.bash_prompt

#!/bin/bash
# vim: set filetype=sh :

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

if tput setaf 1 &> /dev/null; then
	## Formatting
	tput sgr0 # reset colors
	bold=$(tput bold)
	reset=$(tput sgr0)
	declare -A fg_colours=(
		["black"]=$(tput setaf 0)
		["blue"]=$(tput setaf 33)
		["cyan"]=$(tput setaf 37)
		["green"]=$(tput setaf 64)
		["orange"]=$(tput setaf 166)
		["purple"]=$(tput setaf 125)
		["red"]=$(tput setaf 124)
		["violet"]=$(tput setaf 61)
		["white"]=$(tput setaf 15)
		["yellow"]=$(tput setaf 136)
	)
	declare -A bg_colours=(
		["black"]=$(tput setab 0)
		["blue"]=$(tput setab 33)
		["cyan"]=$(tput setab 37)
		["green"]=$(tput setab 64)
		["orange"]=$(tput setab 166)
		["purple"]=$(tput setab 125)
		["red"]=$(tput setab 124)
		["violet"]=$(tput setab 61)
		["white"]=$(tput setab 15)
		["yellow"]=$(tput setab 136)
	)
else
	## Formatting
	bold=''
	reset="\\e[0m"
	declare -A fg_colours=(
		["black"]="\\e[30m"
		["blue"]="\\e[34m"
		["cyan"]="\\e[36m"
		["green"]="\\e[32m"
		["orange"]="\\e[33m"
		["purple"]="\\e[35m"
		["red"]="\\e[31m"
		["violet"]="\\e[35m"
		["white"]="\\e[37m"
		["yellow"]="\\e[33m"
	)
	declare -A bg_colours=(
		["black"]="\\e[40m"
		["blue"]="\\e[44m"
		["cyan"]="\\e[46m"
		["green"]="\\e[42m"
		["orange"]="\\e[43m"
		["purple"]="\\e[45m"
		["red"]="\\e[41m"
		["violet"]="\\e[45m"
		["white"]="\\e[47m"
		["yellow"]="\\e[43m"
	)
fi

PROMPT_LEFT_PROMPT_ELEMENTS=(os_icon context_joined dir vcs)
PROMPT_RIGHT_PROMPT_ELEMENTS=(status background_jobs)

PROMPT_LEFT_SEGMENT_SEPARATOR=''
PROMPT_RIGHT_SEGMENT_SEPARATOR=''
PROMPT_MULTILINE_FIRST_PROMPT_PREFIX=''
PROMPT_MULTILINE_LAST_PROMPT_PREFIX="\033[${fg_colours["cyan"]}╰❱❱❱"

PROMPT_PREVIOUS_ELEMENT=

prompt_git() {
	local s=''
	local branchName=''

	# Check if the current directory is in a Git repository.
	if [ "$(git rev-parse --is-inside-work-tree &>/dev/null; echo "${?}")" == '0' ]; then

		# check if the current directory is in .git before running git checks
		if [ "$(git rev-parse --is-inside-git-dir 2> /dev/null)" == 'false' ]; then

			if [[ -O "$(git rev-parse --show-toplevel)/.git/index" ]]; then
				git update-index --really-refresh -q &> /dev/null
			fi

			# Check for uncommitted changes in the index.
			if ! git diff --quiet --ignore-submodules --cached; then
				s+=' '
			fi

			# Check for unstaged changes.
			if ! git diff-files --quiet --ignore-submodules --; then
				s+=' '
			fi

			# Check for untracked files.
			if [ -n "$(git ls-files --others --exclude-standard)" ]; then
				s+=' '
			fi

			# Check for stashed files.
			if git rev-parse --verify refs/stash &>/dev/null; then
				s+=' '
			fi

		fi

		# Get the short symbolic ref.
		# If HEAD isn’t a symbolic ref, get the short SHA for the latest commit
		# Otherwise, just give up.
		branchName="$(git symbolic-ref --quiet --short HEAD 2> /dev/null || \
			git rev-parse --short HEAD 2> /dev/null || \
			echo '(unknown)')"

