#!/bin/bash
# slackware-upgrade-system - full upgrade of a Slackware installation
# Copyright (C) 2019 Sergey Poznyakoff.
#
# Slackware-upgrade-system is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License as published 
# by the Free Software Foundation; either version 3, or (at your option)
# any later version.
#
# Slackware-upgrade-system is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with slackware-upgrade-system.  If not, see
# <http://www.gnu.org/licenses/>.

set -e

# Slackware root directory
rooturl=
# Log file name
logfile=
# 'y', if dry-run mode is requested
dry_run=
# If 'y', don't ask anything, assume "y" as answer to all quieries
assume_y=
# Output verbosity: '' - normal, 'v' - verbose, 'q' - quiet
verbosity=
# If 'y', install all packages
install_all=
# Names of the series that should be installed in addition to already installed
# packages.  Ignored, if install_all is set.
install_series=
# Names of additional packages.
install_packages=
# Name of the keep-list file.
keep_file=

# Internal variables
remote=
tempdir=${TMP:-/tmp}/slackupg.$$
installed_list=$tempdir/installed.list
avail_index=$tempdir/avail.index
avail_list=$tempdir/avail.list
series_names="a
ap
d
e
f
k
l
n
t
tcl
x
xap
xfce
y
"

function tempdir_create() {
    u=$(umask)
    umask 077
    mkdir $tempdir
    umask $u
}

function tempdir_remove() {
    rm -rf $tempdir
}

function usage() {
    cat <<EOF
usage: $0 [-anqvy] [-k FILE] [-s SERIES] [DIRECTORY]
Upgrade Slackware installation

Options are:

  -a             install all series except kde*
  -h             display this help list and exit
  -k FILE        preserve packages listed in FILE
  -n             dry-run mode: do nothing, print what would have been done
  -p PACKAGE     install additional package
  -q             quiet mode: suppress all messages, except errors
  -s SERIES      additionally install all packages from SERIES
  -v             display messages about individual packages
  -y             assume "yes" to all queries

EOF
}

function getyn() {
    if [ "$assume_y" = y ]; then
	/bin/true
    else
	local dfl=$1
	shift
	case "$dfl" in
	    [yY]) dfl_s=" [Y/n]";;
	    [nN]) dfl_s=" [y/N]";;
	    *)    dfl_s=""; dlf="";;
	esac

	printf "%s$dfl_s? " "$*"
	read REPLY </dev/tty
	case "${REPLY:-$dfl}" in
	    [yY]*)  /bin/true;;
	    *)	/bin/false;;
	esac
    fi
}

function error {
    echo >&2 "$0: $*"
    if [ -n "$logfile" ]; then
	echo >$logfile "$0: $*"
    fi
}

function abend {
    error "$@"
    tempdir_remove
    exit 1
}

function package_file_name() {
    pkg=$(awk -vname=$1 '$1==name { print $2 }' $avail_index)
    if [ -z "$pkg" ]; then
	error "package $name not found in index (should not happen!)"
    else
        echo $pkg
    fi	    
}

function package_name_md5sum() {
    pkg=$(awk -vname=$1 '$1==name { print $3 }' $avail_index)
}

function check_package_md5sum() {
    if [ -n "$checksums" ]; then
	awk -vcname="$1" -vdname="$2" \
	    '$2==cname { print $1 "  " dname }' $checksums | \
	 md5sum --status --check
    fi
}

function all_package_names() {
    grep -v '.*/kde[^/]*/' $avail_index | cut -d ' ' -f 1
}

function series_package_names() {
    grep '.*/'"$1/" $avail_index | cut -d ' ' -f 1
}

function catfile() {
    echo $rooturl/${1#./}
}

function download_curl {
    curl $CURL_OPTIONS -L -sS -o$1 $2
}

function download_wget {
    if ! wget $WGET_OPTIONS -nv -o wget.log -O$1 $2; then
	grep -i "failed\|error" wget.log
	/bin/false
    fi
}

function dnfunc_init() {
    if [ -z "$dnfunc" ]; then
	if curl --version >/dev/null 2>&1; then
	    dnfunc=download_curl
	elif wget --version >/dev/null 2>&1; then
	    dnfunc=download_wget
	else
	    abend "neither curl nor wget is installed"
	fi
    fi
}

function download() {
    local name=$(basename $1)
    local url=$(catfile $1)
    if $dnfunc $name $url; then
        echo $name
    fi
}

function getfile() {
    local name=$(if [ -n "$remote" ]; then
	            download $1
                 else
	            catfile $1
                 fi)
    
