(xmobar): add various monitors, and create a now playing pipe to be read from mpc

.local/bin/initialize_pipes

@@ -1,6 +1,6 @@
 #!/bin/sh
 
-PIPES="volume"
+PIPES="volume now-playing"
 
 for pipe in $PIPES; do
 	echo "" >"/tmp/pipe-$pipe"

.local/bin/monitors

@@ -1,130 +1,304 @@
 #!/bin/sh
 
+STATUS_WELL_COLOR="#31f53e"
+STATUS_OK_COLOR="#f58c31"
+STATUS_UNWELL_COLOR="#f53131"
+
+BATTERY_NAME="BAT1"
 BATTERY_FULL_THRESHOLD=80
-BATTERY_FULL_COLOR="#31f53e"
 
 WIFI_ADAPTER="wlan0"
 
+DISK_ICON_COLOR="#48a3e8"
+
+NOW_PLAYING_COLOR="#e647a1"
+NOW_PLAYING_STATE_COLOR="#ccca4e"
+
 readable_kib() {
-	if [ "$1" -lt 1024 ]; then
+	data="${1:-}"
-		printf "%.1fK\n" "$1"
+	decimals="${2:-}"
-	elif [ "$1" -lt 1048576 ]; then
+	[ -z "$data" ] || [ -z "$decimals" ] && exit
-		printf "%.1fM\n" $(($1 / 1024))
+
+	if [ "$data" -lt 1024 ]; then
+		amt="$1"
+		letter="K"
+	elif [ "$data" -lt 1048576 ]; then
+		amt="$(($1 / 1024))"
+		letter="M"
 	else
-		printf "%.1fG\n" $(($1 / 1048576))
+		amt="$(($1 / 1048576))"
+		letter="G"
 	fi
+
+	printf "%.*f%s\n" "$decimals" "$amt" "$letter"
+}
+
+replace_substring() {
+	original="${1:-}"
+	pattern="${2:-}"
+	replacement="${3:-}"
+	[ -z "$original" ] || [ -z "$pattern" ] && exit
+
+	new="$original"
+	while :; do
+		case "$original" in
+		*"$pattern"*)
+			before_pattern="${original%%"$pattern"*}"
+			after_pattern="${original#*"$pattern"}"
+			new="$before_pattern$replacement$after_pattern"
+			;;
+		*) break ;;
+		esac
+	done
+
+	printf '%s\n' "$new"
 }
 
 monitor_battery() {
-	read -r capacity </sys/class/power_supply/BAT1/capacity
+	read -r capacity </sys/class/power_supply/$BATTERY_NAME/capacity
-	read -r status </sys/class/power_supply/BAT1/status
+	read -r status </sys/class/power_supply/$BATTERY_NAME/status
 
 	if [ "$capacity" -ge "$BATTERY_FULL_THRESHOLD" ] && [ "$status" = "Not charging" ]; then
 		status="Full"
 	fi
+
+	# TODO(frosty): Add more icons based on other statuses.
+	case $status in
+	"Full" | "Charging") icon="" ;;
+	"Not charging") icon="" ;;
+	*) icon="" ;;
+	esac
+
+	# TODO(frosty): Check for other statuses, and print a different color.
 	if [ "$status" = "Full" ]; then
-		printf '<fc=%s>%s%%</fc> (%s)\n' "$BATTERY_FULL_COLOR" "$capacity" "$status"
+		printf '%s  <fc=%s>%s%%</fc> (%s)\n' "$icon" "$STATUS_WELL_COLOR" "$capacity" "$status"
 	else
-		printf '%s%% (%s)\n' "$capacity" "$status"
+		printf '%s  %s%% (%s)\n' "$icon" "$capacity" "$status"
 	fi
 }
 
 monitor_cpu() {
 	while read -r _ user _ system idle _; do
-		initial_user_sys=$((user + system))
+		initial_user_sys="$((user + system))"
-		initial_total=$((user + system + idle))
+		initial_total="$((user + system + idle))"
 		break
 	done </proc/stat
-
+	# TODO(frosty): Allow the user to specify how long to wait via an argument.
 	sleep 1
-
 	while read -r _ user _ system idle _; do
-		current_user_sys=$((user + system))
+		current_user_sys="$((user + system))"
-		current_total=$((user + system + idle))
+		current_total="$((user + system + idle))"
 		break
 	done </proc/stat
 
 	while read -r line; do
-		case $line in
+		case "$line" in
-		*Package\ id\ 0:*) temp=$line ;;
+		*"Package id 0:"*) temp="$line" ;;
 		esac
 	done <<EOF
 $(sensors)
 EOF
 
