#! /usr/bin/env bash
set -ueEo pipefail

SCRIPT_DIR="$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")" && pwd)"

check_tools()
{
    if ! udisksctl status >/dev/null
    then 
        echo "udisks2 is required"
        exit 1
    fi
    if ! wget --version >/dev/null
    then
        echo "wget is required"
        exit 1
    fi
    if ! jigdo-lite --version >/dev/null
    then
        echo "jigdo-file is required"
        exit 1
    fi
}

check_tools

usage() {
cat <<EOF

Upgrade an existant official debian iso to last revision.

options:
    -c|--configfile         Specify a config file 
    -d|--destination        Path or filename to produce the new isofile
    -h|--help               Show this message.
    -i|--isofile            Isofile to upgrade
    -j|--jigdo              Jigdo file local storage path
    -m|--mirror             Download pacakge repository 
    -p|--proxy              specify a optional debian apt proxy
    -v                      Show more output.

Configfile contents example:
http_proxy=http://<ip>:<port>
ISOFILE=$HOME/debian-13.0.0-amd64-netinst.iso
JIGDO=$HOME/jigdo
DESTINATION=$HOME
MIRROR=http://deb.debian.org
EOF
}

main() {

    cd "$SCRIPT_DIR"

    ISOFILE=""
    VERBOSITY=0

    while [[ $# -gt 0 ]]; do
      case $1 in
        -c|--configfile)
            CONFIGFILE=$2
            [[ -z ${CONFIGFILE} ]] && echo "missing argument $1" && exit 1
            if [ -e "${CONFIGFILE}" ]
            then
                # shellcheck source=/dev/null
                source "${CONFIGFILE}"
            else
                echo "ERROR: specified configfile not found"*
                exit 1
            fi
            shift
            shift
        ;;
        -d|--destination)
            DESTINATION=$2
            [[ -z ${DESTINATION} ]] && echo "missing argument $1" && exit 1
            shift
            shift
        ;;
        -h|--help)
            usage
            exit 0
        ;;
        -i|--isofile)
            ISOFILE=$2
            [[ -z ${ISOFILE} ]] && echo "missing argument $1" && exit 1
            shift
            shift
        ;;
        -j|--jigdo)
            JIGDOPATH=$2
            [[ -z ${JIGDOPATH} ]] && echo "missing argument $1" && exit 1
            shift
            shift
        ;;
        -m|--mirror)
            MIRROR=$2
            [[ -z ${MIRROR} ]] && echo "missing argument $1" && exit 1
            shift
            shift
        ;;
        -p|--proxy)
            http_proxy=$2
            [[ -z ${http_proxy} ]] && echo "missing argument $1" && exit 1
            shift
            shift
        ;;
        -v|--verbose)
            VERBOSITY=1
            shift
        ;;
        *)
            echo "ERROR: unknown option: $1"
            usage
            exit 1
        ;;
      esac
    done

    if [ ! -e "$ISOFILE" ]
    then
        echo "ERROR: provide the source isofile."
        exit 1
    fi

    DESTINATION=${DESTINATION:-$(pwd)}
    JIGDOPATH=${JIGDOPATH:-$HOME/jigdo}
    http_proxy=${http_proxy:-}
    if [ ! -d "${JIGDOPATH}" ]
    then
        mkdir -p "${JIGDOPATH}"
    fi
    MIRROR=${MIRROR:-http://deb.debian.org/}

    # debian-13.0.0-amd64-netinst.iso
    bnfile=$(basename "${ISOFILE}")
    distribution=$( echo "${bnfile}" |cut --delimiter='-' --fields=1 )
    majorversion=$( echo "${bnfile}" |cut --delimiter='-' --fields=2 |cut --delimiter='.' --fields=1 )
    minorversion=$( echo "${bnfile}" |cut --delimiter='-' --fields=2 |cut --delimiter='.' --fields=2 )
    incrementalversion=$( echo "${bnfile}" |cut --delimiter='-' --fields=2 |cut --delimiter='.' --fields=3 )
    architecture=$( echo "${bnfile}" |cut --delimiter='-' --fields=3)
    flavor=$( echo "${bnfile}" |cut --delimiter='-' --fields=4 |cut --delimiter='.' --fields=1 )
    extension=$( echo "${bnfile}" |cut --delimiter='-' --fields=4 |cut --delimiter='.' --fields=2 )
    
