#! /bin/sh
#
# Written by Craig Huff
#
#  This program is free software; you can redistribute it and/or modify
#  it under the terms of the GNU General Public License as published by
#  the Free Software Foundation; either version 2 of the License, or
#  (at your option) any later version.
#
## $2 is the time in seconds since the epoch started that Myth wants
## to wake up the system in preparation for the next recording event.
#

# Constants:
#   Seconds system is expected to take from wakeup alarm until ready to do processing
# (5 minutes x 60 seconds = 300)
offset=300

#
## Define where this script should log it's activities.
#
logfile=/var/log/mythtv/alarm.log

#
## Insert blank lines in logfile to separate alarm setting events
#
echo "" >> ${logfile}
echo "" >> ${logfile}

#
## What time was passed by Myth as the wake up time for the next recording?
#
mythtime=`date -u -d "1970-01-01 ${2} seconds" --rfc-3339="seconds" | cut -c1-19`
echo "Mythtime=${mythtime}" >> ${logfile}

#
## Get (from the fill log) the time zap2it requested the next update be made
## and put it in a /bin/date compatible format.
#
nexttime=`cat /var/log/mythtv/mythfilldatabase.log.1 /var/log/mythtv/mythfilldatabase.log | grep NextSuggestedTime | tail -1 | awk '{print $NF}' | sed -e 's/T/ /'`
echo "Filltime=${nexttime}" >> ${logfile}

#
## To ease time comparisons and time adjustments, get the value of nexttime in
## seconds since the start of the epoch (1/1/1970 @ 00:00:00 am).
#
epochtime=`date -u -d "${nexttime}" +%s`

#
## Since the time supplied by zap2it is the time to update the database, we need
## to wake up the system prior to that and allow time to get up to speed, so
## subtract ${advance} seconds from epochtime.
#
epochtime=`expr ${epochtime} - ${offset}`

#
## Convert epochtime into alarm time format
#
filltime=`date -u -d "1970-01-01 ${epochtime} seconds" --rfc-3339="seconds" | cut -c1-19`

#
## Which is sooner?
#
if [ ${2} -lt ${epochtime} ]; then
  waketime=${mythtime}
else
  waketime=${filltime}
fi

#
##   There is a finite chance that the selected wakeup time is EXACTLY
## midnight UTC.
##   In /etc/init.d/halt, we have made the assumption that when
## /proc/acpi/alarm is set for this specific time of day that we DO NOT want to
## wake up when that time arrives.
##   Therefore, test waketime to see if the time of day it contains is
## midnight UTC and if it is, tweak the time to be five seconds earlier
## (00:00:00 -> 23:59:55).
#
if [ "`echo ${waketime} | awk '{print $NF}'`" == "00:00:00" ]; then
  epochtime=`date -u -d "${waketime}" +%s`
  offsettime=`expr ${epochtime} - 5`
  waketime=`date -u -d "1970-01-01 ${offsettime} seconds" --rfc-3339="seconds" | cut -c1-19`
fi

localtime=`date -d "${waketime} UTC" +"%a, %b %d, %Y at %r %Z"`

#
## Now set the ACPI alarm and log the details on this wakeup setting event
#
echo "${waketime}" > /proc/acpi/alarm
echo "On `date +"%a, %b %d, %Y"` at `date +"%r %Z"`," >> ${logfile}
echo "	alarm set to ${waketime} `date -u +%Z`" >> ${logfile}
echo "	which is ${localtime} local time." >> ${logfile}