# Copyright 2012 Hewlett-Packard Development Company, L.P.
# All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.

function unmount_image () {
    # unmount from the chroot
    # Don't use TMP_MOUNT_PATH here, it might not have been set.
    sudo umount -f $TMP_BUILD_DIR/mnt/sys || true
    sudo umount -f $TMP_BUILD_DIR/mnt/proc || true
    sudo umount -f $TMP_BUILD_DIR/mnt/dev || true
    sudo umount -f $TMP_BUILD_DIR/mnt/tmp/in_target.d || true
    # give it a second (ok really 5) to umount XXX - why? should instead track
    # the mount data / lsof etc.
    sleep 5
    # oh ya don't want to forget to unmount the image
    sudo umount -f $TMP_BUILD_DIR/mnt || true
    # having disk corruption issues; one possibility is qemu-nbd not flushing
    # dirty pages on disconnect?
    sync
    if [ -n "$EXTRA_UNMOUNT" ]; then
        $EXTRA_UNMOUNT
    fi
}

function cleanup () {
    unmount_image
    cleanup_dirs
}

function cleanup_dirs () {
    sudo rm -rf $TMP_BUILD_DIR/built
    sudo rm -rf $TMP_BUILD_DIR/mnt
    sudo umount $TMP_BUILD_DIR
    rm -rf $TMP_BUILD_DIR
}

function ensure_nbd () {
    NBD=`which qemu-nbd` || true
    if [ -z "$NBD" ];  then
        echo "Need qemu-nbd to build qcow2 files."
	sudo apt-get install qemu-utils
    fi
    # prep nbd for mounting
    (lsmod | grep '^nbd ') || sudo modprobe nbd max_part=16
}

function ensure_sudo () {
    sudo echo "Ensuring sudo is available"
}

function create_base () {
    mkdir $TMP_BUILD_DIR/mnt
    export TMP_MOUNT_PATH=$TMP_BUILD_DIR/mnt
    # Copy data in to the root.
    TARGET_ROOT=$TMP_MOUNT_PATH run_d root
    if [ -z "$(ls $TMP_MOUNT_PATH | grep -v lost+found)" ] ; then
        # Nothing copied in, use Ubuntu.
	echo "Adding ubuntu element as / had no contents"
        IMAGE_ELEMENT=$($SCRIPT_HOME/element-info --expand-dependencies $IMAGE_ELEMENT ubuntu)
	generate_hooks
	echo "Now building: $IMAGE_ELEMENT"
	TARGET_ROOT=$TMP_MOUNT_PATH run_d root
    fi

    # Configure Image
    # Setup resolv.conf so we can chroot to install some packages
    # XXXX: Should store the old state rather than unlink; then restore later.
    if [ -L $TMP_MOUNT_PATH/etc/resolv.conf ] ; then
        sudo unlink $TMP_MOUNT_PATH/etc/resolv.conf
    fi

    if [ -f $TMP_MOUNT_PATH/etc/resolv.conf ] ; then
        sudo rm -f $TMP_MOUNT_PATH/etc/resolv.conf
    fi

    # Recreate resolv.conf
    sudo touch $TMP_MOUNT_PATH/etc/resolv.conf
    sudo chmod 777 $TMP_MOUNT_PATH/etc/resolv.conf
    # use system configured resolv.conf if available to support internal proxy resolving
    if [ -e /etc/resolv.conf ]
    then
        cat /etc/resolv.conf > $TMP_MOUNT_PATH/etc/resolv.conf
    else
        echo nameserver 8.8.8.8 > $TMP_MOUNT_PATH/etc/resolv.conf
    fi
    mount_proc_dev_sys
}

function mount_proc_dev_sys () {
    # supporting kernel file systems
    sudo mount -t proc none $TMP_MOUNT_PATH/proc
    sudo mount --bind /dev $TMP_MOUNT_PATH/dev
    sudo mount -t sysfs none $TMP_MOUNT_PATH/sys
}

# Helper function to run a command inside the chroot
function run_in_target() {
   # -E to preserve http_proxy
   sudo -E chroot $TMP_MOUNT_PATH "$@"
}

# Helper function to run a directory of scripts inside the chroot
function run_d_in_target() {
    check_element
    # If we can find a directory of hooks to run in the target filesystem, bind
    # mount it into the target and then execute run-parts in a chroot
    if [ -d ${TMP_HOOKS_PATH}/$1.d ] ; then
      sudo mkdir $TMP_MOUNT_PATH/tmp/in_target.d
      sudo mount --bind ${TMP_HOOKS_PATH} $TMP_MOUNT_PATH/tmp/in_target.d
      sudo mount -o remount,ro,bind ${TMP_HOOKS_PATH} $TMP_MOUNT_PATH/tmp/in_target.d
      check_break before-$1 run_in_target bash
      run_in_target dib-run-parts /tmp/in_target.d/$1.d
      check_break after-$1 run_in_target bash
      sudo umount -f $TMP_MOUNT_PATH/tmp/in_target.d
      sudo rmdir $TMP_MOUNT_PATH/tmp/in_target.d
    fi
}

# Run a directory of hooks outside the target.
function run_d() {
    check_element
    check_break before-$1 bash
    if [ -d ${TMP_HOOKS_PATH}/$1.d ] ; then
      run-parts ${TMP_HOOKS_PATH}/$1.d
    fi
    check_break after-$1 bash
}

function prepare_first_boot () {
    check_break before-first-boot run_in_target bash
    if [ -d ${TMP_HOOKS_PATH}/first-boot.d ] ; then
      sudo cp -t $TMP_MOUNT_PATH/etc/ -a $TMP_HOOKS_PATH/first-boot.d
      run_in_target mv /etc/rc.local /etc/rc.local.REAL
      sudo dd of=$TMP_MOUNT_PATH/etc/rc.local <<EOF
#!/bin/bash
set -e
set -o xtrace

touch /var/log/first-boot.d.log
chmod 0600 /var/log/first-boot.d.log

run-parts /etc/first-boot.d >> /var/log/first-boot.d.log 2>&1
rm -fr /etc/first-boot.d
mv /etc/rc.local.REAL /etc/rc.local
exit 0
EOF
      run_in_target chmod 755 /etc/rc.local
    fi
    check_break after-first-boot run_in_target bash
}

function finalise_base () {
    TARGET_ROOT=$TMP_MOUNT_PATH run_d cleanup
    # Now remove the resolv.conf we created above
    sudo rm -f $TMP_MOUNT_PATH/etc/resolv.conf
    # The we need to recreate it as a link
    sudo ln -sf ../run/resolvconf/resolv.conf $TMP_MOUNT_PATH/etc/resolv.conf
}

function compress_image () {
    # Recreate our image to throw away unnecessary data
    test $IMAGE_TYPE != qcow2 && COMPRESS_IMAGE=""
    qemu-img convert ${COMPRESS_IMAGE:+-c} -f raw $TMP_IMAGE_PATH -O $IMAGE_TYPE $TMP_IMAGE_PATH-new
    rm $TMP_IMAGE_PATH
    mv $TMP_IMAGE_PATH-new $TMP_IMAGE_PATH
}

function do_extra_package_install () {
  # Install any packages that were requested with the -p command line option
  if [ "$INSTALL_PACKAGES" != "" ]; then
    run_in_target install-packages ${INSTALL_PACKAGES[@]}
  fi
}

function copy_elements_lib () {
  sudo mkdir -p $TMP_MOUNT_PATH/lib/diskimage-builder
  sudo cp -t $TMP_MOUNT_PATH/lib/diskimage-builder $_LIB/elements-functions
}