#!/bin/bash

source /etc/sorcery/config

function alter_alter() {

  if [ -z "$1" ]; then
    cat <<EOF > /dev/stderr && return 1  
alter [ -a|--alter ] [ -n|--spell spellname ]
                     [ -v|--version version ]
                     command [ args ... ]
EOF
  fi

  
  if [ "$1" == "-n" -o "$1" == "--spell" ]; then SPELL="$2";shift;shift; fi
  if [ "$1" == "-v" -o "$1" == "--version" ]; then VERSION="$2";shift;shift; fi

  source /etc/sorcery/config
  SPELL=${SPELL:=alter}
  [ -z "$VERSION" ] && VERSION=$$
  TMP_LOG=/tmp/$SPELL-$VERSION
  IW_LOG=/tmp/$SPELL-$VERSION.iw
  INST_LOG=$INSTALL_LOGS/$SPELL-$VERSION
  MD5_LOG=$MD5SUM_LOGS/$SPELL-$VERSION
  C_LOG=/tmp/$SPELL-$VERSION.compile.log
  C_FIFO=/tmp/$SPELL-$VERSION.compile.fifo
  C_LOG_COMP=$COMPILE_LOGS/$SPELL-$VERSION$EXTENSION
  CACHE_COMP=$INSTALL_CACHE/$SPELL-$VERSION-$BUILD.tar$EXTENSION
  rm -f  "$C_LOG" 2> /dev/null
  touch  "$C_LOG"
  rm -f  "$C_FIFO" 2> /dev/null
  mkfifo "$C_FIFO"
  message "${MESSAGE_COLOR}Gathering metadata for ${SPELL_COLOR}$SPELL${DEFAULT_COLOR}${MESSAGE_COLOR}.${DEFAULT_COLOR}"
  DATA="$(gaze compile $SPELL 2> /dev/null)" && COM_DATA="$DATA" || COM_DATA=""
  DATA="$(gaze install $SPELL 2> /dev/null)" && INS_DATA="$DATA" || INS_DATA=""
  DATA="$(gaze md5sum  $SPELL 2> /dev/null)" && MD5_DATA="$DATA" || MD5_DATA=""
  [ -n "$COM_DATA" ] && echo "$COM_DATA" > "$C_LOG"
  message "${MESSAGE_COLOR}Altering...${DEFAULT_COLOR}"

  activate_voyeur
  invoke_installwatch
  (
    echo "$@"
    echo "$@" | bash
  ) > $C_FIFO 2>&1
  devoke_installwatch
  touch $IW_LOG $MD5_LOG $C_LOG_COMP
  track
  [ -n "$MD5_DATA" ] && echo "$MD5_DATA" | cut -c35- |
    exists | grep -v "^$LOG_DIRECTORY" > "$TMP_LOG.2" &&
    cat "$TMP_LOG.2" "$INST_LOG" | sort | uniq > "$TMP_LOG.3" ||
    cp "$INST_LOG" "$TMP_LOG.3"
  rm "$TMP_LOG.2" 2> /dev/null
  mv "$TMP_LOG.3" "$INST_LOG"
  create_compile_log
  md5list $INST_LOG $MD5_LOG
  archive
  add_spell "$SPELL" installed "$VERSION"
  rm $C_LOG $C_FIFO
  report_install

  return 0

}

function alter_md5_mend() {

  SINGLE=       #grab a single conflict only instead of all conflicts
  STORE_BASE=${STORE_BASE:=/var/log/sorcery/tmp} # */tmp are often small 
                                  # by default for the backup
  SPELL="$1"
  VERSION="$(gaze -q installed "$SPELL")"

  MD5S="$(
    (
      echo "$MASTER_MD5S" | grep -v " $SPELL-$VERSION$"
      cat "$MD5SUM_LOGS/$SPELL-$VERSION" | cut -c35- | sed -e 's/.*/& -/'
    )
  )"

