#!/bin/sh
#
# openmamba ISO RPM differences report creator
# Copyright (c) 2010 by Silvan Calarco <silvan.calarco@mambasoft.it>
#
TMPDIR=/tmp/isodiff

function create_count_files() {
  local F=$1
  SIZE=0
  rpm -r $TMPDIR/$F -qa --queryformat "%{NAME} %{SIZE}\n" | sort > $TMPDIR/$F-rpm.txt
  > $TMPDIR/$F-rpm-size.txt
  while read line; do
     set -- $line
     SIZE=`expr $SIZE + $2`
     echo "$1 $SIZE" >> $TMPDIR/$F-rpm-size.txt
  done < $TMPDIR/$F-rpm.txt
  echo "Total size: $SIZE"
}

ISOFROM=$1
ISOTO=$2

[ "$ISOFROM" -a "$ISOTO" ] || {
   echo "Usage: $0 from.iso to.iso"
   exit 1
}

[ -e "$ISOFROM" ] || {
   echo "Error: file $ISOFROM does not exist; aborting."
   exit 1
}

[ -e "$ISOTO" ] || {
   echo "Error: file $ISOTO does not exist; aborting."
   exit 1
}

umount $TMPDIR/from 2>/dev/null
umount $TMPDIR/to 2>/dev/null
umount $TMPDIR/isofrom 2>/dev/null
umount $TMPDIR/isoto 2>/dev/null

mkdir -p $TMPDIR/{isofrom,isoto,from,to}
mount -o loop $ISOFROM $TMPDIR/isofrom || {
   echo "Error: cannot mount $ISOFROM; aborting."
   exit 1
}
mount -o loop $ISOTO $TMPDIR/isoto || {
   echo "Error: cannot mount $ISOTO; aborting."
   umount $TMPDIR/isofrom
   exit 1
}
mount -o loop $TMPDIR/isofrom/rootfs.compressed $TMPDIR/from || {
   echo "Error: cannot mount compressed fs inside $ISOFROM; aborting."
   umount $TMPDIR/isofrom
   umount $TMPDIR/isoto
   exit 1
}
mount -o loop $TMPDIR/isoto/rootfs.compressed $TMPDIR/to || {
   echo "Error: cannot mount compressed fs inside $ISOTO; aborting."
   umount $TMPDIR/from
   umount $TMPDIR/isofrom
   umount $TMPDIR/isoto
   exit 1
}

create_count_files from
create_count_files to

> $TMPDIR/diff.txt
while read line; do
   set -- $line
   pkgname=$1
   fromsize=$2
   lineto=`grep "^$pkgname " $TMPDIR/to-rpm.txt 2>/dev/null`
   [ "$lineto" ] && {
      set -- $lineto
      tosize=$2
   } || tosize=0
   diffsize=`expr $tosize - $fromsize`
   [ $diffsize -ne 0 ] && {
      percsize=`echo "scale=2; $diffsize * 100 / $fromsize" | bc` || percsize=0
      echo -e "$pkgname ${tosize} ${fromsize} ${diffsize} ${percsize}" >> $TMPDIR/diff.txt
   }
done < $TMPDIR/from-rpm.txt

while read line; do
   set -- $line
   pkgname=$1
   tosize=$2
   linefrom=`grep "^$pkgname " $TMPDIR/from-rpm.txt 2>/dev/null`
   [ "$linefrom" ] && continue
   echo -e "$pkgname $tosize 0 $tosize 100" >> $TMPDIR/diff.txt
done < $TMPDIR/to-rpm.txt

echo -e "Package\r\t\t\t\t\t N Diff (bytes)" > $TMPDIR/diff-growth.txt
echo "------------------------------------------------------------------------------------" >> $TMPDIR/diff-growth.txt
incr=0
cat $TMPDIR/diff.txt | sort -n -k 4 -r | while read line; do
   set -- $line
   [ ${3} -eq 0 ] && new="*" || new=" "
   incr=`expr $incr + ${4}`
   echo -e "$1\r\t\t\t\t\t ${new} ${4}\r\t\t\t\t\t\t\t (${5}%)\r\t\t\t\t\t\t\t\t\t $incr" >> $TMPDIR/diff-growth.txt
done
umount $TMPDIR/from
umount $TMPDIR/to
umount $TMPDIR/isofrom
umount $TMPDIR/isoto
exit 0