#!/bin/bash

LOG_FILE="../merge.log"
build_host="ka2"
build_dir="/scratch/sfr/next"
build_cmd="bin/build_next"

no_build=false
start_from=""
[ "$NEXT_BUILD_HOST" ] && build_host="$NEXT_BUILD_HOST"
[ "$NEXT_BUILD_DIR" ] && build_host="$NEXT_BUILD_DIR"

[ "$1" = "-n" ] && {
	shift
	no_build=true
}
[ "$1" = "-s" ] && {
	shift
	start_from="$1"
	[ -z "$start_from" ] && {
		echo "-s requires a start tree" 1>&2
		exit 1
	}
	shift
}
[ -n "$1" ] && {
	build_host="$1"
	shift
}
[ -n "$1" ] && {
	build_dir="$1"
	shift
}

log()
{
	echo "$@" | tee -a $LOG_FILE
}

execute()
{
	log "$" $@
	$@ 2>&1 | tee -a $LOG_FILE
	return ${PIPESTATUS[0]}
}

do_rebase()
{
	rbase=${1#*/}
	rbase=${rbase%%:*}
	rtop=${1#*:}
	rbid=$(git rev-parse $2/$rbase)
	rtid=$(git rev-parse $2/$rtop)
	[ "$rbid" = "$rtid" ] && {
		echo Empty tree
		return
	}
	[ "$(git rev-list HEAD..$2/$rtop)" ] || {
		echo Already merged
		return
	}
	execute git clone -s -l -n -q . ../rebase-tmp || {
		echo Clone failed 1>&2
		bash -i || exit
	}
	log '$' cd ../rebase-tmp
	cd ../rebase-tmp
	execute git fetch --no-tags ../next refs/remotes/$2/$rtop:$2/$rtop || {
		echo Fetch of top failed 1>&2
		bash -i || exit
	}
	execute git fetch --no-tags ../next refs/remotes/$2/$rbase:$2/$rbase || {
		echo Fetch of base failed 1>&2
		bash -i || exit
	}
	execute git checkout $2/$rtop || {
		echo Checkout of top failed 1>&2
		bash -i || exit
	}
	execute git rebase --onto master $2/$rbase || {
		echo Rebase failed 1>&2
		bash -i || exit
	}
	log '$' cd ../next
	cd ../next
	execute git pull -f ../rebase-tmp $2/$rtop || {
		echo Pull failed 1>&2
		echo $h >>../merge.debug
		git diff >>../merge.debug 2>&1
		git diff 2>&1 | egrep -q '<<<<<|^\*' && {
			bash -i || exit
		}
	}
	execute rm -rf ../rebase-tmp
}

[ -n "$start_from" ] || {
	cp /dev/null $LOG_FILE
	execute date
	execute git checkout master
	execute git reset --hard stable
}

heads=$(grep -v '^#' ../real_control | awk -F '\t' '$2=="quilt" || $2=="git" { printf("%s/%s ", $3, $5); }')

need_build=false

for h in $heads; do
	tree=${h%%/*}

	[ -n "$start_from" ] && {
		if [ "$tree" = "$start_from" ]; then
			start_from=""
		else
			continue
		fi
	}

	hlog=$(git log -1 --oneline $h) 2>/dev/null
	log Merging $h "($hlog)"
	old_head=$(git rev-parse HEAD)
	[ -x "../pre-merge/$tree" ] && {
		"../pre-merge/$tree" || bash -i || exit
	}
	case "$h" in
	*:*)
		do_rebase $h $tree
		;;
	*)
		execute git merge $h || {
			echo Merge failed 1>&2
			echo $h >>../merge.debug
			git diff >>../merge.debug 2>&1
			git diff 2>&1 | egrep -q '<<<<<|^\*' && {
				bash -i || exit
			}
			GIT_EDITOR=: execute git commit -v -a
			execute git diff -M --stat --summary 'HEAD^..'
		}
		;;
	esac
	[ -f "../merge-fixes/$tree" ] && {
		for p in $(cat "../merge-fixes/$tree"); do
			$(dirname $0)/merge_fix -n "$p" || {
				bash -i || exit
			}
		done
	}
	[ -x "../pre-build/$tree" ] && {
		"../pre-build/$tree" || bash -i || exit
	}
	$no_build && continue
	$need_build || {
		# See if we need to build after merging this tree
		new_head=$(git rev-parse HEAD)
		[ "$old_head" = "$new_head" ] ||
			[ "$(git diff ${old_head}.. | wc -c)" -eq 0 ] ||
				need_build=true
	}
	$need_build ||
		continue
	do_build=$(grep -v '^#' ../real_control | awk -F '	' '$3=="'$tree'" { print $6; }')
	[ "$do_build" = "yes" ] ||
		continue
	git push -f "$build_host":"$build_dir" master:refs/heads/next || {
		echo git push failed 1>&2
		bash -i || exit
	}
	ssh "$build_host" "$build_cmd" || {
		echo Build failed 1>&2
		bash -i || exit
	}
	need_build=false
done

exit 0