#!/bin/bash
#############################################################################
##
## Copyright (C) 2016 The Qt Company Ltd.
## Contact: https://www.qt.io/licensing/
##
## This file is part of the Qt OTA Update module of the Qt Toolkit.
##
## $QT_BEGIN_LICENSE:GPL$
## Commercial License Usage
## Licensees holding valid commercial Qt licenses may use this file in
## accordance with the commercial license agreement provided with the
## Software or, alternatively, in accordance with the terms contained in
## a written agreement between you and The Qt Company. For licensing terms
## and conditions see https://www.qt.io/terms-conditions. For further
## information use the contact form at https://www.qt.io/contact-us.
##
## GNU General Public License Usage
## Alternatively, this file may be used under the terms of the GNU
## General Public License version 3 or (at your option) any later version
## approved by the KDE Free Qt Foundation. The licenses are as published by
## the Free Software Foundation and appearing in the file LICENSE.GPL3
## included in the packaging of this file. Please review the following
## information to ensure the GNU General Public License requirements will
## be met: https://www.gnu.org/licenses/gpl-3.0.html.
##
## $QT_END_LICENSE$
##
#############################################################################
if [ -n "${QT_OSTREE_DEBUG}" ] ; then
    set -x
    VERBOSE="v"
fi
set -e
shopt -s extglob
trap handle_non_zero_exit EXIT

ROOT=$(dirname $(readlink -f $0))
WORKDIR=$PWD

GENERATED_TREE=${WORKDIR}/tree
BOOT_FILE_PATH=${GENERATED_TREE}/usr/lib/ostree-boot
SERVER_ROOT=${WORKDIR}/httpd
CREATE_OTA_SYSROOT=false
OTA_SYSROOT=${WORKDIR}/sysroot
START_HTTPD=false
INVALID_ARGS=false
OS_NAME="qt-os"
BOOTDIR_ON_ROOTFS=false
DEVELOPER=false
# INPUT SYSROOT
INPUT_SYSROOT_ARG_COUNTER=0
BINARY_IMAGE=false
ARCHIVED_SYSROOT=false
DIRTREE_SYSROOT=false
# HARDWARE INTEGRATION
DEVICE=""
BOOTLOADER="u-boot"
UBOOT_ENV_FILE=""
GRUB2_CFG_GENERATOR=""
# REPO
FIRST_COMMIT=false
OSTREE_REPO=${WORKDIR}/ostree-repo
OSTREE_BRANCH=linux/qt
OSTREE_COMMIT_SUBJECT=""
# STATIC DELTA
STATIC_DELTA_ARGS=""
SELF_CONTAINED_PACKAGE=false
SUPERBLOCK=${WORKDIR}/superblock
DELTA_FROM=${OSTREE_BRANCH}^
DELTA_TO=${OSTREE_BRANCH}
# TLS
USE_CLIENT_TLS=false
SERVER_CERT=""
CLIENT_CERT=""
CLIENT_KEY=""
TLS_CERT_PATH=${GENERATED_TREE}/usr/share/ostree/certs/
# GPG
USE_GPG=false
GPG_KEY=""
GPG_HOMEDIR=""
GPG_TRUSTED_KEYRING=""
GPG_KEYS_PATH=${GENERATED_TREE}/usr/share/ostree/trusted.gpg.d/
# DD IMAGE
ROOTFS_TYPE="ext3"
ROOTFS_OPT="-F -L rootfs"
BOOTFS_TYPE="ext2"
BOOTFS_OPT="-F -L boot-ostree"  # When /boot directory is on a separate partition from rootfs, ostree-remount attempts to mount filesystem where LABEL=boot-ostree
BOOTFS_SIZE="65536"             # Boot partition size [in KiB]
RECOVERY_PARTITION=false
RECOVERYFS_TYPE="ext2"
RECOVERYFS_OPT="-F -L recovery"
RECOVERYFS_SIZE="65536"         # Recovery partition size [in KiB]
ROOT_OVERHEAD_FACTOR="3"
PARTITION_ALIGNMENT="4096"      # Set alignment to 4MB [in KiB]
# LOG COLORS
COLOR_DEFAULT='\e[0m'
COLOR_RED='\e[0;31m'
COLOR_GREEN='\e[0;32m'
COLOR_YELLOW='\e[0;33m'

qt_ostree_exit()
{
    # We are done, disable the trap.
    trap - EXIT
    exit ${1}
}

qt_ostree_info()
{
    echo -e ${COLOR_GREEN}[info] ${COLOR_DEFAULT}${1}
}

qt_ostree_warning()
{
    echo -e ${COLOR_YELLOW}[warning] ${COLOR_DEFAULT}${1}
}

qt_ostree_error()
{
    echo -e ${COLOR_RED}[error] ${COLOR_DEFAULT}${1}
    echo
    qt_ostree_exit 1
}

handle_non_zero_exit()
{
    qt_ostree_error "$BASH_COMMAND returned non-zero exit code. For debugging set QT_OSTREE_DEBUG environment variable."
}

print_usage_header()
{
    msg=${1}
    if [ -n "$msg" ] ; then
        echo
        echo $msg
    fi
    echo
    echo "Usage: sudo $0 OPTIONS"
    echo
}

usage()
{
    if [ $DEVELOPER = true ] ; then
        return 0
    fi
    print_usage_header ""

