#!/usr/bin/env bash

## CHECK THAT WE'RE RUNNING BASH
if [ -z "$BASH_VERSION" ]; then
	echo 'This prompt only works in bash!' >&2
	return 1
fi


## DON'T RUN TWICE
if [[ "$_PROMPT_SET" = "true" ]]; then
	_prompt_warning 'Prompt already set!'
	return 0
fi
_PROMPT_SET=true
declare -r _PROMPT_SET


## FUNC
function _fr { [[ -f "$1" ]] && [[ -r "$1" ]]; }
function _frs { _fr "$1" && source "$@"; }
function _dr { [[ -d "$1" ]] && [[ -r "$1" ]]; }


## ENVIRONMENT VARIABLES (defaults, override in ~/.bash_prompt-settings)
_PROMPT_POWER=false							# enable display of battery life in the prompt - this is overridden in the _prompt_setup function below. changing this here is futile
_PROMPT_LEFT="("							# set the left bracket to [ or something if you wish
_PROMPT_RIGHT=")"							# set the right bracket to ] or something if you wish
_PROMPT_HARDCODED_COLORS=false				# set to true if tput fails for your terminal
_PROMPT_EXITSTATUS=true						# enable printing the exit status of the previous command
_PROMPT_DATEFORMAT="%Y-%m-%d %H:%M:%S %Z"	# "date"-compatible formatting string
_PROMPT_DOMAIN=false						# if "false", will cut off any @... part of the username


## DEBUG TRAP FUNCTIONS
_PROMPT_DEBUGTRAP=true						# enable the prompt debug trap (this is REQUIRED for the rest of these options to work)
_PROMPT_TITLE_XTERM=false					# puts the current command as part of the window status in xterm and compatibles
_PROMPT_TITLE_SCREEN=true					# puts the current command as the window name in screen
_PROMPT_TITLE_TERMVAR=false					# use the $TERM variable as part of the title
_PROMPT_TIMER=true							# enable automatic command timer for commands longer than _PROMPT_TIMERLIMIT
_PROMPT_TIMERLIMIT=60						# used by the timer. execution times smaller than this are not reported


## LOAD USER SETTINGS
_frs "${HOME}/.bash_prompt-settings" || :


# the debug trap requires bash 4 to work properly
if ((BASH_VERSINFO[0] < 4)); then
	_PROMPT_DEBUGTRAP=false
fi


# disable python virtualenv prompt - we do this ourselves
export VIRTUAL_ENV_DISABLE_PROMPT=1


## COMMAND TIMER FUNCTIONS
if $_PROMPT_DEBUGTRAP; then
	function _prompt_debug_command
	{
		local command=${BASH_COMMAND%% *}
		if $_PROMPT_TIMER; then
			_prompt_timer_start
		fi
		if [[ -z "${_PROMPT_BASH_COMMAND:-}" ]]; then
			_PROMPT_BASH_COMMAND=${command##*/}
			if $_PROMPT_TITLE_XTERM; then
				_prompt_title_xterm
			fi
			if $_PROMPT_TITLE_SCREEN; then
				_prompt_title_screen
			fi
		fi
	}
	if $_PROMPT_TIMER; then
		function _prompt_timer_start
		{
			_PROMPT_SECONDS=${_PROMPT_SECONDS:-$SECONDS}
		}
		function _prompt_timer_stop
		{
			_PROMPT_SECONDS=$(( SECONDS - ${_PROMPT_SECONDS:-$SECONDS} ))
		}
		function _prompt_seconds2days
		{
			printf "%d days, %02d:%02d:%02d" \
			$(( $1 / 86400 )) \
			$(( $1 / 3600 % 24 )) \
			$(( $1 / 60 % 60 )) \
			$(( $1 % 60 )) |
			sed 's/^1\ days/1\ day/;s/^0\ days,\ //;s/^00://;s/^0//'
		}
	fi
fi


## PRINT COLORED WARNINGS
function _prompt_warning
{
	echo -e "$(sed 's/\\\[//g; s/\\\]//g' <<<"${_PROMPT_COLOR_WARNING}")PROMPT: ${1}$(sed 's/\\\[//g; s/\\\]//g' <<<"${_PROMPT_COLOR_RESET}")" >&2
}


