#!/bin/bash
#
#  svnbranch.sh - helper script for managing subversion branching
#  Copyright (C) 2007  Clifford Wolf <clifford@clifford.at>
#
#  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

set -e
export LC_ALL=C

callsvn_cachedir=""
svncmd="svn"

verbose=0
cacherequested=0
rotategraph=0

while true; do
	if [ "$1" = "-x" ]; then
		set -x
		shift; continue
	fi
	if [ "$1" = "-v" ]; then
		verbose=1
		shift; continue
	fi
	if [ "$1" = "-r" ]; then
		rotategraph=1
		shift; continue
	fi
	if [ "$1" = "-cache" ]; then
		cacherequested=1
		svncmd="svncache"
		shift; continue
	fi
	break
done

callsvn()
{
	if [ $verbose = 1 ]; then
		echo "> $*" >&2
	fi

	if [ -n "$callsvn_cachedir" ]; then
		local cacheid="`echo "$*" | cksum | tr -d ' '`"
		if [ ! -f "$callsvn_cachedir/$cacheid" ]; then
			$svncmd "$@" > "$callsvn_cachedir/$cacheid"
		fi
		cat "$callsvn_cachedir/$cacheid"
	else
		$svncmd "$@"
	fi
}

nl="
"

url_to_parent_ret=""
url_to_parent_url=""
url_to_parent_root=""
url_to_parent_info_args=""
url_to_parent()
{
	local info=`callsvn info $url_to_parent_info_args "$1"`
	local url=`echo "$info" | grep '^URL: ' | sed 's,.*: ,,'`
	local rev=`echo "$info" | grep '^Last Changed Rev: ' | sed 's,.*: ,,'`
	local root=`echo "$info" | grep '^Repository Root: ' | sed 's,.*: ,,'`
	local path="${url#$root}"

	if [ -z "$url" -o -z "$rev" -o -z "$root" -o "$path" = "$url" ]; then
		echo "SVNBRANCH FATAL ERROR IN: url_to_parent '$1'" >&2
		exit 1
	fi

	url_to_parent_url="$url"
	url_to_parent_root="$root"

	url_to_parent_ret="$path@$rev"
}


if [ "$1" = "branch" -a -n "$2" ] && [ $cacherequested = 0 ]; then
	url_to_parent .
	callsvn propset svnbranch:parent "$url_to_parent_ret" .
	callsvn -q propdel svnbranch:tag .
	callsvn copy . "$2"
	# FIXME: Is it possible to use 'svn revert' only on the
	# svnbranch:parent and svnbranch:tag properties?
	callsvn revert .
	exit 0
fi

if [ "$1" = "tag" -a -n "$2" ] && [ $cacherequested = 0 ]; then
	url_to_parent .
	callsvn propset svnbranch:parent "$url_to_parent_ret" .
	callsvn propset svnbranch:tag "1" .
	callsvn copy . "$2"
	# FIXME: Is it possible to use 'svn revert' only on the
	# svnbranch:parent and svnbranch:tag properties?
	callsvn revert .
	exit 0
fi

if [ "$1" = "init" -a -n "$2" ] && [ $cacherequested = 0 ]; then
	url_to_parent "$2"
	callsvn propset svnbranch:parent "$url_to_parent_ret" .
	exit 0
fi

if [ "$1" = "sync" ] && [ $cacherequested = 0 ]; then
	if [ -n "`callsvn propget svnbranch:tag .`" ]; then
		echo "Not syncing a tag: $PWD" >&2
		exit 1
	fi
	old_parent=`callsvn propget svnbranch:parent .`
	if [ -z "$old_parent" ]; then
		echo "Not a branch of anything: $PWD" >&2
		exit 1
	fi
	if [ -z "$2" ]; then
		url_to_parent "."
		url_to_parent_info_args="-r HEAD"
		url_to_parent "$url_to_parent_root$old_parent"
	else
		url_to_parent "$2"
	fi
	callsvn merge "$url_to_parent_root$old_parent" "$url_to_parent_root$url_to_parent_ret" .
	# FIXME: This is for resolving the svnbranch:parent merge conflict.
	# To bad that it seams to be impossible to revert the property only.
	$svncmd revert .
	callsvn propset svnbranch:parent "$url_to_parent_ret" .
	exit 0
fi

