#!/bin/bash
set -x

if [ "${USER}" == "" ] ; then
  USER="`whoami`"
fi
Version="1.10w"
if [ "${USER}" == "gtoal" ] ; then

  # For Anne's WS1400-IP.  Actually now replaced with a WS2902 (WS1600)?
  if [ ! -f /tmp/last-weather-server-contact.txt ]; then
    echo 0 > /tmp/last-weather-server-contact.txt
  fi

  LASTHEARD="$(( `date +%s` - `cat /tmp/last-weather-server-contact.txt`))"
  if [[ $LASTHEARD -gt 3600 && $LASTHEARD -lt 4000 ]]; then
    echo Your weather station has not reported for an hour|mail -s "Weather station down" 9566672500@tmomail.net gtoal
  fi

  Callsign="FW0153"           # replace with yours
  StationIP="192.168.2.240"   # ditto.
  LatLon="2616.99N/09810.37W" # format is important - see APRS docs
  Elevation=39                # elevation of barometer in M above sea level
else
  echo "Error: ${USER}, you must edit this script and configure Callsign/StationIP/LatLon/Elevation to match your own site." 
  exit 1
fi
#
# View results here: http://www.findu.com/cgi-bin/wxpage.cgi?call=FW0153
#
# My server's units:
#   Wind mph
#   Rain in
#   Pressure inhg
#   Temp F
#   Solar w/m^2
#
# My crontab looks like this:
#   SHELL=/bin/sh
#   PATH=/home/gtoal/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
#   4,9,14,19,24,29,34,39,44,49,54,59 * * * * /home/gtoal/bin/ws1400 > /dev/null
#
# alternative scraper for weewx:
#    https://github.com/poblabs/weewx-ObserverIP/blob/master/observerip.py
#
# ecce is a text editor from ecce.sourceforge.net to replace sed/awk:
#    wget http://ecce.sourceforge.net/ecce.c; cc -o ecce ecce.c
#
# if you don't have the 'timeout' command, remove 'timeout nns' from below
#
timeout 100s wget -O /dev/stdout -o /dev/null -q http://${StationIP}/livedata.htm > /tmp/weather.$$
if (( $? != 0 )); then
  exit $?   # probably the house wifi acting up again. Notify or reboot using Kasa switch?
fi
fgrep \</html\> /tmp/weather.$$ > /dev/null
if (( $? != 0 )); then
  exit $?   # partial fetch - should send an SMS alert to let me know...
fi
/usr/local/bin/ecce /tmp/weather.$$ <<EOF > /dev/null 2>&1
(f1/value=/m,k)0
m-0(u.name=".s..f1/"/u.value=".s.=.f1/"/e0m)0
m-0f/Apply=/k0
m-0(rli.export .t/=/i/"/r0i/"/m)0
m-0g
#!/bin/sh
%c
EOF
# AbsPress is coming through as "" if there is a fetch error. Initialise these so they can be tested safely.
AbsPress=0
solarrad=0
source /tmp/weather.$$
# solar radiation not used by weather site, but I use it elsewhere for controlling domestic lighting
solarrad=`echo "scale=0;(${solarrad}+0.5)/1" | bc`
# we have to use bc for rounding because bash is integer only
avgwind=`echo "scale=0;(${avgwind}+0.5)/1" | bc`
gustspeed=`echo "scale=0;(${gustspeed}+0.5)/1" | bc`
outTemp=`echo "scale=0;(${outTemp}+0.5)/1" | bc`
rainofhourly=`echo "scale=0;((${rainofhourly}*100)+0.5)/1" | bc`
rainofdaily=`echo "scale=0;((${rainofdaily}*100)+0.5)/1" | bc`
outHumi=`echo "scale=0;(${outHumi}+0.5)/1" | bc`
#echo "Raw abs pressure in inches: ${AbsPress}"
AbsPress=`echo "(${AbsPress}*33.8637526)" | bc`  # convert to hPa
#echo "Raw abs pressure in hPa: ${AbsPress}"
# CurrTime is initialised in the data from the observerip
CurrTime="`date --date=\"${CurrTime}\"`"
CurrTime="`date -u --date=\"${CurrTime}\" +%d%H%Mz`"

if (( (${outTemp} != 0) && (${outHumi} != 0) )); then
  # (I know, that will fail if the temperature and humidity both really are zero...)

