batchip

#!/usr/bin/env bash
# =============================================================================
#      FileName : batchip
#        Author : marslo
#       Created : 2026-05-15 19:34:29
#    LastChange : 2026-05-18 19:15:47
#   Description : A wrapper around `bat` that colorizes hex color codes in the output. support:
#                 - Hex: #fff, #ffffff, 'ffffff'
#                 - RGB/RGBA: rgb(74, 242, 161), rgba(74, 242, 161, 0.3)
#                 - HSL/HSLA: hsl(120, 100%, 50%), hsla(120, 100%, 50%, 0.5)
#                 - Bare RGB tuples: 255, 50, 127 or 218,112,214
#                 - Named colors: slateblue, olivedrab
# =============================================================================

set -euo pipefail

declare COLOR_NAMES_JSON="${COLOR_NAMES_JSON:-$HOME/.config/css-color-names.json}"
declare -r JSON_URL='https://github.com/bahamas10/css-color-names/raw/master/css-color-names.json'

function _checkjson() {
  [[ -f "${COLOR_NAMES_JSON}" ]] && return 0

  test -f "${COLOR_NAMES_JSON}" || {
    echo -e "\033[0;3mdownloading color names JSON to \033[0;3;35m'${COLOR_NAMES_JSON}'\033[0m from \033[0;3;36m'${JSON_URL}'\033[0;3m ...\033[0m" >&2
    command curl -fsSL --create-dirs -o "${COLOR_NAMES_JSON}" "${JSON_URL}"
  } || {
    echo "Failed to download '${COLOR_NAMES_JSON}', try manual download from '${JSON_URL}'" >&2
    exit 1
  }
}

function _checkbat() {
  type -P bat >/dev/null || {
    echo "Error: 'bat' command not found. Please install 'bat' first." >&2
    exit 1
  }
}

function _decolorize() { sed $'s/\x1b\\[\\([0-9;]*\\)[mGKHfJ]//g'; }

function _color_filter() {
  COLOR_JSON_PATH="${COLOR_NAMES_JSON}" perl -pe '
    BEGIN {
      use JSON::PP;

      sub h2r {
        my ($p, $q, $t) = @_;
        $t += 1 if $t < 0;
        $t -= 1 if $t > 1;
        return $p + ($q - $p) * 6 * $t if $t < 1/6;
        return $q if $t < 1/2;
        return $p + ($q - $p) * (2/3 - $t) * 6 if $t < 2/3;
        return $p;
      }

      # ONLY apply background color, keep original bat foreground color intact
      sub colorize {
          my ($match, $r, $g, $b) = @_;
          $r = int($r + 0.5); $g = int($g + 0.5); $b = int($b + 0.5);
          $r = $r > 255 ? 255 : ($r < 0 ? 0 : $r);
          $g = $g > 255 ? 255 : ($g < 0 ? 0 : $g);
          $b = $b > 255 ? 255 : ($b < 0 ? 0 : $b);

          # determining foreground color
          # -- yiq formula / itu-r rec. 601 standard
          # my $fg = (0.299*$r + 0.587*$g + 0.114*$b) > 175 ? "38;2;0;0;0" : "38;2;255;255;255";
          # -- rec. 709 luma coefficients (emphasizing green for human eye sensitivity)
          my $fg = (0.2126*$r + 0.7152*$g + 0.0722*$b) > 175 ? "38;2;0;0;0" : "38;2;255;255;255";

          # strip out original ANSI codes from the match to get a clean color string for parsing
          my $clean = $match;
          $clean =~ s/\033\[[\d;]*m//g;

          # get original color string without ANSI codes for parsing, but use the original $match for output to preserve any existing formatting
          return "\033[${fg};48;2;${r};${g};${b}m${clean}\033[39;49m";
        }

      %COLOR_NAMES = ();
      my $file = $ENV{COLOR_JSON_PATH};

      if (defined $file && -e $file) {
        if (open(my $fh, "<", $file)) {
          local $/;
          my $json_text = <$fh>;
          close($fh);

          eval {
            my $data = decode_json($json_text);
            while (my ($name, $hex) = each %$data) {
              # skip basic color names - if needed
              # next if $name =~ m/^(red|blue|gray|grey)$/;
              $hex =~ s/#//;
              if (length($hex) == 6) {
                my @rgb = map { hex($_) } ($hex =~ m{..}g);
                $COLOR_NAMES{lc($name)} = \@rgb;
              }
            }
          };
        }
      }
    }

    my $P = qr{(?:\033\[[^\x40-\x7E]*[\x40-\x7E]|\s)*};

