#!/usr/bin/env bash

# Copyright 2016 The Fuchsia Authors
# Copyright (c) 2015 Travis Geiselbrecht
#
# Use of this source code is governed by a MIT-style
# license that can be found in the LICENSE file or at
# https://opensource.org/licenses/MIT

readonly OUTFILE="$1"
readonly DEPFILE="$2"
readonly GIT_DIR="$3"

set -e

GIT_REV="git-$(git --git-dir="$GIT_DIR" rev-parse HEAD 2>/dev/null)"
if [ -n "$(git  --git-dir="$GIT_DIR" status --porcelain --untracked-files=no 2>/dev/null)" ]; then
  GIT_REV+="-dirty"
fi

CONTENTS="// This file is generated by $0.  DO NOT EDIT!
constexpr char kVersionString[] = \"${GIT_REV}\";"

# Update the existing file only if it's changed.
if [ ! -r "$OUTFILE" ] || [ "$(<"$OUTFILE")" != "$CONTENTS" ]; then
  echo "$CONTENTS" > "$OUTFILE"
fi

echo "$OUTFILE: $GIT_DIR/HEAD $GIT_DIR/index" > "$DEPFILE"