    echo "OPTIONS:"
    echo
    echo "--sysroot-image-path FILE or DIR"
    echo
    echo "    A path to a linux sysroot. This argument accepts binary *.img file,"
    echo "    *.tar.gz file or a path to an extracted sysroot."
    echo
    echo "--sysroot-image-path-list \"LIST\""
    echo
    echo "    A space separated list of absolute paths to *.tar.gz files. Use this argument"
    echo "    when a sysroot is composed of several *.tar.gz files."
    echo
    echo "--initramfs FILE"
    echo
    echo "    OSTree boot compatible initramfs. Used also for recovery booting (see"
    echo "    --create-recovery-partition)."
    echo
    echo "--uboot-env-file FILE"
    echo
    echo "    OSTree boot compatible u-boot environment file. If the filename is 'uEnv.txt',"
    echo "    then it will be appended to the OSTree's managed uEnv.txt"
    echo
    echo "--grub2-cfg-generator FILE"
    echo
    echo "    GRUB2 configuration generator script."
    echo
    echo "--kernel-args \"ARGS\""
    echo
    echo "    A list of an additional kernel parameters (passed to the boot loader integration code)."
    echo
    echo "--kernel-version \"VERSION\""
    echo
    echo "    A Linux kernel file in the generated tree is renamed to vmlinuz-\${KERNEL_VERSION}."
    echo "    When this argument is not provided, the script attempts to extract the kernel"
    echo "    version from the original filename of the kernel, if that fails the kernel file"
    echo "    is renamed to vmlinuz-unknown."
    echo
    echo "--ota-json FILE"
    echo
    echo "    JSON file containing an OTA update metadata."
    echo
    echo "--ostree-repo DIR"
    echo
    echo "    Commits the generated tree into this repository. If the repository does not"
    echo "    exist, one is created in the specified location. If this argument is not"
    echo "    provided, a default repository is created in the working directory."
    echo
    echo "--create-self-contained-package"
    echo
    echo "    Creates a self-contained (superblock) update package. This package is saved in the"
    echo "    current working directory."
    echo
    echo "--disable-bsdiff"
    echo
    echo "    The bsdiff algorithm produces smaller updates by taking advantage of how executable"
    echo "    files change. Smaller updates mean a better download efficiency. Applying bsdiff deltas"
    echo "    on the client devices requires extra CPU and memory resources, as well as I/O requests."
    echo "    When generating an update for resource-constrained devices it might be desirable"
    echo "    to disable bsdiff."
    echo

    # NOTE: Disabling, as we don't really use them at the moment.
    #echo "--ostree-branch os/branch-name        Commits the generated update in the specified OSTree branch. A default branch is linux/qt."
    #echo "--ostree-commit-subject \"SUBJECT\"     Commits the generated update with the specified commit subject. A default commit subject is the"
    #echo "                                      date and time when the update was committed."

    echo "--start-trivial-httpd"
    echo
    echo "    Starts a simple web server, hosting the OSTree repository (see --ostree-repo)."
    echo "    The address to the hosted repository is listed in the httpd/httpd-address"
    echo "    file in the working directory."
    echo
    echo "--create-ota-sysroot"
    echo
    echo "    Generates bootable Over-The-Air Update enabled sysroot."
    echo
    echo "--create-recovery-partition"
    echo
    echo "    When provided, a dedicated partition is created right after the rootfs"
    echo "    partition. It duplicates contents of /boot, this partition should be treated"
    echo "    as read-only."
    echo
    echo "TLS AUTHENTICATION"
    echo
    echo "    The --tls-* files will be installed in ${TLS_CERT_PATH#*qt-ostree/tree}."
    echo "    If the sysroot already has pre-installed certificates in this path, the"
    echo "    --tls-* command line arguments can be omitted."
    echo
    echo "--tls-ca-path FILE"
    echo
    echo "    Path to file containing trusted anchors instead of the system CA database."
    echo "    Pins the certificate and uses it for servers authentication."
    echo
    echo "--tls-client-cert-path FILE"
    echo
    echo "    Path to a file for client-side certificate, to present when making requests"
    echo "    to a remote repository."
    echo
    echo "--tls-client-key-path FILE"
    echo
    echo "    Path to a file containing client-side certificate key, to present when making"
    echo "    requests to a remote repository."
    echo
    echo "GPG SIGNING"
    echo
    echo "--gpg-sign KEY-ID"
    echo
    echo "    GPG Key ID to use for signing the commit."
    echo
    echo "--gpg-homedir DIR"
    echo
    echo "    GPG home directory to use when looking for keyrings."
    echo
    echo "--gpg-trusted-keyring FILE"
    echo
    echo "    Adds the provided keyring file to the generated sysroot (see --create-ota-sysroot)"
    echo "    or to the generated update. When providing a new keyring via update, the"
    echo "    new keyring will be used for signature verification only after this update"
    echo "    has been applied. GPG keyring will be installed in:"
    echo "    ${GPG_KEYS_PATH#*qt-ostree/tree}."
    echo
}

validation_error()
{
    error_message=${1}

    if [ $INVALID_ARGS = false ] ; then
        echo
        echo "Following validation errors occurred:"
        echo
    fi
    INVALID_ARGS=true

    echo "error: ${error_message}"
}

validate_arg()
{
    arg=${1}
    value=${2}
    required=${3}
    flag=${4}

    if [ -z "${value}" ] ; then
        if [ ${required} = true ] ; then
            validation_error "${arg} is not set."
        fi
        return 0
    fi

    if [ -n "${flag}" ] && [ ! -${flag} ${value} ] ; then
        case ${flag} in
            d)
                validation_error "${arg} requires a directory path, but ${value} was provided."
                ;;
            f)
                validation_error "${arg} requires a path to a file, but ${value} was provided."
                ;;
            e)
                validation_error "${arg} ${value} is not pointing to an existing file or directory."
                ;;
        esac
        return 0
    fi