    # ==========================================
    # RGB / RGBA: rgb(49, 130, 201), rgba(49, 130, 201, 0.5)
    # ==========================================
    s{(rgba?${P}\([^)]+\))}{
      my $match = $1;
      my $clean = $match; $clean =~ s/\033\[[^\x40-\x7E]*[\x40-\x7E]//g; $clean =~ s/\s//g;
      if ($clean =~ m{^rgba?\((\d{1,3}),(\d{1,3}),(\d{1,3})(?:,([0-9.]+)(%?))?\)}i) {
        my ($r, $g, $b, $av, $ps) = ($1, $2, $3, $4, $5);

        my $a = defined($av) ? $av + 0 : 1;
        $a = $a / 100 if defined($ps) && length($ps) > 0;
        $a = $a > 1 ? 1 : ($a < 0 ? 0 : $a);

        $r = ($r > 255 ? 255 : $r) * $a + 255 * (1 - $a);
        $g = ($g > 255 ? 255 : $g) * $a + 255 * (1 - $a);
        $b = ($b > 255 ? 255 : $b) * $a + 255 * (1 - $a);
        # using `$match` to preserve any existing ANSI codes in the original string
        colorize($match, $r, $g, $b);
      } else {
        $match;
      }
    }gie;

    # ==========================================
    # HSL / HSLA: hsl(266, 70%, 53%), hsla(266, 70%, 53%, 0.6)
    # ==========================================
    s{(hsla?${P}\([^)]+\))}{
      my $match = $1;
      my $clean = $match; $clean =~ s/\033\[[^\x40-\x7E]*[\x40-\x7E]//g; $clean =~ s/\s//g;
      if ($clean =~ m{^hsla?\((\d+(?:\.\d+)?)(?:deg)?,(\d+(?:\.\d+)?)%?,(\d+(?:\.\d+)?)%?(?:,([0-9.]+)(%?))?\)}i) {
        my ($h_val, $s_val, $l_val, $av, $ps) = ($1 % 360, ($2 > 100 ? 100 : $2) / 100, ($3 > 100 ? 100 : $3) / 100, $4, $5);
        my $a = defined($av) ? $av + 0 : 1; $a = $a / 100 if defined($ps) && length($ps) > 0; $a = $a > 1 ? 1 : ($a < 0 ? 0 : $a);
        my ($r, $g, $b);
        if ($s_val == 0) {
          $r = $g = $b = $l_val * 255;
        } else {
          my $q = $l_val < 0.5 ? $l_val * (1 + $s_val) : $l_val + $s_val - $l_val * $s_val;
          my $p = 2 * $l_val - $q;
          $r = h2r($p, $q, $h_val/360 + 1/3) * 255;
          $g = h2r($p, $q, $h_val/360) * 255;
          $b = h2r($p, $q, $h_val/360 - 1/3) * 255;
        }
        $r = $r * $a + 255 * (1 - $a); $g = $g * $a + 255 * (1 - $a); $b = $b * $a + 255 * (1 - $a);
        # using `$match` to preserve any existing ANSI codes in the original string
        colorize($match, $r, $g, $b);
      } else {
        $match;
      }
    }gie;

    # ==========================================
    # HEX COLOR: #78ab37, #0FF
    # ==========================================
    s{(#(?:\033\[[\d;]*m)*(?:[0-9a-fA-F](?:\033\[[\d;]*m)*){3,8}(?![0-9a-fA-F]))}{
      my $match = $1;
      my $h = $match; $h =~ s/\033\[[\d;]*m//g; $h =~ s/#//;
      my $len = length($h);

      # CSS supports 3, 4, 6, or 8 hex digits
      if ($len == 3 || $len == 4 || $len == 6 || $len == 8) {
        $h = join "", map { $_ x 2 } split "", $h if $len == 3 || $len == 4;
        my ($r, $g, $b, $a_hex) = map { hex } ($h =~ m{..}g);

        my $a = defined($a_hex) ? $a_hex / 255 : 1;
        # alpha blending, using 40 instead of 255 to blend with a white background
        my $bg_r = 40; my $bg_g = 40; my $bg_b = 40;

        $r = $r * $a + $bg_r * (1 - $a);
        $g = $g * $a + $bg_g * (1 - $a);
        $b = $b * $a + $bg_b * (1 - $a);

        colorize($match, $r, $g, $b);
      } else {
        $match;
      }
    }gie;

