#!/bin/bash
#
# qamscan.sh
#
# public release 0.6
#
# script to scan DVB device for QAM channels
# for importing into MythTV
#
# P Watkins, 2006

# user input
#
# $tables -- space-delimited list of table types
if [ "$tables" = "" ]; then
  tables="Standard HRC IRC"
fi
#
# $device -- DVB device number
if [ "$device" = "" ]; then
  device="0"
fi
#
# $timeout -- how long to try each channel
if [ "$timeout" = "" ]; then
  timeout=6
fi


if [ "$DISPLAY" == "" ]; then
  echo "No DISPLAY variable found; please run this on a system with X and mplayer" >/dev/stderr
  exit 2
fi

echo -n "making working directory... "
tmpdir=""
while [ "$tmpdir" = "" ]; do
  d="/tmp/qamscan.$RANDOM"
  mkdir -m 0750 $d && tmpdir="$d"
done
echo "work directory is $tmpdir"

get_scan_channels() {
  table="$1"
  atscdumpfile=${tmpdir}/atscscan_results-${table}.txt
  cat $atscdumpfile > ${tmpdir}/scan_channels.txt
  num=`wc -l < ${tmpdir}/scan_channels.txt`
  if [ $num -lt 1 ]; then
    return
  fi
  if [ $num -gt 0 ]; then
    echo "found $num channels, making $HOME/.azap/channels.conf"
    mkdir $HOME/.azap 2>/dev/null
    if [ \( -f $HOME/.azap/channels.conf \) -a \( \! -f ${tmpdir}/channels.conf.$$ \) ]; then
      echo "copying $HOME/.azap/channels.conf to ${tmpdir}/channels.conf.$$"
      cp -p $HOME/.azap/channels.conf ${tmpdir}/channels.conf.$$
    fi
    cat ${tmpdir}/scan_channels.txt > $HOME/.azap/channels.conf
  else
    echo "No channels found"
  fi
}

test_lock() {
  name="$1"
  start=`date +%s`
  stop=`expr $start + $timeout`
  echo "trying to tune $name"
  ${HERE}/dvb-apps/util/szap/azap -a $device -r "$name" &
  sleep 2
  mplayer_test "$name"
}

mplayer_test() {
  name="$1"
  echo "Testing $table channel $name in mplayer"
  mplayer -v -nosound /dev/dvb/adapter${device}/dvr0 >${tmpdir}/mplayer.out &
  sleep $timeout
  killall azap
  killall -9 azap
  killall mplayer
  killall -9 mplayer
  sleep 1 # give killall time
  # alternate? mplayer -nosound "dvb://$name"
  ans="N"
  mplayer_count=`grep "Found video stream" ${tmpdir}/mplayer.out |wc -l`
  if [ $mplayer_count -gt 0 ]; then
    echo
    echo "This (channel $name) looks like a channel we can tune!"
    echo
    ans="Y"
  fi
  #ask "Should we use this channel ($name)?"
  if [ "$ans" = "Y" ]; then
    echo "$name" >> ${tmpdir}/good_channels.txt
    cat $HOME/.azap/channels.conf >> $tmpdir/channels.conf.new
  fi
}

ask() {
  q="$1"
  ans=""
  while [ "$ans" = "" ]; do
    printf "%s (Y or N) " "$q"
    read ans
    ans=`echo $ans | tr '[:lower:]' '[:upper:]'`
    if [ \( "$ans" != "Y" \) -a \( "$ans" != "N" \) ]; then
      ans=""
    fi
  done
}

show_vm() {
  v=`grep VmallocUsed /proc/meminfo`
  echo "`date`: vmalloc = $v" | tee -a ${tmpdir}/vminfo.txt
}

HERE=`pwd`
cd dvb-apps/util/scan
if [ $? -ne 0 ]; then
  echo "please cd to the directory that contains 'dvb-apps/'" >/dev/stderr
  exit 1
fi

for table in $tables; do
 if [ ! -f "${HOME}/channels.conf.new" ]; then
  # look for channels
  if [ -f "${HOME}/atscscan_results-$table.txt" ]; then
    echo "not scanning; using using  ${HOME}/atscscan_results-$table.txt"
    echo "If you want a fresh scan, remove or rename ${HOME}/atscscan_results-$table.txt"
    echo "and run this script again"
    cat "${HOME}/atscscan_results-$table.txt" > ${tmpdir}/atscscan_results-$table.txt
  else
    echo "About to scan $table frequencies with atscscan;"
    printf "%s" "This could take some time. Press [Enter] to continue."
    read foo
    show_vm
    ./atscscan -v -A 3 atsc/us-Cable-${table}-center-frequencies-QAM256 > ${tmpdir}/atscscan_results-$table.txt
    show_vm
   if [ -f "${HOME}/atscscan_results-$table.txt.add" ]; then
     echo "merging scan results with ${HOME}/atscscan_results-$table.txt.add"
     cat ${tmpdir}/atscscan_results-$table.txt  "${HOME}/atscscan_results-$table.txt.add" | sort | uniq > $tmpdir/scan_sorted
     mv $tmpdir/scan_sorted  ${tmpdir}/atscscan_results-$table.txt
   fi
  fi
  echo "About to parse atscscan output..."
  get_scan_channels $table
  if [ -s ${tmpdir}/scan_channels.txt ]; then
    # found channels!
    echo <<EOMSG

We are about to test each channel. 
Typically you'll see one of two things:
  - some text output, but no video
  - some text output, and video in a separate
    mplayer window, but only for a few seconds
This script asks mplayer to print verbose console
output, and it looks in that output for suggestions
that mplayer was able to tune the channel, so that
you don't have to sit in front of your computer and
make decisions based on channels that obviously don't
work.

Once the script has found a good set of channels, it
will give you an opportunity to watch each one and
choose a new name.

EOMSG
  
    cat /dev/null > ${tmpdir}/good_channels.txt
    numch=`wc -l <  ${tmpdir}/scan_channels.txt`
    i=1
    echo "About to test $numch channels"
    while [ $i -le $numch ]; do
      head -$i  ${tmpdir}/scan_channels.txt | tail -1 > $HOME/.azap/channels.conf
      name=`head -$i  ${tmpdir}/scan_channels.txt | tail -1 | awk -F\: '{print $1}'`
      echo "`date` testing ${i}th channel of ${numch}, $name" >> ${tmpdir}/status.txt
      vt=`dmesg | grep vmalloc | grep -v '^Kernel command line'`
      if [ "$vt" != "" ]; then
        echo "WARNING: vmalloc errors; you need to boot with more vmalloc" | tee -a ${tmpdir}/status.txt
      fi
      show_vm
      test_lock $name
      i=`expr $i + 1`
    done
  fi
 else
  cp ${HOME}/channels.conf.new $tmpdir/
  cp ${HOME}/channels.conf.new $tmpdir/scan_channels.txt
  cut -d: -f1 < ${HOME}/channels.conf.new > $tmpdir/good_channels.txt
 fi
  if [ -s ${tmpdir}/scan_channels.txt ]; then
      numchannels=`wc -l < ${tmpdir}/good_channels.txt`
      if [ $numchannels -gt 0 ]; then
        channels=""
        for c in `cat ${tmpdir}/good_channels.txt`; do
          channels="${channels}, $c"
        done
        echo "We found the following $numchannels channels:"
        echo $channels | sed 's:^, ::'
        ask "Do you want to rename these channels?"
        if [ $ans = "Y" ]; then
          cat /dev/null > $tmpdir/renamed
          names=""
          # count how many channels to try
          count=`wc -l < $tmpdir/channels.conf.new`
          i=1
          while [ $i -le $count ]; do
            # tune one by one; rebuild channels.conf in case there are name conflicts
            head -$i $tmpdir/channels.conf.new | tail -1 > $HOME/.azap/channels.conf
            name=`awk -F\: '{print $1}' < $HOME/.azap/channels.conf`
            printf 'About to tune "%s"; exit mplayer when ready to rename\n' "$name"
            printf 'Press Enter to continue'
            read x
            # tune the channel
            ${HERE}/dvb-apps/util/szap/azap -a $device -r "$name" >/dev/null 2>/dev/null &
            # tell mpayer to display it
            mplayer -nosound /dev/dvb/adapter${device}/dvr0 >/dev/null 2>/dev/null
            # user has terminated mplayer
            killall azap >/dev/null 2>/dev/null
            killall -9 azap >/dev/null 2>/dev/null
            # now ask what name to use
            ans="N"
            while [ $ans = "N" ]; do
              printf 'What should we name that channel? '
              read name
              # only safe characters
              name=`echo $name | sed 's:[^a-zA-Z0-9\ \/\-\_]::g'`
              # make sure that name isn't already in use
              used=`grep "^${name}:" $tmpdir/renamed | wc -l`
              if [ $used -gt 0 ]; then
                echo "Name \"$name\" is already in use; pick another"
              else
                # looks like a good name; prompt for confirmation to be sure no typos
                ask "Confirm: should we use \"$name\" for this channel?"
              fi
            done
            # we have a good name for the channel; add it to the "renamed" work file
            sed "s,^[^\\:]*:,$name:," < $HOME/.azap/channels.conf >> $tmpdir/renamed
            # and add it to our list
            names="${names}, $name"
            # and incr 1
            i=`expr $i + 1`
          done
          # re-create the channels.conf file with the newly renamed channels
          cat $tmpdir/renamed > $HOME/.azap/channels.conf
          # echo what we have
          names=`echo $names | sed 's:, $::'`
          echo "New channel names in $HOME/.azap/channels.conf: $names"
        fi
        ask "Should we rebuild channels.conf with these channels?"
        if [ "$ans" = "Y" ]; then
          cat $tmpdir/channels.conf.new > $HOME/.azap/channels.conf 
          echo "$HOME/.azap/channels.conf has been rebuilt"
          dupes=`awk -F\: '{print $1}' < $HOME/.azap/channels.conf|sort|uniq -c|awk '$1 > 1 {print}'|wc -l`
          if [ $dupes -gt 0 ]; then
            echo "WARNING: $HOME/.azap/channels.conf has some lines with duplicate channel names!"
          fi
          echo "You should now try to import this using mythtvsetup"
          exit 0
        fi
      fi
    exit
  fi
done

# if we got here, we didn't find channels or didn't agree to update channels.conf
if [ -f "${tmpdir}/channels.conf.$$" ]; then
  echo "restoring $HOME/.azap/channels.conf"
  cp -p "${tmpdir}/channels.conf.$$" $HOME/.azap/channels.conf
fi