    case ${arg} in
        --gpg-trusted-keyring)
            if [[ ${GPG_TRUSTED_KEYRING} != *.gpg ]] ; then
                validation_error "--gpg-trusted-keyring expects gpg keyring file with the .gpg extension, but ${GPG_TRUSTED_KEYRING} was provided."
            fi
            ;;
        --sysroot-image-path)
            INPUT_SYSROOT_ARG_COUNTER=$(( $INPUT_SYSROOT_ARG_COUNTER + 1 ))
            if [ -d "${SYSROOT_IMAGE_PATH}" ] ; then
                if [[ ! -e "${SYSROOT_IMAGE_PATH}/usr" || ! -e "${SYSROOT_IMAGE_PATH}/bin" ]] ; then
                    validation_error "--sysroot-image-path ${SYSROOT_IMAGE_PATH} does not seem to point to an linux sysroot."
                fi
                DIRTREE_SYSROOT=true
            elif [ -f "${SYSROOT_IMAGE_PATH}" ] ; then
                if [[ ${SYSROOT_IMAGE_PATH} = *.img ]] ; then
                    BINARY_IMAGE=true
                elif [[ ${SYSROOT_IMAGE_PATH} = *.tar.gz ]] ; then
                    ARCHIVED_SYSROOT=true
                fi
            fi
            ;;
        --sysroot-image-path-list)
            INPUT_SYSROOT_ARG_COUNTER=$(( $INPUT_SYSROOT_ARG_COUNTER + 1 ))
            ARCHIVED_SYSROOT=true
            SYSROOT_IMAGE_PATH="${SYSROOT_IMAGE_PATH_LIST}"
            for archive in ${SYSROOT_IMAGE_PATH} ; do
                if [[ "${archive}" != /* || "${archive}" != *.tar.gz || ! -e "${archive}" ]] ; then
                    validation_error "--sysroot-image-path-list expects list of absolute paths to an existing *.tar.gz files, but \"${SYSROOT_IMAGE_PATH_LIST}\" was provided."
                    break
                fi
            done
            ;;
    esac
}

parse_args()
{
    while [ $# -gt 0 ] ; do
        case "${1}" in
          --create-ota-sysroot)
              CREATE_OTA_SYSROOT=true
              ;;
          --create-recovery-partition)
              RECOVERY_PARTITION=true
              ;;
          --start-trivial-httpd)
              START_HTTPD=true
              ;;
          --ostree-repo)
              OSTREE_REPO=$(realpath -ms ${2})
              shift 1
              ;;
          --create-self-contained-package)
              SELF_CONTAINED_PACKAGE=true
              ;;
          --disable-bsdiff)
              STATIC_DELTA_ARGS="--disable-bsdiff"
              ;;
          --uboot-env-file)
              UBOOT_ENV_FILE=$(realpath -ms ${2})
              shift 1
              ;;
          --grub2-cfg-generator)
              GRUB2_CFG_GENERATOR=$(realpath -ms ${2})
              shift 1
              ;;
          --kernel-args)
              KERNEL_ARGS="${2}"
              shift 1
              ;;
          --kernel-version)
              KERNEL_VERSION="${2}"
              shift 1
              ;;
          --ota-json)
              OTA_JSON=$(realpath -ms ${2})
              shift 1
              ;;
          --tls-ca-path)
              SERVER_CERT=$(realpath -ms ${2})
              shift 1
              ;;
          --tls-client-cert-path)
              CLIENT_CERT=$(realpath -ms ${2})
              USE_CLIENT_TLS=true
              shift 1
              ;;
          --tls-client-key-path)
              CLIENT_KEY=$(realpath -ms ${2})
              USE_CLIENT_TLS=true
              shift 1
              ;;
          --ostree-branch)
              OSTREE_BRANCH=${2}
              shift 1
              ;;
          --ostree-commit-subject)
              OSTREE_COMMIT_SUBJECT=${2}
              shift 1
              ;;
          --sysroot-image-path)
              SYSROOT_IMAGE_PATH=$(realpath -ms ${2})
              shift 1
              ;;
          --sysroot-image-path-list)
              SYSROOT_IMAGE_PATH_LIST=${2}
              shift 1
              ;;
          --initramfs)
              INITRAMFS=$(realpath -ms ${2})
              shift 1
              ;;
          --gpg-sign)
              GPG_KEY=${2}
              USE_GPG=true
              shift 1
              ;;
          --gpg-homedir)
              GPG_HOMEDIR=$(realpath -ms ${2})
              USE_GPG=true
              shift 1
              ;;
          --gpg-trusted-keyring)
              GPG_TRUSTED_KEYRING=$(realpath -ms ${2})
              shift 1
              ;;
          --ostree) # intentionally undocumented
              OSTREE=$(realpath -ms ${2})
              shift 1
              ;;
          --developer) # intentionally undocumented
              DEVELOPER=true
              ;;
          -h | -help | --help)
              usage
              qt_ostree_exit 0
              ;;
          -*)
              validation_error "Unknown parameter: ${1}"
              usage
              qt_ostree_exit 1
              ;;
        esac
        shift 1
    done

    # Check if running as root.
    if [ $(id -u) -ne 0 ]; then
        print_usage_header "You need root privileges to run this script."
        qt_ostree_exit 1
    fi

    # Check for OSTree dependency.
    validate_arg "--ostree" "${OSTREE}" false f
    if [ -z "${OSTREE}" ] ; then
        OSTREE=$(readlink -m "${ROOT}"/ostree)
    fi
    if [ ! -x "${OSTREE}" ] ; then
        qt_ostree_error "Needed command 'ostree' not found in SDK"
    fi

    validate_arg "--sysroot-image-path" "${SYSROOT_IMAGE_PATH}" false e
    validate_arg "--sysroot-image-path-list" "${SYSROOT_IMAGE_PATH_LIST}" false
    case ${INPUT_SYSROOT_ARG_COUNTER} in
      0) validation_error "--sysroot-image-path or --sysroot-image-path-list is required." ;;
      2) validation_error "--sysroot-image-path and --sysroot-image-path-list are mutually exclusive." ;;
    esac

