#! /bin/bash

#*********************************************************************
#
# fai-mirror -- create and manage a partial mirror for FAI
#
# This script is part of FAI (Fully Automatic Installation)
# (c) 2004-2019, Thomas Lange, lange@informatik.uni-koeln.de
#
#*********************************************************************
# 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 2 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; see the file COPYING. If not, write to the
# Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
# MA 02111-1307, USA.
#*********************************************************************

# variables: NFSROOT, FAI_CONFIGDIR, FAI_ETC_DIR

export FAI_ROOT=/ # do not execute in chroot, needed for install_packages call
export PATH=$PATH:/usr/sbin

trap "umount_dirs" EXIT ERR
# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
usage() {

    echo "fai-mirror -- create and manage a partial mirror for FAI."
    echo "Please read the manual page fai-mirror(1)."
    exit
}
# - - - - - - - - - - - - - - - - - - - - - - - - - -
die() {

    local e=$1   # first parameter is the exit code
    shift

    echo "$@" >&2 # print error message
    exit $e
}
# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
excludeclass() {

    # removes/excludes all classes in $* from $classes
    local insert eclasses newclass c e

    eclasses="$*"
    eclasses=${eclasses//,/ }

    for c in $classes; do
        insert=1
        for e in $eclasses; do
          [ $c = $e ] && insert=0
        done
        [ $insert = 1 ] && newclass="$newclass $c"
    done
    classes="$newclass"
}
# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
umount_dirs() {

    [ "$FAI_DEBMIRROR" ] && umount $MNTPOINT 2>/dev/null 1>&2 || true
}
# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
cleandirs() {

    return # currently nothing to do
}
# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
initialize() {

    # TODO: root is only needed when FAI_DEBMIRROR is defined. Then we
    # must mount a directory

    # we only need some empty dirs
    set -e
    mkdir -p $mirrordir/Packages
    set +e
}
# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
delete_base_packages() {
    echo "WARNING: base packages can't be deleted on RPM based operating systems." >&2
}
# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
add_base_packages() {
    echo "WARNING: base packages can't be added on RPM based operating systems." >&2
}
# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
set-classes() {

    local addclasses
    # if -c is given, ignore -x
    if [ -n "$cclasses" ]; then
        export classes=${cclasses//,/ }
        return
    fi

    set +e
    # all available file names are classes
    classes=$(cd $FAI_CONFIGDIR/package_config; ls -1 | grep -E -i "^[a-zA-Z0-9_-]+$")
    addclasses=$(grep -h PACKAGES $FAI_CONFIGDIR/package_config/* | sed -e 's/#.*//' | awk '{printf $3"\n"$4"\n"$5"\n"$6"\n"}')
    export classes=$(echo -e "$classes\n$addclasses\n" | sort | uniq)
    [ -n "$exclasses" ] && excludeclass $exclasses
    set -e
}
# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
mk_class_var_list() {

    # create a list of files named class/*.var that contain a definition of a  variable that is
    # used in package_config/<classes>

    # we assume, that variables used in package_config are defined in class/*.var.
    # For all classes search if there's a variables used in package_config/CLASS
    # For all variables found look which files class/CLASS.var define these variables.

    local -a variables=()
    local filelist classlist sourefiles
    local c i f

    #filelist: all files in package_config which are also a defined class
    for c in $classes; do
	if [ -f $FAI_CONFIGDIR/package_config/$c ]; then
	    filelist+=" $c"
	fi
    done

    if [ -z "$filelist" ]; then
	   return
    fi

    # make the list of variables that are used
    # regex: $abc or ${abc}
    variables=($(cd $FAI_CONFIGDIR/package_config;grep -h -P -o '\$[A-Za-z0-9_]+|\$\{[A-Za-z0-9_]+\}' $filelist|sort|uniq))

    # debug
    #for v in ${variables[@]}; do
    #    echo Variable found: $v
    #done

    # create a regex like varname= for all variables
    for i in ${!variables[@]}; do
	variables[i]=$(echo ${variables[i]} | tr -d /{}$/)
	variables[i]+="="
    done