    # ==========================================
    # BARE RGB TUPLES - 223,174,45
    # ==========================================
    s{(\033\[[\d;]+m.*?\033\[39;49m)(*SKIP)(*FAIL)|(?<!\d)(\d{1,3}(?:\033\[[\d;]*m|\s)*,(?:\033\[[\d;]*m|\s)*\d{1,3}(?:\033\[[\d;]*m|\s)*,(?:\033\[[\d;]*m|\s)*\d{1,3})(?!\d)}{
      my $match = $&;
      my $clean = $match; $clean =~ s/\033\[[\d;]*m//g; $clean =~ s/\s//g;
      my ($r, $g, $b) = split /,/, $clean;
      if (defined $r && defined $g && defined $b && $r <= 255 && $g <= 255 && $b <= 255) {
        colorize($match, $r, $g, $b);
      } else {
        $match;
      }
    }gie;

    # ==========================================
    # QUOTED BARE HEX - "A0CC2F"
    # ==========================================
    s{([\x27\x22])(?:\033\[[\d;]*m)*((?:(?:\033\[[\d;]*m)*[0-9a-fA-F]){3,8})(?:\033\[[\d;]*m)*\1}{
      my $match = $&;
      my $h = $2;
      # trim bat highlight ANSI codes
      $h =~ s/\033\[[\d;]*m//g;
      my $len = length($h);

      # valid hex lengths are 3 (RGB), 4 (RGBA), 6 (RRGGBB), or 8 (RRGGBBAA)
      if ($len == 3 || $len == 4 || $len == 6 || $len == 8) {
        my $calc_h = ($len == 3 || $len == 4) ? join("", map { $_ x 2 } split "", $h) : $h;
        my ($r, $g, $b, $a_hex) = map { hex } ($calc_h =~ m{..}g);
        my $a = defined($a_hex) ? $a_hex / 255 : 1;
        my $bg_r = 40; my $bg_g = 40; my $bg_b = 40;

        $r = $r * $a + $bg_r * (1 - $a);
        $g = $g * $a + $bg_g * (1 - $a);
        $b = $b * $a + $bg_b * (1 - $a);

        colorize($match, $r, $g, $b);
      } else {
        $match;
      }
    }gie;

    # ==========================================
    # NAMED COLORS - mediumslateblue
    # ==========================================
    s{(?<![a-zA-Z\-])(m?(?:\033\[[\d;]*m|\s)*)([a-zA-Z\-]{3,20})(?![a-zA-Z\-])}{
      my $full_match = $&;
      my $prefix = $1;
      my $word = $2;
      my $clean_word = lc($word); $clean_word =~ s/\033\[[\d;]*m//g; $clean_word =~ s/\s//g;

      if (exists $COLOR_NAMES{$clean_word}) {
        my ($r, $g, $b) = @{$COLOR_NAMES{$clean_word}};
        $prefix . colorize($word, $r, $g, $b);
      } else {
        $full_match;
      }
    }gie;
  '
}

# main
function batchip() {
  local _dopage=true
  local _decolor=false
  # strip BAT_OPTS and set BAT_STYLE=plain to avoid interference with our colorization logic
  local -a _envcmd=( env -u BAT_OPTS BAT_STYLE=plain )
  local -a _batcmd=( command bat --color=always --paging=never )

  # intercept certain arguments that should bypass the colorization logic
  for arg in "$@"; do
    case "${arg}" in
      --list-*|-h|--help|-V|--version|--diagnostics|--cache-dir|cache ) _checkbat; exec command bat "$@" ;;
      --paging=never|-P                                               ) _dopage=false ;;
      --paging=always                                                 ) _dopage=true  ;;
      --language|--language=*|-l|--file-name|--file-name=*.*          ) _decolor=true ;;
    esac
  done

  # download color names json if necessary
  _checkjson

  # filter mode / pipe mode: no args && stdin is not a TTY then not invoking `bat`
  if [[ ! -t 0 ]]; then
    local _pager="${BAT_PAGER:-${PAGER:-less -R -F -X}}"
    # `command cat style.css | batchip`
    if [[ $# -eq 0 ]]; then
      _color_filter
    # `command bat --color always style.css | batchip --language css`
    elif "${_decolor}"; then
      _checkbat
      _decolorize | "${_envcmd[@]}" "${_batcmd[@]}" "$@" | _color_filter
    else
      _checkbat
      "${_envcmd[@]}" "${_batcmd[@]}" "$@" | _color_filter
    fi |
    if [[ "${_dopage}" == true && -t 1 ]]; then ${_pager}; else command cat; fi
    return
  fi

  # wrapper mode: `batchip style.css [OPTIONS ...]`
  _checkbat
  local _pager="${BAT_PAGER:-${PAGER:-less -R -F -X}}"
  "${_envcmd[@]}" "${_batcmd[@]}" "$@" | _color_filter |
  if [[ "${_dopage}" == true && -t 1 ]]; then ${_pager}; else command cat; fi
}

batchip "$@"

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