#!/bin/bash
# percent bar / progress bar - Hires rendering from ratio of two integers 
# Using bash's integers.             (C) 2021 - F-Hauri.ch
# Licensed by GNU GENERAL PUBLIC LICENSE Version 3
# shellcheck disable=SC2154 # referenced but not assigned (eyear ??)
# shellcheck disable=SC2034 # appears unused (week ??)
# Usage:
#   percentBar <INT> <INT> <VARNAME> [BAR WIDTH]
#     Store in $VARNAME, a string containing '<percent float> <bar string>'
#   prettyPercentBar [-(l|n)] [-w STRING WIDTH] <INT> <INT> <VARNAME>
#   - First int must be smaller than secnd int.
#   - [-l]: text on left side, [-n]: no text
#     Store a formated string containing bar with or without percent string...

percentBar() {
    local _pB_percent _pB_lastChar _pB_blankString _pB_barString
    local -i _pB_totLen _pB_barLen _pB_blankLen _pB_prop _pB_strLen=${4:-80}
    _pB_prop=" $1 * 100000 / $2 "	_pB_totLen=' 8 * _pB_strLen '
    _pB_percent=00$_pB_prop
    printf -v _pB_percent %.2f "${_pB_percent::-3}.${_pB_percent: -3}"
    _pB_prop="
	(10#${_pB_percent/.}>10000?10000:10#${_pB_percent/.})*_pB_totLen/10000"
    _pB_barLen=' _pB_prop%8 '
    (( _pB_barLen )) && _pB_strLen+=-1 &&
	printf -v _pB_lastChar '\\U258%X' $(( 16 - _pB_barLen ))||
	    _pB_lastChar=''
    _pB_barLen=' _pB_prop / 8 '
    _pB_blankLen=' _pB_strLen - _pB_barLen '
    printf -v _pB_barString '%*s' "$_pB_barLen" ''
    printf -v _pB_barString '%b' "${_pB_barString// /\\U2588}$_pB_lastChar"
    printf -v _pB_blankString '%*s' "$_pB_blankLen" ''
    printf -v "${3:-renderedBar}" '%s %s%s' \
	   "$_pB_percent" "$_pB_barString" "$_pB_blankString"
}

prettyPercentBar() {
    local _pB_percent _pB_lastChar \
	  _pB_blankString _pB_barString _pB_txtSide=right
    local -i _pB_totLen _pB_strLen _pB_prop _pB_barLen _pB_blankLen
    while [ "${1::1}" = "-" ];do
	case ${1:1} in
	    l ) _pB_txtSide=left;;
	    n ) _pB_txtSide=none;;
	    w ) shift;_pB_strLen=$1;;
	    * ) echo "Unknown arh: '$1'.";return 1;;
	esac
	shift
    done
    ((_pB_strLen)) || {
	((COLUMNS)) && _pB_strLen="$COLUMNS"
	((_pB_strLen)) || read -r _pB_strLen < <(tput cols)
	((_pB_strLen)) || _pB_strLen=80
    }
    if [ "$_pB_txtSide" = "none" ] ;then
	_pB_totLen=' 8 * _pB_strLen '
    else
	_pB_totLen=' 8 * ( _pB_strLen - 8 ) '
    fi
    _pB_prop="$1*100000/$2"
    _pB_percent=00$_pB_prop
    printf -v _pB_percent %.2f "${_pB_percent::-3}.${_pB_percent: -3}"
    _pB_prop="
	(10#${_pB_percent/.}>10000?10000:10#${_pB_percent/.})*_pB_totLen/10000"
    _pB_barLen=' _pB_prop % 8 '
    (( _pB_barLen )) &&
	printf -v _pB_lastChar '\\U258%X' $(( 16 - _pB_barLen ))||
	    _pB_lastChar=''
    _pB_barLen=' _pB_prop / 8 '
    _pB_blankLen=' ( _pB_totLen - _pB_prop ) / 8 '
    printf -v _pB_barString '%*s' "$_pB_barLen" ''
    printf -v _pB_barString '%b' "${_pB_barString// /\\U2588}$_pB_lastChar"
    printf -v _pB_blankString '%*s' "$_pB_blankLen" ''
    printf -v _pB_barString '%s%s' "$_pB_barString" "$_pB_blankString"
    if [ "$_pB_txtSide" = "none" ] ;then
	printf -v "$3" '\e[47m%s\e[0m' "${_pB_barString}"
    elif [ "$_pB_txtSide" = "left" ] ;then
	printf -v "$3" '%6.2f%% \e[47m%s\e[0m' \
	   "$_pB_percent" "${_pB_barString}"
    else
	printf -v "$3" '\e[47m%s\e[0m %6.2f%%' "${_pB_barString}" "$_pB_percent"
    fi
}

# End of functions definition.
# Exit here if script is sourced:
[ "$0" = "${BASH_SOURCE[0]}" ] || {
    true
    return 0
}

# Tests and demo, from there:
declare -i numTests=$1 st=${EPOCHREALTIME/.} s1 s2 e
((numTests)) || for ((;${EPOCHREALTIME/.}-st<24000;numTests+=1)) { :;}
numTests=' numTests < 200 ? 200 : numTests '
		    
COLUMNS=$(tput cols)
s1=${EPOCHREALTIME/.}
for ((i=0;i<=numTests;i++)) ;do
    percentBar $i "$numTests" res $((COLUMNS - 8))
    printf  '\r\e[48;5;243;38;5;28m%s\e[0m %6s%%' "${res#* }" "${res%% *}"
done
s2=${EPOCHREALTIME/.} s1=s2-s1
printf '%d loop: %s\U00B5s\n' "$numTests" $s1
s2=${EPOCHREALTIME/.}
for ((i=0;i<=numTests;i++)) ;do
    prettyPercentBar $i "$numTests" res
    printf  '\r%s' "$res"
done
e=${EPOCHREALTIME/.} s2=e-s2
printf '%d loop: %s\U00B5s (simple) - %s\U00B5s (pretty) ->\n' \
       "$numTests" $s1 $s2
percentBar $s1 $s2 res $((COLUMNS / 2 ))
printf  '\r\e[48;5;177;38;5;163m%s\e[0m %6s%%\n' "${res#* }" "${res%% *}"

numTests=numTests/4
printf '\n\e[42C\e[1mHit <return> key to stop!\e[0m\n\n\n\n\n\n\n\e[8A\e7' &&
    for ((i=0;i<=numTests;i++));do
	o=1
	for l in 1 2 3 5 8 13 20 40 $((COLUMNS-7));do
	    percentBar $i $numTests bar$((o++)) $l
	done
	(( i == numTests )) && read -rst .8 _
	printf '\e8';p="${bar9%% *}"
	printf '%s\e[48;5;23;38;5;41m%s\e[0m%6.2f%%%b' 'In 1 char width: ' \
	    "${bar1#* }" "$p" ,\\n 'with 2 chars: ' "${bar2#* }" "$p" ,\\n \
	    'or 3 chars: ' "${bar3#* }" "$p" ,\\n 'in 5 characters: ' \
	    "${bar4#* }" "$p" ,\\n 'in 8 chars: ' "${bar5#* }" "$p" .\\n \
	    'There are 13 chars: ' "${bar6#* }" "$p" ,\\n '20 chars: ' \
	    "${bar7#* }" "$p" ,\\n 'then 40 chars' "${bar8#* }" "$p" \
    	    ', or full width:\n' '' "${bar9#* }" "$p" ''
	((i)) || read -rst .5 _
	read -rst .01 _ && break
done