    # classlist: make list of files in class, which are also a class
    for c in $classes; do
	if [ -f $FAI_CONFIGDIR/class/$c.var ]; then
	    classlist+=" $FAI_CONFIGDIR/class/$c.var"
	fi
    done
    # look for variable definition in this list
    for f in $classlist; do
	for i in ${!variables[@]}; do
	    if grep -q -P "${variables[i]}" $f; then
		sourefiles+=" $f"
		break
	    fi
	done
    done

    # these files contain a variable definition which is needed
    echo $sourefiles
}
# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

preserve=0
verbose=0
add=1
qflag=-q
bcount=0
setvariables=0
while getopts "a:bBvhx:pc:C:m:s:P:V" opt ; do
    case "$opt" in
        a) arch=$OPTARG ;;
        B) add=0 ; ((bcount++)) ;;
        b) add=2 ; ((bcount++)) ;;
        C) cfdir=$OPTARG ;;
        h) usage ;;
        x) exclasses="$OPTARG";;
        c) cclasses="$OPTARG";;
        m) MAXPACKAGES="$OPTARG";;
        p) preserve=1;;
	s) csdir="$OPTARG";;
        v) verbose=1; vflag=-v; qflag='';;
        V) setvariables=1 ;;
        P) aptpref="$OPTARG";;
        ?) die 1 "Unknown option";;
    esac
done
shift $(($OPTIND - 1))

# use FAI_ETC_DIR from environment variable
[ -n "$FAI_ETC_DIR" -a -z "$cfdir" ] && echo "Using environment variable \$FAI_ETC_DIR."
# use -C option if present otherwise use $FAI_ETC_DIR or default to /etc/fai
[ -z "$cfdir" ] && cfdir=${FAI_ETC_DIR:=/etc/fai}
cfdir=$(readlink -f $cfdir) # canonicalize path
[ ! -d "$cfdir" ] && die 6 "$cfdir is not a directory"
[ "$verbose" -eq 1 ] && echo "Using configuration files from $cfdir"
[ $bcount -gt 1 ] && die 7 "You can't use -b and -B simultaneously."
. $cfdir/fai.conf
. $cfdir/nfsroot.conf
: ${MNTPOINT:=/media/mirror}  # default value
export NFSROOT

if [ -n "$csdir" ]; then
    FAI_CONFIGDIR=$csdir # override by -s
fi
command -v repotrack >&/dev/null || die 8 "repotrack not found. Please install the yum-utils package."
[ -n "$exclasses" -a -n "$cclasses" ] && die 3 "Options -x and -c not allowed at the same time."

# use first argument if given, use variable mirrordir if not argument was given
[ -n "$1" ] && mirrordir=$1
[ -z "$mirrordir" ] && die 2 "Please give the absolute path to the mirror."
{ echo $mirrordir | grep -E -q '^/'; } || die 4 "Mirrordir must start with a slash /."

[ -d $FAI_CONFIGDIR/package_config ] || die 6 "Can't find package config files in $FAI_CONFIGDIR."

# set default if undefined
: ${MAXPACKAGES:=1}
export MAXPACKAGES

set-classes
if [ "$setvariables" -eq 1 ]; then
    flist=$(mk_class_var_list)
    set -a
    for f in $flist; do
	echo Sourcing variable definitions in $f
	source $flist
    done
    set +a
fi

initialize

# if we are using nfs mounts for Debian mirror, this may fail here, since inside a chroot environment different dir are used
# if sources.list includes file AND FAI_DEBMIRROR is defined we have to mount
# otherwise mounting is not needed. call task_mirror
if [ "$FAI_DEBMIRROR" ]; then
    mkdir -p $MNTPOINT
    mount -r $FAI_DEBMIRROR $MNTPOINT || exit 9
fi

[ $add -eq 1 ] && add_base_packages
echo "Downloading packages for classes:" $classes
for pkg in $(FAI=$FAI_CONFIGDIR install_packages -N -l); do
  if repotrack ${qflag} -p $mirrordir/Packages ${pkg}; then
    :
  else
    die 9 "ERROR when downloading packages. Your mirror is broken. Use fai-mirror -v for details."
  fi
done

umount_dirs
trap "" EXIT ERR
[ $add -eq 0 ] && delete_base_packages

# allow package without the .deb suffix. At least they must start with a char and contain an underscore or hyphen
createrepo ${qflag} $mirrordir

echo "$0 finished."
echo -n "Mirror size and location: ";du -sh $mirrordir
cleandirs