#!/bin/bash

#
# This script is intended to help with sharing a recorded resolution cache for
# use with git's rerere. It assumes that the cache is available in an orphaned
# branch of a remote repository.
#
# Run the following command to initialize the repository with a cache:
#
#   $ rr-cache init [branch]
#
# Where branch is the name of the (remote) branch that contains the cache. If
# omitted, origin/rr-cache will be used by default. The init command creates a
# local branch named rr-cache and clones it into the .git/rr-cache directory.
#
# Commands other than init are passed unmodified to git and are run on the new
# repository created in the .git/rr-cache subdirectory.
#

case $1 in
	init)
		if test -d .git/rr-cache; then
			echo "error: directory .git/rr-cache already exists"
			exit 1
		fi

		if test -z "$2"; then
			ref=origin/rr-cache
		else
			ref="$2"
		fi

		remote=${ref%/*}
		branch=${ref#*/}

		if test "$remote" != "$ref" -o "$branch" != "$ref"; then
			echo "initializing rr-cache using remote branch $remote/$branch"
			git branch rr-cache "$remote/$branch"
			branch=rr-cache
		else
			echo "initializing rr-cache using local branch $branch"
		fi

		git clone -b $branch . .git/rr-cache
		;;

	*)
		git --git-dir=.git/rr-cache/.git --work-tree=.git/rr-cache "$@"
		;;
esac