#!/bin/bash
#  Copyright (C) 2007-2011  Matias A. Fonzo, Santiago del Estero, AR
#
#  This program 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 of the License, or
#  (at your option) any later version.
#
#  This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.

# Localización % Idioma:
TEXTDOMAINDIR=/usr/share/locale
TEXTDOMAIN=remove

VERSION=2.6

# Funciones #

# Una función para mostrar mensajes normales:
msg() { local LC_ALL ; printf '%s\n' "$@"; }

# Una función para mensajes de advertencia:
warn() { local LC_ALL; printf '%b\n' "$@" >&2; }

usage() {
  msg $"Removes one or more packages installed in your system."            \
       ""                                                                  \
      $"Usage: remove [options] package_name.tlz ..."                      \
       ""                                                                  \
      $"Options:"                                                          \
      $"  -h, --help                Show this help and exit."              \
      $"  -v, --version             Show the version of the program."      \
      $"  -k, --keep                Keep temporary files on the"           \
      $"                            temporary directory (debugging)."      \
      $"  -q, --quiet               Supress output messages."              \
      $"  -w, --warn                Warn about of the files and"           \
      $"                            directories that will be removed."     \
       ""
}

version() {
  msg "remove $VERSION"                                                    \
      "Copyright (C) 2007-2011 Matias A. Fonzo <selk@dragora.org>."        \
      "License GPLv3+: GNU GPL version 3 or later:"                        \
      "<http://gnu.org/licenses/gpl.html>"                                 \
      "This is free software: you are free to change and redistribute it." \
      "There is NO WARRANTY, to the extent permitted by law."
}

# Opciones:
while (( $# )); do
  case "$1" in
    -k|--keep)
      OPT=KEEP
      shift
      ;;
    -q|--quiet)
      OPT=QUIET
      shift
      ;;
    -w|--warn)
      OPT=WARN
      shift
      ;;
    -[h?]|--help)
      usage
      exit 0
      ;;
    -[vV]|--version)
      version
      exit 0
      ;;
    -*)
      warn $"${0##*/}: Invalid option: $1"
      exit 1
      ;;
    *)
      break;
  esac
done

# Si no hay argumentos, llama a la función de ayuda:
(( $# == 0 )) && { usage ; exit 0; }

# Comprobamos la variable de entorno ROOT:
if [[ -n $ROOT && ! -d $ROOT ]]; then
  warn $"${0##*/}: ROOT=${ROOT}: Invalid directory"
  exit 1;
fi

umask 022

# Chequeo de sanidad.
#
# Comprueba si el sistema de archivos
# se encuentra en modo de sólo-lectura:
if ! touch ${ROOT}/pkg-remove$$ ; then
  warn $"The filesystem (on $ROOT) is in read-only mode."
  exit 1;
fi
rm -f ${ROOT}/pkg-remove$$

# Base de datos por defecto:
DB="${ROOT}/var/db"

# Asegura la existencia de las partes de la base de datos:
for directory in \
 pkg/removed \
 pkg/removed/pre-post \
 pkg/removed/post-install \
 pkg/removed/description
do
  if [[ ! -d ${DB}/$directory ]]; then
    mkdir -p "${DB}/$directory"
  fi
done

# Creación de un directorio temporal seguro:
TMP="${DB}/tmp"
if [[ ! -d $TMP ]]; then
  mkdir -p -m 0700 "$TMP"
fi

# Crea los archivos temporales de forma segura:
S=$RANDOM$$

# Hace que algunos comandos corran más rápido:
export LC_ALL=C

# Más Funciones #

# Una función para reflejar el nombre base:
_basename() { local name ; name=${1##*/} ; printf "${name%$2}"; }

cat_except() {
  ( cd "$1"
    mapfile -n 2 -t lines < <(find . -maxdepth 1 -type f -print)
    if (( ${#lines[*]} == 2 )); then
      find . -maxdepth 1 -type f ! -name "$2" -exec cat '{}' +
    fi
  )
}

move_install() {
  local dirName=$1 fileName=$2
  if [[ -r ${DB}/pkg/${dirName}/$fileName ]]; then
    ( cd ${DB}/pkg/$dirName
      install -m 0644 $fileName -D ${DB}/pkg/removed/${dirName}/$fileName
      rm -f $fileName
    )
  fi
}

empty_dir() {
  shopt -s nullglob dotglob
  files=( $@ )
  shopt -u nullglob dotglob
  if (( ${#files[*]} == 0 )); then
    return 0;
  else
    return 1;
  fi
}

keep_lnk() {
  while read link ; do
    if [[ -L ${ROOT}/$link ]]; then
      if [[ $OPT != WARN ]]; then
        msg $"${ROOT}/${link}: Symlink found in another package.  Dodging."
      else
        msg $"LINK -> ${ROOT}/$link"
      fi
    else
      warn $"WARNING: ${ROOT}/${link}: Symlink non-existent, found in another package.  Dodging."
    fi
  done
}

keep_file() {
  while read file ; do
    [[ -f ${ROOT}/$file ]] || continue;
    if [[ -r ${ROOT}/$file ]]; then
      if [[ $OPT != WARN ]]; then
        msg $"${ROOT}/${file}: File found in another package.  Dodging."
      else
        if [[ ${ROOT}/$file -nt ${DB}/pkg/$pkgname ]]; then
          warn $"WARNING: ${ROOT}/${file}: Changed after package installation."
        fi
        msg $"FILE -> ${ROOT}/$file"
      fi
    else
      warn $"WARNING: ${ROOT}/${file}: File non-existent, found in another package.  Dodging."
    fi
  done
}