## TITLES
function _prompt_title_xterm
{
	local prompt_term
	if $_PROMPT_TITLE_TERMVAR; then
		prompt_term="$TERM"
	else
		prompt_term=""
	fi
	local title="${SSH_CONNECTION:+"ssh: "}${prompt_term:+"${prompt_term}: "}${USER}@${HOSTNAME}:${PWD}"
	if
		$_PROMPT_DEBUGTRAP &&
		$_PROMPT_TITLE_XTERM
	then
		title="${_PROMPT_BASH_COMMAND:+$_PROMPT_BASH_COMMAND [}${title}${_PROMPT_BASH_COMMAND:+]}"
	fi
	case "$TERM" in
		*xterm*|*rxvt*|Eterm|mlterm)
			printf '\e]0;%s\a' "$title" #echo -ne "\e]0;${title}\a"
		;;
		*)
		;;
	esac
}
function _prompt_title_screen
{
	if
		$_PROMPT_DEBUGTRAP &&
		$_PROMPT_TITLE_SCREEN &&
		[[ "$TERM" = "screen"* ]]
	then
		local title="${_PROMPT_BASH_COMMAND:-"bash"}"
		# shellcheck disable=SC1003
		 printf '\ek%s\e\\' "$title" #echo -ne "\ek${title}\e\\"
	fi
}


## SETUP FUNCTION - DETERMINES COLORS AND TWEAKS
function _prompt_setup
{
	# we have to use hardcoded colors if tput is not available, or not working
	if ! $_PROMPT_HARDCODED_COLORS; then
		local tput="tput"
		if [[ "$(uname -s 2>/dev/null)" = "FreeBSD"* ]] && [[ -e /usr/local/bin/tput ]]; then
			tput=/usr/local/bin/tput
		fi
		if { ! type $tput &>/dev/null || ! $tput sgr0 &>/dev/null || [[ -z "$($tput sgr0)" ]]; }; then
			_PROMPT_HARDCODED_COLORS=true
		fi
	fi

	local reset black red green orange blue magenta cyan light_gray dark_gray light_red light_green yellow light_blue light_magenta light_cyan white bold
	if $_PROMPT_HARDCODED_COLORS; then
		# format: =$'\\[\e[0-1;30-37;40-47m\\]'
		# dark/bright ; fg color ; bg color   (00 for any of them = reset)
		reset=$'\\[\e[m\\]'

		black=$'\\[\e[0;30m\\]'
		red=$'\\[\e[0;31m\\]'
		green=$'\\[\e[0;32m\\]'
		orange=$'\\[\e[0;33m\\]'
		blue=$'\\[\e[0;34m\\]'
		magenta=$'\\[\e[0;35m\\]'
		cyan=$'\\[\e[0;36m\\]'
		light_gray=$'\\[\e[0;37m\\]'

		dark_gray=$'\\[\e[1;30m\\]'
		light_red=$'\\[\e[1;31m\\]'
		light_green=$'\\[\e[1;32m\\]'
		yellow=$'\\[\e[1;33m\\]'
		light_blue=$'\\[\e[1;34m\\]'
		light_magenta=$'\\[\e[1;35m\\]'
		light_cyan=$'\\[\e[1;36m\\]'
		white=$'\\[\e[1;37m\\]'
	else
		reset="\\[$($tput sgr0)\\]"

		black="${reset}\\[$($tput setaf 0)\\]"
		red="${reset}\\[$($tput setaf 1)\\]"
		green="${reset}\\[$($tput setaf 2)\\]"
		orange="${reset}\\[$($tput setaf 3)\\]"
		blue="${reset}\\[$($tput setaf 4)\\]"
		magenta="${reset}\\[$($tput setaf 5)\\]"
		cyan="${reset}\\[$($tput setaf 6)\\]"
		light_gray="${reset}\\[$($tput setaf 7)\\]"

		bold=$($tput bold)
		dark_gray="${reset}\\[${bold}$($tput setaf 0)\\]"
		light_red="${reset}\\[${bold}$($tput setaf 1)\\]"
		light_green="${reset}\\[${bold}$($tput setaf 2)\\]"
		yellow="${reset}\\[${bold}$($tput setaf 3)\\]"
		light_blue="${reset}\\[${bold}$($tput setaf 4)\\]"
		light_magenta="${reset}\\[${bold}$($tput setaf 5)\\]"
		light_cyan="${reset}\\[${bold}$($tput setaf 6)\\]"
		white="${reset}\\[${bold}$($tput setaf 7)\\]"
		unset bold
	fi

