#!/usr/bin/env bash
# lmms(1) completion                                       -*- shell-script -*-
# use shellcheck: "shellcheck -e bash <filename>"

_lmms_array_contains ()
{
    local e match="$1"
    shift
    for e; do [[ "$e" == "$match" ]] && return 0; done
    return 1
}

_lmms_long_param_of()
{
    case "$1" in
        -a)
            echo "float"
            ;;
        -b)
            echo "bitrate"
            ;;
        -c)
            echo "config"
            ;;
        -f)
            echo "format"
            ;;
        -i)
            echo "interpolation"
            ;;
        -l)
            echo "loop"
            ;;
        -m)
            echo "mode"
            ;;
        -o)
            echo "output"
            ;;
        -p)
            echo "profile"
            ;;
        -s)
            echo "samplerate"
            ;;
        -x)
            echo "oversampling"
            ;;
        *)
            echo ""
            ;;
    esac
}

_lmms_conv_old_action ()
{
    case "$1" in
        -d|--dump)
            echo "dump"
            ;;
        -r|--render)
            echo "render"
            ;;
        --rendertracks)
            echo "rendertracks"
            ;;
        -u|--upgrade)
            echo "upgrade"
            ;;
        *)
            echo ""
            ;;
    esac
}

_lmms()
{
    local cword=$COMP_CWORD
    local cur="${COMP_WORDS[COMP_CWORD]}"

    # call routine provided by bash-completion
    _init_completion || return
    
    local params filemode filetypes
    local i # counter variable
    local pars_global pars_noaction pars_render actions shortargs
    pars_global=(--allowroot --config --help --version)
    pars_noaction=(--geometry --import)
    pars_render=(--float --bitrate --format --interpolation)
    pars_render+=(--loop --mode --output --profile)
    pars_render+=(--samplerate --oversampling)
    actions=(dump compress render rendertracks upgrade)
    actions_old=(-d --dump -r --render --rendertracks -u --upgrade)
    shortargs+=(-a -b -c -f -h -i -l -m -o -p -s -v -x)

    local prev prev2
    if [ "$cword" -gt 1 ]
    then
        prev=${COMP_WORDS[cword-1]}
    fi
    if [ "$cword" -gt 2 ]
    then
        prev2=${COMP_WORDS[cword-2]}
    fi
        
    # don't show shortargs, but complete them when entered
    if [[ $cur =~ ^-[^-]$ ]]
    then
        if _lmms_array_contains "$cur" "${shortargs[@]}"
        then
            COMPREPLY=( "$cur" )
        fi
        return
    fi
        
    #
    # please keep those in order like def_pars_args above
    #
    case $prev in
        --bitrate|-b)
            params="64 96 128 160 192 256 320"
            ;;
        --config|-c)
            filetypes='xml'
            filemode='existing_files'
            ;;
        --format|-f)
            params='wav ogg mp3'
            ;;
        --geometry)
            # we can not name all possibilities, but this helps the user
            # by showing them how the format is
            params='0x0+0+0'
            ;;
        --interpolation|-i)
            params='linear sincfastest sincmedium sincbest'
            ;;
        --import)
            filetypes='mid|midi|MID|MIDI|rmi|RMI|h2song|H2SONG'
            filemode='existing_files'
            ;;
        --mode|-m)
            params='s j m'
            ;;
        --output|-o)
            # default assumption: could be both
            local render=1 rendertracks=1
            for i in "${!COMP_WORDS[@]}"
            do
                if [[ ${COMP_WORDS[i]} =~ ^(render|-r|--render)$ ]]
                then
                    rendertracks=
                elif [[ ${COMP_WORDS[i]} =~ ^(rendertracks|--rendertracks)$ ]]
                then
                    render=
                fi
            done
            if [ "$rendertracks" ]
            then
                filemode='existing_directories'
            fi
            if [ "$render" ]
            then
                # filemode files is a superset of "existing directories"
                # so it's OK to overwrite the filemode='existing_directories'
                # from above
                filetypes='wav|ogg|mp3'
                filemode='files'
            fi
            ;;
        --profile|-p)
            filemode='files'
            ;;
        --samplerate|-s)
            # these are the ones suggested for zyn
            # if you think more are required,
            # remove this comment and write a justification
            params='44100 48000 96000 192000'
            ;;
        --oversampling|-x)
            params='1 2 4 8'
            ;;
        *)
            local action_found