extract_lnk() { awk '$2 == "Link:" { print $3 }'; }

delete_lnk() {
  while read link ; do
    if [[ -L ${ROOT}/$link ]]; then
      if [[ $OPT != WARN ]]; then
        if [[ $OPT != QUIET ]]; then
          rm -v -rf ${ROOT}/$link
        else
          rm -rf ${ROOT}/$link
        fi
      else
        msg $"LINK -> ${ROOT}/$link"
      fi
    else
      msg $"${ROOT}/${link}: Symlink no longer exists.  Dodging."
    fi
  done
}

delete_file() {
  while read file ; do
    [[ -d ${ROOT}/$file ]] && continue;
    if [[ -r ${ROOT}/$file || -L ${ROOT}/$file ]]; then
      if [[ $OPT != WARN ]]; then
        if [[ $OPT != QUIET ]]; then
          rm -v -rf ${ROOT}/$file
        else
          rm -rf ${ROOT}/$file
        fi
      else
        if [[ ${ROOT}/$file -nt ${DB}/pkg/$pkgname ]]; then
          warn $"WARNING: ${ROOT}/${file}: Changed after package installation."
        fi
        msg $"FILE -> ${ROOT}/$file"
      fi
    else
      msg $"${ROOT}/${file}: No longer exists.  Dodging."
    fi
  done
}

delete_dir() {
  sort -r | while read dir ; do
    [[ -d ${ROOT}/$dir ]] || continue;
    if [[ $OPT != WARN ]]; then
      if empty_dir "${ROOT}/${dir%/}/*" ; then
        if [[ $OPT != QUIET ]]; then
          rmdir -v ${ROOT}/$dir
        else
          rmdir ${ROOT}/$dir
        fi
      else
        warn $"rmdir: ${ROOT}/${dir}: Directory not empty."
      fi
    else
      msg $"DIR  -> ${ROOT}/$dir"
    fi
  done
}

# Loop:
for package in "$@" ; do
  pkgname=$(_basename $package .tlz)

  # Simple package_name notación.
  #
  # Comprueba la disponibilidad del paquete buscando
  # una coincidencia en la base de datos. Intentando
  # encontrar el paquete por su nombre largo, como
  # "name-version-arch-build":
  if [[ ! -e ${DB}/pkg/$pkgname ]]; then
    if ls ${DB}/pkg/${pkgname}* &>/dev/null ; then
      for long_name in ${DB}/pkg/${pkgname}* ; do
        short_name=${long_name##*/}
        if printf "$short_name" | grep -qwo "$pkgname" ; then
          pkgname=$short_name
        fi
      done
    fi
  fi

  # Si el paquete está disponible, manos a la obra:
  if [[ -f ${DB}/pkg/$pkgname ]]; then
    # Imprime un mensaje según la opción:
    if [[ $OPT != WARN ]]; then
      msg "" $"< Removing ${DB}/pkg/$pkgname ..." ""
    else
      msg "" "% Scanning ${DB}/pkg/$pkgname ..." ""
    fi
    cat_except ${DB}/pkg $pkgname | sort -u > ${TMP}/filelist$S
    if [[ -f ${DB}/pkg/post-install/$pkgname ]]; then
      cat_except ${DB}/pkg/post-install $pkgname | extract_lnk | sort -u > ${TMP}/linklist$S
      extract_lnk < ${DB}/pkg/post-install/$pkgname | sort -u > ${TMP}/deletelnk$S
      ( cd $TMP
        sort deletelnk$S linklist$S | uniq -d | keep_lnk
        sort deletelnk$S linklist$S linklist$S | uniq -u | delete_lnk
      )
    else
      find ${DB}/pkg/post-install -maxdepth 1 -type f -exec cat '{}' + | \
       extract_lnk | sort -u > ${TMP}/linklist$S
      mv ${TMP}/filelist$S ${TMP}/filelist$S.moved
      sort -u ${TMP}/linklist$S ${TMP}/filelist$S.moved > ${TMP}/filelist$S
    fi
    sort ${DB}/pkg/$pkgname ${TMP}/filelist$S | uniq -d | keep_file
    sort ${DB}/pkg/$pkgname ${TMP}/filelist$S ${TMP}/filelist$S | \
     uniq -u > $TMP/uniq$S
    delete_file < ${TMP}/uniq$S
    delete_dir < ${TMP}/uniq$S

    # Si la opción KEEP no está activada, borramos los archivos temporales:
    if [[ $OPT != KEEP ]]; then
      rm -f \
       ${TMP}/linklist$S ${TMP}/deletelnk$S ${TMP}/filelist$S* ${TMP}/uniq$S
    fi

    # Si la opción WARN no está activada, movemos los
    # archivos de pre y post instalación:
    if [[ $OPT != WARN ]]; then
      move_install pre-post $pkgname
      move_install post-install $pkgname

      # También, los archivos de descripción:
      if [[ -d ${DB}/pkg/description ]]; then
        ( cd ${DB}/pkg/description
          for file in ${pkgname}_?? ; do
            if [[ -f $file ]]; then
              mv $file ${DB}/pkg/removed/description
              lzip -fF ${DB}/pkg/removed/description/$file
            fi
          done
        )
      fi

      # Mueve el registro del paquete al directorio de removidos:
      mv ${DB}/pkg/$pkgname ${DB}/pkg/removed/
    fi
  else
    warn "${DB}/pkg/${pkgname}: No such package"
    CODE=1
    continue;
  fi
done

exit $CODE