    validate_arg "--initramfs" "${INITRAMFS}" false f
    validate_arg "--uboot-env-file" "${UBOOT_ENV_FILE}" false f
    validate_arg "--grub2-cfg-generator" "${GRUB2_CFG_GENERATOR}" false f
    validate_arg "--ota-json" "${OTA_JSON}" true f
    validate_arg "--gpg-homedir" "${GPG_HOMEDIR}" false d
    validate_arg "--gpg-trusted-keyring" "${GPG_TRUSTED_KEYRING}" false f
    if [[ $USE_GPG = true && ( -z "${GPG_KEY}" || -z "${GPG_HOMEDIR}" ) ]] ; then
        # Note: --gpg-homedir is not required when keyring is stored in a standard path,
        # but just to be sure that a commit won't fail, we require both of these args.
        validation_error "Must specify both --gpg-sign and --gpg-homedir for GPG signing feature."
    fi

    validate_arg "--tls-ca-path" "${SERVER_CERT}" false f
    validate_arg "--tls-client-cert-path" "${CLIENT_CERT}" false f
    validate_arg "--tls-client-key-path" "${CLIENT_KEY}" false f
    if [[ $USE_CLIENT_TLS = true && ( -z "${CLIENT_CERT}" || -z "${CLIENT_KEY}" ) ]] ; then
        validation_error "Must specify both --tls-client-cert-path and --tls-client-key-path for TLS client authentication feature."
    fi

    if [ ! -d ${OSTREE_REPO}/objects ] ; then
        FIRST_COMMIT=true
    fi
    if [[ $FIRST_COMMIT = true && $SELF_CONTAINED_PACKAGE = true ]] ; then
        validation_error "Can not generate a self-contained package (--create-self-contained-package), when --ostree-repo points to a non-existing repository."
    fi

    if [ $INVALID_ARGS = true ] ; then
        usage
        qt_ostree_exit 1
    fi
    # Report.
    qt_ostree_info "Using ostree ${OSTREE}"
    qt_ostree_info "OTA JSON: " && echo "$(cat ${OTA_JSON})"
}

umount_mount_points()
{
    cd ${WORKDIR}/

    dir_list="boot-mount rootfs-mount boot-dd rootfs-dd recovery-dd"
    did_umount=false
    for dir in $dir_list ; do
        if mountpoint -q ${dir} ; then
            did_umount=true
            umount ${dir}
        fi
        rm -rf ${dir}
    done

    if [ ${did_umount} = true ] ; then
        sync
    fi
}

clean_workdir()
{
    cd ${WORKDIR}/

    # Remove immutable attribute.
    chattr -if ${OTA_SYSROOT}/ostree/deploy/*/deploy/* || true
    rm -rf ${OTA_SYSROOT}
    rm -rf ${GENERATED_TREE}

    chmod -x ${ROOT}/ostree-grub-generator
}

find_in_sysroot()
{
    target=${1}
    target_path=$(find ${GENERATED_TREE} -type f -name ${target})
    if [ -z "${target_path}" ] ; then
        qt_ostree_error "Failed to find \"${target}\" in the provided sysroot"
    fi
}

# Doc: call find_in_sysroot() before using path_in_sysroot(). Combining these
# two functions would result in executing handle_non_zero_exit() when a target
# file is not found. And instead of getting a normal error message we would also
# get an error message from handle_non_zero_exit(), when using the "combined"
# version within command substitutions: path=$(find_in_sysroot "some-file").
path_in_sysroot()
{
    target=${1}
    target_path=$(find ${GENERATED_TREE} -type f -name ${target})
    echo ${target_path}
}

get_kernel_info()
{
    # Find kernel image.
    # Note: It might be a good idea to expose KERNEL as command line argument, when
    # the existing search algorithm is not sufficient.
    cd ${BOOT_FILE_PATH}/
    for boot_file in *; do
        if file -b ${boot_file} | grep -qi "kernel"; then
            KERNEL=${BOOT_FILE_PATH}/${boot_file}
            break
        fi
    done
    if [ -z "${KERNEL}" ] ; then
        qt_ostree_error "Failed to find kernel image in ${BOOT_FILE_PATH}"
    fi
    qt_ostree_info "Using kernel image ${KERNEL}"

    # Extract kernel version from a filename.
    if [ -z "${KERNEL_VERSION}" ] ; then
        KERNEL_VERSION=$(basename "${KERNEL}" | grep -o -E "[1-4]\.[0-9][0-9]*\.[0-9][0-9]*" || true)
        if [ -z "${KERNEL_VERSION}" ] ; then
            qt_ostree_warning "${KERNEL} filename does not contain kernel version. The kernel version can be
                               provided with the --kernel-version command line argument."
            KERNEL_VERSION="unknown"
        fi
    fi

    qt_ostree_info "Kernel version: ${KERNEL_VERSION}"
}

organize_boot_files()
{
    if [ $(ls ${GENERATED_TREE}/boot/ | wc -l) != 0 ]; then
        mv -f ${GENERATED_TREE}/boot/* ${BOOT_FILE_PATH}/
    fi

    get_kernel_info

    # Clean up from broken symbolic links.
    find -L ${BOOT_FILE_PATH}/ -type l -delete
    # .. and files with a reserved prefix.
    rm -rf initramfs*

