#!/bin/bash

export SCRIPT=$(basename $0)
usage()
{
	cat <<EOF
Usage:
  $SCRIPT create <ticket>
	This creates a new feature branch for <ticket>.

  $SCRIPT [--full] checkout <ticket>
	This checks out a feature branch for <ticket>.
	The option --full also checks out the binaries. Without that option,
	the "bin" directory is linked to that one of the original branch.

  $SCRIPT sync
	This performs a original-->clone merge.

  $SCRIPT [--close] merge
	This performs a clone-->original merge. If --close is passed, the
	clone branch is deleted after a successful merge.

Example:
	# create a feature branch for FFL-2345
	src/_TOOLS/merge/feature create FFL-2345
	# check it out
	src/_TOOLS/merge/feature checkout FFL-2345
	# go ahead and make some changes
	cd ../feature/FFL-2345; ...; svn ci -m "..." ...; ...
	# synchronize with trunk (i.e. original-->clone merge)
	src/_TOOLS/merge/feature sync
	# make more changes
	...; svn ci -m "..." ...; ...
	# merge current state of feature to trunk (i.e. clone-->original merge)
	src/_TOOLS/merge/feature merge
	# make even more changes
	...; svn ci -m "..." ...; ...
	# synchronize with trunk, merge current state of feature to trunk and
	# close feature
	src/_TOOLS/merge/feature sync
	src/_TOOLS/merge/feature --close merge
	# afterwards, remove checkout
	cd ..; rm -rf FFL-2345
EOF
	exit 1
}
export -f usage

allowed_options="--review-merge --full --close"

rootdir=${0%/*}
. "$rootdir/include/config.inc"
. "$rootdir/include/options.inc"
. "$rootdir/include/display.inc"
. "$rootdir/include/utility.inc"
. "$rootdir/include/cleanup.inc"
. "$rootdir/include/svn.inc"
. "$rootdir/include/repo-info.inc"
. "$rootdir/include/branching.inc"
. "$rootdir/include/ticket.inc"

case $1 in
-*)
	error "Unknown option: $1"
	usage
	;;
esac

#
# determine readlink and sed
#
type -p gsed >/dev/null && SED=gsed || SED=sed
type -p greadlink > /dev/null && READLINK=greadlink || READLINK=readlink

# full checkout including bin/
has_option "--full" && full_checkout=1 || full_checkout=
# close branch after merge
has_option "--close" && close_after_merge=1 || close_after_merge=

do_create()
{
	local ticket=$1
	[ -n "$ticket" ] || usage

	local_this=$local_root$rel_path
	remote_this=$remote_root$rel_path
	remote_feature=$remote_root$rel_path_base/feature/$ticket

	do_svn_quiet copy -m "$ticket: feature branch opened" "$local_this" "$remote_feature" ||
		error "Branch creation failed: $(tail -n 1 "$SVN_LOG")"
}

do_checkout()
{
	local ticket=$1
	[ -n "$ticket" ] || usage

	local_this=$local_root$rel_path
	local_feature=$local_root$rel_path_base/feature/$ticket
	remote_feature=$remote_root$rel_path_base/feature/$ticket

	do_svn_quiet checkout --depth=immediates "$remote_feature" "$local_feature" ||
		error "Checkout failed: $(tail -n 1 "$SVN_LOG")"
	do_svn_quiet update --set-depth infinity "$local_feature/src" ||
		error "Checkout failed: $(tail -n 1 "$SVN_LOG")"

	if [ -n "$full_checkout" ]
	then
		do_svn_quiet update --set-depth infinity "$local_feature/bin" ||
			error "Checkout failed: $(tail -n 1 "$SVN_LOG")"
	else
		for arch in "$local_this/bin"/*
		do
			ln -s "$arch" "$local_feature/bin"
		done
	fi
}

do_sync()
{
	local ticket=${rel_path##*/}
	local_feature=$local_root$rel_path_base/feature/$ticket

	# find original branch this one has been cloned from
	local copy_from=$(svn log --stop-on-copy -v --xml "$local_feature" |
		xmllint --xpath 'string(/log/logentry[last()]/paths/path/@copyfrom-path)' - 2>/dev/null)
	if [ -z "$copy_from" ]
	then
		error "Cannot determine the branch the feature branch has been cloned from"
	fi

	$rootdir/merge-changesets --review-merge ${copy_from#/}/src ${rel_path#/}/src FFL "" "$@" || return $?
}

do_merge()
{
	local ticket=${rel_path##*/}
	local_feature=$local_root$rel_path_base/feature/$ticket
	remote_feature=$remote_root$rel_path_base/feature/$ticket

	# find original branch this one has been cloned from
	local copy_from=$(svn log --stop-on-copy -v --xml "$local_feature" |
		xmllint --xpath 'string(/log/logentry[last()]/paths/path/@copyfrom-path)' - 2>/dev/null)
	if [ -z "$copy_from" ]
	then
		error "Cannot determine the branch the feature branch has been cloned from"
	fi

	$rootdir/merge-changesets --all-commits --review-merge ${rel_path#/}/src ${copy_from#/}/src FFL || return $?
	if [ -n "$close_after_merge" ]
	then
		do_svn_quiet delete -m "$ticket: feature branch closed" "$remote_feature" ||
			error "Branch deletion failed: $(tail -n 1 "$SVN_LOG")"
	fi
}

load_repo_info

repo_uri=$(LC_ALL=C svn info $(dirname $($READLINK -f $0))/../.. |
	$SED -n 's/^URL: \(.*\)\/src$/\1/p' 2>/dev/null)
if [ -z "$repo_uri" ]
then
	error "Could not determine source branch -- do you call this script from a SVN repository checkout?"
	exit 2
fi

case $repo_uri in
$remote_root/*)
	rel_path=${repo_uri#$remote_root}
	;;
*)
	error "Incompatible branch URI \"$repo_uri\", it does not start with \"$remote_root\""
	;;
esac

rel_path_base=$(echo "$rel_path" | $SED -n 's,^\(/branches/[^/]\+\).*,\1,p')
if [ -z "$rel_path_base" ]
then
	error "Cannot determine relative path base for \"$rel_path\""
fi

cmd=$1
shift

[ -n "$cmd" ] || usage

case $cmd in
create|checkout|sync|merge)
	do_$cmd "$@"
	;;
*)
	error "Unknown command $cmd"
	;;
esac