##
## Load with `autoload -U zgitinit; zgitinit'
##

typeset -gA zgit_info
zgit_info=()

zgit_chpwd_hook() {
	zgit_info_update
}

zgit_preexec_hook() {
	if [[ $2 == git\ * ]] || [[ $2 == *\ git\ * ]]; then
		zgit_precmd_do_update=1
	fi
}

zgit_precmd_hook() {
	if [ $zgit_precmd_do_update ]; then
		unset zgit_precmd_do_update
		zgit_info_update
	fi
}

zgit_info_update() {
	zgit_info=()

	local gitdir=$(git rev-parse --git-dir 2>/dev/null)
	if [ $? -ne 0 ] || [ -z "$gitdir" ]; then
		return
	fi

	zgit_info[dir]=$gitdir
	zgit_info[bare]=$(git rev-parse --is-bare-repository)
	zgit_info[inwork]=$(git rev-parse --is-inside-work-tree)
}

zgit_isgit() {
	if [ -z "$zgit_info[dir]" ]; then
		return 1
	else
		return 0
	fi
}

zgit_inworktree() {
	zgit_isgit || return
	if [ "$zgit_info[inwork]" = "true" ]; then
		return 0
	else
		return 1
	fi
}

zgit_isbare() {
	zgit_isgit || return
	if [ "$zgit_info[bare]" = "true" ]; then
		return 0
	else
		return 1
	fi
}

zgit_head() {
	zgit_isgit || return 1

	if [ -z "$zgit_info[head]" ]; then
		local name=''
		name=$(git symbolic-ref -q HEAD)
		if [ $? -eq 0 ]; then
			if [[ $name == refs/(heads|tags)/* ]]; then
				name=${name#refs/(heads|tags)/}
			fi
		else
			name=$(git name-rev --name-only --no-undefined --always HEAD)
			if [ $? -ne 0 ]; then
				return 1
			elif [[ $name == remotes/* ]]; then
				name=${name#remotes/}
			fi
		fi
		zgit_info[head]=$name
	fi

	echo $zgit_info[head]
}

zgit_branch() {
	zgit_isgit || return 1
	zgit_isbare && return 1

	if [ -z "$zgit_info[branch]" ]; then
		local branch=$(git symbolic-ref HEAD 2>/dev/null)
		if [ $? -eq 0 ]; then
			branch=${branch##*/}
		else
			branch=$(git name-rev --name-only --always HEAD)
		fi
		zgit_info[branch]=$branch
	fi

	echo $zgit_info[branch]
	return 0
}

zgit_tracking_remote() {
	zgit_isgit || return 1
	zgit_isbare && return 1

	local branch
	if [ -n "$1" ]; then
		branch=$1
	elif [ -z "$zgit_info[branch]" ]; then
		branch=$(zgit_branch)
		[ $? -ne 0 ] && return 1
	else
		branch=$zgit_info[branch]
	fi

	local k="tracking_$branch"
	local remote
	if [ -z "$zgit_info[$k]" ]; then
		remote=$(git config branch.$branch.remote)
		zgit_info[$k]=$remote
	fi

	echo $zgit_info[$k]
	return 0
}

zgit_tracking_merge() {
	zgit_isgit || return 1
	zgit_isbare && return 1

	local branch
	if [ -z "$zgit_info[branch]" ]; then
		branch=$(zgit_branch)
		[ $? -ne 0 ] && return 1
	else
		branch=$zgit_info[branch]
	fi

	local remote=$(zgit_tracking_remote $branch)
	[ $? -ne 0 ] && return 1
	if [ -n "$remote" ]; then # tracking branch
		local merge=$(git config branch.$branch.merge)
		if [ $remote != "." ]; then
			merge=$remote/$(basename $merge)
		fi
		echo $merge
		return 0
	else
		return 1
	fi
}

zgit_isindexclean() {
	zgit_isgit || return 1
	if git diff --quiet --cached 2>/dev/null; then
		return 0
	else
		return 1
	fi
}

zgit_isworktreeclean() {
	zgit_isgit || return 1
	if git diff --quiet 2>/dev/null; then
		return 0
	else
		return 1
	fi
}

zgit_hasuntracked() {
	zgit_isgit || return 1
	local -a flist
	flist=($(git ls-files --others --exclude-standard))
	if [ $#flist -gt 0 ]; then
		return 0
	else
		return 1
	fi
}

zgit_hasunmerged() {
	zgit_isgit || return 1
	local -a flist
	flist=($(git ls-files -u))
	if [ $#flist -gt 0 ]; then
		return 0
	else
		return 1
	fi
}

zgit_svnhead() {
	zgit_isgit || return 1

	local commit=$1
	if [ -z "$commit" ]; then
		commit='HEAD'
	fi

	git show --raw $commit | \
		grep git-svn-id | \
			sed -re 's/^\s*git-svn-id: .*@([0-9]+).*$/\1/'
}

zgit_rebaseinfo() {
	zgit_isgit || return 1
	if [ -d $zgit_info[dir]/rebase-merge ]; then
		dotest=$zgit_info[dir]/rebase-merge
	elif [ -d $zgit_info[dir]/.dotest-merge ]; then
		dotest=$zgit_info[dir]/.dotest-merge
	elif [ -d .dotest ]; then
		dotest=.dotest
	else
		return 1
	fi

	zgit_info[dotest]=$dotest

	zgit_info[rb_onto]=$(cat "$dotest/onto")
	zgit_info[rb_upstream]=$(cat "$dotest/upstream")
	if [ -f "$dotest/orig-head" ]; then
		zgit_info[rb_head]=$(cat "$dotest/orig-head")
	elif [ -f "$dotest/head" ]; then
		zgit_info[rb_head]=$(cat "$dotest/head")
	fi
	zgit_info[rb_head_name]=$(cat "$dotest/head-name")

	return 0
}

zgitinit() {
	typeset -ga chpwd_functions
	typeset -ga preexec_functions
	typeset -ga precmd_functions
	chpwd_functions+='zgit_chpwd_hook'
	preexec_functions+='zgit_preexec_hook'
	precmd_functions+='zgit_precmd_hook'
}

zgitinit
zgit_info_update

# vim:set ft=zsh: