#!/bin/bash
#
# Copyright (c) 2023 Wind River Systems, Inc.
#
# SPDX-License-Identifier: Apache-2.0
#
# Utility for adding patch metadata to the iso
# Debian patches are sequential and uses ostree
# so any patch will produce an updated iso, this
# utility injects the patch metadata into the iso.
# During install the kickstart will copy the metadata
# into the right location and the sw-patch query
# command will output the correct patch level
#

source "$(dirname $0)/image-utils.sh"

if [ -z "${STX_BUILD_HOME}" ]; then
    echo "Required environment variable STX_BUILD_HOME is not set"
    exit 1
fi

if [ -z "${MY_REPO}" ]; then
    echo "Required environment variable MY_REPO is not set"
    exit 1
fi

DEPLOY_DIR="${STX_BUILD_HOME}/localdisk/deploy"
OSTREE_REPO="${DEPLOY_DIR}/ostree_repo"

function usage() {
    echo ""
    echo "Usage: "
    echo "   $(basename $0) -i <input filename.iso> -o <output filename.iso> [ -p ] <patch> ..."
    echo "        -i <file>: Specify input ISO file"
    echo "        -o <file>: Specify output ISO file"
    echo "        -p <file>: Patch files. You can call it multiple times."
    echo ""
}

function extract_metadata() {
    local patchesdir=${BUILDDIR}/patches
    local patchfile=$1
    local patchid=$(basename $patchfile .patch)
    local ostree_log=$(ostree --repo=${OSTREE_REPO} log starlingx)

    echo "Extracting ${patchfile}"
    # Extract it
    tar xf ${patchfile} -O metadata.tar | tar x -O > ${patchesdir}/${patchid}-metadata.xml
    if [ $? -ne 0 ]; then
        echo "Failed to extract metadata from ${patchfile}"
        exit 1
    fi

    # Verify if top commit from metadata exist in ostree log
    xml_base=$(xmllint --xpath "string(//contents/ostree/commit1/commit)" ${patchesdir}/${patchid}-metadata.xml)
    if [[ "$ostree_log" != *"$xml_base"* ]]; then
        echo "Error, xml base commit does not exist in ostree log."
        echo "patch base: ${xml_base}"
        echo "ostree log:"
        ostree --repo=${BUILDDIR}/ostree_repo log starlingx
        exit 1
    fi
}

declare INPUT_ISO=
declare OUTPUT_ISO=
declare ORIG_PWD=$PWD
declare DO_UPGRADES=1

while getopts "i:o:p:" opt; do
    case $opt in
        i)
            INPUT_ISO=$OPTARG
            ;;
        o)
            OUTPUT_ISO=$OPTARG
            ;;
        p)
            PATCH_FILES+=($OPTARG)
            ;;
        *)
            usage
            exit 1
            ;;
    esac
done

if [ -z "$INPUT_ISO" -o -z "$OUTPUT_ISO" ]; then
    usage
    exit 1
fi

if [ ! -f ${INPUT_ISO} ]; then
    echo "Input file does not exist: ${INPUT_ISO}"
    exit 1
fi

if [ -f ${OUTPUT_ISO} ]; then
    echo "Output file already exists: ${OUTPUT_ISO}"
    exit 1
fi

for PATCH in "${PATCH_FILES[@]}";
do
    if [ ! -f ${PATCH} ]; then
        echo "Patch file dos not exists: ${PATCH}"
        exit 1
    fi

    if [[ ! ${PATCH} =~ \.patch$ ]]; then
        echo "Specified file ${PATCH} does not have .patch extension"
        exit 1
    fi
done

shift $((OPTIND-1))

declare MNTDIR=
declare BUILDDIR=

function check_requirements {
    local -a required_utils=(
        rsync
        mkisofs
        isohybrid
        implantisomd5
        ostree
        xmllint
    )
    if [ $UID -ne 0 ]; then
        # If running as non-root user, additional utils are required
        required_utils+=(
            guestmount
            guestunmount
        )
    fi

    local -i missing=0

    for req in ${required_utils[@]}; do
        which ${req} >&/dev/null
        if [ $? -ne 0 ]; then
            echo "Unable to find required utility: ${req}" >&2
            let missing++
        fi
    done

    if [ ${missing} -gt 0 ]; then
        echo "One or more required utilities are missing. Aborting..." >&2
        exit 1
    fi
}

function mount_iso {
    if [ $UID -eq 0 ]; then
        # Mount the ISO
        mount -o loop ${INPUT_ISO} ${MNTDIR}
        if [ $? -ne 0 ]; then
            echo "Failed to mount ${INPUT_ISO}" >&2
            exit 1
        fi
    else
        # As non-root user, mount the ISO using guestmount
        guestmount -a ${INPUT_ISO} -m /dev/sda1 --ro ${MNTDIR}
        rc=$?
        if [ $rc -ne 0 ]; then
            # Add a retry
            echo "Call to guestmount failed with rc=$rc. Retrying once..."