  # I also have a pm2.5/pm10 sensor. They are not handled here.

  SeaPress=`echo "(${AbsPress} - 0.3) * e(5.2553026 * l(1 + (0.0000845115 * (${Elevation} / e(0.190284 * l(${AbsPress} - 0.3))))));" | bc -l`
  #echo "Corrected pressure: ${SeaPress}"
  SeaPress=`echo "scale=0;((${SeaPress}*10)+0.5)/1" | bc`  # scale and round
  #echo "Scaled Corrected pressure: ${SeaPress}"

  # apply dubious index corrections to move data towards MADIS (optional, experimental 2019/5/25)
  if [ "${USER}" == "gtoal" ] ; then
    # Currently the report at https://weather.gladstonefamily.net/site/F0153 shows Average barometer error of 0.0
    # and average daily temperature error of 0.0!  The humidity is crazily off but that is due to problems at the
    # MADIS side... (their estimate oscillates wildly).  So the small tweaking below seems to be worthwhile.
    # 3.8 millibars added 20210831 - corrections seem seasonal
    SeaPress=`echo "scale=0;(${SeaPress} - 13 + 38 + 8 - 1 )/1" | bc`
    #echo "Scaled and tweaked Corrected pressure: ${SeaPress}"
    # offset
    outTemp=`echo "(${outTemp} - 1.5);" | bc -l`
    # scale.  84 is about where the actual and madis lines cross.
    outTemp=`echo "(${outTemp} - 84);" | bc -l`
    outTemp=`echo "(${outTemp} * 0.75);" | bc -l`
    outTemp=`echo "(${outTemp} + 84);" | bc -l`
    # 1.0 added 20210831  - fixes ave but needs to be stretched a little - midpoint around 87 or 88
    outTemp=`echo "(${outTemp} - 2.8 );" | bc -l`
    # lowered by 2.9 on 20210831
    # lowered by 5.1 on 20211218 to -2.8
    outHumi=`echo "(${outHumi} - 1.3 - 2.9 + 0.8);" | bc -l`
    avgwind=`echo "(${avgwind} * 3.1 * 1.5);" | bc -l`
    gustspeed=`echo "(${guestspeed} * 3.1);" | bc -l`
  fi


  if [[ "$SeaPress" != "" ]]; then
    if [ "${USER}" == "gtoal" ] ; then  # The data for CWOP is also used in my home automation system:
      /usr/bin/logger -d -p user.notice -t Weather "solar: ${solarrad} rain: ${rainofhourly} temp: ${outTemp} humidity: ${outHumi} pressure: ${SeaPress}"
    fi
  fi
  
  # reformat values with leading zeroes immediately prior to sending.  Otherwise misinterpreted as hex constants in expressions :-(
  outTemp=`printf %03d ${outTemp}`
  outHumi=`printf %02d ${outHumi}`
  if ((${outHumi} == 100)); then
    outHumi="00"  # special case - I guess 100% humidity is more likely than 0%
  fi
  avgwind=`printf %03d ${avgwind}`
  windir=`printf %03d ${windir}`
  gustspeed=`printf %03d ${gustspeed}`
  rainofhourly=`printf %03d ${rainofhourly}`
  rainofdaily=`printf %03d ${rainofdaily}`
  if [[ "$SeaPress" != "" ]]; then
    ( echo "user ${Callsign} pass -1 vers gtoal.com/wx/ws1400.sh ${Version}"; sleep 3; echo "${Callsign}>APRS,TCPIP*:@${CurrTime}${LatLon}_${windir}/${avgwind}g${gustspeed}t${outTemp}r${rainofhourly}p${rainofdaily}h${outHumi}b${SeaPress}http://gtoal.com/wx/ws1400.sh;${Version}" ) | nc -C -q 3 cwop.aprs.net 14580 > /dev/null 2>&1
  fi
  date +%s > /tmp/last-weather-server-contact.txt
fi
rm /tmp/weather.$$
exit 0