#!/bin/bash

set -eo pipefail

ARCH="$(uname -m)"
IMAGE_TYPE='default'
RELEASE='8'
BASE_DIR='./result'
PROGRAM_DIR="$(dirname -- "$0")"
VERSION='0.0.1'

show_usage() {
    echo -e 'Generates an MSVSphere container image RootFS and Dockerfile\n'
    echo -e 'Usage: build-image.sh [OPTION]...\n'
    echo '  -h, --help             show this message and exit'
    echo "  -r, --release RELEASE  target MSVSphere release, default is ${RELEASE}"
    echo '  -t, --type TYPE        image type, supported values are: default, systemd.'
    echo "                         Default value is '${IMAGE_TYPE}'"
    echo "  -o, --output DIR       output directory path, default is ${BASE_DIR}"
    echo '  -v, --version          show program version and exit'
}

log_error() {
    echo "ERROR  : ${1}" >&2
}

gen_dockerfile() {
    local -r image_name="${1}"
    local -r build_date="$(date --rfc-3339=seconds --utc)"
    echo 'FROM scratch'
    echo "ADD ${image_name} /"
    echo ''
    # see https://github.com/opencontainers/image-spec/blob/master/annotations.md for details
    echo "LABEL org.opencontainers.image.title=\"MSVSphere ${RELEASE} ${ARCH} ${IMAGE_TYPE} image\""
    echo 'LABEL org.opencontainers.image.vendor="MSVSphere"'
    echo 'LABEL org.opencontainers.image.licenses="MIT"'
    echo "LABEL org.opencontainers.image.created=\"${build_date}\""
    echo 'LABEL org.opencontainers.image.authors="Eugene Zamriy <ezamriy@msvsphere.ru>"'
    echo 'LABEL org.opencontainers.image.source="https://git.inferitos.ru/msvsphere/docker-images"'
    echo ''
    #
    case "${IMAGE_TYPE}" in
    default)
        echo 'CMD ["/bin/bash"]'
        ;;
    systemd)
        echo 'STOPSIGNAL SIGRTMIN+3'
        echo ''
        echo 'CMD ["/sbin/init"]'
        ;;
    *)
        log_error "unsupported image type ${IMAGE_TYPE}"
        exit 1
        ;;
    esac
}

collect_logs() {
    local -r logs_dir="${1}/logs"
    mkdir "${logs_dir}"
    if [[ -d anaconda ]]; then
        mv anaconda "${logs_dir}/"
    fi
    mv ./*.log "${logs_dir}/"
}

main() {
    local -r image_name="msvsphere-${RELEASE}-${IMAGE_TYPE}.tar.xz"
    local -r ks_file="${PROGRAM_DIR}/kickstarts/msvsphere-${RELEASE}-${IMAGE_TYPE}.ks"
    local -r project="MSVSphere ${RELEASE} ${IMAGE_TYPE} Docker image"
    local -r result_dir="${BASE_DIR%%/}/${RELEASE}-${IMAGE_TYPE}"
    local -r docker_file="${result_dir}/Dockerfile"
    if [[ -d "${result_dir}" ]]; then
        log_error "directory ${result_dir} is already exist, please remove it first"
        exit 1
    elif [[ ! -f "${ks_file}" ]]; then
        log_error "kickstart file ${ks_file} is not found"
        exit 1
    fi
    # generate RootFS tarball
    livemedia-creator --no-virt --make-tar \
        --project "${project}" \
        --releasever "${RELEASE}" \
        --image-name "${image_name}" \
        --ks "${ks_file}" \
        --resultdir "${result_dir}" \
        --anaconda-arg "--nosave all"
    # generate Dockerfile and save build logs
    gen_dockerfile "${image_name}" >"${docker_file}"
    collect_logs "${result_dir}"
}

if [[ "${BASH_SOURCE[0]}" == "${0}" ]]; then
    ARGS=()
    while [[ $# -gt 0 ]]; do
        case ${1} in
        -h | --help)
            show_usage
            exit 0
            ;;
        -r | --release)
            if [[ -z "${2}" ]]; then
                log_error 'release is required'
                exit 2
            fi
            RELEASE="${2}"
            shift
            shift
            ;;
        -t | --type)
            case "${2}" in
            default | systemd)
                IMAGE_TYPE="${2}"
                ;;
            *)
                log_error "unsupported image type '${2}'"
                exit 2
                ;;
            esac
            shift
            shift
            ;;
        -o | --output)
            if [[ -z "${2}" ]]; then
                log_error 'output directory path is required'
                exit 2
            fi
            BASE_DIR="${2}"
            shift
            shift
            ;;
        -v | --version)
            echo "${VERSION}"
            exit 0
            ;;
        -*)
            log_error "unknown option ${1}"
            exit 2
            ;;
        *)
            ARGS+=("${1}")
            shift
            ;;
        esac
    done
    main
fi