-	temp=${temp#Package id 0:*+}
+	if [ -n "$temp" ]; then
-	temp=${temp%%°*}
+		temp="${temp#Package id 0:*+}"
-	temp=${temp%.*}
+		temp="${temp%%°*}"
+		temp="${temp%.*}"
+	fi
 
-	printf '%s°C (%.*f%%)\n' "$temp" 0 $(((current_user_sys - initial_user_sys) * 100 / (current_total - initial_total)))
+	usage_percent="$(printf '%i\n' $(((current_user_sys - initial_user_sys) * 100 / (current_total - initial_total))))"
+	case "$usage_percent" in
+	[0-9] | [0-3][0-9]) color="$STATUS_WELL_COLOR" ;;
+	[4-5][0-9]) color="$STATUS_OK_COLOR" ;;
+	*) color="$STATUS_UNWELL_COLOR" ;;
+	esac
+
+	if [ -n "$temp" ]; then
+		printf '%s°C (<fc=%s>%i%%</fc>)\n' "$temp" "$color" "$usage_percent"
+	else
+		printf '<fc=%s>%i%%</fc>\n' "$color" "$usage_percent"
+	fi
 }
 
 monitor_load() {
 	while read -r one five fifteen _; do
-		load_one=$one
+		load_one="$one"
-		load_five=$five
+		load_five="$five"
-		load_fifteen=$fifteen
+		load_fifteen="$fifteen"
 	done </proc/loadavg
 
-	printf '%s %s %s\n' "$load_one" "$load_five" "$load_fifteen"
+	# TODO(frosty): Find a less cursed way to achieve this.
+	load_one_color=
+	load_five_color=
+	load_fifteen_color=
+	for load in load_one load_five load_fifteen; do
+		case "$(eval 'printf "%i\n" "\$$load"')" in
+		[0-3]) eval "${load}_color=#cccccc" ;;
+		[4-7]) eval "${load}_color=$STATUS_OK_COLOR" ;;
+		*) eval "${load}_color=$STATUS_UNWELL_COLOR" ;;
+		esac
+	done
+
+	printf '<fc=%s>%s</fc> <fc=%s>%s</fc> <fc=%s>%s</fc>\n' "$load_one_color" "$load_one" "$load_five_color" "$load_five" "$load_fifteen_color" "$load_fifteen"
 }
 
 monitor_memory() {
 	while read -r label size _; do
-		case $label in
+		case "$label" in
-		MemTotal:) total_mem=$size ;;
+		"MemTotal:") total_mem="$size" ;;
-		MemAvailable:) free_mem=$size ;;
+		"MemAvailable:") free_mem="$size" ;;
 		esac
 	done </proc/meminfo
-	used_mem=$((total_mem - free_mem))
+	used_mem="$((total_mem - free_mem))"
+	usage_percent="$((used_mem * 100 / total_mem))"
 
-	printf '%s (%s%%)\n' "$(readable_kib "$used_mem")" $((used_mem * 100 / total_mem))
+	# TODO(frosty): Add other colors for usage percentages.
+	if [ "$usage_percent" -lt 50 ]; then
+		printf '%s (<fc=%s>%s%%</fc>)\n' "$(readable_kib "$used_mem" 1)" "$STATUS_WELL_COLOR" "$usage_percent"
+	else
+		printf '%s (%s%%)\n' "$(readable_kib "$used_mem" 1)" "$usage_percent"
+	fi
 }
 
-monitor_network() {
+monitor_ssid() {
-	address=$(ip route get 1)
-	address=${address#* via * dev * src }
-	address=${address% uid *}
-
-	ssid=
 	while read -r line; do
 		case $line in
-		*Connected\ network*)
+		*"Connected network"*) ssid="$line" ;;
-			ssid=${line##*Connected network}
-			ssid="${ssid#"${ssid%%[![:space:]]*}"}"
-			;;
 		esac
 	done <<EOF
 $(iwctl station "$WIFI_ADAPTER" show)
 EOF
+	[ -z "$ssid" ] && exit
+	ssid="${ssid##*Connected network}"
+	ssid="${ssid#"${ssid%%[![:space:]]*}"}"
 
-	printf '<fc=#fc7932>%s</fc> @ %s\n' "$address" "$ssid"
+	# TODO(frosty): Add other icons based on the connection status.
+	icon=""
+
+	printf '%s %s\n' "$icon" "$ssid"
+}
+
+monitor_local_ip() {
+	# TODO(frosty): Add a fallback value when offline.
+	address="$(ip route get 1)"
+	address="${address#* via * dev * src }"
+	address="${address% uid *}"
+
+	printf '%s\n' "$address"
 }
 
 monitor_volume() {
-	volume=$(wpctl get-volume @DEFAULT_AUDIO_SINK@)
+	volume="$(wpctl get-volume @DEFAULT_AUDIO_SINK@)"
-	volume=${volume% \[MUTED\]}
+	volume="${volume% \[MUTED\]}"
-	volume=${volume#Volume: }
+	volume="${volume#Volume: }"
-	volume=${volume%.*}${volume#*.}
+	volume="${volume%.*}${volume#*.}"
-	volume=${volume#0}
+	volume="${volume#0}"
 