    # OSTree deploy requires vmlinuz-*, with optional initramfs-*.
    if [ -n "${INITRAMFS}" ] ; then
        bootcsum=$(cat ${KERNEL} ${INITRAMFS} | sha256sum | cut -f 1 -d ' ')
        cp ${INITRAMFS} ${BOOT_FILE_PATH}/initramfs-${KERNEL_VERSION}-${bootcsum}
        qt_ostree_info "Using initramfs for booting"
    else
        qt_ostree_info "Not using initramfs for booting"
        bootcsum=$(cat ${KERNEL} | sha256sum | cut -f 1 -d ' ')
    fi
    mv ${KERNEL} ${BOOT_FILE_PATH}/vmlinuz-${KERNEL_VERSION}-${bootcsum}

    touch ${BOOT_FILE_PATH}/.ostree-bootcsumdir-source

    # Boot loader companions.
    if [[ "${BOOTLOADER}" = "u-boot" && -n "${UBOOT_ENV_FILE}" ]] ; then
        cp ${UBOOT_ENV_FILE} ${BOOT_FILE_PATH}/
        name=$(basename ${UBOOT_ENV_FILE})
        if [ "${name}" != "uEnv.txt" ] ; then
            # Must be a boot script then.
            if file -b $name | grep -qi "ASCII text"; then
                qt_ostree_info "Add u-boot header to a boot script at: ${BOOT_FILE_PATH}/${name} ..."
                mv ${name} ${name}-tmp
                # The added header embedds timestamp of the time when 'mkimage' was executed. This results
                # in a new checksum even if nothing has really changed in the file. Set a consistent
                # timestamp as U-Boot utilizes https://reproducible-builds.org/specs/source-date-epoch/
                SOURCE_DATE_EPOCH=1 mkimage -A arm -O linux -T script -C none -a 0 -e 0 -n "boot script" -d ${name}-tmp ${name}
                rm ${name}-tmp
            fi
        fi
    elif [ "${BOOTLOADER}" = "grub2" ] ; then
        if [ -z "${GRUB2_CFG_GENERATOR}" ] ; then
            # Use default generator.
            GRUB2_CFG_GENERATOR=${ROOT}/ostree-grub-generator
        fi
        chmod +x ${GRUB2_CFG_GENERATOR}
        find_in_sysroot "ostree-grub-generator"
        cp ${GRUB2_CFG_GENERATOR} $(path_in_sysroot "ostree-grub-generator")
        # Add default root= for initramfs context.
        if [[ -z "${KERNEL_ARGS}" && -n "${INITRAMFS}" ]] ; then
            KERNEL_ARGS="root=LABEL=rootfs"
        fi
    fi

     # NOTE: This file is used by higher level API.
    touch ${BOOT_FILE_PATH}/kargs
    if [ -n "${KERNEL_ARGS}" ] ; then
        qt_ostree_info "Additional kernel command line arguments: $KERNEL_ARGS"
        for karg in ${KERNEL_ARGS} ; do
            kargs="${kargs} --karg=$karg"
        done
        echo $kargs > ${BOOT_FILE_PATH}/kargs
    fi
}

adjust_sysroot_layout()
{
    # Adjust rootfs according to OSTree guidelines.
    cd ${GENERATED_TREE}
    mkdir -p sysroot/ostree/
    ln -s sysroot/ostree/ ostree
    mkdir -p sysroot/tmp/
    rm -rf tmp/
    ln -s sysroot/tmp/ tmp
    # The sysroot should not have a traditional UNIX /etc; instead, it should include /usr/etc.
    if [ -e etc/ ] ; then
        mv etc/ usr/
    fi
    # It's recommended that operating systems ship all of their content in /usr.
    # NOTE: $usr_move and $var_symlinks could be configurable via command line arguments.
    usr_move="bin lib sbin data"
    mkdir -p usr/system/
    for dir in $usr_move ; do
        if [ -d ${dir} ] ; then
            mv ${dir} usr/system/
            ln -s usr/system/${dir} ${dir}
        fi
    done
    # Everything in /var is preserved across upgrades. Add symlinks so that paths from
    # ${var_symlinks} point into /var. OSTree by design does not update contents in /var.
    # It is OS responsibily to handle /var. OS can run post-upgrade scripts to copy the
    # updates files to /var if required.
    var_symlinks="home mnt media opt"
    for dir in $var_symlinks ; do
        if [ -d ${dir} ] ; then
            if [ -z "$(find ${dir} -type f)" ]; then
                rm -rf ${dir}
            else
                ro_paths=$(sed 's/ /, /g' <<< ${usr_move})
                qt_ostree_warning "Found some contents in: /${dir}. It is recommended that operating system ships all
                                   \nof its contents in /usr or in one of the following top level directories: [$ro_paths].
                                   \n/${dir} will be a part of an update, but it won't be protected by the /usr read-only mount
                                   \nset by default. Any changes users will do in this directory WILL BE LOST ON THE NEXT UPGRADE"
                continue
            fi
            mkdir -p var/${dir}
            ln -s var/${dir} ${dir}
        fi
    done
}

convert_to_ostree_sysroot()
{
    cd ${GENERATED_TREE}
    find_in_sysroot "ostree"
    find_in_sysroot "ostree-remount"

    organize_boot_files

    # OSTree requires /etc/os-release file (see The Boot Loader Specification).
    if [ ! -e ${GENERATED_TREE}/etc/os-release ] ; then
        echo "PRETTY_NAME=\"${OS_NAME}\"" > ${GENERATED_TREE}/etc/os-release
    fi

    init_system=$(basename $(readlink -f ${GENERATED_TREE}/sbin/init))
    if [ "$init_system" != "systemd" ] ; then
        qt_ostree_error "Failed to detected systemd init support on the image"
    fi

    adjust_sysroot_layout

    # OTA metadata.
    cp ${OTA_JSON} ${GENERATED_TREE}/usr/etc/qt-ota.json

    # Add trusted GPG keyring file.
    if [ -n "${GPG_TRUSTED_KEYRING}" ] ; then
        cp ${GPG_TRUSTED_KEYRING} ${GPG_KEYS_PATH}
    fi

