dotfiles/shell/bash/prompt

#!/usr/bin/env bash

COLOR_RESET='\[\e[0m\]'
# TODO: if root, background instead?
PROMPT_SUCCESS_COLOR='\[\e[0;34m\]'
PROMPT_FAILURE_COLOR='\[\e[0;31m\]'
DIR_COLOR='\[\e[0;35m\]'

MAX_PATH_PIECE_CHARS=${BASH_PROMPT_MAX_PATH_PIECE_CHARS:-3}

# prompt rendering functions
preprocess_pwd() {
	p="$PWD"
	[[ "$p" == "/" ]] && echo "/" && return 1
	[[ "$p" == "${NICE_HOME}" ]] && echo "~" && return 0
	# with ellipsis
	#echo "$(<<< "$p" cut -c2- | awk '{split($0,p,"/");for(k in p){if(k==length(p)){printf "/%s",p[k]}else{if(length(p[k])>'"$((MAX_PATH_PIECE_CHARS+1))"'){printf "/%.'"$((MAX_PATH_PIECE_CHARS))"'s…",p[k]}else{printf "/%s",p[k]}}}}')"
	# without ellipsis
	echo "$(<<< "$p" cut -c2- | awk '{split($0,p,"/");for(k in p){if(k==length(p)){printf "/%s",p[k]}else{printf "/%.'"$MAX_PATH_PIECE_CHARS"'s",p[k]}}}')"
}
export -f "preprocess_pwd"

prompt_command_func()
{
	RET=$?
	history -a # commit history to prevent data loss from edge cases
	# set the color of user@host based on the result of the previous command
	if [[ $RET -eq 0 ]]; then
		STATUS_COLOR=$PROMPT_SUCCESS_COLOR
	else
		STATUS_COLOR=$PROMPT_FAILURE_COLOR
	fi
	PS1="$STATUS_COLOR\u@\h$COLOR_RESET $DIR_COLOR$(preprocess_pwd)$COLOR_RESET "
}
export -f "prompt_command_func"
export PROMPT_COMMAND="prompt_command_func"