#!/bin/sh

# Displays today's precipication chance (☔), and daily low (🥶) and high (🌞).
# Usually intended for the statusbar.

url="${WTTRURL:-wttr.in}"
weatherreport="${XDG_CACHE_HOME:-$HOME/.cache}/weatherreport"

# Get a weather report from 'wttr.in' and save it locally.
getforecast() { { rg -q -m1 '^up$' /sys/class/net/w*/operstate || rg -q -m1 '^up$' /sys/class/net/e*/operstate; } &&
	curl -sf "$url/$LOCATION" --output "$weatherreport" && touch "$weatherreport"
}

# Forecast should be updated only once a day.
checkforecast() {
	[ "$(stat -c %y "$weatherreport" 2>/dev/null |
		cut -d' ' -f1)" = "$(date '+%Y-%m-%d')" ]
}

getprecipchance() {
	echo "$weatherdata" | sed '16q;d' |    # Extract line 16 from file
		rg -wo "[0-9]*%" |           # Find a sequence of digits followed by '%'
		sort -rn |                     # Sort in descending order
		head -1q                       # Extract first line
}

getdailyhighlow() {
	echo "$weatherdata" | sed '13q;d' |      # Extract line 13 from file
		rg -o "m[-+]?[0-9]+" | # Find temperatures in the format "m<signed number>"
		sed 's/[+m]//g' |                # Remove '+' and 'm'
		sort -g |                        # Sort in ascending order
		sed -e 1b -e '$!d'               # Extract the first and last lines
}

readfile() { weatherdata="$(bat "$weatherreport")" ;}

showweather() {
	readfile
	# shellcheck disable=SC2046,SC2183
	printf "☔%s ❄️%s° 🌞%s°\n" "$(getprecipchance)" $(getdailyhighlow)
}

case $BLOCK_BUTTON in
	1) setsid -f "$TERMINAL" -e less -Sf "$weatherreport" >/dev/null 2>&1 ;;
	2) getforecast && showweather ;;
	3) notify-send "🌈 Weather module" "\- Left click for full forecast.
- Middle click to update forecast.
☔: Chance of rain/snow
❄️: Daily low
🌞: Daily high" ;;
	8) setsid -f "$TERMINAL" -e "$EDITOR" "$0" >/dev/null 2>&1 ;;
esac

# shellcheck disable=SC2015
checkforecast && showweather ||
	( flock -n 9 &&
		( tries=0; while [ $tries -ne 100 ]; do
			getforecast && break ||
				{ tries=$((tries+1)); sleep .1; }
		done
		! checkforecast &&
			until getforecast; do sleep 60; done
		pkill -RTMIN+5 "${STATUSBAR:-waybar}"
		) &
	echo ) 9>"${XDG_RUNTIME_DIR}/sb-forecast.lock"