            guestmount -a ${INPUT_ISO} -m /dev/sda1 --ro ${MNTDIR}
            rc=$?
            if [ $rc -ne 0 ]; then
                echo "Call to guestmount failed with rc=$rc. Aborting..."
                exit $rc
            fi
        fi
    fi
}

function unmount_iso {
    if [ $UID -eq 0 ]; then
        umount ${MNTDIR}
    else
        guestunmount ${MNTDIR}
    fi
    rmdir ${MNTDIR}
}

function cleanup() {
    if [ -n "$MNTDIR" -a -d "$MNTDIR" ]; then
        unmount_iso
    fi

    if [ -n "$BUILDDIR" -a -d "$BUILDDIR" ]; then
        chmod -R +w $BUILDDIR
        \rm -rf $BUILDDIR
    fi

}

check_requirements

trap cleanup EXIT

MNTDIR=$(mktemp -d -p $PWD patchiso_mnt_XXXXXX)
if [ -z "${MNTDIR}" -o ! -d ${MNTDIR} ]; then
    echo "Failed to create mntdir. Aborting..."
    exit $rc
fi

BUILDDIR=$(mktemp -d -p $PWD patchiso_build_XXXXXX)
if [ -z "${BUILDDIR}" -o ! -d ${BUILDDIR} ]; then
    echo "Failed to create builddir. Aborting..."
    exit $rc
fi

# Mount the ISO
mount_iso

rsync -a --exclude 'ostree_repo' ${MNTDIR}/ ${BUILDDIR}/
rc=$?
if [ $rc -ne 0 ]; then
    echo "Call to rsync ISO content. Aborting..."
    exit $rc
fi

unmount_iso

# Fix for permission denied if not running as root
chmod +w ${BUILDDIR}
chmod -R +w ${BUILDDIR}/isolinux

# Create the directory where metadata will be stored
mkdir -p ${BUILDDIR}/patches
chmod -R +w ${BUILDDIR}/patches

echo "Copying only the latest commit from ostree_repo..."
ostree --repo=${BUILDDIR}/ostree_repo init --mode=archive-z2 
ostree --repo=${BUILDDIR}/ostree_repo pull-local --depth=0 ${OSTREE_REPO} starlingx
ostree --repo=${BUILDDIR}/ostree_repo summary --update
echo "Updated iso ostree commit:"
ostree --repo=${BUILDDIR}/ostree_repo log starlingx

echo "Extracting patch metadata"
for PATCH in "${PATCH_FILES[@]}";
do
    extract_metadata $PATCH
done

echo "Packing iso..."
# get the install label
ISO_LABEL=$(grep -ri instiso "${BUILDDIR}"/isolinux/isolinux.cfg | head -1 | xargs -n1 | awk -F= /instiso/'{print $2}')
if [ -z "${ISO_LABEL}" ] ; then
    echo "Error: Failed to get iso install label"
fi
echo "ISO Label: ${ISO_LABEL}"

# Repack the ISO
mkisofs -o "${OUTPUT_ISO}" \
    -A "${ISO_LABEL}" -V "${ISO_LABEL}" \
    -quiet -U -J -joliet-long -r -iso-level 2 \
    -b isolinux/isolinux.bin -c isolinux/boot.cat -no-emul-boot \
    -boot-load-size 4 -boot-info-table \
    -eltorito-alt-boot \
    -e efi.img \
    -no-emul-boot \
    "${BUILDDIR}"

isohybrid --uefi ${OUTPUT_ISO}
implantisomd5 ${OUTPUT_ISO}

# Sign the .iso with the developer private key
openssl dgst -sha256 \
    -sign ${MY_REPO}/build-tools/signing/dev-private-key.pem \
    -binary \
    -out ${OUTPUT_ISO/%.iso/.sig} \
    ${OUTPUT_ISO}
rc=$?
if [ $rc -ne 0 ]; then
    echo "Call to $(basename ${SETUP_PATCH_REPO}) failed with rc=$rc. Aborting..."
    exit $rc
fi

echo "Patched ISO: ${OUTPUT_ISO}"