#!/bin/sh
#
# (C) Copyright  Florian  La Roche, <flla@stud.uni-sb.de>
# See the GNU Copyright...

version="0.10"

ErrorExit(){
   echo $*;
   exit 1;
}

Usage(){
  cat <<EOF
Make - Handle compilation and installation of source packages - $version.
(C) Copyright Florian La Roche, <flla@stud.uni-sb.de>

All source packages must be tar'd and gzip'd. Normally, they shouldn't be
modified from the general public release. Instead, all changes for Linux
are stored in an extra context diff. The context diff tries to install
everything with all features included and in a good place.

In the following description, "package" refers to a tar'd and gzip'd source
code, which is in the file "package.tar.gz" and the corresponding context
diff is in "package.dif".

Make extract package	Untar "package.tar.gz" and patch it with "package.dif".
Make compile package	Change into the source directory, call make for
			"Makefile.Linux" with the target 'compile'.
Make install package	Change into the source directory and call make for
			"Makefile.Linux" with the target 'install'.
Make diff package	Make new context diffs for that source package.
Make remove package	Remove the extracted source directory.

Do a 'Make info' to get some more information for creating new context diffs.

EOF
  return
}

# This function gets as input all file names that have to be changed for
# Linux. If the file didn't exist, we create it with "touch". Then we
# save the original source file with a call to "ci" (check in), which is
# part of the revision control system (rcs) from GNU.
RCS(){
   while read input; do
	# Extract the directory name from the file.
	dir_name=`dirname $input`
	# Check, if the directory exists.
	if [ ! -d $dir_name ]; then
		# The dir doesn't exist, create it.
		mkdir $dir_name
	fi
	if [ ! -e $input ]; then
		# If $input doesn't exist, create an empty file with "touch".
		touch $input
	fi
	# Save the original source code with "ci".
	ci -q -t-Original -l $input || ErrorExit "ci failed on $input."
   done
}

# Takes as parameters a list of source packages to extract.
Extract(){
   while read input; do
	if [ ! -f $input.tar.gz ]; then
		echo "Cannot find $input.tar.gz."
	elif [ ! -f $input.dif ]; then
		echo "Cannot find $input.dif."
	else
		echo -n "Decompress and extract $input, "
		tar xzf $input.tar.gz || ErrorExit "Tar failed on $input."
		cd $input || ErrorExit "cd failed on $1."
		echo -n "set up rcs, "
		cat ../$input.dif | gawk '/^---/ { print $2 }' | RCS
		echo "patch sources."
		patch -s -p0 <../$input.dif || ErrorExit "Patch failed on $1."
		cd ..
	fi
   done
}

# Make new context diffs for a source package.
Diff(){
   while read inp; do
	echo "Make rcs diffs for $inp"
	cd $inp || ErrorExit "Cd failed on $inp."
	find * -name '*,v' | sed 's/,v$//' | sort | \
		xargs -r -ihugo rcsdiff -q -u -L hugo hugo > ../$inp.dif
	cd ..
   done
}

Make(){
   while read input; do
	echo "###########################################################################"
	echo "Make $1 in subdir $input."
	cd $input || ErrorExit "Cd failed on $input."
	make $1 -f Makefile.Linux || \
		ErrorExit "Make $1 failed on $input."
	cd ..
   done
}

Remove(){
   while read input; do
	if [ -f $input.tar.gz -a -f $input.dif ]; then
		echo "Remove directory $input."
		rm -fr $input
	fi
   done
}

CheckPackages(){
   while read input; do
	if [ -f $input.tar.gz ]; then
		echo $input
	fi
   done
}

#####################################################################
# Main Program
#####################################################################

if [ $# = 2 ]; then
   if [ "extract" = "$1" ]; then
	echo $2 | Extract
   elif [ "$1" = "compile" -o "$1" = "install" ]; then
	echo $2 | Make $1
   elif [ "$1" = "diff" ]; then
	echo $2 | Diff
   elif [ "$1" = "remove" ]; then
	echo $2 | Remove
   else
	Usage
   fi
elif [ $# = 1 -a "$1" = "extract" ]; then
   ls *.tar.gz | sed 's/.tar.gz$//' | Extract
elif [ $# = 1 -a "$1" = "info" ]; then
   cat <<EOF
If you have a new source package, called "diff-2.6.tar.gz", extract it with
"tar xzf diff-2.6.tar.gz". Then change into the source directory with
"cd diff-2.6". Before you change any file in the source directory, you have
to save the old version with "ci -l filename". Just enter "." to the
asked question. This will create a file "filename,v", which contains the old
source code. If you make context diffs later on, your source directory is just
scanned for "*,v" and context diffs are generated for those files.
If you have to create a new file, first create an empty file with "touch file"
and then save it with "ci -l file".
You have to create the file "Makefile.Linux", which is for GNU make, with the
targets 'compile' and 'install'.
'compile' just compiles everything in the source directory.
'install' should be invoked as root, so that everything can be installed.
EOF
elif [ $# = 1 ]; then
   echo -n "Checking for installed packages..."
   find * -type d -maxdepth 0 -print | CheckPackages > Make.tmp
   echo " Done."

   if [ "$1" = "compile" -o "$1" = "install" ]; then
	Make $1 < Make.tmp
   elif [ "$1" = "diff" ]; then
	Diff < Make.tmp
   elif [ "$1" = "remove" ]; then
	Remove < Make.tmp
   else
	Usage
   fi
   rm -f Make.tmp
else
  Usage
fi

exit 0