# args: source, newroot, mountpoint
_mnt_dmsnapshot() {
    local img="${1}"
    local mnt="${2}"
    local img_fullname="${img##*/}";
    local img_name="${img_fullname%%.*}"
    local dm_snap_name="${dm_snap_prefix}_${img_name}"
    local ro_dev ro_dev_size rw_dev

    ro_dev=$(losetup --find --show --read-only "${img}")
    echo ${ro_dev} >> /run/miso/used_block_devices
    ro_dev_size=$(blockdev --getsz ${ro_dev})

    if [[ "${cow_persistent}" == "P" ]]; then
        if [[ -f "/run/miso/cowspace/${cow_directory}/${img_name}.cow" ]]; then
            msg ":: Found '/run/miso/cowspace/${cow_directory}/${img_name}.cow', using as persistent."
        else
            msg ":: Creating '/run/miso/cowspace/${cow_directory}/${img_name}.cow' as persistent."
            truncate -s "${cow_spacesize}" "/run/miso/cowspace/${cow_directory}/${img_name}.cow"
        fi
    else
        if [[ -f "/run/miso/cowspace/${cow_directory}/${img_name}.cow" ]]; then
            msg ":: Found '/run/miso/cowspace/${cow_directory}/${img_name}.cow' but non-persistent requested, removing."
            rm -f "/run/miso/cowspace/${cow_directory}/${img_name}.cow"
        fi
        msg ":: Creating '/run/miso/cowspace/${cow_directory}/${img_name}.cow' as non-persistent."
        truncate -s "${cow_spacesize}" "/run/miso/cowspace/${cow_directory}/${img_name}.cow"
    fi

    rw_dev=$(losetup --find --show "/run/miso/cowspace/${cow_directory}/${img_name}.cow")
    echo ${rw_dev} >> /run/miso/used_block_devices

    dmsetup create ${dm_snap_name} --table "0 ${ro_dev_size} snapshot ${ro_dev} ${rw_dev} ${cow_persistent} ${cow_chunksize}"

    _mnt_dev "/dev/mapper/${dm_snap_name}" "${mnt}" "-w" "defaults"
    echo $(readlink -f /dev/mapper/${dm_snap_name}) >> /run/miso/used_block_devices
}

# args: source, newroot, mountpoint
_mnt_overlayfs() {
    local src="${1}"
    local newroot="${2}"
    local mnt="${3}"
    local work_dir="/run/miso/overlay_root/work"
    local upper_dir="/run/miso/overlay_root/upper"

    mkdir -p "${upper_dir}" "${work_dir}"

    mount -t overlay overlay -o lowerdir="${src}",upperdir="${upper_dir}",workdir="${work_dir}" "${newroot}${mnt}"
}

# args: /path/to/image_file, mountpoint
_mnt_sfs() {
    local img="${1}"
    local mnt="${2}"
    local img_fullname="${img##*/}"
    local sfs_dev
    local oper=$( [[ -n "${ip}" && -n "${miso_http_srv}" ]] && echo "mv" || echo "cp" )

    if [[ "${copytoram}" == "y" ]]; then
        msg -n ":: Copying squashfs image to RAM..."
        if ! "${oper}" "${img}" "/run/miso/copytoram/${img_fullname}" ; then
            echo "ERROR: while copy '${img}' to '/run/miso/copytoram/${img_fullname}'"
            launch_interactive_shell
        fi
        img="/run/miso/copytoram/${img_fullname}"
        msg "done."
    fi
    sfs_dev=$(losetup --find --show --read-only "${img}")
    echo ${sfs_dev} >> /run/miso/used_block_devices
    _mnt_dev "${sfs_dev}" "${mnt}" "-r" "defaults"
}

# args: device, mountpoint, flags, opts
_mnt_dev() {
    local dev="${1}"
    local mnt="${2}"
    local flg="${3}"
    local opts="${4}"

    mkdir -p "${mnt}"

    msg ":: Mounting '${dev}' to '${mnt}'"

    while ! poll_device "${dev}" 30; do
        echo "ERROR: '${dev}' device did not show up after 30 seconds..."
        echo "   Falling back to interactive prompt"
        echo "   You can try to fix the problem manually, log out when you are finished"
        launch_interactive_shell
    done

    if mount -o "${opts}" "${flg}" "${dev}" "${mnt}"; then
        msg ":: Device '${dev}' mounted successfully."
    else
        echo "ERROR; Failed to mount '${dev}'"
        echo "   Falling back to interactive prompt"
        echo "   You can try to fix the problem manually, log out when you are finished"
        launch_interactive_shell
    fi
}

