#!/bin/bash

# Copyright (c) 2010 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.

# Load common constants.  This should be the first executable line.
# The path to common.sh should be relative to your script's location.
. "$(dirname $0)/common.sh"

# Script must be run inside the chroot
restart_in_chroot_if_needed $*

DEFINE_string version "" \
  "Assume current chroot version is this."
DEFINE_boolean force_latest "${FLAGS_false}" \
  "Assume latest version and recreate the version file"
DEFINE_boolean skipfirst "${FLAGS_false}" \
  "Skip the first upgrade. This may be dangerous."

FLAGS "$@" || exit 1

VERSION_FILE=~/.version

######################################################################

# Latest version is the version of last upgrade.d file.
# Name format is ${number}_${short_description}
# Versions must be -n sorted, that is, the first continuous sequence
# of numbers is what counts. 12_ is before 111_, etc.
LATEST_VERSION=$(
  ls "$(dirname $0)/upgrade.d" | grep "^[0-9]*_" | \
  sort -n | tail -n 1 | cut -f1 -d'_'
)
CHROOT_VERSION=$(cat ${VERSION_FILE})
# Check if it's a number.
if ! [ "${CHROOT_VERSION}" -ge "0" ] &> /dev/null; then
  error "Your chroot version file ${VERSION_FILE} is bogus: ${CHROOT_VERSION}"
  exit 1
fi

if [ -n "${FLAGS_force_latest}" ]; then
  echo "${LATEST_VERSION}" > "${VERSION_FILE}"
  exit 0
fi

if [ -n "${FLAGS_skipfirst}" ]; then
  if [ "${CHROOT_VERSION}" -lt "${LATEST_VERSION}" ]; then
    CHROOT_VERSION=$(expr ${CHROOT_VERSION} + 1)
  fi
fi

if [ -n "${FLAGS_version}" ]; then
  # Check if it's a number.
  if [ "${FLAGS_version}" -ge "0" ] &> /dev/null; then
    CHROOT_VERSION="${FLAGS_version}"
  else
    error "Trying to force invalid version: ${FLAGS_version}"
    exit 1
  fi
fi

# default goes here
if ! [ -f "${VERSION_FILE}" ]; then
  warn "Warning: chroot of unknown version, assuming 0"
  echo "0" > "${VERSION_FILE}"
fi

if [ "${LATEST_VERSION}" -gt "${CHROOT_VERSION}" ]; then
  echo "Outdated chroot found"

  pushd "$(dirname $0)/upgrade.d/" 1> /dev/null
  for n in $(seq "$(expr ${CHROOT_VERSION} + 1)" "${LATEST_VERSION}"); do
    # Deprecation check; Deprecation can be done by removing old upgrade
    # scripts and causing too old chroots to have to start over.
    # This also means that the scripts have to form a continuous sequence.
    if ! [ -f ${n}_* ]; then
      error "Fatal: Upgrade ${n} doesn't exist."
      error "Your chroot is too old, you need to re-create it!"
      exit 1
    fi

    info "Rollup $(echo ${n}_*)"

    # Attempt the upgrade.
    # NOTE: We source the upgrade scripts because:
    # 1) We can impose set -something on them.
    # 2) They can reuse local variables and functions (fe. from common.sh)
    # A side effect is that the scripts have to be internally enclosed in
    # a code block, otherwise simply running "exit" in any of them would
    # terminate the master script, and there would be no way to pass the
    # return value from them.
    if ! source ${n}_*; then
      error "Fatal: failed to upgrade ${n}!"
      exit 1
    fi
    echo "${n}" > "${VERSION_FILE}"
  done
  popd 1> /dev/null
fi