#!/bin/ksh -p

# patchcompare: from http://www.bolthole.com/solaris

patchdir=`dirname $0`
cd $patchdir
CURR_LIST=/tmp/patchlist.$$
showrev -p >$CURR_LIST

usage()
{
#	print "patchcompare  -- will print out list of patches not installed"
	print "patchcompare -v  prints out install state of all patches in dir"
	print "patchcompare [-v] -l  prints out details about needed patches"
}


# print out patches. if verbose var set, also print out
# patches we know are installed.
simplelist(){

	for patch in 1?????-?? ; do

	 nawk -v patch=$patch -v v="$verbose" '
	   $2 == patch {  found=1; if(v) print $2" present"; exit; }
	          END  { if(found==0) print patch" not found"; }' $CURR_LIST
	done
}


# print a plain list of missing patches
# In theory, we need to check to see if there is a higher rev of a patch
# already installed, OR if a patch has been obsoleted.
#  (if obsolete, it should be removed from the patch dir and the
#   new one placed there)
missingpatches(){

	for patch in 1?????-?? ; do

	 nawk -v patch=$patch '
	   $2 == patch {  found=1; exit; }
	          END  { if(found==0) {
		             print patch;
		          }
		       }  ' $CURR_LIST
	done
}


#Given a specific patchID, print its synopsis, IFF we have one
# or more of the component packages that it patches.
printifneeded()
{
	neededflag=0

	shortpatch=${1:%-*}
	if [[ ! -z "$DIAGFILE"  ]] ; then
		if grep '^'$shortpatch'.*OBSOLETED' $DIAGFILE >/dev/null ; then
			$dprint "$1 is an OBSOLETED patch"
			return
		fi
	fi

	# If we find even one package that might be updated by
	# the patch, then we potentially need the patch.
	# Otherwise... we dont!
	for ppatched in ` nawk -F= '$1 == "PKG" {print $2}' $1/*/pkginfo`
	do

		if pkgparam $ppatched PKG >/dev/null 2>&1; then
			neededflag=1
			break
		fi
	done

	if [[ $neededflag -eq 0 ]] ; then
	
		$dprint $1 NOT needed. No applicable packages installed
		return
	fi

	# Check for a more recent version of the patch installed
	# But do this AFTER check for valid packages, since
	# sometimes people pkgrm packages, but stuff stays
	# around in /var/sadm/patch, apparently.
	latestrev=`nawk '$2 ~ /^'$shortpatch'/ { print $2}' $CURR_LIST| sort|tail -1`
	
	if [[ "$latestrev" != "" ]] ; then
		instrev=${latestrev#*-}
		newrev=${1#*-}

		#$dprint DEBUG $1: installed rev is $instrev, new rev is $newrev
		# Note: do NOT use -ge.
		# Sometimes, patches appear in /var/sadm/patch, but
		# not in showrev. Reinstall, to fix showrev
		if [[ $instrev -gt $newrev ]] ; then
			$dprint "Installed rev ($shortpatch-$instrev) is newer. $1 not needed"
			return
		fi
	fi

	sed -n 's/^Synopsis:/'$1:'/p' $1/README.$1

	
}

# First get a list of all patches in the dir that are not present,
# and dont have a newer rev installed.
# THEN, check to see if 
neededpatches(){
	for p in `missingpatches` ; do
		#sed -n 's/^Synopsis:/'$p:'/p' $p/README.$p

		printifneeded $p		
	done
}
#     cmd="grep Synopsis: "patch"/README."patch;



if [[ "$1" = "-h" ]] || [[ "$1" = "" ]] ; then
	usage
	exit
fi

if [[ "$1" = "-v" ]] ; then
	dprint=print
	verbose=1
	shift
else
	dprint=:
fi

if [[ -f patchdiag.xref ]] ; then
	DIAGFILE=patchdiag.xref
	$dprint "Using $DIAGFILE to check for obsoleted patches"
fi


if [[ "$1" = "-l" ]] ; then
	neededpatches
else
	simplelist
fi

rm $CURR_LIST