#!/bin/bash
# hsv-rbg-browser.sh -- bash script for browsing RGB <-> HSV Colors.
# Version: 0.11 -- Last update: Fri Oct 25 07:12:06 2024
# Read colors from screen, clipboard and/or command line.
# (C) 2018-2024 Felix Hauri - felix@f-hauri.ch
# Licensed under terms of GPL v3. www.gnu.org
# Color browser using hsv<->rgb functions: hsvrgb.sh in same directory.
# Require: tput, xclip, colorpicker

SRCDIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
# shellcheck source=./hsvrgb.sh
if [ -e "$SRCDIR/hsvrgb.sh" ]; then . "$SRCDIR/hsvrgb.sh"
   else echo >&2 "Functions file 'hsvrgb.sh' not found."; exit 1
fi

pasteLoop=false
# shellcheck disable=SC2064 # I want to store stty setting in trap command
trap "stty '$(stty -g)'" 0 1 2 3 6 15
stty -echo

declare -i cols
readGrSizes() {
    cols=$( tput 'cols' )
    printf -v ColFmt '%*s' "$cols" ''
    ColFmt=${ColFmt// /'\e[48;2;%d;%d;%d;38;2;%d;%d;%dm\U2590'}
    ColFmt+='\e[0m'
}
refresh() {
    readGrSizes
    start=${EPOCHREALTIME/.}
    printf "\e8\e[J%s" "$clearPanel"
    drawLines
    showValues
}
trap refresh WINCH
readGrSizes

