#!/bin/bash

# Copyright (c) 2011 The Chromium OS Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

SCRIPT_ROOT=$(readlink -f $(dirname "$0")/..)
. "${SCRIPT_ROOT}/common.sh" || exit 1

# We're invoked only by build_image, which runs in the chroot
assert_inside_chroot

# Flags
DEFINE_string root ""      \
  "The root file system to check."

# Parse command line
FLAGS "$@" || exit 1
eval set -- "${FLAGS_ARGV}"

# Die on any errors
set -e

# Check all parts of a pipe
set -o pipefail

ROOT="$FLAGS_root"
if [[ ! -d "$ROOT" ]]; then
  die "Root FS does not exist ($ROOT)"
fi

BINARIES="$ROOT/usr/bin/Xorg
          $ROOT/boot/vmlinuz
          $ROOT/sbin/session_manager
          $ROOT/bin/sed
          $ROOT/opt/google/chrome/chrome"

EXITCODE=0
for i in $BINARIES; do
  if ! [[ -f $i ]]; then
    error "cannot find $i"
    EXITCODE=1
  fi
done

# Extract the version number from lines like:
# kCrosAPIMinVersion = 29,
# kCrosAPIVersion = 30
extract_cros_version() {
  NAME="$1"
  FILE="$2"
  VERSION=$(perl -ne "print \$1 if /^\\s*${NAME}\\s*=\\s*(\\d+)/" "$FILE")
  test -z "$VERSION" && die "Failed to get $NAME from $FILE"
  echo $VERSION
}

# Check the libcros version compatibility, like we do in libcros at run time.
# See also platform/cros/version_check.cc and load.cc.
check_cros_version() {
  CHROME_CROS="${ROOT}/opt/google/chrome/include/chromeos_cros_api.h"
  SYSTEM_CROS="${ROOT}/usr/include/cros/chromeos_cros_api.h"

  if [ ! -f "$SYSTEM_CROS" ]; then
    echo "test_build_root: Missing libcros headers."
    return 1
  fi


  if [ ! -f "$CHROME_CROS" ]; then
    # For compatiblity with old versions of Chrome which don't install headers
    # and already check the libcros version, skip the check here.
    return 0
  fi

  # Get the version of libcros in the chromium tree.
  VERSION=$(extract_cros_version kCrosAPIVersion "${CHROME_CROS}")

  # Get the min version of libcros in the chromium os tree.
  MIN_VERSION=$(extract_cros_version kCrosAPIMinVersion "${SYSTEM_CROS}")

  # Get the max version of libcros in the chromium os tree.
  MAX_VERSION=$(extract_cros_version kCrosAPIVersion "${SYSTEM_CROS}")

  if [ "$MIN_VERSION" -gt "$VERSION" ]; then
    echo "test_build_root: System libcros not compatible with Chromium."
    echo "Chromium requires version $VERSION, but system provides $MIN_VERSION"
    echo "or later."
    return 1
  fi
  if [ "$VERSION" -gt "$MAX_VERSION" ]; then
    echo "test_build_root: System libcros not compatible with Chromium headers."
    echo "Chromium requires version $VERSION, but system provides $MAX_VERSION"
    echo "or earlier."
    return 1
  fi
  return 0
}

check_cros_version || EXITCODE=1

exit $EXITCODE