#!/bin/sh
# git-publish-branch [-d] [branch] [repository]

unset delete
unset force
if [ "$1" = "-d" ]; then
    delete=1
    shift
elif [ "$1" = "-f" ]; then
    force=1
    shift
fi

unset branch
unset remote

if [ $# -eq 1 ]; then
    branch=$1
elif [ $# -eq 2 ]; then
    branch=$1
    remote=$2
elif [ $# -gt 2 ]; then
    echo "Usage: $0 [branch] [repository]" >&2
    exit 1
fi

if [ -z "$branch" ]; then
    branch=$(git symbolic-ref HEAD)
    branch=${branch//refs\/heads\//}
fi

if [ -z "$remote" ]; then
    remote=origin
fi

local_ref=$(git show-ref "heads/$branch")
remote_ref=$(git show-ref "remotes/$remote/$branch")
remote_config=$(git config "branch.$branch.merge")

if [ $delete ]; then
    # Delete the remote branch
    if [ -n "$remote_ref" ]; then
	git push "$remote" ":refs/heads/$branch"
    else
	echo "$remote has to remote branch $branch" >&2
    fi

    # Remove local configs for remote branch
    if [ -n "$local_ref" ]; then
	git config --unset "branch.$branch.remote"
	git config --unset "branch.$branch.merge"
	git config --unset "branch.$branch"
    fi
elif [ $force ]; then
    if [ -z "$local_ref" ]; then
	echo "no local branch $branch" >&2
	exit 1
    elif [ -z "$remote_ref" ]; then
	echo "$remote has no branch $branch" >&2
	exit 1
    elif [ -z "$remote_config" ]; then
	echo "local branch $branch is not a tracking branch" >&2
	exit 1
    fi

    # Delete the remote branch
    if [ -n "$remote_ref" ]; then
	git push "$remote" ":refs/heads/$branch"
    else
	echo "$remote has to remote branch $branch" >&2
    fi

    # Push the new branch
    git push "$remote" "+$branch:refs/heads/$branch"
else
    if [ -z "$local_ref" ]; then
	echo "no local branch $branch" >&2
	exit 1
    elif [ -n "$remote_ref" ]; then
	echo "$remote already has branch $branch" >&2
	exit 1
    elif [ -n "$remote_config" ]; then
	echo "local branch $branch is already a tracking branch" >&2
	exit 1
    fi

    git push "$remote" "$branch:refs/heads/$branch"
    git config "branch.$branch.remote" "$remote"
    git config "branch.$branch.merge" "refs/heads/$branch"
fi