  TOTAL=$(echo -n "$MD5S" | wc -l)
  message "${MESSAGE_COLOR}Checking $TOTAL files for conflicts with ${SPELL_COLOR}$SPELL-$VERSION${DEFAULT_COLOR}${MESSAGE_COLOR}...${DEFAULT_COLOR}" > /dev/stderr
  RESULTS="$(
    echo -n "$MD5S" | sort -s -k1 | sed -e 's/\(.*\) \(.*\)/\2 \1/' |
    (
      FILE=
      COUNT=0
      while read LINE; do
        if [ "${LINE:0:2}" == '- ' ]; then
          FILE="${LINE:2}"
        else
          if [ "${LINE#* }" == "$FILE" ]; then
            echo "$LINE"
            [ -n "$SINGLE" ] && FILE=
          fi
        fi
        [ "$((++COUNT))" != "${COUNT%%000}" ] && # increment and check for mod 1000
        progress_bar $COUNT $TOTAL 60 > /dev/stderr
      done
      clear_line > /dev/stderr
    ) | sort
  )"

  if [ -n "$RESULTS" ]; then
    TOTAL="$(echo "$RESULTS" | wc -l)"
    SPELLS="$(echo "$RESULTS" | cut -d' ' -f1 | sort | uniq)"
    TOTSP="$(echo "$SPELLS" | wc -l)"
    FILES="$(echo "$RESULTS" | cut -d' ' -f2 | sort | uniq)"
    STORE=$STORE_BASE/$SPELL-$VERSION.$$
    mkdir -p "$STORE"
    mkdir -p "$STORE/tmp/sorcery"
    message "${MESSAGE_COLOR}Cleaning $TOTAL old md5sums from $TOTSP spells and creating $SPELL-undo-$VERSION store.${DEFAULT_COLOR}" > /dev/stderr
    echo "$SPELLS" |
    (
      COUNT=0
      while read SPVER; do
        SPFLS="$(echo "$RESULTS" | grep "^$SPVER " | cut -d' ' -f2)"
        echo "$SPFLS" |
        sed -e 's/[^a-zA-Z0-9*.+]/\\&/g' |
        sed -e 's/.*/\\:&: d/' |
        sed -i -f - "$MD5SUM_LOGS/$SPVER"    
        if [ "$COMPRESSBIN" == "tar" ]; then
          echo "$SPFLS" | 
            tar -f $INSTALL_CACHE/$SPVER-*.tar \
            -kx -T /dev/stdin -C "$STORE" 2> /dev/null
        else
          echo "$SPFLS" | 
            tar --"$COMPRESSBIN" -f $INSTALL_CACHE/$SPVER-*.tar$EXTENSION \
            -kx -T /dev/stdin -C "$STORE" 2> /dev/null
        fi
        progress_bar $((++COUNT)) $TOTSP 60 > /dev/stderr
      done
      clear_line > /dev/stderr  
    )
    message "${MESSAGE_COLOR}Creating ${SPELL_COLOR}$SPELL-undo${DEFAULT_COLOR}${MESSAGE_COLOR} spell for ${SPELL_COLOR}$SPELL-$VERSION${DEFAULT_COLOR}${MESSAGE_COLOR}.${DEFAULT_COLOR}" > /dev/stderr
    ORIGSPELL="$SPELL"
    SPELL="$SPELL-undo"
    cd "$STORE"
    INST_LOG="$STORE.log"
    mkdir -p "$STORE$MD5SUM_LOGS"
    MD5S_LOG="$STORE$MD5SUM_LOGS/$SPELL-$VERSION"
    touch "$MD5S_LOG"
    echo -n "$RESULTS" > "$STORE/tmp/sorcery/$SPELL-$VERSION-backup.md5"
    find * > "$INST_LOG"
    md5list "$INST_LOG" "$MD5S_LOG" # relative to STORE instead of absolute
    CACHE_COMP="$INSTALL_CACHE/$SPELL-$VERSION-$BUILD.tar$EXTENSION"
    archive # No install log nor compile cache needed or wanted since we are 
            # only doing md5sum deletions from other spells, the undeleted 
            # form should only restore the md5sums to the proper location.
    rm -rf "$STORE"
    return 1
  else
    message "${MESSAGE_COLOR}No md5sum conflicts with ${SPELL_COLOR}$SPELL-$VERSION${DEFAULT_COLOR}${MESSAGE_COLOR} detected.${DEFAULT_COLOR}" > /dev/stderr
    return 0
  fi