if [ "$1" = "diff" ]; then
	url_to_parent "."
	parent=`callsvn propget svnbranch:parent .`
	if [ -z "$parent" ]; then
		echo "Not a branch of anything: $PWD" >&2
		exit 1
	fi
	if [ $# = 1 ]; then
		callsvn diff "$url_to_parent_root$parent" "$url_to_parent_url"
	else
		prev=${parent##*@}; parent=${parent%@*}
		if [ -n "$prev" ]; then prev="@$prev"; fi
		shift; for file; do
			callsvn diff "$url_to_parent_root$parent/$file$prev" "$url_to_parent_url/$file"
		done
	fi
	exit 0
fi

if [ "$1" = "merge" -a -n "$2" ] && [ $cacherequested = 0 ]; then
	if [ -n "`callsvn propget svnbranch:tag .`" ]; then
		echo "Not merging to a tag: $PWD"
		exit 1
	fi
	url_to_parent "$2"
	parent=`callsvn propget svnbranch:parent "$2"`
	callsvn merge "$url_to_parent_root$parent" "$2" .
	# FIXME: This is for resolving the svnbranch:parent merge conflict.
	# To bad that it seams to be impossible to revert the property only.
	$svncmd revert .
	exit 0
fi


list=""

generate_list()
{
	local url="$1" filter="$2"
	if [ "${url#$filter}" != "$url" ]; then
		local parent=`callsvn propget svnbranch:index $url`
		if [ -n "parent" ]; then
			if [ -n "$list" ]; then
				list="$list$nl"
			fi
			list="$list$url"
		fi
	fi
	for url in `callsvn propget svnbranch:index "$1" | grep . | perl -le '
			my $filter = '"'$filter'"';
			sub svnasterisk($$) {
				my ($a,$b) = @_; my $ret="";
				return "" if index($a, $filter) and index($filter, $a);
				open(P,". '"'$callsvn_cachedir/api.sh'"'; callsvn ls '\''$_[0]'\''|");
				while (<P>) { next unless s/\/\n$//; $ret.="$a$_$b\n"; }
				close P; return $ret;
			}
			while (<>) {
				$_='\'"$1/"\''.$_;
				1 while s!^(.*?/|)\*(.*)\n?!svnasterisk($1,$2)!me;
				foreach (split /\n/) {
					print unless index($_, $filter) and index($filter, $_);;
				}
			}'`
	do
		generate_list "$url" "$filter"
	done
}

show_list()
{
	callsvn_cachedir="`mktemp -d`"
	{ declare -f callsvn; declare -p verbose svncmd callsvn_cachedir; } > "$callsvn_cachedir/api.sh"
	if [ -z "$*" ]; then
		url_to_parent "."
		generate_list "$url_to_parent_root" "$url_to_parent_url"
	else
		for url in "$@"; do
			if [ "$url" = "/" ]; then
				url_to_parent "."
				url="$url_to_parent_root"
			fi
			url_to_parent "$url"
			generate_list "$url_to_parent_root" "$url_to_parent_url"
		done
	fi
	{
		while read url; do
			parent=`callsvn propget svnbranch:parent "$url"`
			url_to_parent_info_args=""
			url_to_parent "$url"
			if [ -n "$parent" ]; then
				if [ -n "`callsvn propget svnbranch:tag "$url"`" ]; then
					echo "TAG $parent $url_to_parent_ret"
				else
					echo "BRANCH $parent $url_to_parent_ret"
				fi
				url_to_parent_info_args="-r HEAD"
				url_to_parent "$url"
				echo "HEAD $url_to_parent_ret"
				url_to_parent "$url_to_parent_root$parent"
				echo "HEAD $url_to_parent_ret"
			fi
		done < <( echo "$list" | grep .; )
	} | sort -u
	rm -rf "$callsvn_cachedir"
	callsvn_cachedir=""
}

if [ "$1" = "list" ]; then
	shift
	show_list "$@"
	exit 0

fi

if [ "$1" = "graph" -o "$1" = "show" ]; then
	outdir=""; mode="$1"; shift
	if [ "$mode" = "show" ]; then
		outdir="`mktemp -d`/"
	fi
	echo "Generating ${outdir}svnbranch.dot."
	if [ "$*" = "-" ]; then
		cat
	else
		show_list "$@"
	fi | perl -e '

		my @history;
		my @branches;
		my %head_nodes;
		my %nodes;
		my %tags;
		my $nc=0;