_verify_checksum() {
    local _status
    cd "/run/miso/bootmnt/${misobasedir}/${arch}"
    md5sum -c $1.md5 > /tmp/checksum.log 2>&1
    _status=$?
    cd "${OLDPWD}"
    return ${_status}
}

_verify_signature() {
    local _status
    cd "/run/miso/bootmnt/${misobasedir}/${arch}"
    gpg --homedir /gpg --status-fd 1 --verify $1.sfs.sig 2>/dev/null | grep -qE '^\[GNUPG:\] GOODSIG'
    _status=$?
    cd "${OLDPWD}"
    return ${_status}
}

_find_dev_by_path () {
    local path="${1}"
    local tmp_mnt=/tmp_mnt
    local _mnt
    local a d
    local device

    [[ "$path" ]] || return 1

    mkdir -p "${tmp_mnt}"

    for a in 1 2 3; do
        for d in $(awk '{ print "/dev/"$4 }' /proc/partitions); do

            # If the device is already mounted, it shouldn't be
            # unmounted after the check.

            grep -q "^$d " /proc/mounts && {
                _mnt=$(grep "^$d " /proc/mounts | cut -d ' ' -f 2)
                unmount=
            } || {
                mount -r -t auto "${d}" "${tmp_mnt}" 2> /dev/null || continue
                _mnt="${tmp_mnt}"
                unmount=true
            }

            # File exists in $d. Save $d on $device.

            [[ -f "${_mnt}/${path}" ]] && device="${d}"
            [[ "${unmount}" ]] && umount "${tmp_mnt}" 2> /dev/null || true
            [[ "${device}" ]] && {
                echo "${device}"
                return
            }

        done
        sleep 1
    done
    return 1
}

run_hook() {
    [[ -z "${arch}" ]] && arch="$(uname -m)"
    [[ -z "${copytoram_size}" ]] && copytoram_size="75%"
    [[ -z "${misobasedir}" ]] && misobasedir="manjaro"

    [[ -z "${dm_snap_prefix}" ]] && dm_snap_prefix="manjaro"
    misodevice=$(_find_dev_by_path /.miso)
    [[ -z "${misodevice}" ]] && misodevice="/dev/disk/by-label/${misolabel}"
    [[ -z "${cow_spacesize}" ]] && cow_spacesize="256M"
    [[ -z "${overlay_root_size}" ]] && overlay_root_size="75%"

    if [[ -n "${cow_label}" ]]; then
        cow_device="/dev/disk/by-label/${cow_label}"
        [[ -z "${cow_persistent}" ]] && cow_persistent="P"
    elif [[ -n "${cow_device}" ]]; then
        [[ -z "${cow_persistent}" ]] && cow_persistent="P"
    else
        cow_persistent="N"
    fi

    [[ -z "${cow_flags}" ]] && cow_flags="defaults"
    [[ -z "${cow_directory}" ]] && cow_directory="persistent_${misolabel}/${arch}"
    [[ -z "${cow_chunksize}" ]] && cow_chunksize="8"

    # set mount handler for miso
    mount_handler="miso_mount_handler"
}

# This function is called normally from init script, but it can be called
# as chain from other mount handlers.
# args: /path/to/newroot
miso_mount_handler() {
    local newroot="${1}"

    if ! mountpoint -q "/run/miso/bootmnt"; then
        _mnt_dev "${misodevice}" "/run/miso/bootmnt" "-r" "defaults"
        if [[ "${copytoram}" != "y" ]]; then
            echo $(readlink -f ${misodevice}) >> /run/miso/used_block_devices
        fi
    fi