    if [[ ${VERBOSITY} -gt 0 ]]
    then
        echo "isofile = ${ISOFILE}"
        echo "reconstructed = ${distribution}-${majorversion}.${minorversion}.${incrementalversion}-${architecture}-${flavor}.iso"
    fi

    if [ "${extension}" != "iso" ]
    then
        echo "Not implemented for extension : ${extension}"
        exit 1
    fi

    if [ "${distribution}" != "debian" ]
    then
        echo "Not implemented for distribution : ${distribution}"
        exit 1
    fi

    case ${flavor} in
        netinst)
            cdimagejigdodirectory="jigdo-cd"
        ;;
        *)
            echo "Not implemented for flavor : ${flavor}"
            exit 1
        ;;
    esac

    case ${majorversion} in
    13)
        # https://cdimage.debian.org/cdimage/release/current/amd64/jigdo-cd/debian-13.5.0-amd64-netinst.jigdo
        jigdorooturl="https://cdimage.debian.org/cdimage/release/current"
        cdimagetargeturl="${jigdorooturl}/${architecture}/${cdimagejigdodirectory}"
    ;;
    12)
        # https://cdimage.debian.org/cdimage/archive/
        # https://cdimage.debian.org/cdimage/archive/12.14.0/i386/jigdo-cd/debian-12.14.0-i386-netinst.jigdo
        jigdorooturl=https://cdimage.debian.org/cdimage/archive
        # compute the target url is required for archive section
        cdimagearchiveindex=/tmp/jigdo-${majorversion}-index.html
        if wget ${jigdorooturl} --output-document "${cdimagearchiveindex}"
        then
            targetversion=$( grep "[DIR]" "${cdimagearchiveindex}" | grep "a href=\"${majorversion}" | cut --delimiter='.' --fields=2 | sort --numeric-sort | tail --lines=1 )
            cdimagetargeturl="${jigdorooturl}/${majorversion}.${targetversion}.${incrementalversion}/${architecture}/${cdimagejigdodirectory}"
        else
            echo "download error ${cdimagetargeturl}/SHA512SUMS"
            echo "check your network connection"
            exit 1
        fi
    ;;
    *)
        echo "Not implemented"
        exit 1
    esac

    sha512filelist=${JIGDOPATH}/jigdo-${distribution}-${majorversion}-last-${architecture}-${flavor}-sha512sum

    if [[ ${VERBOSITY} -ge 0 ]]
    then
        echo "isofile = ${ISOFILE}"
        echo "reconstructed = ${distribution}-${majorversion}.${minorversion}.${incrementalversion}-${architecture}-${flavor}.iso"
        echo "cdimagetargeturl = ${cdimagetargeturl}"
        echo "sha512filelist = ${sha512filelist}"
    fi

    if wget "${cdimagetargeturl}/SHA512SUMS" --output-document "${sha512filelist}"
    then
        # retrieve the cdimage "directory checksum" to extract last "current" version
        targetjigdoname=$( grep "${distribution}-${majorversion}.*-${architecture}-${flavor}.jigdo" "${sha512filelist}" | cut --delimiter=' ' --fields=3 )
        targettemplatename=$( grep "${distribution}-${majorversion}.*-${architecture}-${flavor}.template" "${sha512filelist}" | cut --delimiter=' ' --fields=3 )
        targetversion=$( echo "${targetjigdoname}" | cut --delimiter='-' --fields=2 | cut --delimiter='.' --fields=2 )
        if [[ ${minorversion} -gt ${targetversion} ]]
        then
            echo "Rule violated : your version is more advanced than target"
            echo "Not implemented"
            exit 1
        elif [[ ${minorversion} -lt ${targetversion} ]]
        then
            # download jigdo if not already done or bad checksum
            jigdofilepath=$(find "${JIGDOPATH}" -name "${distribution}-${majorversion}.${targetversion}.${incrementalversion}-${architecture}-${flavor}.jigdo")
            if [[ ! -e "${jigdofilepath}" ]] || ! sha512sum --ignore-missing --check "${sha512filelist}" "${jigdofilepath}"
            then
                if wget "${cdimagetargeturl}/${targetjigdoname}" --output-document "${JIGDOPATH}/${targetjigdoname}"
                then
                    jigdofilepath="${JIGDOPATH}/${targetjigdoname}"
                    pushd "${JIGDOPATH}" || exit 1
                        echo "sha512sum --ignore-missing --check ${sha512filelist}"
                        if ! sha512sum --ignore-missing --check "${sha512filelist}"
                        then
                            echo "download error : bad checksum : ${cdimagetargeturl}/${targetjigdoname}"
                            echo "check your network connection"
                            exit 1
                        fi
                    popd
                fi
            else
                echo "jigdo file ${jigdofilepath} is ok"
            fi
            # download template if not already done or bad checksum
            templatefilepath=$(find "${JIGDOPATH}" -name "${distribution}-${majorversion}.${targetversion}.${incrementalversion}-${architecture}-${flavor}.template")
            if [[ ! -e "${templatefilepath}" ]] || ! sha512sum --ignore-missing --check "${sha512filelist}" "${templatefilepath}"
            then
                if wget "${cdimagetargeturl}/${targettemplatename}" --output-document "${JIGDOPATH}/${targettemplatename}"
                then
                    templatefilepath="${JIGDOPATH}/${targettemplatename}"
                    pushd "${JIGDOPATH}" || exit 1
                        echo "sha512sum --ignore-missing --check ${sha512filelist}"
                        if ! sha512sum --ignore-missing --check "${sha512filelist}"
                        then
                            echo "download error : bad checksum : ${cdimagetargeturl}/${targettemplatename}"
                            echo "check your network connection"
                            exit 1
                        fi
                    popd
                fi
            else
                echo "template file ${templatefilepath} is ok"
            fi
        else
            echo "Already on the last version"
            exit 0
        fi
    else
        echo "download error ${cdimagetargeturl}/SHA512SUMS"
        echo "check your network connection"
        exit 1
    fi

    # mount loop image
    looplog=/tmp/udisks_loop-setup_$(basename "${ISOFILE}").log
    mountlog=/tmp/udisks_mount_$(basename "${ISOFILE}").log

    if ! ( [ ! -d "/media/$(whoami)" ] && ! find "/media/$(whoami)" -maxdepth 1 -type d -name "*${majorversion}.${minorversion}.${incrementalversion}*${architecture}*" )
    then
        if udisksctl loop-setup --read-only --file="${ISOFILE}" | tee "${looplog}"
        then
            blockdevice=$( cut --delimiter=' ' --fields=5 "${looplog}" | cut --delimiter='.' --fields=1 )
            devicename=$( echo "${blockdevice}" | cut --delimiter='/' --fields=3 )
        else
            echo "ERROR : loop-setup"
            exit 1
        fi
        if [[ ! "${blockdevice}" =~ ^/dev/loop*$ ]] && lsblk | grep "^${devicename}"
        then
            if udisksctl mount --block-device "${blockdevice}p1" | tee "${mountlog}"
            then
                if ! grep --quiet "^Mounted" "${mountlog}"
                then
                    echo "ERROR : mount"
                    exit 1
                fi
            else
                echo "ERROR : mount"
                exit 1
            fi
        else
            echo "ERROR : loop-setup"
            echo "It may not work by ssh or systemd-run because of polkit"
            echo "See https://github.com/coldfix/udiskie/wiki/Permissions"
            exit 1
        fi
    fi

    # MOUNTPATH=$( find "/media/$(whoami)" -maxdepth 1 -type d -name "*${majorversion}.${minorversion}.${incrementalversion}*${architecture}*" )

    if [ -n "${http_proxy}" ]
    then
        proxyoption="-e http_proxy=${http_proxy}"
    else
        proxyoption=""
    fi
    cat > "${HOME}"/.jigdo-lite <<EOF
jigdo=''
debianMirror='${MIRROR}/debian/'
nonusMirror='${MIRROR}/debian-non-US/'
tmpDir='${JIGDOPATH}/db'
jigdoOpts='--cache jigdo-file-cache.db'
wgetOpts='-nv --passive-ftp --dot-style=mega --continue --timeout=30 ${proxyoption} '
scanMenu='$( find "/media/$(whoami)" -maxdepth 1 -type d -name "*${majorversion}.${minorversion}.${incrementalversion}*${architecture}*" )/'
filesPerFetch='30'
EOF

    if jigdo-lite --noask "${jigdofilepath}"
    then
        echo "completed"
    else
        echo "Error: something was wrong"
        exit 1
    fi

}

if [[ "${BASH_SOURCE[0]}" == "$0" ]]; then
    main "$@"
fi