declare -ai xtR xtG xtB
getTermColors() { # Don't understand why this take time under mate or gnome term
    local _i
    local _chr _r _g _b
    for _i in {0..255}; do
	printf '\e]4;%d;?;\e\134' "$_i" >/dev/tty
	IFS='' read -sd \\ -r _chr
	_chr=${_chr#*:}
	IFS=/ read -r _r _g _b <<<"${_chr%$'\e'}"
	# shellcheck disable=SC2034 # Bad handling of integer
	xtR[_i]="16#$_r / 257" xtG[_i]="16#$_g / 257" xtB[_i]="16#$_b / 257"
	printf '\r\e[48;2;%d;%d;%dm %3d \e[0m' \
	       "${xtR[_i]}" "${xtR[_i]}" "${xtR[_i]}" "$_i"
    done
}
declare -A namedColors
getNamedColors() {
    local -i _r _g _b
    local cname rgbfile tries=(/{lib{64,},etc,usr/{lib,share}}/X1*1/rgb.txt)
    read -ra tries <<<"${tries[*]//*X1?1?rgb*}"
    if ! [[ -f ${tries[0]} ]]; then
	echo >&2 "WARNING: Color file 'X11/rgb.txt' not found!"
	return
    fi
    rgbfile=${tries[0]}
    while read -r cname ; do
	case $cname in
	    [0-9]* )
		read -r _r _g _b cname <<<"$cname"
		namedColors[$cname]="$_r $_g $_b"
		namedColors[${cname,,}]="$_r $_g $_b"
	esac
    done <"$rgbfile"
}
oldClipBoard=''
parseClipBoard() {
    local string
    read -r string < <(xclip -o 2>/dev/null)
    string=${string//[^0-9a-zA-Z),(# ]}
    [[ "$string" == "$oldClipBoard" ]] && return
    oldClipBoard="$string"
    crtColorFromString "$string";
}
crtColorFromString() {
    local string="$*"
    local -i arcol
    case $string in
	'#'???????????? )
	    arcol=( "16#${string:1:4}/257" "16#${string:5:4}/16"
		    "16#${string:9:4}/257" )
	    ;;
	'#'????????? )
	    arcol=( "16#${string:1:3}/16" "16#${string:4:3}/16"
		    "16#${string:7:3}/16" )
	    ;;
	'#'?????? )
	    arcol=( "16#${string:1:2}" "16#${string:3:2}" "16#${string:5:2}" )
	    ;;
	'#'??? )
	    arcol=( "16#${string:1:1}*17" "16#${string:2:1}*17"
		    "16#${string:3:1}*17" )
	    ;;
	'rgb('*')' | 'rgba('*')' )
	    read -ra arcol <<<"${string//[rgba),(]/ }"
	    ;;
	* )
	    [[ -v namedColors["$string"] ]] || return 1
	    read -ra arcol <<<"${namedColors["$string"]}"
	    ;;
    esac
    if [ "${arcol[2]}" ]; then
	r=${arcol[0]}
	g=${arcol[1]}
	b=${arcol[2]}
	rehsv
    fi
}
peekFromScreen() {
    local peek
    read -r peek < <(colorpicker --one-shot --short)
    r=$((16#${peek:1:2}))
    g=$((16#${peek:3:2}))
    b=$((16#${peek:5:2}))
    rehsv
}
closestColor() {
    local -i _r=$1 _g=$2 _b=$3 _idx _crt _closest=292742550
    local -n _res=$4
    for _idx in {0..255}; do
	[[ ${xtR[_idx]}.${xtG[_idx]}.${xtB[_idx]} == $_r.$_g.$_b ]] &&
	    _res=$_idx && return
	_crt='((xtR[_idx]-_r )*3)**2+((xtG[_idx]-_g)*6)**2+(xtB[_idx]-_b)**2'
	(( _crt < _closest )) && {
	    _closest=$_crt
	    # shellcheck disable=SC2034 # Bad handling of namref 
	    _res=$_idx
	}
    done
    return 1
}
closestNamedColor() {
    local _idx
    local -i _r=$1 _g=$2 _b=$3 _crt _closest=292742550 _nr _ng _nb
    local -n _res=$4 
    for _idx in "${!namedColors[@]}"; do
	read -r _nr _ng _nb <<<"${namedColors[$_idx]}"
	[[ $_nr.$_ng.$_nb == $_r.$_g.$_b ]] && _res=$_idx && return
	_crt='((_nr-_r )*3)**2+((_ng-_g)*6)**2+(_nb-_b)**2'
	(( _crt < _closest )) && {
	    _closest=$_crt
	    # shellcheck disable=SC2034 # Bad handling of namref 
	    _res=$_idx
	}
    done
    return 1
}
# shellcheck disable=SC2059 # Format string was built 
drawLines(){ 
    local -ia sl=() vl=() hl=() rl=() gl=() bl=() colors
    local -i i
    local sint # {r,g,b,h,s,v}_blank
    for ((i=0 ; 2*cols > i ; i++ ))
    do
        rgb $((17950000*i/cols/100000)) "$s" "$v" colors
        hl+=("${colors[@]}")
        sint=0000$((i*100000/cols))
        rgb "$h" ${sint::-5}.${sint: -5} "$v" colors
        sl+=("${colors[@]}")
        rgb "$h" "$s" $((25600000*i/cols/100000)) colors
        vl+=("${colors[@]}")
	rl+=("$((25600000*i/cols/100000))" "$g" "$b") 
	gl+=("$r" "$((25600000*i/cols/100000))" "$b") 
	bl+=("$r" "$g" "$((25600000*i/cols/100000))") 
    done
    printf -v Hline "$ColFmt" "${hl[@]}"
    printf -v Sline "$ColFmt" "${sl[@]}"
    printf -v Vline "$ColFmt" "${vl[@]}"
    printf -v Rline "$ColFmt" "${rl[@]}"
    printf -v Gline "$ColFmt" "${gl[@]}"
    printf -v Bline "$ColFmt" "${bl[@]}"
}
printf -v retsym[0] %b \\U2BC8
showValues() {
    local sv sn ccret cnret
    h_blank=00$((1000*cols*h/360))
    printf -v h_blank "%.0f" ${h_blank::-3}.${h_blank: -3}
    printf -v h_blank '%*s' $((h_blank>(cols-1)?(cols-1):h_blank)) ''
    printf -v s_blank %.6f "$s"
    s_blank=00$((1000*cols*10#${s_blank/.}/1000000))
    printf -v s_blank "%.0f" ${s_blank::-3}.${s_blank: -3}
    printf -v s_blank '%*s' $((s_blank>(cols-1)?(cols-1):s_blank)) ''
    v_blank=00$((1000*cols*v/255))
    printf -v v_blank "%.0f" ${v_blank::-3}.${v_blank: -3}
    printf -v v_blank '%*s' $((v_blank>(cols-1)?(cols-1):v_blank)) ''

