b; _perl6_seper 0 yeilds -a -1
    cnt=$1; shift
    sep=$1; shift
    args=("$@")
    idx=0
    zarg=0
    for ((iter=0; iter<=$cnt; iter++)); do
        zarg=1
        while [[ "$idx" -lt "${#args[@]}" ]]; do
            zarg=0
            arg="${args[$idx]}"; ((idx++))
            [[ "$arg" == "$sep" ]] && {
                [ "$iter" -eq "$cnt" ] && return 0
                break
            }
            [[ "$iter" == "$cnt" ]] && printf "%s\n" "${arg}" # Im not sure how this will handle spaces
        done
        [ "$zarg" -ne "0" ] && return 1
        iterend=$iter
    done
    [ "$iterend" -eq "$cnt" ] && return 0 # may chose to do 3 way in future
    return 1
}
# NOTE: This slows things down!
# Taken from gentoo's adaption of Ian Macdonald's bash_completion.
# (Adapted from bash_completion by Ian Macdonald <ian@caliban.org>)
# This removes any options from the list of completions that have
# already been specified on the command line.
_perl6_rem() {
    rep_words=($(_perl6_seper '0' '--' "$@")) # It looks like we can quote all of these without error. consider doing so.
    assoc_words=($(_perl6_seper '1' '--' "$@"))
    nospace_words=($(_perl6_seper '2' '--' "$@"))
        COMPREPLY=($(echo "${COMP_WORDS[@]}" | \
        (while read -d ' ' i; do
            [[ -z ${i} ]] && continue
        _perl6_repeatable "${i}" "${rep_words[@]}" && continue
        COMPREPLY=($(_perl6_assoc "${i}" "${assoc_words[@]}"))
        # flatten array with spaces on either side,
            # otherwise we cannot grep on word boundaries of
            # first and last word
            COMPREPLY=" ${COMPREPLY[@]} "
            # remove word from list of completions
            COMPREPLY=("${COMPREPLY/ ${i%% *} / }") # FIXME doesnt work for --target\= and alike
        done
        echo ${COMPREPLY[@]})))
    [[ "${#COMPREPLY[@]}" -eq "1" ]] && _perl6_repeatable "$COMPREPLY" "${nospace_words[@]}" && compopt -o nospace
        return 0
}

_panda() {
    local cur prev words cword
    _init_completion || return
    list_args="--verbrose --installed"
    install_args="--notests --nodeps"
    case $prev in
        install|--notests|--nodeps)
            #COMPREPLY=( $( compgen -W 'install $install_args $( _panda_modules )'  -- "$cur" ) )
            COMPREPLY=( $( compgen -W 'install $install_args'  -- "$cur" ) )
            _perl6_match 'install' "${COMP_WORDS[@]}" && COMPREPLY+=( $( compgen -W '$( _panda_modules )'  -- "$cur" ) )
            _perl6_rem;
            return 0
            ;;
        list|--verbrose|--installed)
            #COMPREPLY=( $( compgen -W 'list $list_args $( _panda_modules )' -- "$cur" ) )
            COMPREPLY=( $( compgen -W 'list $list_args' -- "$cur" ) )
            _perl6_match 'list' "${COMP_WORDS[@]}" && COMPREPLY+=( $( compgen -W '$( _panda_modules )'  -- "$cur" ) )
            _perl6_rem;
            return 0
            ;;
        search|info|update)
            COMPREPLY=( $( compgen -W '$( _panda_modules )'  -- "$cur" ) )
            _perl6_rem;
            return 0
            ;;
    esac
    if [[ "$cur" == * ]]; then
        COMPREPLY=( $( compgen -W '$list_args $install_args update info search install list' -- "$cur" ) )
    fi
}

_perl6() {
    local cur prev words cword
    _init_completion || return
    echo "$cur" > /home/beck/tmp.tmp
    case $prev in
            --encoding)
                COMPREPLY=( $( compgen -W 'utf8'  -- "$cur" ) )
                return 0
                ;;
    esac
    longargs="--doc --help --stagestats --ll-exception --profile"
    unlong="--target\= --trace\= --encoding\= --output\="
    shortargs="-c -h -e -n -p -t -o -v"
    unshort=''
    repargs="--output --encoding -e -n -p -o" # Repeatable Arguments
    assocargs="-h --help"   # Assosiated Arguments (only ones that cannot repeat)
    if [[ "$cur" == --* ]]; then
        COMPREPLY=( $( compgen -W '$longargs $unlong' -- "$cur" ) )
        _perl6_rem $repargs '--' $assocargs -- $unlong
    elif [[ "$cur" == -* ]]; then
        COMPREPLY=( $( compgen -W '$shortargs' -- "$cur" ) )
        _perl6_rem $repargs '--' $assocargs
    fi
} # &&
complete -F _perl6 -o default perl6{,m,j,p} perl6-debug-{m,j,p}
complete -F _panda -o default panda