#!/bin/bash


###########################################
#
# DON'T CHANGE THIS FILE WITHOUT TALKING TO
# KLIEBER FIRST!!!!!!!!!!!!!!!!!!!!!!!!!!!!
#
###########################################

#
# This file creates snapshots of Portage and moves them to the correct location so they get uploaded to OSU's mirror
#
# Author: Kurt Lieber
# Version: 0.2
#
# Based on the script by Martin Holzer
#
#
# CHANGELOG
#
# 0.3 - delta integration, and better error handling.
# 0.2 - added features to create symlinks to latest version of the snapshot
# 0.1 - original version


#
# Define locations for stuff
#

MASTER="/home/gmirror/rsync" #where the master repository lives
TEMP="/home/gmirror/snapshots-tmp/" #working directory
#UPLOAD="/home/gmirror/upload/" #temp location for testing
UPLOAD="/mnt/distfiles/snapshots/" #real location
HISTORY="7" #number in dsays of previous snapshots to keep
DELTA_UPLOAD="${UPLOAD}/deltas/"

CP=/bin/cp
GPG=/usr/bin/gpg
LN=ln
LZMA=/usr/bin/lzma
MD5SUM=/usr/bin/md5sum
MV=/bin/mv
RM=/bin/rm
SED=/bin/sed

#
# used to name the file
#

DELTA_BASE=`/bin/date -d '-2 day' +%Y%m%d`
DELTA_FILENAME="portage-${DELTA_BASE}.tar.bz2"
YESTERDAY=`/bin/date -d yesterday +%Y%m%d`
FILENAME="portage-${YESTERDAY}.tar.bz2"

#
# GPG info
#

#SIGNKEYID="D8BA32AA"
#SIGNKEYID="7DDAD20D"
SIGNKEYID="239C75C4"

if [ ! -e "${UPLOAD}/${DELTA_FILENAME}" ]; then
	echo "Previous snapshot does not exist: '${UPLOAD}/${DELTA_FILENAME}'"
	exit 1
fi

#
# copy gmirror's copy of the gentoo-x86 repository to a temp location
#

#/usr/bin/sudo /bin/rm -rf ${TEMP}/portage
#/bin/mkdir -p ${TEMP}/portage
#/bin/cp -a -R ${MASTER}/* ${TEMP}/portage/ || { echo "cp failed, $?"; exit 1; }
#/usr/bin/sudo /bin/chown -R 250:250 ${TEMP}/portage
mkdir -p ${TEMP} || { echo "mkdir failed, $?"; exit 1; }
cd ${TEMP} || { echo "cd failed, $?"; exit 1; }


#
# create the tarball and move it to the right location
#

rm -rf portage || { echo "rm failed, $?"; exit 1; }
# gnu tar-1.16 will fail with '/bin/tar: portage/metadata: file changed as we read it'
# unless we make a copy because datestamp.sh runs every minute.
# Use cp -rl to make it a cheap copy (using hardlinks).
cp -rl "$MASTER" portage || { echo "cp failed, $?"; exit 1; }
/bin/tar --owner=portage --group=portage -cf ${FILENAME%.bz2} portage || { echo "tar failed, $?"; exit 1; }
rm -rf portage
#/bin/tar --exclude=CVS -cf ${FILENAME%.bz2} portage
# Disk space is limited, so it is freed ASAP.
#/usr/bin/sudo /bin/rm -rf ${TEMP}/portage
/usr/bin/md5sum ${FILENAME%.bz2} > ${FILENAME}.umd5sum
bzip2 -k9 ${FILENAME%.bz2}

# Sanity check the tarball size and bail out if it appears abnormal.
current_size=$(stat -c '%s' "${FILENAME}")
previous_size=$(stat -c '%s' "${UPLOAD}/${DELTA_FILENAME}")
if [ ${current_size} -lt ${previous_size} ]; then
	size_difference=$(expr ${previous_size} - ${current_size})
	difference_ratio=$(expr ${previous_size} / ${size_difference})
	if [ ${difference_ratio} -lt 5 ]; then
		echo "Snapshot size has decreased by more than 20% in one day!!!"
		echo "${FILENAME} ${current_size} bytes"
		echo "${DELTA_FILENAME} ${previous_size} bytes"
		exit 1
	fi
fi

"$LZMA" -k "${FILENAME%.*}" || exit $?
for f in "${FILENAME}" "${FILENAME%.*}".lzma ; do
	"$CP" "${FILENAME}".umd5sum "${UPLOAD}${f}".umd5sum || exit $?
	"$MD5SUM" "$f" > "$f".md5sum || exit $?
	"$GPG" --batch -u "${SIGNKEYID}" --armor --detach-sign \
		--output "$f".gpgsig "$f" || exit $?
	"$MV" "$f" "$f".md5sum "$f".gpgsig "${UPLOAD}"/ || exit $?
done

bzip2 -dkc ${UPLOAD}/${DELTA_FILENAME} > orig
PATCH=snapshot-${DELTA_BASE}-${YESTERDAY}.patch.bz2
/usr/bin/differ -f bdelta orig ${FILENAME%.bz2} ${PATCH%.bz2}
bzip2 -9 ${PATCH%.bz2}
/usr/bin/md5sum ${PATCH} > ${PATCH}.md5sum
/bin/chmod 644 ${PATCH}{,.md5sum}
/bin/mv ${PATCH}{,.md5sum} ${DELTA_UPLOAD}
"$RM" orig ${FILENAME%.bz2} "${FILENAME}".umd5sum || exit $?

#
# create some symlinks
#

cd ${UPLOAD}
for f in "${FILENAME}" "${FILENAME%.*}".lzma ; do
	ext=${f##*.}
	"$LN" -sf "$f" "${UPLOAD}"portage-latest.tar.${ext} || exit $?
	"$RM" -f "${UPLOAD}"portage-latest.tar.${ext}.md5sum || exit $?
	"$SED" "s/${f}\$/portage-latest.tar.${ext}/" "${UPLOAD}"${f}.md5sum > \
		"${UPLOAD}"portage-latest.tar.${ext}.md5sum || exit $?
	"$LN" -sf "${f}".gpgsig "${UPLOAD}"portage-latest.tar.${ext}.gpgsig || exit $?
done

#
# tidy up
#

/usr/bin/find ${UPLOAD} -maxdepth 1 -mtime +${HISTORY} | /usr/bin/xargs /bin/rm -f

#clean up old snapshots.
~gmirror/scripts/clean-old-deltas.py "${DELTA_UPLOAD}" "${YESTERDAY}" $(stat -c '%s' "${UPLOAD}/${FILENAME}")