		while (<>) {
			if (/^TAG (\S+) (\S+)/) {
				$tags{$2} = 1;
			}
			if (/^(BRANCH|TAG) (\S+) (\S+)/) {
				$nodes{$2} = $nc++;
				$nodes{$3} = $nc++;
				push @branches, [ $2, $3];
			}
			if (/^HEAD (\S+)/) {
				$head_nodes{$1} = 1;
				$nodes{$1} = $nc++;
			}
		}

		print "digraph G {\n";

		foreach $n (keys %nodes) {
			if ($n =~ /(.*)\@(.*)/) {
				my ($base, $rev) = ($1, $2);
				my $history_prev_node;
				my $history_prev_rev = -1;
				foreach (keys %nodes) {
					next unless /(.*)\@(.*)/;
					if ($1 eq $base && $2 < $rev && $2 > $history_prev_rev) {
						$history_prev_node = $_;
						$history_prev_rev = $2;
					}
				}
				if (defined $history_prev_node) {
					push @history, [ $history_prev_node, $n ];
				}
			}
			print "node${nodes{$n}} ";
			if (defined $head_nodes{$n}) {
				my $x = $n; $x =~ s/\@.*//;
				print "[label=\"$x\", shape=box";
				print ", style=filled" if defined $tags{$n};
			} else {
				print "[label=\"$n\", shape=octagon";
				print ", style=filled, fillcolor=red" if defined $tags{$n};
			}
			print "];\n";
		}

		foreach (@history) {
			my ($prev, $next) = @$_;
			print "node${nodes{$prev}} -> node${nodes{$next}} [color=green, style=bold];\n";
		}

		foreach (@branches) {
			my ($parent, $branch) = @$_;
			if (defined $head_nodes{$parent} and not defined $tags{$branch} != '$rotategraph') {
				print "node${nodes{$parent}} -> node${nodes{$branch}} [color=blue, style=bold];\n";
			} else {
				print "node${nodes{$parent}} -> node${nodes{$branch}} [color=blue, style=bold, minlen=0];\n";
			}
		}

		print "}\n";

	' > ${outdir}svnbranch.dot
	echo "Generating ${outdir}svnbranch.ps."
	dot -Tps -o ${outdir}svnbranch.ps ${outdir}svnbranch.dot
	if [ "$mode" = "show" ]; then
		( kghostview ${outdir}svnbranch.ps; rm -rf "$outdir"; ) &
	fi
	exit 0
fi

if [ "$1" = "propagate" ]; then
	svncmd="svn" url_to_parent "."
	start_url="${url_to_parent_url#$url_to_parent_root}"
	cat > propagate.sh << EOT
#!/bin/bash
#
# Auto-generated by svnbranch - do not change!

url_root="$url_to_parent_root"
last_ok=1000
cmd="x"

EOT
	cat >> propagate.sh << 'EOT'

cleancheck() {
	local ret=0
	while read line; do
		ret=1
		echo "$line"
	done < <( svn st --no-ignore | grep -v '^\(\?      propagate\.sh\| [CM]   \.\)$'; )
	return $ret
}

V() {
	echo "> $*"
	"$@"
}

X() {
	if [ $1 -gt $last_ok ]; then
		echo
		echo "***"
		echo "*** $2"
		echo "***"
		if ! cleancheck; then
			echo "Cleancheck failed!"
			exit 1
		fi
		V svn switch "${url_root}$2" || exit 1
		V svn up || exit 1
		V svnbranch sync || exit 1
		if cleancheck; then
			V svn revert . || exit 1
		else
			while [ "$cmd" != "y" -a "$cmd" != "a" ]; do
				echo "*** Changes synced to: $2 ***"
				read -p "Commit this to the Repository? ([Y]es, [A]ll, [Q]uit) " cmd
				[ "$cmd" == "Y" ] && cmd="y"
				[ "$cmd" == "A" ] && cmd="a"
				[ "$cmd" == "Q" ] && exit 1
				[ "$cmd" == "q" ] && exit 1
			done
			V svn commit -m 'svnbranch sync (via svnbranch propagate)' || exit 1
			[ "$cmd" == "y" ] && cmd="x"
		fi
		sed -i "s,^last_ok=.*,last_ok=$1," $0 || exit 1
	fi
}

svn up || exit 1
if ! cleancheck; then
	echo "Cleancheck failed!"
	exit 1
fi

EOT
	if [ -n "$2" ]; then
		cat "$2"
	else
		show_list "$url_to_parent_root"
	fi | perl -e '

		my %path;
		my $nr = 1000;

