#!/bin/bash

# Domoticz Server Information
USERNAME=<domoticz username>
PASSWORD=<domoticz password>
HOSTNAME=<domoticz server fqdn or ip>
HOSTPORT=<domoticz server listening port>
HOSTPROTOCOL=<domoticz server protocol (http/https)>
SWITCHIDX=<idx of the rain expected switch>
PREDICTIONIDX=<idx of the rain forecast mm/h custom sensor>

# Buienradar Information
LAT=<your latitude>
LON=<your longitude>
URL="https://gadgets.buienradar.nl/data/raintext?lat=${LAT}&lon=${LON}"

# Script variables
TEMPFILENAME=/tmp/rain.tmp
CHECKMINUTES=15
CURRENTTIME=`date +%R`
CURRENTHOUR=`echo "${CURRENTTIME}" | cut -d':' -f1`
CURRENTMINUTE=`echo "${CURRENTTIME}" | cut -d':' -f2`
CHECKLINES=$((CHECKMINUTES/5))
TOTALLINES=0
TOTALRAIN=0

# Get Buienradar prediction
if ! curl -L -o "${TEMPFILENAME}" "${URL}" >/dev/null 2>&1; then
	echo Failed to retrieve Buienradar prediction!
	exit 1
fi
PREDICTION=`sed $'s/[^[:print:]\t]//g' "${TEMPFILENAME}"`

# Parse Buienradar prediction and caclulate amount of rain
while IFS= read -r LINE; do
	TIME=`echo "${LINE}" | cut -d'|' -f2`
	HOUR=`echo "${TIME}" | cut -d':' -f1`
	MINUTE=`echo "${TIME}" | cut -d':' -f2`
	if [ "${HOUR}" -lt "${CURRENTHOUR}" ]; then continue; fi
	if [ "${HOUR}" -eq "${CURRENTHOUR}" ] && [ "${MINUTE}" -lt "${CURRENTMINUTE}" ]; then continue; fi
	RAIN=`echo "${LINE}" | cut -d'|' -f1 |sed 's/^0*//'`
	TOTALLINES=$((TOTALLINES+1))
	TOTALRAIN=$((TOTALRAIN+RAIN))
	if [ "${TOTALLINES}" -eq "${CHECKLINES}" ]; then break; fi
done < <(printf '%s\n' "${PREDICTION}")

AVERAGERAIN=$((TOTALRAIN / TOTALLINES))
AVERAGERAINMM=`echo "" | awk "END { print 10^((${AVERAGERAIN}-109)/32) }" | awk '{printf "%.1f\n", $0}'`

# Update rain prediction
if ! curl "${HOSTPROTOCOL}://${USERNAME}:${PASSWORD}@${HOSTNAME}:${HOSTPORT}/json.htm?type=command&param=udevice&idx=${PREDICTIONIDX}&nvalue=0&svalue=${AVERAGERAINMM}" >/dev/null 2>&1; then
	echo Failed to switch ON
	exit 1
fi

# Get the current state of the switch in Domoticz
if ! CURRENTSTATE=`curl "${HOSTPROTOCOL}://${USERNAME}:${PASSWORD}@${HOSTNAME}:${HOSTPORT}/json.htm?type=devices&rid=${SWITCHIDX}" 2>/dev/null |grep Status |awk '{print $3}' |sed 's/\"//g' |sed 's/\,//g'`; then
	echo Failed to retrieve current state!
	exit 1
fi

# Set Domoticz switch to ON if rain is predicted
if [ "${AVERAGERAIN}" -ge "99" ] && [ "${CURRENTSTATE}" == "Off" ]; then
	if ! curl "${HOSTPROTOCOL}://${USERNAME}:${PASSWORD}@${HOSTNAME}:${HOSTPORT}/json.htm?type=command&param=switchlight&idx=${SWITCHIDX}&switchcmd=On" >/dev/null 2>&1; then
		echo Failed to switch ON
		exit 1
	fi
fi

# Set Domoticz switch to OFF if no rain is predicted
if [ "${AVERAGERAIN}" -lt "99" ] && [ "${CURRENTSTATE}" == "On" ]; then
	if ! curl "${HOSTPROTOCOL}://${USERNAME}:${PASSWORD}@${HOSTNAME}:${HOSTPORT}/json.htm?type=command&param=switchlight&idx=${SWITCHIDX}&switchcmd=Off" >/dev/null 2>&1; then
		echo Failed to switch OFF
		exit 1
	fi
fi