#!/bin/bash
# Author: Mike Frysinger <vapier@gmail.com>; released into the public domain; suck it.

# This is for bash.
BASH_PREFIX="\e"
# And this is the portable one.
POSIX_PREFIX="\033"
# Default to bash.
PREFIX=${BASH_PREFIX}

show_env() {
	local c colors=(
		GOOD="\$'${PREFIX}[32;01m'"
		WARN="\$'${PREFIX}[33;01m'"
		BAD="\$'${PREFIX}[31;01m'"
		HILITE="\$'${PREFIX}[36;01m'"
		BRACKET="\$'${PREFIX}[34;01m'"
		NORMAL="\$'${PREFIX}[0m'"
	)
	for c in "${colors[@]}" ; do
		[[ -t 0 ]] || c="${c%=*}="
		echo "${c}"
	done
}

check256() {
	if [[ ${TERM} != *-256color ]] ; then
		(
		echo "warning: TERM (${TERM}) does not end in '-256color';"
		echo "warning: trying to use 256 colors might not work."
		) >&2
	fi
}

showit() {
	local col="${PREFIX}[${1};${2}m"
	printf '%bthis color is: %s   %b\n' "${col}" "${col}" "${PREFIX}[0m"
}

main() {
	if [[ $1 == "--posix" ]] ; then
		PREFIX=${POSIX_PREFIX}
		shift
	fi
	case $1 in
	--env)
		show_env
		;;
	""|16|system)
		for i in {0..1} ; do
			for j in {30..37} ; do
				showit ${i} ${j}
			done
		done
		;;
	cube|6x6x6)
		check256
		for n in {16..231} ; do
			showit "38;05" $(printf '%03i' ${n})
		done
		;;
	gr[ae]y)
		check256
		for n in {232..255} ; do
			showit "38;05" ${n}
		done
		;;
	all|256)
		for x in system cube gray ; do
			echo "### SET: ${x}"
			"$0" ${x}
		done
		;;
	ncurses|curses|mutt|nano)
		colors=(
			black
			red
			green
			yellow
			blue
			magenta
			cyan
			white
		)
		norm=$(tput sgr0)
		bold=$(tput bold)
		blackfg=$(tput setaf 0)
		for seta in "af" "ab" ; do
			[[ ${seta} == "af" ]] && ground=fore || ground=back
			for pfx in "" "bright" ; do
				for (( i = 0; i < ${#colors[@]}; ++i )) ; do
					[[ ${pfx} == "bright" ]] && printf "${bold}"
					[[ ${seta} == "ab" ]] && printf "${blackfg}"
					echo "$(tput set${seta} ${i})this is ${ground}ground color '${pfx}${colors[i]}'${norm}"
				done
			done
		done
		;;
	*)
		cat <<-EOF
			usage: $0 [--posix] [colors]

			Colors:
			 - --env        - show env you can eval in a shell
			 - 16, system   - show basic colors (default)
			 - cube, 6x6x6  - show most extended colors
			 - gray         - show gray scale
			 - all, 256     - show all colors
			 - curses       - show ncurses color names (used by mutt, nano, etc...)
		EOF
		exit 1
		;;
	esac
}
main "$@"