    if [ -n "$2" ]; then
	ascname=$(if [ -n "$remote" ]; then
	            download $1.asc
                  else
	            catfile $1.asc
                  fi)
	if [ -n "$ascname" ] \
	    && ${GPG:-gpg} --verify $ascname $name 2>/dev/null; then
  	    :
        else
	    error "gpg verification failed for $name"
	    return
    	fi
    fi

    if [ -n "$checksums" ] && ! check_package_md5sum $1 $name; then
	error "ERROR: $1: checksum failed"
	name=
    fi
    echo $name
}

function dropfile() {
    if [ -n "$remote" ]; then
	rm $1
    fi
}    

function upgrade_package() {
    local name=$1
    shift
    if [ -n "$dry_run" ]; then
	echo "upgradepkg $@ $name"
    else
	file=$(getfile $name)
	if [ -n "$file" ]; then
	    if [ "$verbosity" = 'v' ]; then
		upgradepkg "$@" $file | tee -a $logfile | sed -n -e '/^| Upgrading/s/^| //p'
	    else
		upgradepkg "$@" $file >> $logfile
	    fi
	    dropfile $file
	fi
    fi
}

function version_gt() {
    test "$(echo "$@" | tr " " "\n" | sort -V | head -n 1)" != "$1"
}

while getopts "ahknp:qs:vy" OPTION
do
    case $OPTION in
	a) install_all=y;;
	h) usage
	   exit 0;;
	k) keep_file=$OPTARG;;
	n) dry_run=y;;
	p) install_packages="$install_packages $OPTARG";;
	q) verbosity=q;;
	v) verbosity=v;;
	s) install_series="$install_series $OPTARG";;
	y) assume_y=y;;
	*) usage >&2
	   exit 1
    esac
done

shift $(($OPTIND - 1))
case $# in
    0) ;;
    1) rooturl=$1;;
    *) error "unexpected arguments"
       usage >&2
       exit 1
esac

if [ $(id -u) != "0" ]; then
    abend "must be root"
fi

# Sanity check
if [ ! -s /etc/os-release ]; then
    abend "/etc/os-release doesn't exist"
fi

. /etc/os-release

if [ "$ID" != "slackware" ]; then
    abend "this doesn't seem to be a Slackware installation"
fi

case "$(uname -m)" in
    i?86)   ARCH=;;
    x86_64) ARCH=64;;
    *)      abend "architecture $(uname -m) is not yet supported"
esac

tempdir_create
cd $tempdir

mirrors_url=https://mirrors.slackware.com/slackware
if [ -z "$rooturl" ]; then
    dnfunc_init
    if ! $dnfunc index.html $mirrors_url; then
	abend "exiting"
	exit 1
    fi
    version_rx=$(echo $VERSION | sed -e 's/\./\\./g')
    new_version=$(cat index.html |\
      tr '<' '\n' |\
      sed -n -r \
	  -e 's/.*^a href="slackware'$ARCH'-([[:digit:].]+)\/?".*/\1/p'|\
      sed -n -e "/$version_rx/{" -en -ep -e '}' )
    if [ -n "$new_version" ]; then
	rooturl="$mirrors_url/slackware$ARCH-$new_version"
	error "info: using $rooturl as distribution top-level URL"
    else
	abend "can't find distribution newer than $VERSION; please supply URL if you have any"
    fi
fi    

# Check if rooturl is local or remote
case $rooturl in
    /*) unset remote
	;;
    http://*|https://*|ftp://*|ftps://*)
	dnfunc_init
	remote=1
	;;
    *)  abend "root directory must be absolute file name or URL"
esac

if [ -z "$remote" ]; then
    # Check if rooturl exists and contains the necessary files and directories
    if [ ! -d $rooturl ]; then
	abend "$rooturl does not exist"
    fi
fi

# Check if rooturl contains all we need
error "info: verifying distribution..."

#
# Download CHECKSUMS.md5. So far it is the only file that is gpg-checked.
# For the rest we rely on MD5 sums.
checksums=$(getfile CHECKSUMS.md5 gpg)
if [ -z "$checksums" ]; then
    abend "CHECKSUMS.md5 not found in $rooturl"
fi

announce=$(tail +13 $checksums | \
       sed -n -r\
           -e 's/^[0-9a-fA-F]+[[:space:]]+(\.\/ANNOUNCE\.[[:digit:]_]+)$/\1/p')
if [ -z "$announce" ]; then
    abend "ANNOUNCE not found in $rooturl"
fi    
file=$(getfile $announce)
if [ -z "$file" ]; then
    abend "file $announce not found in $rooturl"
fi    

newversion=$(echo "$announce" | sed -e 's/\.\/ANNOUNCE\.//' -e 's/_/./g')
if [ -z "$newversion" ]; then
    abend "cannot determine new version"
fi