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

		echo -e "${branchName}${s}"
	else
		echo -e 'none'
	fi
}

context_prompt() {
	# Highlight the user name when logged in as root.
	if [[ "${USER}" == "root" ]]; then
		user_name="\033[${fg_colours["red"]}\\u\033[${fg_colours["${current_fg_colour}"]}"
	else
		user_name="\\u"
	fi

	local cloud=""
	if [[ -f /proc/cpuinfo ]] && grep -q "^flags.* hypervisor" /proc/cpuinfo && [[ ! -d "/mnt/c/Windows/" ]]; then
		cloud="☁️ "
	fi
	# Highlight the hostname when connected via SSH.
	if [[ "${SSH_TTY}" ]]; then
		host_name="\033[${bold}${cloud}\\h\033[${reset_bold}"
	else
		host_name="${cloud}\\h"
	fi

	echo -e "${user_name}@${host_name}"
}

declare -A segment_colour_map=(
	["os_icon_fg"]="white"
	["os_icon_bg"]="black"
	["context_fg"]="yellow"
	["context_bg"]="black"
	["dir_fg"]="black"
	["dir_bg"]="blue"
	["vcs_fg"]="black"
	["vcs_bg"]="green"
	["line_end_fg"]="white"
	["line_end_bg"]="black"
)
declare -A segment_content_map=(
	["os_icon"]=''
	["context"]="$(context_prompt)"
	["dir"]="\\w"
	["vcs"]="\$(prompt_git)"
)
declare -A segment_logo_map=(
	["os_icon"]=''
	["context"]=""
	["dir"]=" "
	["vcs"]=""
)

segment_generate() {
	local joined="${2}"
	local current_segment="${1}"
	local segment_output=''

	if [ -n "${PROMPT_PREVIOUS_ELEMENT}" ]; then
		if [ ! "${joined}" ]; then
			local fg_colour="${segment_colour_map["${PROMPT_PREVIOUS_ELEMENT}_bg"]}"
			local bg_colour="${segment_colour_map["${current_segment}_bg"]}"
			segment_output+="\033[${fg_colours["${fg_colour}"]}${bg_colours["${bg_colour}"]}"
			segment_output+="${PROMPT_LEFT_SEGMENT_SEPARATOR}"
			unset fg_colour bg_colour
		fi
	fi

	local fg_colour="${segment_colour_map["${current_segment}_fg"]}"
	local bg_colour="${segment_colour_map["${current_segment}_bg"]}"
	segment_output+="\033[${fg_colours["${fg_colour}"]}${bg_colours["${bg_colour}"]}"
	unset fg_colour bg_colour
	[ -n "${segment_logo_map["${current_segment}"]}" ] && segment_output+=" ${segment_logo_map["${current_segment}"]} "
	segment_output+="${segment_content_map["${current_segment}"]}"
	PS1+="${segment_output}"
	PROMPT_PREVIOUS_ELEMENT="${current_segment}"
}

segment_line_end() {
	local current_segment="${FUNCNAME[0]:8}"
	local segment_output=

	local fg_colour="${segment_colour_map["${PROMPT_PREVIOUS_ELEMENT}_bg"]}"
	local bg_colour="${segment_colour_map["${current_segment}_bg"]}"
	segment_output+=" \033[${fg_colours["${fg_colour}"]}${bg_colours["${bg_colour}"]}"
	segment_output+="${PROMPT_LEFT_SEGMENT_SEPARATOR} "
	unset fg_colour bg_colour

	PS1+="${segment_output}"
	PROMPT_PREVIOUS_ELEMENT="${current_segment}"
}

PS1="\\n" # newline
for segment in "${PROMPT_LEFT_PROMPT_ELEMENTS[@]}"; do
	segment_generate ${segment/_joined/ joined}
done
segment_line_end
PS1+="\033[${reset}\\n"
PS1+="${PROMPT_MULTILINE_LAST_PROMPT_PREFIX}\033[${reset} " # Prompt prefix (and reset color/formatting)
export PS1

PS2="\033[${fg_colours["yellow"]}→ \033[${reset}"
export PS2