#!/bin/bash
#
# monitor.sh -- top-level ignition orchestrator.
#
# Watches $122 on CAN-IHS for ignition state changes and uses them to
# coordinate several other in-vehicle Pi processes:
#
#   On ignition-on transition:
#     - CPU governor -> ondemand (more power while the engine runs)
#     - Spawn autocollect.sh   (vehicle-statistics collector)
#     - Spawn dump (any)       (black-box CAN-traffic recorder)
#     - Spawn autohvac         (remote-start HVAC automation;
#                               exits on its own if not remote-started)
#
#   On ignition-off transition:
#     - Kill the black-box recorder
#     - CPU governor -> powersave (energy efficient while parked)
#
# Originally created: 01.2022 by jmccorm
# Last updated:       05.2026 (polish by magikh0e)
#
# RELATION TO OTHER ON-SITE SCRIPTS
#   This script is a SUPERSET of Blackbox_monitor.sh -- both watch
#   $122 and gate the dump recorder's lifecycle on engine state, but
#   monitor.sh additionally manages the CPU governor and spawns
#   autocollect / autohvac.  If you're running monitor.sh, you do NOT
#   also run Blackbox_monitor.sh -- you'd end up with two competing
#   dump recorders.  See the parent index entry for disposition
#   guidance.
#
# REQUIRES
#   - can-utils (candump)             apt install can-utils
#   - cpufreq policy0 writable        echo X > /sys/devices/system/cpu/
#                                       cpufreq/policy0/scaling_governor
#                                     (write requires root or appropriate
#                                     udev rule; if /sys path is missing
#                                     set GOVERNOR=false)
#   - /home/pi/bin/autocollect, dump, autohvac on PATH
#   - CAN-IHS up at 125 kbps          on can0 in this script
#
# REVISION NOTES (2026-05-16)
#   - Fixed `[ ... ]]` syntax error on the sleep-30 line.
#   - Replaced 64-bit-broken `printf %d 0x$IGNITION` comparison with
#     a portable top-32-bits hex-to-decimal extraction.  Original
#     code worked on 32-bit Pi (Pi 3 and older) because bash printf
#     overflowed the value; on 64-bit Pi 4 / 5 the larger int range
#     would make the comparison always-true and falsely report
#     "engine running" on every frame.
#   - Fixed "IGNITIOIN" typo in tail comment.
#   - Quoted variables passed to candump cut chain.
#   - Header documents the relation to Blackbox_monitor.sh so a
#     reader doesn't accidentally run both.

PATH=$PATH:/home/pi/bin
touch /tmp/monitor

# 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=false # Values: true,false,raw
# AUTOMATICALLY TUNE THE CPU GOVERNOR? (ONDEMAND VS POWERSAVE?)
GOVERNOR=true

# 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 $(date) MONITOR: Initializing.
echo $(date) MONITOR: uptime $(uptime | cut -d, -f1-2)
if [ "$GOVERNOR" == "true" ] ; then
  echo $(date) MONITOR: Changing CPU governor to: POWERSAVE
  echo "powersave" > /sys/devices/system/cpu/cpufreq/policy0/scaling_governor
fi

# 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 $IGNITION TO A *DECIMAL NUMBER* SO WE CAN DO EASY COMPARISONS.
#
# Original jmccorm 2022 code did:
#     IGNITION=$( printf %d 0x$IGNITION )
# which relied on 32-bit bash arithmetic overflowing the full 64-bit
# payload value down to the top word.  On 64-bit bash (Pi 4 / 5)
# the printf returns the full 64-bit integer and the comparison
# below would always be true -- every frame would look like "engine
# running."  The fix below explicitly extracts the top 32 bits.
#
# RUN MODE OR ENGINE STARTING/RUNNING: top word >= 0x04000000
# ACCESSORY MODE OR VEHICLE OFF:       top word <  0x04000000

PAYLOAD=$( echo "$IGNITION" | cut -d"#" -f2 )
IGNITION=$(( 16#${PAYLOAD:0:8} ))

# 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.

    echo $(date) MONITOR: Vehicle starting up.

    if [ "$GOVERNOR" == "true" ] ; then
      echo $(date) MONITOR: Changing CPU governor to: ONDEMAND
      echo "ondemand" > /sys/devices/system/cpu/cpufreq/policy0/scaling_governor
    fi

    # START THE AUTOMATED COLLECTION OF VEHICLE STATISTICS

    echo $(date) MONITOR: Starting Autocollect script.
    /home/pi/bin/autocollect &

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

    echo $(date) MONITOR: Starting Black Box Recorder.
    nohup /home/pi/bin/dump any > /dev/null &
    dumpid="$!"
    sleep 2
    dumpid=$( pgrep -P $dumpid )
    [ "$DEBUG" == "true" ] && 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.

    # THIS SCRIPT WAS ORIGINALLY DESIGNED FOR A RASPBERRY
    # PI THAT RECEIVED CONSTANT POWER. SO IF THIS SCRIPT
    # SAW THAT THE ENGINE WAS ALREADY RUNNING, IT WOULD NOT
    # LAUNCH THE AUTOHVAC SCRIPT BECAUSE IT THOUGHT IT MAY
    # HAVE BEEN REBOOTED WHILE THE ENGINE WAS RUNNING.
    #
    # NOW THAT I HAVE THE RASPBERRY PI POWERING ON WITH
    # THE VEHICLE'S IGNITION (AND BOOTING 30 SECONDS AFTER
    # THAT), THE TEST IS NO LONGER NEEDED. BUT THE LOGIC
    # IS LEFT IN PLACE, JUST IT LOOKS FOR AN ABSURD VALUE
    # OF 123456 INSTEAD OF 99 AS IT'S TEST CONDITION.

    if [ $LASTIGNITION != 123456 ] ; then
      echo $(date) MONITOR: Starting AutoHVAC

      # The timing of autohvac expects that it's been called after the
      # Raspberry Pi had to time booting, which would have been a
      # good 30 seconds after the car started. So if the engine WASN'T
      # already running when this script began, this adds a 30 second
      # delay so that we wait the same amount (and have reproducible
      # timings) whether or not the Raspberry Pi had been running or if
      # it had to take time booting from scratch.

      [ $LASTIGNITION != 99 ] && sleep 30

      # 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 $(date) MONITOR: Black Box Recorder ended.
      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.

    if [ "$GOVERNOR" == "true" ] ; then
      echo $(date) MONITOR: Changing CPU governor to: POWERSAVE
      echo "powersave" > /sys/devices/system/cpu/cpufreq/policy0/scaling_governor
    fi
    [ "$DEBUG" == "true" ] && echo ""
  fi
fi

# KEEP TRACK OF WHAT THE PREVIOUS STATE OF THE IGNITION 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 its value.

LASTIGNITION=$IGNITION

done