    r_blank=00$((1000*cols*r/255))
    printf -v r_blank "%.0f" ${r_blank::-3}.${r_blank: -3}
    printf -v r_blank '%*s' $((r_blank>(cols-1)?(cols-1):r_blank)) ''
    g_blank=00$((1000*cols*g/255))
    printf -v g_blank "%.0f" ${g_blank::-3}.${g_blank: -3}
    printf -v g_blank '%*s' $((g_blank>(cols-1)?(cols-1):g_blank)) ''
    b_blank=00$((1000*cols*b/255))
    printf -v b_blank "%.0f" ${b_blank::-3}.${b_blank: -3}
    printf -v b_blank '%*s' $((b_blank>(cols-1)?(cols-1):b_blank)) ''
    closestColor "$r" "$g" "$b" sv
    ccret=$?
    closestNamedColor  "$r" "$g" "$b" sn
    cnret=$?
    # shellcheck disable=SC2059 # Format string was built 
    # shellcheck disable=SC2154 # sv was assigned by nameref
    # shellcheck disable=SC2086 # namedColors are groups of 3 values
    printf "$format" \
	   "$Hline" "$h_blank" "$Sline" "$s_blank" "$Vline" "$v_blank" \
	   "$Rline" "$r_blank" "$Gline" "$g_blank" "$Bline" "$b_blank" \
	   "$r" "$g" "$b" "$r" "$g" "$b" "$r" "$g" "$b" "$h" "$s" "$v" \
	   ${namedColors[$sn]} "$r" "$g" "$b" "$sn" "${retsym[cnret]}" \
	   ${namedColors[$sn]} "$sv" "$step" "$sv" "${retsym[ccret]}" "$sv"
    printf $'\e[21C%\04714d\U00B5s\e[K\e[37D' $(( ${EPOCHREALTIME/.} -start ))
}
# shellcheck disable=SC2154 # variable out assigned by nameref
rehsv() { hsv "$r" "$g" "$b" out;h=${out[0]} s=${out[1]} v=${out[2]};}
rergb() { rgb "$h" "$s" "$v" out;r=${out[0]} g=${out[1]} b=${out[2]};}
showUsage() {
    printf '\e8\e[K'
    printf '\n\e[K  %-12b %b' '\e8\e[KHSV-RGB Color browser' \
	'\n\e[K---------------------' '' '' '\e[2DKeyboard interaction:' ''{,,}\
	'[RrGgBbVvLl]'	\
	     "Incrase/decrase [R,G,B,Val|Lum] by step ($step), from 0 to 255." \
	'[HhTt]'	'Incrase/decrase Hue (Tint) loop over 0 - 359.' \
	'[Ss]'		"Increase/decrase Saturation by .002x step ($step)." \
	'' '' '[Cc]'	'Toggle Color bar rendering (upper C fix HSV)' \
	'' '' '[p]'	'Paste color from clipboard' '[P]' \
	'Toggle loop mode \e[3mPaste Color from clipboard\e[23m every .3sec'\
	'[k]'		'peeK color on screen' \
	'' '' '[+-]'	"Incrase/decrase step. ($step)" \
	'[fF]'		'Refresh display (or ^L)' \
	'' '' '[uU]'	'show Usage (this)' \
	'[qQ]'		'Quit.' \
	'' '' "\\e[2D${0##*/} - $(sed -ne '2s/^# //p' "$0")" ''
    read -rsn 1 -t 20 _
    start=${EPOCHREALTIME/.}
    printf "\e8%s" "$clearPanel"
    showValues
}
printf "   Initialisation: 1 read TERM color map...\r"

getTermColors
getNamedColors

printf "   Initialisation: 2 open console space, build output format...\r"