		while (<>) {
			if (/^BRANCH (\S+) (\S+)/) {
				my ($parent, $child) = ($1, $2);
				$parent =~ s/@.*//;
				$child =~ s/@.*//;
				push @{$path{$parent}}, $child;
			}
		}

		sub rec($) {
			my $parent = $_[0];
			foreach my $child (@{$path{$parent}}) {
				printf "X %d \"%s\"\n", ++$nr, $child;
				rec($child);
			}
		}

		rec("'"$start_url"'");

		print "\necho\n";
		print "echo \"***\"\n";
		print "echo \"*** FINISH\"\n";
		print "echo \"***\"\n";
		print "V svn switch \"\${url_root}'"$start_url"'\"\n\n";

	' >> propagate.sh
	chmod +x propagate.sh
	exit 0
fi


cat << 'EOT'

                                SVNBRANCH HELP
                                ==============

Svnbranch is a small shellscript for managing complex subversion branch
and merge szenarios.

It is using two directory properties to hold its metadata:


  svnbranch:parent

	The absolute (i.e. relative to the repository root) path to the 
	directory from which this directory has been branched off. This
	path always contains a peg revision ("@RevNum" suffix).


  svnbranch:tag

	Set to '1' on tags (and does not exist on branches). A tag is
	technically the same as a branch but does not follow its parent
	(i.e. 'sync' is an invalid operation on a tag).


  svnbranch:index

	A list of relative pathnames to subdirectories which do have
	svnbranch:index or svnbranch:parent properties. They must be
	set explicitely by the administrator and are used for gathering
	a list of all branches and parents in the 'list', 'show' and
	'graph' modes. Svnbranch evaluates only '*' wildcards which
	match an entire directory in svnbranch:index.


The svnbranch call semantic is pretty simmilar to the one of 'svn', the
first argument beeing a mode of operation followed by arguments:


  svnbranch branch URL

	Creates a branch of the current working directory with the
	specified URL in the repository.

	This basically is an 'svn cp . URL' with the svnbranch:parent
	property set to the working copy URL and revision.


  svnbranch tag URL

	Creates a tag of the current working directory with the
        specified URL in the repository.

	It does the same thing as 'svnbranch branch' but also sets
	the svnbranch:tag property.


  svnbranch init URL

	Create a svnbranch:parent property in the current working copy
	and use the specified URL as parent.


  svnbranch sync [URL]

	Only valid in a working copy of a branch. Syncs changes made
	in the parent into the branch and updates the svnbranch:parent
	property. When a URL is given the parent is changed to the
	specified parent.

	This is basically an 'svn merge OLD-PARENT NEW-PARENT' combined
	with an updated of the svnbranch:parent property.


  svnbranch [-cache] diff [FILE..]

	Only valid in a working copy of a branch. Shows the difference
	between the branch and its parent.


  svnbranch merge URL

	Merge the changes from the branches parent to the branch into
	the current working directory.


  svnbranch [-cache] list [URL..]

	Use the svnbranch:index properties to create a list of all branches
	below the current working directory (or the given URL) and show
	their relations.

	This is issueing a lot of calls to 'svn'. So do not wonder when this
	commands (and its variations below) take a while to complete.

	Use '/' as URL to create the list for the entire repository.


  svnbranch [-cache] [-r] graph [URL..]

	Like 'svnbranch list' but using graphviz to graph the data.

	With '-' as argument this reads a prior generated 'svnbranch list'
	output as input and graph it.


  svnbranch [-cache] [-r] show [URL..]

	Like 'svnbranch graph' but also open the graph in kghostview.


  svnbranch [-cache] propagate [filename]

	Generates a propagate.sh script for propagating all changes comitted to
	the local directory to non-tag branches and stop at the first conflict.
	The conflicts can be resolved and the respective changes commited manually.
	After that propagate.sh can be restarted. It will simply continue where
	it has stopped.

	The output of an 'svnbranch list' with all relevant information can
	be passed as command line argument. If it is missing, 'svnbranch propagate'
	will do a repository-wide 'svnbranch list' (which may take a while).


Calling svnbranch with the option -v (before the mode) makes svnbranch write
out a message for every 'svn' command it invokes.

Calling svnbranch with the option -cache (for the modes which support it)
makes svnbranch use 'svncache' instead of 'svn'.

Calling svnbranch with the option -r (for the graph modes) rotates the graph so
that tags are plotted vertically and branches are plotted vertically.

EOT

exit 1