    # Enable TLS support.
    mkdir -p ${TLS_CERT_PATH}
    if [ -n "${SERVER_CERT}" ] ; then
        cp ${SERVER_CERT} ${TLS_CERT_PATH}
    fi
    if [ $USE_CLIENT_TLS = true ] ; then
        cp ${CLIENT_CERT} ${CLIENT_KEY} ${TLS_CERT_PATH}
    fi
}

create_self_contained_package()
{
    qt_ostree_info "Generating a self-contained update package ..."
    # Disable fallback objects, so all objects would be included in the generated
    # delta and applying the delta would not require an Internet connection.
    "${OSTREE}" --repo=${OSTREE_REPO} static-delta generate  ${STATIC_DELTA_ARGS} \
                --min-fallback-size=0 --inline --filename=${SUPERBLOCK}

    if [ ! -e "${SUPERBLOCK}" ] ; then
        qt_ostree_error "Something failed, ${SUPERBLOCK} does not exist"
    fi
    qt_ostree_info "Generated a self-contained update package: ${SUPERBLOCK}"
}

commit_generated_tree()
{
    # Commit the generated tree into OSTree repository.
    if [ $FIRST_COMMIT = true ] ; then
        mkdir -p ${OSTREE_REPO}
        qt_ostree_info "Initializing new OSTree repository in ${OSTREE_REPO}"
        "${OSTREE}" --repo=${OSTREE_REPO} init --mode=archive-z2
    fi

    if [ -z "${OSTREE_COMMIT_SUBJECT}" ] ; then
        current_time=$(date +"%m-%d-%Y %T")
        OSTREE_COMMIT_SUBJECT="Generated commit subject: ${current_time}"
    fi
    if [ $USE_GPG = true ] ; then
        GPG_ARGS="--gpg-sign=${GPG_KEY} --gpg-homedir=${GPG_HOMEDIR}"
    fi

    if [ $FIRST_COMMIT = false ] ; then
        prev_rev=$("${OSTREE}" --repo=${OSTREE_REPO} rev-parse ${OSTREE_BRANCH})
    fi
    qt_ostree_info "Committing the generated tree into a repository at ${OSTREE_REPO} ..."
    "${OSTREE}" --repo=${OSTREE_REPO} commit \
                --tree=dir=${GENERATED_TREE} \
                -b ${OSTREE_BRANCH} -s "${OSTREE_COMMIT_SUBJECT}" \
                --skip-if-unchanged \
                ${GPG_ARGS} \
                --owner-uid=0 --owner-gid=0
    new_rev=$("${OSTREE}" --repo=${OSTREE_REPO} rev-parse ${OSTREE_BRANCH})
    if [[ $FIRST_COMMIT = false && ${prev_rev} = ${new_rev} ]] ; then
        qt_ostree_info "There are no new changes in the sysroot. A new update won't be generated."
        qt_ostree_exit 0
    fi

    STATIC_DELTA_ARGS="${STATIC_DELTA_ARGS} --from=${DELTA_FROM} --to=${DELTA_TO}"
    if [ $SELF_CONTAINED_PACKAGE = true ] ; then
        create_self_contained_package
    fi
    # Pulling static deltas via HTTP is on hold due to several UX issues: https://github.com/ostreedev/ostree/issues/475
    # if [ $FIRST_COMMIT = false ] ; then
    #     qt_ostree_info "Generating static delta  ..."
    #     "${OSTREE}" --repo=${OSTREE_REPO} static-delta generate ${STATIC_DELTA_ARGS}
    # fi

    "${OSTREE}" --repo=${OSTREE_REPO} summary -u ${GPG_ARGS}

    qt_ostree_info "Checking the repository for consistency ..."
    if [ $DEVELOPER = false ] ; then
        "${OSTREE}" --repo=${OSTREE_REPO} fsck
    fi
}

configure_boot_loader()
{
    qt_ostree_info "Configuring ${BOOTLOADER} boot loader"

    if [ "${BOOTLOADER}" = "u-boot" ] ; then
        mkdir -p ${OTA_SYSROOT}/boot/loader.0/
        ln -s loader.0 ${OTA_SYSROOT}/boot/loader
        touch ${OTA_SYSROOT}/boot/loader/uEnv.txt
        ln -s loader/uEnv.txt ${OTA_SYSROOT}/boot/uEnv.txt
        # Add convenience symlinks, for details see ostree/src/libostree/ostree-bootloader-uboot.c
        for file in ${BOOT_FILE_PATH}/* ; do
            name=$(basename $file)
            if [[ ! -f $file || $name == *.dtb || $name == initramfs-* || $name == vmlinuz-* ]] ; then
                continue
            fi
            ln -sf loader/${name} ${OTA_SYSROOT}/boot/${name}
        done
    elif [ "${BOOTLOADER}" = "grub2" ] ; then
        mkdir -p ${OTA_SYSROOT}/boot/grub2/
        ln -s ../loader/grub.cfg ${OTA_SYSROOT}/boot/grub2/grub.cfg
        export OSTREE_GRUB2_EXEC=${GRUB2_CFG_GENERATOR}
    fi
}

populate_filesystem_images()
{
    mkdir rootfs-dd boot-dd
    mount boot.${BOOTFS_TYPE} boot-dd/
    mount rootfs.${ROOTFS_TYPE} rootfs-dd/

    if [ $BOOTDIR_ON_ROOTFS = true ]; then
        # The whole sysroot on the same partition.
        cp -rP --preserve=all ${OTA_SYSROOT}/* rootfs-dd/
    else
        # boot/ directory on a separate boot partition.
        cp -rP --preserve=all ${OTA_SYSROOT}/!(boot) rootfs-dd/
        cp -rP --preserve=all ${OTA_SYSROOT}/boot/* boot-dd/
    fi

    case "${DEVICE}" in
        *intel-corei7*|*nuc*)
            mcopy -s -i boot.${BOOTFS_TYPE} ${BOOT_FILE_PATH}/EFI ::/EFI
            ;;
    esac

    if [ $RECOVERY_PARTITION = true ] ; then
        mkdir recovery-dd
        mount recovery.${RECOVERYFS_TYPE} recovery-dd/
        cp -rf ${BOOT_FILE_PATH}/* recovery-dd/
        cd recovery-dd
        ln -s vmlinuz-* vmlinuz
        if [ -n "${INITRAMFS}" ] ; then
            ln -s initramfs-* initramfs
        fi
        cd -
    fi