}

function alter_md5mend() {

  [ -z "$1" ] && echo "Please provide spells to mend as arguments" > /dev/stderr && return 1

  TOTAL=$(gaze installed | wc -l)

  message "${MESSAGE_COLOR}Gathering md5sums from $TOTAL spells...${DEFAULT_COLOR}" > /dev/stderr
  MASTER_MD5S="$(
    (
      COUNT=0
      for i in $(
        gaze installed |
        cut -d: -f1,4 | tr : -
      ); do
        cat "$MD5SUM_LOGS/$i" | sed -e 's/.*/'"$i"':&/'
        progress_bar $((++COUNT)) $TOTAL 60 > /dev/stderr
      done | sed -e 's/\(.*\):\(.*\)  \(.*\)/\3 \1/'
      clear_line > /dev/stderr
    )
  )"

  for spell in $*; do
    alter_md5_mend "$spell"
  done
  return 0

}

function alter_pre_link() {

  ARGS="$@"

  if [ ! -f "/etc/prelink.conf" ]; then
    message "${MESSAGE_COLOR}Gathering binary directories for prelinking (this could take a long while)...${DEFAULT_COLOR}"
    find / -perm +001 2> /dev/null |
    while read LINE; do
      [ ! -h "$LINE" ] && file $LINE 2> /dev/null |
      grep -q ELF && echo "$LINE"
    done |
    grep -v '/src/\|/lib/modules\|/root/\|/home/' |
    sed -e 's/[^/]*$//' | uniq |
    sort | uniq > /etc/prelink.conf
  fi

  alter_alter -n smgl-prelink '
    /usr/sbin/prelink -v '"$ARGS"' | tee /tmp/prelink.$$.output
    grep "Prelinking\\|Linking" /tmp/prelink.$$.output |cut -d" " -f2 | 
    sort | uniq |
    while read PRELINKED; do
       touch "$PRELINKED"
    done
    rm /tmp/prelink.$$.output
  '

}

function alter_prelink {

  if gaze -q installed prelink | grep -q 'not installed'; then
    cast prelink || (
      message "${MESSAGE_COLOR}Unable to statisfy prelink dependency, quitting.${DEFAULT_COLOR}"
      return 1
    )
  fi

  if [ -z "$1" ]; then
    alter_pre_link -afmR
  else
    alter_pre_link "$@"
  fi
  alter_md5mend smgl-prelink

}

function alter_strip_do() {

  ARGS="$@"

  if [ ! -f "/etc/prelink.conf" ]; then
    message "${MESSAGE_COLOR}Gathering binary directories for stripping (this could take a long while)...${DEFAULT_COLOR}"
    find / -perm +001 2> /dev/null |
    while read LINE; do
      [ ! -h "$LINE" ] && file $LINE 2> /dev/null |
      grep -q ELF && echo "$LINE"
    done |
    grep -v '/src/\|/lib/modules\|/root/\|/home/' |
    sed -e 's/[^/]*$//' | uniq |
    sort | uniq > /etc/prelink.conf
  fi