start=${EPOCHREALTIME/.}

step=3

format='\e8Hue\e[K\n%s\n\e[K%s\U25B2\nSaturation\e[K\n%s\n\e[K%s\U25B2\n'
format+='Value\e[K\n%s\n\e[K%s\U25B2\nRed\e[K\n%s\n\e[K%s\U25B2\n'
format+='Green\e[K\n%s\n\e[K%s\U25B2\nBlue\e[K\n%s\n\e[K%s\U25B2\n'
format+=' R: %3d, G: %3d, B: %3d  => #%02X%02X%02X  \e[0;48;2;%d;%d;%dm    \e[0'
format+='m\n H: %3d, S: %06.5f, V: %3d      \e[0;48;2;%d;%d;%dm    '
format+='\e[0m\e[0;48;2;%d;%d;%dm    \e[0m\n Name: %-25s%1s\e[0;48;2;%d;%d;%dm'
format+='    \e[0m\e[48;5;%dm    \e[0m\e[11C%3d\n'
format+='              1 byte ANSI -> [%3d]  %1s\e[48;5;%dm    \e[0m | \e[2D'

# shellcheck disable=SC2015 # Set crtColor from $* or default to hsv(204,.5,128)
[[ $1 ]] && crtColorFromString "$*" || {
	h=204 s=.5 v=128
	rergb
    }
drawLines
renderColor=$(( ( ${EPOCHREALTIME/.} - start ) < 100000 ))

printf -v clearPanel \
'\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n%43s%s\n%43s%s\n%43s%s\n%43s%s\r\e[21A\e7'\
       \| ' Use keys [RGBHSV] to change values,' \| \
       ' Lower case to lower, upper to higher' \| \
       ' by step:    [+-] (in/de)crase step.' \| \
       $' or [\e[1mu\e[0m] for \47\e[1mUsage\e[0m\47.'
echo -n "$clearPanel"
tput civis
while :; do
    [[ "$r $g $b" != "$oldcolors" ]] && {
	start=${EPOCHREALTIME/.}
	((renderColor)) && drawLines
	oldcolors="$r $g $b"
	showValues
    }
    $pasteLoop && parseClipBoard
    if IFS= read -rsn 1 -t .02 keypress; then
	case $keypress in
	    q|Q ) break ;;
	    u|U ) showUsage ;;
	    c|C ) if ((renderColor=1-renderColor)) ; then
		      drawLines
		  else
		      or=$r og=$g ob=$b
		      h=204 s=.8 v=204
		      rergb
  		      drawLines
		      r=$or g=$og b=$ob
		      rehsv
		  fi
		  ;;
	    - ) step=$(( step-1 >   1 ? step-1 :   1 ));showValues ;;
	    + ) step=$(( step+1 < 128 ? step+1 : 128 ));showValues ;;
	    r ) r=$(( r-step > 0 ? r-step : 0 ))   ;rehsv;;
	    R ) r=$(( r+step < 255 ? r+step : 255));rehsv;;
	    g ) g=$(( g-step > 0 ? g-step : 0 ))   ;rehsv;;
	    G ) g=$(( g+step < 255 ? g+step : 255));rehsv;;
	    b ) b=$(( b-step > 0 ? b-step : 0 ))   ;rehsv;;
	    B ) b=$(( b+step < 255 ? b+step : 255));rehsv;;
	    t|h ) h=$(( ( h+360 - step ) % 360 ))  ;rergb;;
	    T|H ) h=$(( ( h+step ) % 360 ))        ;rergb;;
	    v|l ) v=$(( v-step > 0 ? v-step : 0 ))   ;rergb;;
	    V|L ) v=$(( v+step < 255 ? v+step : 255));rergb;;
	    s ) printf -v s %.6f "$s"
		s=00000$(( s=10#${s/.}, s-step*2000 > 0 ? s-step * 2000 : 0 ))
		printf -v s %.5f ${s::-6}.${s: -6} ;rergb;;
	    S ) printf -v s %.6f "$s"
		s=00000$(( s=10#${s/.}, s+step*2000 < 1000000 ?
			   s+step*2000:1000000))
		printf -v s %.5f ${s::-6}.${s: -6} ;rergb;;
	    f|$'\f' ) printf "\e8\e[J%s" "$clearPanel"; drawLines;showValues;;
	    p ) parseClipBoard;;
	    P ) if $pasteLoop; then pasteLoop=false; else pasteLoop=true; fi ;;
	    k ) peekFromScreen;;
	    * ) printf '\e[32C[%03d]\e[37D' \'"$keypress"
	esac
	unset keypress
    fi
done
echo $'\e[0m'
tput cnorm