# MONITOR
# Monitors the vehicle's ignition switch to determine when
# certain processes are launched or killed.

# TUNABLE VARIABLES

# Name for the CAN-IHS interface (can0, can1, vcan0, etc)
CANIHS=can0

# Name of the WiFi device used in ifconfig, iwconfig
WIFIDEV=wlan0

# ENABLE OR DISABLE DEBUG STATEMENTS
DEBUG=true   # Values: true,false,raw

# LOCAL VARIABLES WHICH STORE STATE INFORMATION

dumpid=0
LASTIGNITION=99

# Wait five seconds and then change the CPU governor to powersave mode.

sleep 5
echo "powersave" > /sys/devices/system/cpu/cpufreq/policy0/scaling_governor

# CONSTANTLY MONITOR THE IGNITION SWITCH FOR ITS LATEST VALUE.

candump -L $CANIHS,0122:0FFFF | while read TIME BUS IGNITION
do

[ $DEBUG == "raw" ] && echo CAN-IHS data: $IGNITION
HEADER="TIME   : $TIME $( date )\nDATA   : $IGNITION"

# CONVERT $IGNITION TO A *DECIMAL NUMBER* SO WE CAN DO EASY COMPARISONS
# RUN MODE OR ENGINE STARTING/RUNNING: GREATER THAN 67108863
# ACCESSORY MODE OR VEHICLE OFF:       LESS    THAN 67108864

IGNITION=$( echo $IGNITION | cut -d"#" -f2 )
IGNITION=$( printf %d 0x$IGNITION )

# DEBUGGING STATEMENT

[ $DEBUG == "raw" ] && echo IGNITION: $IGNITION   LASTIGNITION: $LASTIGNITION

# WHEN ENGINE GOES FROM OFF TO ON, LAUNCH OUR ROUTINES.

if [ $IGNITION -gt 67108863 ] ; then
  if [ $LASTIGNITION -lt 67108864 ] ; then
    [ $DEBUG == "true" ] && echo -e $HEADER
    [ $DEBUG == "true" ] && echo "EVENT : VEHICLE HAS BEEN TURNED ON"

    # CHANGING CPU GOVERNOR TO THE ONDEMAND POLICY
    # Make more CPU power available while the engine is running.

    [ $DEBUG == "true" ] && echo "ACTION: CHANGING CPU GOVERNOR TO ONDEMAND"
    echo "ondemand" > /sys/devices/system/cpu/cpufreq/policy0/scaling_governor

    # STARTING THE BLACK BOX RECORDER, STORING INTO: /home/pi/log

    [ $DEBUG == "true" ] && echo "ACTION: STARTING BLACK BOX RECORDER"
    nohup /home/pi/bin/dump any > /dev/null &
    dumpid="$!"
    sleep 2
    dumpid=$( pgrep -P $dumpid )
    echo "DUMP STARTED, PID: $dumpid"

    # A SHORT DELAY BEFORE STARTING THE NEXT SECTION
    sleep 5

    # STARTUP ROUTINE FOR HVAC AUTOMATION AFTER IGNITION-START
    # When the vehicle is started, we want the remote-start HVAC automation routine
    # to run. The only exemption is if the engine was already running when this
    # script was launched. If that's the case ($LASTIGNITION == 99), then we do nothing.

    if [ $LASTIGNITION != 99 ] ; then
      [ $DEBUG == "true" ] && echo "ACTION: STARTING HVAC AUTOMATION FOR REMOTE-START"

      # The heater routine will exit if the vehicle was not remote started.
      # Either way, it will shortly terminate after starting and does not need monitoring.

      /home/pi/bin/autohvac &
    fi
    [ $DEBUG == "true" ] && echo ""
  fi
fi

# ENGINE IS NO LONGER RUNNING, KILL THE BLACK BOX

if [ $IGNITION -lt 67108864 ] ; then
  if [ $LASTIGNITION -gt 67108863 ] ; then
    [ $DEBUG == "true" ] && echo -e $HEADER
    [ $DEBUG == "true" ] && echo "EVENT : VEHICLE HAS BEEN TURNED OFF"
    [ $DEBUG == "true" ] && echo "ACTION: TERMINATING BLACK BOX RECORDER"

    # KILLING THE BLACK BOX RECORDER (IF ACTIVE)

    if [ $dumpid -gt 0 ] ; then
      sleep 2
      echo "ENGINE OFF, KILLING DUMP."
      pkill -TERM -P $dumpid
      kill -TERM $dumpid
      dumpid=0
    fi

    # CHANGING CPU GOVERNOR TO THE POWERSAVE POLICY
    # Become more energy efficient while the engine is not running.

    [ $DEBUG == "true" ] && echo "ACTION: CHANGING CPU GOVERNOR TO POWERSAVE"
    echo "powersave" > /sys/devices/system/cpu/cpufreq/policy0/scaling_governor
    [ $DEBUG == "true" ] && echo ""
  fi
fi

# KEEP TRACK OF WHAT THE PREVIOUS STATE OF THE IGNITIOIN SWITCH WAS.
# This is how we can tell if it has changed or not, since we want to
# take action only when there has been a change in it's value.

LASTIGNITION=$IGNITION

done