sxhkd-shortcuts

#!/usr/bin/env bash

# --- Environment variables ---
: ${XDG_CONFIG_HOME:=${HOME}/.config}

# --- Constants ---
__SCRIPT__="$(realpath "$0")"
__SCRIPT_NAME__="$(basename "$__SCRIPT__")"

# --- Global variables ---
_VERBOSE=false
_SHORTCUTS_MAX_WIDTH="0" # `0` = automatic width
_SHORTCUTS_MIN_WIDTH="0" # `0` = automatic width
_SXHKD_PID=""


usage() {
    echo "
  Usage:
    ${__SCRIPT_NAME__} <sxhkd-pid>
    ${__SCRIPT_NAME__} [options] <sxhkd-pid>

  OPTIONS:
    -h, --help                   Print this help
    -v, --verbose                Verbose output
    --shortcuts-min-with <num>   Set minimum width of the shortcuts column. Set
                                 to \`0\` for automatic width (default: ${_SHORTCUTS_MAX_WIDTH})
    --shortcuts-max-with <num>   Limit the width of the shortcuts column. Set to
                                 \`0\` for automatic width (default: ${_SHORTCUTS_MAX_WIDTH})
"
}


parse_args() {
    while [[ $# > 0 ]]; do
        case $1 in
            '-h'|'--help')
                usage
                exit
                ;;
            '-v'|'--verbose')
                _VERBOSE=true
                ;;
            '--shortcuts-min-width')
                _SHORTCUTS_MIN_WIDTH="$2"
                shift
                if [[ ! $_SHORTCUTS_MIN_WIDTH =~ ^[0-9]+$ ]]; then
                    echo "ERROR: Invalid value for --shortcuts-min-width. Must be numeric." >&2
                    exit 1
                fi
                check_min_max_width
                ;;
            '--shortcuts-max-width')
                _SHORTCUTS_MAX_WIDTH="$2"
                shift
                if [[ ! $_SHORTCUTS_MAX_WIDTH =~ ^[0-9]+$ ]]; then
                    echo "ERROR: Invalid value for --shortcuts-max-width. Must be numeric." >&2
                    exit 1
                fi
                check_min_max_width
                ;;
            '-'*)
                echo "ERROR: Invalid option: ${1}" >&2
                exit 1
                ;;
            *)
                if [[ -n $_SXHKD_PID ]]; then
                    echo "ERROR: Too many arguments: ${1}" >&2
                    exit 1
                fi

                _SXHKD_PID="$1"
                ;;
        esac

        shift
    done
}

main() {
    parse_args "$@"

    check_sxhkd_pid

    local config_files
    get_sxhkd_config_files config_files
    parse_config_files "${config_files[@]}"
}

verbose() {
    if [[ $_VERBOSE != true ]]; then
        return
    fi

    echo >&2 "${__SCRIPT_NAME__}: $@"
}


check_sxhkd_pid() {
    if [[ -z $_SXHKD_PID ]]; then
        echo "ERROR: Missing argument <sxhkd-pid>!" >&2
        usage >&2
        exit 1
    fi

    if [[ ! -d /proc/${_SXHKD_PID} ]]; then
        echo "ERROR: PID ${_SXHKD_PID} does not exist."
        exit 1
    fi
}



get_sxhkd_config_files() {
    local -n out_array="$1"

    local sxhkd_cmdline="$(
        < "/proc/${_SXHKD_PID}/cmdline" \
            tr '\0' '\n' \
            | tail -n+2
    )"
    local sxhkd_args
    array_from_lines sxhkd_args "$sxhkd_cmdline"
    verbose "XXXXXXXXX ${sxhkd_args}"
    verbose "XXXXXXXXX ${sxhkd_args[@]}"

    local sxhkd_config="${XDG_CONFIG_HOME}/sxhkd/sxhkdrc"
    local sxhkd_extra_configs=()

    local i
    for (( i=0; i < ${#sxhkd_args[@]}; i++ )); do
        local arg="${sxhkd_args[i]}"
        verbose "sxhkd cmdline[${i}]: ${arg}"

        case "$arg" in
            # Handle default config file
            '-c')
                arg="${sxhkd_args[i+1]}"
                let i++

                verbose "Default config file: $arg"
                sxhkd_config="$arg"
                ;;
            # Skip other options
            '-'*)
                continue
                ;;
            # Handle extra config files
            *)
                if [[ ! -f $arg ]]; then
                    verbose "Ignoring sxhkd argument \"${arg}\" as config file because a file with that name does not exist."
                    continue
                fi
                verbose "Extra config file: $arg"
                sxhkd_extra_configs+=( "$arg" )
                ;;
        esac
    done

    out_array=( "$sxhkd_config" "${sxhkd_extra_configs[@]}" )
}


parse_config_files() {
    local files=( "$@" )

    cat "${files[@]}" \
        | awk \
            -v MIN_WIDTH="$_SHORTCUTS_MIN_WIDTH" \
            -v MAX_WIDTH="$_SHORTCUTS_MAX_WIDTH" \
            '''
                BEGIN {
                    desc=""
                    keys=""
                }

                /^\s*$|^\s/ {
                    desc=""
                    keys=""

                    next
                }

                /^#:\s/ {
                    if (desc == "") {
                        sub(/^#:\s+/, "")
                        desc=$0
                    }

                    next
                }

                /^[^#]+$/ {
                    keys=$0

                    if (MIN_WIDTH > 0 && length(keys) < MIN_WIDTH) {
                        keys=sprintf("%-" MIN_WIDTH "s", keys)
                    }
                    if (MAX_WIDTH > 0 && length(keys) > MAX_WIDTH) {
                        keys=substr(keys,1,MAX_WIDTH - 1) "…"
                    }
                    print keys "\t" desc

                    desc=""
                    keys=""

                    next
                }
            ''' \
        | column -t -s $'\t' -o '  | '
}

#| sort -t '#' -k2 \
#| rofi -dmenu -i -no-show-icons --width 1000 -p sxhkd


array_from_lines() {
    local -n array_name="$1"   # Use nameref for indirection
    local lines="$2"

    #if [[ ! $array_name =~ ^[a-zA-Z_-]+$ ]]; then
    #    echo >&2 "array_from_lines: ERROR: Array name \"${array_name}\" is invalid"
    #    exit 1
    #fi

    local ifs_bak="$IFS"
    IFS=$'\n'
    array_name=( $lines )
    IFS="$ifs_bak"
}


check_min_max_width() {
    if [[ $_SHORTCUTS_MAX_WIDTH > 0 ]] && [[ $_SHORTCUTS_MIN_WIDTH -gt $_SHORTCUTS_MAX_WIDTH ]]; then
        echo "WARNING: --shortcuts-min-width is larger than --shortcuts-max-width. Ignoring min-width." >&2
        _SHORTCUTS_MIN_WIDTH=0
    fi
}

main "$@"