            # Is an action specified?
            if [ "$cword" -gt 1 ]
            then
                local wrd
                for wrd in "${COMP_WORDS[@]}"
                do
                    # action named explicitly?
                    if _lmms_array_contains "$wrd" "${actions[@]}"
                    then
                        action_found=$wrd
                        break
                    # deprecated action name?
                    elif _lmms_array_contains "$wrd" "${actions_old[@]}"
                    then
                        action_found="$(_lmms_conv_old_action "$wrd")"
                        break
                    # no-action params found?
                    elif _lmms_array_contains "$wrd" "${pars_noaction[@]}"
                    then
                        action_found=none
                        break
                    fi
                done
            fi
            
            if [[ $prev =~ -e|--help|-h|-version|-v ]]
            then
                # the -e flag (from --import) and help/version
                # always mark the end of arguments
                return
            fi
            
            if [[ "$action_found" =~ dump|none|^$ ]] && [[ $prev =~ \.mmpz? ]]
            then
                # mmp(z) mark the end of arguments for those actions
                return
            fi
            
            local savefiletypes='mmpz|mmp'
            local params_array
            
            # find parameters/filetypes/dirtypes depending on actions
            if ! [ "$action_found" ]
            then
                params_array=( "${actions[@]}" "${pars_global[@]}" "${pars_noaction[@]}")
                filemode="existing_files"
                filetypes="$savefiletypes"
            elif [ "$action_found" == "none" ]
            then
                params_array=( "${pars_noaction[@]}" )
                filemode="existing_files"
                filetypes="$savefiletypes"
            elif [ "$action_found" == "dump" ]
            then
                filemode="existing_files"
                filetypes="mmpz"
            elif [ "$action_found" == "upgrade" ]
            then
                if [ "$prev" == "upgrade" ]
                then
                    filemode="existing_files"
                    filetypes="$savefiletypes"
                elif [ "$prev2" == "upgrade" ]
                then
                    filemode="files"
                    filetypes="$savefiletypes"
                fi
            elif [[ "$action_found" =~ render(tracks)? ]]
            then
                if [[ "$prev" =~ render(tracks)? ]]
                then
                    filemode="existing_files"
                    filetypes="$savefiletypes"
                else
                    params_array=( "${pars_render[@]}" )
                fi
            fi
            
            # add params_array to params, but also check the history of comp words
            local param
            for param in "${params_array[@]}"
            do
                local do_append=1
                for i in "${!COMP_WORDS[@]}"
                do
                    if [ "$i" -ne 0 ] && [ "$i" -ne "$cword" ]
                    then
                        # disallow double long parameters
                        if [ "${COMP_WORDS[$i]}" == "$param" ]
                        then
                            do_append=
                        # disallow double short parameters
                        elif [ "--$(_lmms_long_param_of "${COMP_WORDS[$i]}")" == "$param" ]
                        then
                            do_append=
                        # --help or --version must be the first parameters
                        elif [ "$cword" -gt 1 ] && [[ $param =~ --help|--version ]]
                        then
                            do_append=
                        fi
                    fi
                done
                if [ "$do_append" ]
                then
                    params+="$param "
                fi
            done
        ;;
    esac
    
    case $filemode in
        
        # use completion routine provided by bash-completion
        # to fill $COMPREPLY
        
        existing_files)
            _filedir "@($filetypes)"
        ;;

        existing_directories)
            _filedir -d
        ;;
        
        files)

            # non existing files complete like directories...
            _filedir -d
            
            # ...except for non-completing files with the right file type
            if [ ${#COMPREPLY[@]} -eq 0 ]
            then
                if ! [[ "$cur" =~ /$ ]] && [ "$filetypes" ] && [[ "$cur" =~ \.($filetypes)$ ]]
                then
                    # file ending fits, we seem to be done
                    COMPREPLY=( "$cur" )
                fi
            fi
        ;;
        
    esac

    if [ "$params" ]
    then
        # none of our parameters contain spaces, so deactivate shellcheck's warning
        # shellcheck disable=SC2207
        COMPREPLY+=( $(compgen -W "${params}" -- "${cur}") )
    fi
}

complete -F _lmms lmms