-	printf '%s%%\n' "$volume"
+	# TODO(frosty): Add other icons based on the current device (headphones, speakers, etc.).
+	icon=""
+
+	printf '%s %s%%\n' "$icon" "$volume"
 }
 
 monitor_uptime() {
-	up=$(uptime -p)
+	# TODO(frosty): Find the uptime without calling another command.
-	up=${up#up }
+	up="$(uptime -p)"
-	up=${up//,}
+	up="$(replace_substring "$up" 'up ' '')"
-	up=${up// day/d}
+	up="$(replace_substring "$up" ',' '')"
-	up=${up// days/d}
+	up="$(replace_substring "$up" ' days' 'd')"
-	up=${up// minutes/m}
+	up="$(replace_substring "$up" ' day' 'd')"
-	up=${up// minute/m}
+	up="$(replace_substring "$up" ' hours' 'h')"
-	up=${up// hours/h}
+	up="$(replace_substring "$up" ' hour' 'h')"
-	up=${up// hour/h}
+	up="$(replace_substring "$up" ' minutes' 'm')"
+	up="$(replace_substring "$up" ' minute' 'm')"
 
 	printf '%s\n' "$up"
 }
 
+monitor_date() {
+	date '+%-I:%M:%S %p'
+}
+
+monitor_disk() {
+	disk="${2:-}"
+	use_icon="${3:-0}"
+	[ -z "$disk" ] || [ ! -d "$disk" ] && exit 1
+
+	# TODO(frosty): Allow more icons to be added using an rc file.
+	if [ "$use_icon" -eq 1 ]; then
+		case "$disk" in
+		"/") icon="" ;;
+		"/home") icon="" ;;
+		*) icon="" ;;
+		esac
+	else
+		case "$disk" in
+		"/home") icon="~" ;;
+		*) icon="$disk" ;;
+		esac
+	fi
+
+	i=0
+	while read -r _ size used _; do
+		case "$i" in
+		0) ;;
+		1)
+			size_amt="$size"
+			used_amt="$used"
+			;;
+		*) break ;;
+		esac
+		i="$((i + 1))"
+	done <<EOF
+$(df "$disk")
+EOF
+	[ -z "$size_amt" ] || [ -z "$used_amt" ] && exit 1
+
+	printf '<fc=%s>%s</fc> %s/%s (<fc=%s>%s%%</fc>)\n' "$DISK_ICON_COLOR" "$icon" "$(readable_kib "$used_amt" 0)" "$(readable_kib "$size_amt" 0)" "$STATUS_WELL_COLOR" "$((used_amt * 100 / size_amt))"
+}
+
+monitor_now_playing() {
+	mpc_output="$(mpc)"
+
+	while read -r line; do
+		now_playing="$line"
+		break
+	done <<EOF
+$mpc_output
+EOF
+
+	i=0
+	while read -r state _; do
+		case "$i" in
+		0) ;;
+		1)
+			case "$state" in
+			\[*\]) play_state="$state" ;;
+			esac
+			;;
+		*) break ;;
+		esac
+		i="$((i + 1))"
+	done <<EOF
+$mpc_output
+EOF
+
+	if [ -z "$now_playing" ] || [ -z "$play_state" ]; then
+		printf 'N/A\n'
+		exit
+	fi
+	play_state="${play_state#\[}"
+	play_state="${play_state%\]}"
+
+	# TODO(frosty): Split the artist and track names, and truncate each one separately.
+	if [ "${#now_playing}" -gt 47 ]; then
+		now_playing="${now_playing%"${now_playing#??????????????????????????????????????????????}"}..."
+	fi
+
+	printf '<fc=%s>%s</fc> <fc=%s>[%s]</fc>\n' "$NOW_PLAYING_COLOR" "$now_playing" "$NOW_PLAYING_STATE_COLOR" "$play_state"
+}
+
 if command -v monitor_"$1" >/dev/null 2>&1; then
-	monitor_"$1"
+	"monitor_$1" "$@"
+else
+	exit 1
 fi

.local/bin/pipe_now-playing

@@ -0,0 +1,6 @@
+#!/bin/sh
+
+PIPE_FILE="/tmp/pipe-now-playing"
+[ -p "$PIPE_FILE" ] || mkfifo "$PIPE_FILE"
+
+monitors now_playing >"$PIPE_FILE"