#!/bin/sh
# universal slack updater

# USER CONFIG SECTION START

# point this to the slack version directory of your favorite slack server
server="http://anorien.warwick.ac.uk/mirrors/slamd64/slamd64-12.1"
#server="http://slackware.mirrors.tds.net/pub/slackware/slackware-12.1"

# patches directory and main packages directory
patches="$server/patches"
slack="$server/slackware"

# config directory
config=~/.usu

# temporary directory
temp=/tmp/usu

# USER CONFIG SECTION END, it's recommended you do NOT edit below this line
#______________________________________________________________________________

# function that chops up package names in given directory
chopnames()
{
  # filter the list for names, version, arch, release
  cut -d - -f 1 "$1/revpacknames" | rev >> "$1/release"
  cut -d - -f 2 "$1/revpacknames" | rev >> "$1/arch"
  cut -d - -f 3 "$1/revpacknames" | rev >> "$1/version"
  cut -d - -f 1-3 --complement "$1/revpacknames" | rev >> "$1/names"
}

# insure sanity of config directory
# if config is a directory
if test -d "$config"
then
  # if blacklist is not a file
  if test ! -f "$config/blacklist"
  then
    rm -rf "$config/blacklist"
    echo > "$config/blacklist"
  fi
  # if update is not a directory
  if test ! -d "$config/update"
  then
    rm -f "$config/update"
    mkdir "$config/update"
  fi
  # if original is not a directory
  if test ! -d "$config/original"
  then
    rm -f "$config/original"
    mkdir "$config/original"
  fi
# if config is not a directory
else
  rm -f "$config"
  mkdir "$config"
  mkdir "$config/update"
  mkdir "$config/original"
  echo > "$config/blacklist"
fi

# clear and ready the temporary directory
if test -e "$temp"
then
  rm -rf "$temp"
fi
mkdir "$temp"
mkdir "$temp/packages"
mkdir "$temp/installed"
mkdir "$temp/update"
mkdir "$temp/original"
cd "$temp"

# get list of packages to be updated if newer
if ! wget -N -P "$config/update" "$patches/CHECKSUMS.md5"
then
  echo
  echo "Error downloading $patches/CHECKSUMS.md5 from server !"
  echo
  # fail
  exit 1
fi

# get list of original packages if newer
if ! wget -N -P "$config/original" "$slack/CHECKSUMS.md5"
then
  echo
  echo "Error downloading $slack/CHECKSUMS.md5 from server !"
  echo
  # fail
  exit 1
fi

# filter these lists for tgz only
cat "$config/update/CHECKSUMS.md5" | grep './packages/.*.tgz$' > update/filtered.md5
cat "$config/original/CHECKSUMS.md5" | grep './*/.*.tgz$' > original/filtered.md5

# generate list of update package names and its reverse
cat update/filtered.md5 | sed 's|/| |g' | awk '{ print $4 }' | sed 's|.tgz||g' | sort > update/packnames
rev update/packnames > update/revpacknames

# generate list of original package names and its reverse
cat original/filtered.md5 | sed 's|/| |g' | awk '{ print $4 }' | sed 's|.tgz||g' | sort > original/packnames
rev original/packnames > original/revpacknames

# generate installed packages list and its reverse
ls -1 /var/log/packages > installed/packnames
rev installed/packnames > installed/revpacknames

# run chopnames in the three directories
chopnames update
chopnames installed
chopnames original

# for every name in update see if there is a match in installed
comm -12 installed/names update/names > preaddnamematch

# add new packages if they are not installed
comm -23 update/names original/names > newname
comm -23 newname installed/names >> preaddnamematch

# sort
sort preaddnamematch > preblacknamematch

# remove blacklisted items if blacklist is not empty
if test $(cat $config/blacklist | wc -w) == 0
then
  cat preblacknamematch > namematch
else
  comm -3 preblacknamematch $config/blacklist > namematch
fi

# restore spaces for update
comm namematch update/names | sed 's|\t|#|' | awk '{ print $2 }' > updatenamematch

# restore spaces for installed
comm namematch installed/names | sed 's|\t|#|' | awk '{ print $2 }' > installednamematch

# generate update table
paste updatenamematch update/version update/arch update/release | sed '/^\t/ d' > updatetable

# generate installed table
paste installednamematch installed/version installed/arch installed/release | sed '/^\t/ d' > installedtable

# generate main table
paste updatetable installedtable > table

# parse main table
awk '{
    # arch
    if ( $3 == $7 )
    {
        # version
        if ( $2 == $6 )
        {
            # release
            if ( $4 != $8 )
            {
                printf("%s-%s-%s-%s.tgz\n", $1, $2, $3, $4);
            }
        }
        else
        {
            printf("%s-%s-%s-%s.tgz\n", $1, $2, $3, $4);
        }
    }
}' table > install

# if install is empty, system is up-to-date, else get packages and generate md5sums file
if test $(cat install | wc -w) == 0
then
  echo
  echo "Your system is up-to-date !"
  echo
  # success
  exit 0
else
  # get packages
  if ! wget -P packages -i install -B "$patches/packages/"
  then
    echo
    echo "Warning downloading a package from server has falied !"
    echo
  fi
  # generate md5sum
  while read line
  do
    grep "$line" update/filtered.md5 >> md5sum.md5
  done < install
  # check md5sums
  if md5sum -c md5sum.md5
  then
    echo
    echo "Packages have been downloaded to $temp/packages"
    echo "So, to install them run this as root:"
    echo
    echo "upgradepkg $temp/packages/*"
    echo
    # success
    exit 0
  else
    echo
    echo "md5sums do NOT match !"
    echo
    # failure
    exit 1
  fi
fi