# Create list and index of available files
tail +13 $checksums | \
 sed -r \
     -n \
     -e 's/^[0-9a-fA-F]+[[:space:]]+(\.\/slackware(64)?\/.*\/(.*)-[^-]+-(i386|x86(_64)?|arm|noarch|fw)-[[:digit:]]+(_.*)?\.t.z)$/\3 \1/p' | \
 tee $avail_index | awk '{print $1}' | sort > $avail_list

# Initialize log file name
logstem=/var/log/slackware-upgrade-system-$VERSION-$newversion
logfile=$logstem.log

# Check if pkgdir exists and contains the necessary files and directories
for series in $series_names
do
    n=$(sed -n -r -e 's/^[^[:space:]]+[[:space:]]+(\.\/slackware(64)?\/'$series'\/.*\.t.z)$/\1/p' $avail_index | head -1)
    if [ -z "$n" ]; then
	abend "no files in series $series"
    fi
    file=$(getfile $n)
    if [ -z "$file" ]; then
	abend "exiting"
    fi
    dropfile $file
done    

# Build a list of installed packages
ls /var/log/packages |\
 sed -r -e 's/-[^-]+-(i386|x86(_64)?|arm|noarch|fw)-[[:digit:]]+(_.*)?//' |\
 sort > $installed_list

# Build a list of packages to install
(if [ -n "$install_all" ]; then
    all_package_names
else    
    comm -1 -2 $installed_list $avail_list
fi    
for s in $install_series
do
    series_package_names $s
done
if [ -n "$install_packages" ]; then
    echo $install_packages
fi) | sort -u  > candidates

# Build a list of packages that should be removed after install
remove_list=$logstem.removed

comm -2 -3 $installed_list candidates > $remove_list.$$
if [ -s "$keep_file" ]; then
    grep -v '^#' $keep_file | \
	tr -s '\n' | sort | comm -2 -3 $remove_list.$$ - > $remove_list
    rm $remove_list.$$
else
    mv $remove_list.$$ $remove_list
fi

# Disable interrupts during critical section
trap '' HUP INT QUIT ABRT

if [ -s $remove_list -a "$verbosity" != 'q' ]; then
    (cat <<EOF
INFO: The following packages will be removed.  You will have to manually
restore them after the upgrade.  The package names are preserved for you
in the file $remove_list:

EOF
cat $remove_list) | ${PAGER:-more}
fi

if ! version_gt $newversion $VERSION; then
    if ! getyn n "Distribution version $newversion is same or lower than current version $VERSION. Downgrade"; then
	tempdir_remove
	echo Exiting
	exit 0
    fi
fi

if ! getyn n "Ready for upgrade from $VERSION to $newversion. Continue"; then
    tempdir_remove
    echo "Exiting"
    exit 0
fi

# Upgrade the glibc shared libraries.
echo "$0: Upgrading shared libraries"
upgrade_package $(package_file_name glibc-solibs)

# Upgrade the package utilities and related tools.
echo "$0: Upgrading package utilities"
for pkg in pkgtools tar xz findutils
do
    upgrade_package $(package_file_name $pkg)
done

# Upgrade the rest of packages
egrep -v '^(glibc-solibs|pkgtools|tar|xz|findutils)$' candidates |\
while read name
do
    package_file_name $name
done | sort -u | \
while read pkg
do
    s=$(basename ${pkg%/*})
    if [ "$prev" != "$s" ]; then
	echo "$0: installing selected files from series $s"
	prev=$s
    fi
    upgrade_package $pkg --install-new
done

if [ -s $remove_list ]; then
    echo "$0: removing packages"
    if [ -n "$dry_run" ]; then
	:
    elif [ "$verbosity" = 'v' ]; then
	removepkg $(cat $remove_list) | tee -a $logfile | grep '^Removing package'
    else
	removepkg $(cat $remove_list) >> $logfile
    fi
    echo "$0: see $remove_list for the list of packages that have been removed"
fi

echo "$0: upgrade finished; see $logfile for details"

tempdir_remove

conffiles=$logstem.conffiles
find /etc /usr/lib*/ /usr/share/vim -name "*.new" 2>/dev/null | \
    sort > $conffiles
if [ ! -s "$conffiles" ]; then
    rm $conffiles
fi

if [ "$verbosity" != 'q' ]; then
    echo "IMPORTANT!"
    if [ -s "$conffiles" ]; then
	cat <<EOF
Some of your config files may need fixing.  Please check the files from this
list and compare them with their counterparts without the ".new" suffix.
Remove the "*.new" files when finished.  The list of files follows:

EOF
	cat $conffiles
	cat <<EOF

For your convenience, this list is preserved in the file $conffiles.

EOF
    fi
    cat <<EOF
*Before* attempting to reboot your system, please make sure that the
bootloader has been updated for the new kernel!

Good luck!
EOF
fi