	# no colors for dumb terminals
	if [[ "$TERM" = "dumb" ]]; then
		# these should also be marked readonly
		_PROMPT_COLOR_DARK=""
		_PROMPT_COLOR_LIGHT=""
		_PROMPT_COLOR_HIGHLIGHT=""
		_PROMPT_COLOR_WARNING=""
		_PROMPT_COLOR_RESET=""
	else
		_PROMPT_COLOR_HIGHLIGHT=$white
		_PROMPT_COLOR_WARNING=$red
		_PROMPT_COLOR_RESET=$reset

		# changes based on UID and roles
		if /cathedral/userbin/hostlist hasrole battery 2>/dev/null; then
			_PROMPT_POWER=true
		fi

		if (( UID == 0 )); then
			_PROMPT_COLOR_DARK=$red
			_PROMPT_COLOR_LIGHT=$light_red
			_PROMPT_COLOR_WARNING=$yellow
		else
			_PROMPT_COLOR_DARK=$green
			_PROMPT_COLOR_LIGHT=$light_green
			if $sourced; then
				if
				(
					source /cathedral/src/lib/hostlist 2>/dev/null &&
					hl_hasrole xorg 2>/dev/null &&
					( hl_hasrole system 2>/dev/null || hl_hasrole roadwarrior 2>/dev/null )
				)
				then
					_PROMPT_COLOR_DARK=$dark_gray
					_PROMPT_COLOR_LIGHT=$light_gray
				fi
			fi
		fi
		local OVERRIDE="${HOME}/.bash_prompt-colors"
		if [[ -f "$OVERRIDE" ]] && [[ -r "$OVERRIDE" ]]; then
			source "$OVERRIDE"
		fi
	fi

	# set the PS2 prompt here - easily overridable
	export PS2="${_PROMPT_COLOR_DARK}>${_PROMPT_COLOR_RESET} "

	# set PS3 (used with select)
	export PS3="${_PROMPT_COLOR_DARK}#?${_PROMPT_COLOR_RESET} "

	# set PS4 (used with tracing output, set -x)
	# ${0} and ${LINENO} are single-quoted, so they'll be evaluated when they're displayed instead of now
	export PS4="+"'${0}'":"'${LINENO}'" ${_PROMPT_COLOR_DARK}->${_PROMPT_COLOR_RESET} "

	# check if /proc/loadavg is readable
	[[ -f "/proc/loadavg" ]] && [[ -r "/proc/loadavg" ]] && _PROMPT_LOADAVG=true || _PROMPT_LOADAVG=false

	# check if uptime is available
	type uptime &>/dev/null && _PROMPT_UPTIME=true || _PROMPT_UPTIME=false

	# check if git is available
	type git &>/dev/null && _PROMPT_GIT=true || _PROMPT_GIT=false
}


## RESTORE TRAPS (used by prompt command)
function _prompt_command_cleanup
{
	if $_PROMPT_DEBUGTRAP; then
		# clean the titles
		unset _PROMPT_BASH_COMMAND
		_prompt_title_xterm
		_prompt_title_screen

		# reset timer
		unset _PROMPT_SECONDS
	fi

	# traps
#	if [[ -n "${_PROMPT_SAVED_INTTRAP:-}" ]]; then
#		eval "$_PROMPT_SAVED_INTTRAP"
#	else
#		trap - INT
#	fi
#	if [[ -n "${_PROMPT_SAVED_DEBUGTRAP:-}" ]]; then
#		eval "$_PROMPT_SAVED_DEBUGTRAP"
#	fi
}


## PROMPT COMMAND
## THIS RUNS FOR EVERY PROMPT - DON'T MAKE THIS HEAVIER THAN IT ALREADY IS
function _prompt_command
{
	# grab status first
	_PROMPT_CODE=$?

	# disable debug trap
	if $_PROMPT_DEBUGTRAP; then
#		_PROMPT_SAVED_INTTRAP=$(trap -p INT)
#		_PROMPT_SAVED_DEBUGTRAP=$(trap -p DEBUG)
#		trap '_prompt_command_cleanup; return' INT
		trap - DEBUG
	fi

	# run any preexisting prompt command
	if [[ -n "$_PROMPT_COMMAND_OLD" ]]; then
		eval "$_PROMPT_COMMAND_OLD"
	fi

	# get the last history number, and the associated command
	local history_number
	history_number=$(history 1)
	history_number=${history_number%% *}

	# if the exit status was 127, the command was not found. Let's remove it from history
	if [[ -n "${history_number:-}" ]]; then
		if (( _PROMPT_CODE == 127 )) && { [[ -z "${_PROMPT_HISTORYPOS:-}" ]] || (( ${_PROMPT_HISTORYPOS:-$history_number} < history_number )); }; then
			history -d "$history_number"
		else
			_PROMPT_HISTORYPOS=$history_number
		fi
	fi

	# if you changed the prompt yourself, we don't want to override it
	if [[ -n "${_PROMPT_PS1:-}" ]] && [[ -n "${PS1:-}" ]] && [[ "$_PROMPT_PS1" != "$PS1" ]]; then
		_prompt_command_cleanup
		return
	fi

	# verify the debug trap
	if $_PROMPT_DEBUGTRAP; then
		if
			[[ "$PROMPT_COMMAND" != "$_PROMPT_COMMAND" ]] #||
#			[[ -n "${_PROMPT_SECONDS:-}" ]] && [[ "$_PROMPT_SECONDS" = *[!-0-9]* ]] ||
#			[[ -z "${SECONDS:-}" ]] || [[ "$SECONDS" = *[!-0-9]* ]] ||
#			[[ "$_PROMPT_SAVED_DEBUGTRAP" != "$_PROMPT_DEBUG_COMMAND" ]]
		then
			_prompt_warning 'Debug trap disabled!'
			_PROMPT_DEBUGTRAP=false
			_PROMPT_TIMER=false
		else
			_prompt_timer_stop
		fi
	fi

	# if we spent less than the time limit, unset the timer and the prompt wont include it
	if $_PROMPT_TIMER && (( _PROMPT_SECONDS < _PROMPT_TIMERLIMIT )); then
		unset _PROMPT_SECONDS
	fi

	# the exit status will not function if we're running more than this prompt command
	if $_PROMPT_EXITSTATUS; then
		if [[ "$PROMPT_COMMAND" != "$_PROMPT_COMMAND" ]]; then
			_prompt_warning 'Exit status display disabled!'
			_PROMPT_EXITSTATUS=false
			unset _PROMPT_CODE
		fi
	else
		unset _PROMPT_CODE
	fi

	# various stuff for the prompt
	local load _PROMPT_JUNK
	if $_PROMPT_LOADAVG; then
		IFS=" " read -r load _PROMPT_JUNK </proc/loadavg
	elif $_PROMPT_UPTIME; then
		load=$(LC_NUMERIC=C uptime 2>/dev/null | sed -e 's/.*load averages*: \(.*\...\),* \(.*\...\),* \(.*\...\).*/\1/' -e 's/ //g')
	fi

	# powah!
	local acpi
	if $_PROMPT_POWER; then
		local ACstat=""
		local charge=""
		acpi="$(acpi 2>/dev/null)"
	
		if [[ -n "$acpi" ]]; then
			case "${acpi}" in
				*Charging*)
					ACstat="^"
				;;
				*Discharging*)
					ACstat="v"
				;;
				*Full*)
					ACstat="="
				;;
				*Unknown*) # draining to avoid trickle charging
					ACstat="="
				;;
			esac
			charge="${acpi%\%*}%"
			charge="${charge##*\ }"
		fi
	fi

	# git support
	local git
	if $_PROMPT_GIT; then
		git=$(git branch 2>/dev/null | grep '^\*' | head -n 1)
		if [[ -n "${git}" ]]; then
			git=${git:2}
		fi
	fi

	# show background jobs
	local _PROMPT_JOBS_RUNNING
	local _PROMPT_JOBS_STOPPED
	read -r _PROMPT_JOBS_RUNNING < <(jobs -pr | wc -l)
	read -r _PROMPT_JOBS_STOPPED < <(jobs -ps | wc -l)
	if (( _PROMPT_JOBS_RUNNING == 0 )) && (( _PROMPT_JOBS_STOPPED == 0 )); then
		unset _PROMPT_JOBS_RUNNING
		unset _PROMPT_JOBS_STOPPED
	fi

	# unset _PROMPT_PS1 - this avoids a timing issue where the user presses ctrl+c in between the setting of _PROMPT_PS1 and PS1, breaking the prompt
	unset _PROMPT_PS1

	# username
	local user
	if $_PROMPT_DOMAIN || [[ -z "${USER:-}" ]]; then
		user="\\u"
	else
		user=${USER%%@*}
	fi

	# make prompt - to make formatting somewhat readable, this is on several lines. DO NOT INDENT
PS1="\
${_PROMPT_COLOR_DARK},-${_PROMPT_LEFT}\
${_PROMPT_COLOR_LIGHT}${user}${_PROMPT_COLOR_DARK}@\
${_PROMPT_COLOR_LIGHT}\\h${_PROMPT_COLOR_DARK}\
${_PROMPT_RIGHT}-\
${_PROMPT_CODE:+${_PROMPT_COLOR_DARK}${_PROMPT_LEFT}${_PROMPT_COLOR_HIGHLIGHT}${_PROMPT_CODE}${_PROMPT_COLOR_DARK}${_PROMPT_RIGHT}-}\
${load:+${_PROMPT_COLOR_DARK}${_PROMPT_LEFT}${_PROMPT_COLOR_HIGHLIGHT}${load}${_PROMPT_COLOR_DARK}${_PROMPT_RIGHT}-}\
${acpi:+${_PROMPT_COLOR_DARK}${_PROMPT_LEFT}${_PROMPT_COLOR_HIGHLIGHT}${ACstat}${charge}${_PROMPT_COLOR_DARK}${_PROMPT_RIGHT}-}\
${_PROMPT_COLOR_DARK}${_PROMPT_LEFT}${_PROMPT_COLOR_HIGHLIGHT}$(date +"$_PROMPT_DATEFORMAT")${_PROMPT_COLOR_DARK}${_PROMPT_RIGHT}\
${_PROMPT_JOBS_RUNNING:+${_PROMPT_COLOR_DARK} - ${_PROMPT_COLOR_LIGHT}${_PROMPT_JOBS_RUNNING}${_PROMPT_COLOR_DARK}|${_PROMPT_COLOR_LIGHT}${_PROMPT_JOBS_STOPPED}${_PROMPT_COLOR_DARK}}\
${_PROMPT_SECONDS:+${_PROMPT_COLOR_DARK} - ${_PROMPT_COLOR_LIGHT}$(_prompt_seconds2days ${_PROMPT_SECONDS})}\
${_PROMPT_COLOR_RESET}\\n\
${_PROMPT_COLOR_DARK}|-${_PROMPT_LEFT}${_PROMPT_COLOR_LIGHT}$(pwd)${_PROMPT_COLOR_DARK}${_PROMPT_RIGHT}\
${VIRTUAL_ENV:+${_PROMPT_COLOR_DARK} - ${_PROMPT_COLOR_LIGHT}python:${VIRTUAL_ENV##*/}}\
${git:+${_PROMPT_COLOR_DARK} - ${_PROMPT_COLOR_LIGHT}git:${git}}\
${_PROMPT_COLOR_RESET}\\n\
${_PROMPT_COLOR_DARK}\\\`-${_PROMPT_COLOR_HIGHLIGHT}\\\$${_PROMPT_COLOR_RESET} \
"

	# _PROMPT_PS1 is used to check if the prompt has changed the next time we run
	_PROMPT_PS1="${PS1}"

	# cleanup
	_prompt_command_cleanup

	# reset debug
	trap "$_PROMPT_DEBUG_COMMAND" DEBUG
}


## RUN SETUP
_prompt_setup
unset _prompt_setup


# TIMER AND PROMPT COMMAND
declare -ft _prompt_command_cleanup
declare -ft _prompt_command

_PROMPT_COMMAND_OLD="${PROMPT_COMMAND:-}"
PROMPT_COMMAND='_prompt_command'
_PROMPT_COMMAND=$PROMPT_COMMAND

if $_PROMPT_DEBUGTRAP; then
	# workaround for stupid bug where using a debug command overwrites $_
	_PROMPT_DEBUG_COMMAND='_PROMPT_ARG=$_; _prompt_debug_command; : "$_PROMPT_ARG"'
	trap "$_PROMPT_DEBUG_COMMAND" DEBUG
#	_PROMPT_DEBUG_COMMAND="$(trap -p DEBUG)"
fi


# vim: tabstop=4:softtabstop=4:shiftwidth=4:noexpandtab