    # When mounting a loopback, the kernel doesn't know that the backing device
    # is a file on the same media. Do an explicit sync call.
    sync
    umount_mount_points
}

# Disk layout:
#
#    0                      -> PARTITION_ALIGNMENT       - reserved to boot loader      (not partitioned)
#    PARTITION_ALIGNMENT    -> bootfs_size_aligned       - kernel and other data        (boot partition)
#    bootfs_size_aligned    -> rootfs_size_aligned       - rootfs                       (rootfs partition)
#    rootfs_size_aligned    -> recoveryfs_size_aligned   - recovery initramfs + kernel  (optional recovery partition)
#
#  --------------------- --------------------- --------------------- ------------------------- ---------------------
# | PARTITION_ALIGNMENT | bootfs_size_aligned | rootfs_size_aligned | recoveryfs_size_aligned | PARTITION_ALIGNMENT |
#  --------------------- --------------------- --------------------- ------------------------- ---------------------

get_aligned_size()
{
    size=${1}
    aligned_size=$(( ${size} + ${PARTITION_ALIGNMENT} - 1 ))
    aligned_size=$(( ${aligned_size} - ${aligned_size} % ${PARTITION_ALIGNMENT} ))
    echo ${aligned_size}
}

assemble_dd_image()
{
    cd ${WORKDIR}
    qt_ostree_info "Assembling a deployable image ..."
    # Align partition sizes and calculate total binary image size.
    sysroot_size=$(du -sk ${OTA_SYSROOT}/ | cut -f1)
    rootfs_size=$(echo ${sysroot_size}*${ROOT_OVERHEAD_FACTOR} | bc | cut -f1 -d'.')
    bootfs_size_aligned=$(get_aligned_size ${BOOTFS_SIZE})
    rootfs_size_aligned=$(get_aligned_size ${rootfs_size})
    image_size=$(( ${PARTITION_ALIGNMENT} + ${bootfs_size_aligned} + ${rootfs_size_aligned} + ${PARTITION_ALIGNMENT} ))
    if [ $RECOVERY_PARTITION = true ] ; then
        recoveryfs_size_aligned=$(get_aligned_size ${RECOVERYFS_SIZE})
        image_size=$(( ${image_size} + ${recoveryfs_size_aligned} ))
    fi

    # Initialize a sparse file.
    image="${DEVICE}-ota.img"
    rm -f ${image}
    dd if=/dev/zero of=${image} bs=1k count=0 seek=${image_size}

    # Create a partition table.
    bootfs_start=${PARTITION_ALIGNMENT}
    bootfs_end=$(( ${PARTITION_ALIGNMENT} + ${bootfs_size_aligned} ))
    rootfs_end=$(( ${bootfs_end} + ${rootfs_size_aligned} ))
    if [ "${BOOTFS_TYPE}" = "vfat" ] ; then
        fs_type="FAT32"
    fi

    parted -s ${image} mklabel msdos
    parted -s ${image} unit KiB mkpart primary ${fs_type} ${bootfs_start} ${bootfs_end}
    parted -s ${image} unit KiB mkpart primary ${bootfs_end} ${rootfs_end}
    if [ $RECOVERY_PARTITION = true ] ; then
        recoveryfs_end=$(( ${rootfs_end} + ${recoveryfs_size_aligned} ))
        parted -s ${image} unit KiB mkpart primary ${rootfs_end} ${recoveryfs_end}
    fi
    parted -s ${image} set 1 boot on
    parted ${image} print

    # Create filesystem images.
    rm -f rootfs.${ROOTFS_TYPE} boot.${BOOTFS_TYPE} recovery.${RECOVERYFS_TYPE}
    dd if=/dev/zero of=boot.${BOOTFS_TYPE} seek=${bootfs_size_aligned} count=0 bs=1k
    mkfs.${BOOTFS_TYPE} ${BOOTFS_OPT} boot.${BOOTFS_TYPE}
    dd if=/dev/zero of=rootfs.${ROOTFS_TYPE} seek=${rootfs_size_aligned} count=0 bs=1k
    mkfs.${ROOTFS_TYPE} ${ROOTFS_OPT} rootfs.${ROOTFS_TYPE}
    if [ $RECOVERY_PARTITION = true ] ; then
        dd if=/dev/zero of=recovery.${RECOVERYFS_TYPE} seek=${recoveryfs_size_aligned} count=0 bs=1k
        mkfs.${RECOVERYFS_TYPE} ${RECOVERYFS_OPT} recovery.${RECOVERYFS_TYPE}
    fi

    populate_filesystem_images

    # Burn partitions.
    dd if=boot.${BOOTFS_TYPE} of=${image} conv=notrunc seek=${bootfs_start} bs=1k
    dd if=rootfs.${ROOTFS_TYPE} of=${image} conv=notrunc seek=${bootfs_end} bs=1k
    if [ $RECOVERY_PARTITION = true ] ; then
        dd if=recovery.${RECOVERYFS_TYPE} of=${image} conv=notrunc seek=${rootfs_end} bs=1k
    fi
    sync

    qt_ostree_info "Created a binary image - ${image}, deployable with the dd command" \
    && echo "Example dd command: sudo dd bs=4M if=${image} of=/dev/sdX && sync"
}

create_ota_sysroot()
{
    qt_ostree_info "Creating OTA enabled sysroot ..."
    cd ${WORKDIR}

    mkdir -p ${OTA_SYSROOT}/sysroot/
    export OSTREE_SYSROOT=${OTA_SYSROOT}
    "${OSTREE}" admin init-fs ${OTA_SYSROOT}
    "${OSTREE}" admin os-init ${OS_NAME}

    configure_boot_loader

    qt_ostree_info "Checking out filesystem tree from ${OSTREE_REPO} repository"
    "${OSTREE}" --repo=${OTA_SYSROOT}/ostree/repo pull-local --remote=${OS_NAME} ${OSTREE_REPO} ${OSTREE_BRANCH}

    if [ -e "${BOOT_FILE_PATH}"/kargs ] ; then
        "${OSTREE}" admin deploy $(cat "${BOOT_FILE_PATH}"/kargs) --os=${OS_NAME} ${OS_NAME}:${OSTREE_BRANCH}
    else
        "${OSTREE}" admin deploy --os=${OS_NAME} ${OS_NAME}:${OSTREE_BRANCH}
    fi

