#!/bin/sh

DEFAULT_COLOR="#cccccc"
STATUS_WELL_COLOR="#31f53e"
STATUS_OK_COLOR="#f58c31"
STATUS_UNWELL_COLOR="#f53131"

BATTERY_NAME="BAT1"
BATTERY_EMPTY_THRESHOLD=20
BATTERY_FULL_THRESHOLD=80

WIFI_ADAPTER="wlan0"

DISK_ICON_COLOR="#48a3e8"

NOW_PLAYING_COLOR="#e647a1"
NOW_PLAYING_STATE_COLOR="#ccca4e"

readable_kib() {
	data="${1:-}"
	decimals="${2:-}"
	[ -z "$data" ] || [ -z "$decimals" ] && exit

	if [ "$data" -lt 1024 ]; then
		amt="$1"
		letter="K"
	elif [ "$data" -lt 1048576 ]; then
		amt="$(($1 / 1024))"
		letter="M"
	else
		amt="$(($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/$BATTERY_NAME/capacity
	read -r status </sys/class/power_supply/$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 $status in
	"Full" | "Charging")
		icon=""
		color="$STATUS_WELL_COLOR"
		;;
	"Not charging")
		icon=""
		color="$STATUS_OK_COLOR"
		;;
	*)
		icon=""
		color="$DEFAULT_COLOR"
		;;
	esac

	if [ "$capacity" -le "$BATTERY_EMPTY_THRESHOLD" ] && [ "$status" != "Charging" ]; then
		color="$STATUS_UNWELL_COLOR"
	fi

	printf '%s  <fc=%s>%s%%</fc> (%s)\n' "$icon" "$color" "$capacity" "$status"
}

monitor_cpu() {
	while read -r _ user _ system idle _; do
		initial_user_sys="$((user + system))"
		initial_total="$((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="$((user + system))"
		current_total="$((user + system + idle))"
		break
	done </proc/stat

	while read -r line; do
		case "$line" in
		*"Package id 0:"*) temp="$line" ;;
		esac
	done <<EOF
$(sensors)
EOF

	if [ -n "$temp" ]; then
		temp="${temp#Package id 0:*+}"
		temp="${temp%%°*}"
		temp="${temp%.*}"
	fi

	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="$DEFAULT_COLOR" ;;
	[4-5][0-9]) color="$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="$one"
		load_five="$five"
		load_fifteen="$fifteen"
	done </proc/loadavg

	# 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 "$label" in
		"MemTotal:") total_mem="$size" ;;
		"MemAvailable:") free_mem="$size" ;;
		esac
	done </proc/meminfo
	used_mem="$((total_mem - free_mem))"

	usage_percent="$((used_mem * 100 / total_mem))"
	case "$usage_percent" in
	[0-9] | [1-3][0-9]) color="$DEFAULT_COLOR" ;;
	[4-6][0-9]) color="$STATUS_OK_COLOR" ;;
	*) color="$STATUS_UNWELL_COLOR" ;;
	esac

	printf '%s (<fc=%s>%s%%</fc>)\n' "$(readable_kib "$used_mem" 1)" "$color" "$usage_percent"
}

monitor_ssid() {
	while read -r line; do
		case $line in
		*"Connected network"*) ssid="$line" ;;
		esac
	done <<EOF
$(iwctl station "$WIFI_ADAPTER" show)
EOF
	[ -z "$ssid" ] && exit
	ssid="${ssid##*Connected network}"
	ssid="${ssid#"${ssid%%[![:space:]]*}"}"

	# 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="$(wpctl get-volume @DEFAULT_AUDIO_SINK@)"
	volume="${volume% \[MUTED\]}"
	volume="${volume#Volume: }"
	volume="${volume%.*}${volume#*.}"
	volume="${volume#0}"

	# TODO(frosty): Add other icons based on the current device (headphones, speakers, etc.).
	icon=""

	printf '%s %s%%\n' "$icon" "$volume"
}

monitor_uptime() {
	# TODO(frosty): Find the uptime without calling another command.
	up="$(uptime -p)"
	up="$(replace_substring "$up" 'up ' '')"
	up="$(replace_substring "$up" ',' '')"
	up="$(replace_substring "$up" ' days' 'd')"
	up="$(replace_substring "$up" ' day' 'd')"
	up="$(replace_substring "$up" ' hours' 'h')"
	up="$(replace_substring "$up" ' hour' 'h')"
	up="$(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_$1" "$@"
else
	exit 1
fi