#!/bin/rc -e
rfork en
. /sys/lib/git/common.rc

fn update{
	upstream=$1
	url=$2
	dir=$3
	dflag=()
	if(! ~ $#debug 0)
		dflag='-d'
	{git/get $dflag -u $upstream $url >[2=3] || die $status} | awk '
	/^remote/{
		if($2=="HEAD")
			next
		ref=$2
		hash=$3
		gsub("^refs/heads", "refs/remotes/'$upstream'", ref)
		outfile = ".git/"ref
		system("mkdir -p `{basename -d "outfile"}");
		print hash > outfile;
		close(outfile);
	}
	' |[3] tr '\x0d' '\x0a'
}

gitup

flagfmt='d:debug, q:quiet, f:fetchonly,
	u:upstream upstream'
args=''
eval `''{aux/getflags $*} || exec aux/usage

if(~ $#upstream 0)
	upstream=origin
remote=`$nl{git/conf 'remote "'$upstream'".url'}
if(~ $#remote 0){
	remote=$upstream
	upstream=THEM
}

update $upstream $remote
if (~ $fetchonly 1)
	exit

local=`{git/branch}
remote=`{git/branch | subst '^(refs/)?heads' 'remotes/'$upstream}

# we have local commits, but the remote hasn't changed.
# in this case, we want to keep the local commits untouched.
if(~ `{git/query HEAD $remote @} `{git/query $remote}){
	echo 'up to date' >[1=2]
	exit
}
# The remote repository and our HEAD have diverged: we
# need to merge.
if(! ~ `{git/query HEAD $remote @} `{git/query HEAD}){
	>[1=2]{
		echo ours:	`{git/query HEAD}
		echo theirs:	`{git/query $remote}
		echo common:	`{git/query HEAD $remote @}
		echo git/merge $remote
	}
	exit diverged
}
# The remote is directly ahead of the local, and we have
# no local commits that need merging.
if(~ $#quiet 0)
	git/log -s -e $local'..'$remote
echo $remote':' `{git/query $local} '=>' `{git/query $remote}
git/branch -mnb $remote $local
exit ''