    "${OSTREE}" admin status

    # OSTree does not touch the contents of /var, it is the OS responsibility to manage this directory.
    rm -rf ${OTA_SYSROOT}/ostree/deploy/${OS_NAME}/var/
    cp -rd ${GENERATED_TREE}/var/ ${OTA_SYSROOT}/ostree/deploy/${OS_NAME}/

    assemble_dd_image
}

extract_sysroot()
{
    mkdir ${GENERATED_TREE}/
    mkdir -p ${BOOT_FILE_PATH}/

    if [ $BINARY_IMAGE = true ] ; then
        # Extract binary image.
        image=${SYSROOT_IMAGE_PATH}
        qt_ostree_info "Extracting ${image} ..."
        units=$(fdisk -l ${image} | grep Units | awk '{print $(NF-1)}')
        # The boot partition not always is marked properly.
        boot_start=$(fdisk -l ${image} | grep ${image}1 | awk '{print $2}')
        if [ "${boot_start}" == "*" ] ; then
            boot_start=$(fdisk -l ${image} | grep ${image}1 | awk '{print $3}')
        fi
        rootfs_start=$(fdisk -l ${image} | grep ${image}2 | awk '{print $2}')
        boot_offset=$(( ${units} * ${boot_start} ))
        rootfs_offset=$(( ${units} * ${rootfs_start} ))

        cd ${WORKDIR}/
        mkdir boot-mount rootfs-mount
        mount -o loop,offset=${boot_offset} ${image} boot-mount/
        mount -o loop,offset=${rootfs_offset} ${image} rootfs-mount/
        cp -rp${VERBOSE}d boot-mount/* ${BOOT_FILE_PATH}
        cp -rp${VERBOSE}d rootfs-mount/* ${GENERATED_TREE}
    elif [ $ARCHIVED_SYSROOT = true ] ; then
        # Extract *.tar.gz image files.
        for image in ${SYSROOT_IMAGE_PATH} ; do
            qt_ostree_info "Extracting ${image} ..."
            if [[ $(basename ${image}) == *boot* ]] ; then
                tar --preserve -C ${BOOT_FILE_PATH} -x${VERBOSE}f ${image}
            else
                tar --preserve -C ${GENERATED_TREE} -x${VERBOSE}f ${image}
            fi
        done
    elif [ $DIRTREE_SYSROOT = true ] ; then
        image=${SYSROOT_IMAGE_PATH}
        qt_ostree_info "Copying ${image} ..."
        cp -rp${VERBOSE}d ${image}/* ${GENERATED_TREE}
    else
        qt_ostree_error "Failed to extract ${SYSROOT_IMAGE_PATH}"
    fi
}

start_httpd_server()
{
    # Start a trivial httpd server on localhost.
    qt_ostree_info "Starting a local HTTP server"
    rm -rf ${SERVER_ROOT}
    mkdir ${SERVER_ROOT}
    cd ${SERVER_ROOT}
    ln -s ${OSTREE_REPO} ostree
    "${OSTREE}" trivial-httpd --autoexit --daemonize -p ${SERVER_ROOT}/httpd-port
    PORT=$(cat ${SERVER_ROOT}/httpd-port)
    echo "http://127.0.0.1:${PORT}/ostree" > ${SERVER_ROOT}/httpd-address
    qt_ostree_info "OTA update repository available at $(cat ${SERVER_ROOT}/httpd-address)"
}

detect_target_device()
{
    hostname_file=${GENERATED_TREE}/etc/hostname
    DEVICE=$(cat ${hostname_file})
    if [ -z "${DEVICE}" ] ; then
        qt_ostree_error "No hostname specified in ${hostname_file}"
    fi

    case "${DEVICE}" in
        # Intel NUC requires a special handling as it is quite different from
        # other meta-boot2qt reference devices.
        *intel-corei7*|*nuc*)
            BOOTLOADER="grub2"
            BOOTFS_TYPE="vfat"
            BOOTFS_OPT="-n boot"
            BOOTDIR_ON_ROOTFS=true
            ;;
    esac

    qt_ostree_info "Detected ${DEVICE} device with ${BOOTLOADER} boot loader"
}

print_summary()
{
    # Print sysroot diff.
    if [ $FIRST_COMMIT = false ] ; then
        qt_ostree_info "Files (C)hanged / (M)odified / (D)eleted since the previous version:"
        "${OSTREE}" --repo=${OSTREE_REPO} diff ${OSTREE_BRANCH}^ ${OSTREE_BRANCH}
    fi
}

main()
{
    parse_args "$@"

    umount_mount_points
    clean_workdir

    extract_sysroot
    detect_target_device

    convert_to_ostree_sysroot
    commit_generated_tree

    if [ $CREATE_OTA_SYSROOT = true ] ; then
        create_ota_sysroot
    fi

    if [ $START_HTTPD = true ] ; then
        start_httpd_server
    fi

    umount_mount_points
    if [ $DEVELOPER = false ] ; then
        clean_workdir
    fi

    print_summary
    qt_ostree_info "All done."
    qt_ostree_exit 0
}

main "$@"