.bash_prompt

#!/usr/bin/env bash

if [[ $COLORTERM = gnome-* && $TERM = xterm ]] && infocmp gnome-256color >/dev/null 2>&1
then
	export TERM='gnome-256color'
elif infocmp xterm-256color >/dev/null 2>&1
then
	export TERM='xterm-256color'
fi
case "$TERM" in
	xterm-color|*-256color) color_support=y;;
esac

if [ -x "${PREFIX:-/usr}/bin/tput" ] && tput setaf 1 &>/dev/null
then
	color_support=y
	tput sgr0 # is this necessary?
	#shellcheck disable=SC2155
	RESET=$(tput sgr0)
	#shellcheck disable=SC2155
	BOLD=$(tput bold)
	#shellcheck disable=SC2155
	RED=$(tput setaf 9)
elif [ -n "${color_support:-}" ]; then
	RESET="\e[0m"
	BOLD="\e[1m"
	RED="\e[31m"
fi

last_exit() {
	local -r e=$?
	[[ $e -ne 0 ]] && \
		echo -e "${1:-}$(printf '%02x\n' $e)${2:-} "
	return $e
}
# https://unix.stackexchange.com/questions/105958/terminal-prompt-not-wrapping-correctly

PS1=''
PS2=''
if [ -n "${color_support:-}" ]; then
	PS1+="\[${BOLD}\]"
	PS1+="\$(last_exit \"\[${RED}\]\" \"\[${RESET}\]\[${BOLD}\]\")"
else
	PS1+="\$(last_exit)"
fi

[[ -z "${TERMUX_VERSION:-}" ]] && PS1+='\u '
PS1+='\w'
PS2+='→ '

# this check saves energy if git isn't installed
if git --version &>/dev/null; then
	branch_stat() {
		git rev-parse --is-inside-work-tree &>/dev/null || return
		
		#shellcheck disable=SC2155
		local branch_name="$(\
			git symbolic-ref --quiet --short HEAD 2> /dev/null || \
			git describe --all --exact-match HEAD 2> /dev/null || \
			git rev-parse --short HEAD 2> /dev/null || \
			echo '(?)' \
		)"

		local s=''

		git diff --quiet --ignore-submodules --cached \
		|| s+='+' # uncommitted
	
		git diff-files --quiet --ignore-submodules -- \
		|| s+='!' # unstaged

		[[ -n "$(git ls-files --others --exclude-standard)" ]] \
		&& s+='?' # untracked

		git rev-parse --verify refs/stash &>/dev/null \
		&& s+='$' # stashed

		[[ -n "$s" ]] && s=" $s"

		# "//" unambiguously delimits paths and branches,
		# because it should never be a substr of either.
		echo " // ${branch_name}${s}"
	}

	PS1+='$(branch_stat)'
fi

# common sufix (intentional typo)
PS1+=' > '
if [ -n "${color_support:-}" ]; then
	PS1+="\[${RESET}\]"
	PS2+="\[${RESET}\]"
fi
unset color_support
export PS1
export PS2