  alter_alter -n smgl-strip '
    find $(cat /etc/prelink.conf) -perm +001 2> /dev/null |
    while read LINE; do
      [ ! -h "$LINE" ] && file $LINE 2> /dev/null |
      grep -q ELF && echo "$LINE"
    done |
    while read STRIPFILE; do
      cp "$STRIPFILE" /tmp/tostrip.$$
      strip '"$ARGS"' /tmp/tostrip.$$
      if [ "$(md5sum < /tmp/tostrip.$$)" == "$(md5sum < "$STRIPFILE")"    ]; then
        echo "$STRIPFILE" already stripped, skipping.
        rm /tmp/tostrip.$$
      else 
        if [ "$(ldd /tmp/tostrip.$$ | md5sum)" == "$(ldd "$STRIPFILE"    | md5sum)" ]; then 
          echo "$STRIPFILE stripped and verified."
          # uncomment the following to make backups before mving stripped bins
          # mkdir -p "/var/log/sorcery/tmp/smgl-strip.$$/${STRIPFILE%/*}"
          # cp "$STRIPFILE" "/var/log/sorcery/tmp/smgl-strip.$$/$STRIPFILE"
          mv /tmp/tostrip.$$ "$STRIPFILE"
        else
          echo "$STRIPFILE corrupted by strip, skipping"
        fi
      fi
    done
  '

}

function alter_strip {

  if [ -z "$1" ]; then
    alter_strip_do
  else
    alter_strip_do "$@"
  fi
  alter_md5mend smgl-strip

}

function alter_about() {

cat <<EOF | less && exit 0
alter: about: alter is a utility to modify and add to spells' installs.

(C) 2004 Seth Alan Woolley and The Source Mage Team, initial release.
LICENSE: GPL v2 or higher.

Run alter without arguments to see a basic syntax guide.

Alter has two main uses:

"alter":  
    This is the basic use of alter.  Any command run on its command line
will be run as if it was run at the end of the cast, inside the cast of
the spell that is being altered.  By default, it operates on the spell
"alter".  If the spell doesn't exist, it is "created".  This is useful
for adding files to spells.  See md5mend to modify files in spells by
replacing them with in an alter session.  When used together, with alter
run first, then md5mend run second, you should end up with a rather
clean system.  Running alter to touch a file, then md5mending, then
dispelling the alter spell will remove a file from the sytem cleanly. 
In all, any modification of an installed spell couild be done while
maintaining somewhat logical md5sum logs.

"md5mend":
    This is a secondary use of alter.  Any spells specified on its
command line get analyzed in the order specified.  If "environmental"
spells installed on the machine have conflicting md5 entries with the
"analyzed" spell, md5mend will remove them from the environmental spells
but keep them in the analyzed spell.  For example, if you run it on
coreutils, psmisc and util-linux will have their /bin/kill purged from
their md5sum records.  This however leaves them in the install logs of
the environmental spells because they actually were installed by the
spell.  The purpose is to enable a more intelligent cast --fix.  a
forced dispel -d env_spell env_version will restore the environmental
md5log and restore the binary from the environmental spell, so this is
undoable piecemeal, or, you can use the shotgun undo cache created,
however if more than three spells had the same file, it will use the
version appearing in the environmental spell that is first in
alphabetical order.

Alter has two shortcut uses:

"prelink" or "strip":
    These are two commonly used alter shortcuts.  Prelinking optimizes
the link space among all the binaries on the system.  Strip strips 
all the binaries on the system one by one, and confirms that they are 
sane before installing them.
    The first time you run either prelink or strip, alter creates the
/etc/prelink.conf file if you don't already have one.  This part can
take up to an hour depending on processor speed and how full your disks
are, or as little as five minutes.  The content of the file is merely a
listing, one directory per line, of all the directories that contain
binaries that should be touched by prelink or this version of strip.  
Feel free to ctrl-c this process and make it yourself if you are 
impatient. The script, however, is very thorough and accurate, so it's 
not a bad idea to simply let the script run its course.
    Both prelink and strip take quite a while to run everything through
because the md5mend process will essentially have to touch every archive
and md5sum file on your system.  Be sure you have plenty of space
available for the caches (if you have ARCHIVE=on).  1.5 times the
installed uncompressed binary size (averages about 1-2 gigs on most
installs, less for servers, more for desktops).
    If you want to both strip and prelink, strip before you prelink 
seems to work better.
    If you run prelink and get lots of -fPIC warnings, try upgrading
some of the spells, if it doesn't work, file a bug and CC
seth@tautology.org on it and he will add -fPIC to the CFLAGS of the spell
(alternatively, do this yourself and append an attachment to the bug).  
zlib needs -DPIC -fPIC.  Prelinking doesn't like non-PIC'd binaries.  It 
won't hurt anything, it will just ignore them.
    In my experience (Seth), stripping decreases file size, but doesn't
increase the speed, and prelink makes the files slightly bigger
(negligible), but decreases load time, often dramatically for C++ apps
with many links (read: KDE).

    For further study, RTFS or drop into the freenode #sourcemage 
channel and ask swoolley or the room for some urls or questions.

FAQ:

    Q: How do I prelink my whole system?
    A: alter -p

    Q: How do I strip debugging info from my whole system?
    A: alter -s
    
    Q: I recompiled some libraries, and it slowed down.
    A: Recompiling makes prelinking pointless, rerun alter -p upon each update.

    Q: How do I add a file /bin/file to a spell coreutils?
    A: mv /tmp/file /bin/file; alter -n coreutils touch /bin/file

    Q: How do I delete a file /bin/file from coreutils?
    A: alter -n coreutils-removed touch /bin/file; alter -m coreutils-removed; dispel coreutils-removed

    Q: How do I modify a file /bin/file from coreutils?
    A: patch /bin/file < /tmp/file.patch; alter -n coreutils touch /bin/file

    Q: How do I undo an alter?
    A: There's no exact undo, but it's good enough if you've been using
       only spells and alter:
       
       # you did this but regretted it
       alter -n alter-to-remove -v 31337 touch /bin/file # an alter
       alter -m alter-to-remove              # md5mend it

       # undo the above
       dispel alter-to-remove                # do this step only if the files 
                                             # it touched aren't critical.  If
                                             # they are, set REAP=no before.
       dispel -d alter-to-remove-undo 31337  # to unpack the undo cache

EOF

}

[ -z "$1" ] && cat <<EOF > /dev/stderr && exit 1
alter: usage: 
  alter [ { -a | --alter   } ] # -a/--alter are ignored as this is default
        [ { -n | --spell   } spell:=alter ]
        [ { -v | --version } version:=<installed> ] 
        command [ args  ... ]
  alter   { -m | --md5mend }
        spell   [ spell ... ]
  alter   { -p | --prelink }
        [ prelink_args:=-afmR ]
  alter   { -s | --strip   }   # shortcut to strip all binaries
        [ strip_args:=        ]
  alter   { -h | --about   }   # learn about alter and what it does

  default environment variables:
    STORE_BASE=/var/log/sorcery/tmp
  To drastically save space, turn ARCHIVE=off in /etc/sorcery/local/config
  To undo with ARCHIVE=on:
    dispel -d <spell-name>-undo <spell-version>
    alter -m <spell-name>-undo

  NOTE:  Never directly dispel an alter with REAP=on unless
  ****:  you want to delete everything the alter touched!
  ****:  Use the undo archives as they have no install log.
EOF

case "$1" in
	-m|--md5mend              ) shift; alter_md5mend "$@" ;;
	-p|--prelink              ) shift; alter_prelink "$@" ;;
	-s|--strip                ) shift; alter_strip   "$@" ;;
	-a|--alter                ) shift; alter_alter   "$@" ;;
        -h|--about                ) shift; alter_about   "$@" ;;
	-n|--spell|-v|--version|* )        alter_alter   "$@" ;;
esac