    if [[ "${checksum}" == "y" ]]; then
        for fs in rootfs desktopfs mhwdfs livefs; do
            if [[ -f "/run/miso/bootmnt/${misobasedir}/${arch}/${fs}.sfs" ]]; then
                if [[ -f "/run/miso/bootmnt/${misobasedir}/${arch}/${fs}.md5" ]]; then
                    msg -n ":: Self-test requested, please wait..."
                    if _verify_checksum "${fs}"; then
                        msg "done. Checksum is OK, continue booting."
                    else
                        echo "ERROR: one or more files are corrupted"
                        echo "see /tmp/checksum.log for details"
                        launch_interactive_shell
                    fi
                else
                    echo "ERROR: checksum=y option specified but ${misobasedir}/${arch}/${fs}.md5 not found"
                    launch_interactive_shell
                fi
            fi
        done
    fi

    if [[ "${verify}" == "y" ]]; then
        for fs in rootfs desktopfs mhwdfs livefs; do
            if [[ -f "/run/miso/bootmnt/${misobasedir}/${arch}/${fs}.sfs" ]]; then
                if [[ -f "/run/miso/bootmnt/${misobasedir}/${arch}/${fs}.sfs.sig" ]]; then
                    msg -n ":: Signature verification requested, please wait..."
                    if _verify_signature "${fs}"; then
                        msg "done. Signature is OK, continue booting."
                    else
                        echo "ERROR: one or more files are corrupted"
                        launch_interactive_shell
                    fi
                else
                    echo "ERROR: verify=y option specified but ${misobasedir}/${arch}/${fs}.sfs.sig not found"
                    launch_interactive_shell
                fi
            fi
        done
    fi

    if [[ "${copytoram}" == "y" ]]; then
        msg ":: Mounting /run/miso/copytoram (tmpfs) filesystem, size=${copytoram_size}"
        mkdir -p /run/miso/copytoram
        mount -t tmpfs -o "size=${copytoram_size}",mode=0755 copytoram /run/miso/copytoram
    fi

    if [[ -n "${cow_device}" ]]; then
        _mnt_dev "${cow_device}" "/run/miso/cowspace" "-r" "${cow_flags}"
        echo $(readlink -f ${cow_device}) >> /run/miso/used_block_devices
        mount -o remount,rw "/run/miso/cowspace"
    else
        msg ":: Mounting /run/miso/cowspace (tmpfs) filesystem, size=${cow_spacesize}..."
        mkdir -p /run/miso/cowspace
        mount -t tmpfs -o "size=${cow_spacesize}",mode=0755 cowspace /run/miso/cowspace
    fi
    mkdir -p -m 0700 "/run/miso/cowspace/${cow_directory}"

    msg -n ":: Mounting overlay root (tmpfs) filesystem, size=${overlay_root_size}..."
    mkdir -p /run/miso/overlay_root
    mount -t tmpfs -o "size=${overlay_root_size}",mode=0755 overlay_root /run/miso/overlay_root

    local src="/run/miso/bootmnt/${misobasedir}/${arch}"
    local dest_sfs="/run/miso/sfs" dest_img="/run/miso/img"
    local lower_dir

    for sfs in livefs mhwdfs desktopfs rootfs; do
        if [[ -f "${src}/${sfs}.sfs" ]]; then
            _mnt_sfs "${src}/${sfs}.sfs" "${dest_sfs}/${sfs}"
            if [[ -f "${dest_sfs}/${sfs}/${sfs}.img" ]]; then
                mkdir -p ${dest_img}
                lower_dir=${lower_dir:-}${lower_dir:+:}"${dest_img}/${sfs}"
                _mnt_dmsnapshot "${dest_sfs}/${sfs}/${sfs}.img" "${dest_img}/${sfs}"
            else
                lower_dir=${lower_dir:-}${lower_dir:+:}"${dest_sfs}/${sfs}"
            fi
        fi
    done

    _mnt_overlayfs "${lower_dir}" "${newroot}" "/"

    if [[ "${copytoram}" == "y" ]]; then
        umount -d /run/miso/bootmnt
        mkdir -p /run/miso/bootmnt/${misobasedir}/${arch}
        mount -o bind /run/miso/copytoram /run/miso/bootmnt/${misobasedir}/${arch}
    fi
}

# vim:ft=sh:ts=4:sw=4:et: