#!/bin/sh

set -e

RED="\033[1;33;31m"
GREEN="\033[1;33;32m"
YELLOW="\033[1;33;33m"
BLUE="\033[1;33;34m"
WHITE="\033[1;33;37m"
NORMAL="\033[0m"

# FIXME: getopt
# FIXME: -f for forced indices download

MODE="$(basename ${0} | awk -F. '{ print $2 }')"

case "${MODE}" in
	engywuck)
		UPSTREAM_DISTRIBUTIONS="buster buster-updates buster-proposed-updates"
		DOWNSTREAM_DISTRIBUTION="engywuck"
		DOWNSTREAM_MIRROR="https://apt.progress-linux.org/packages"
		DOWNSTREAM_TAG="progress"
		;;

	engywuck-backports)
		UPSTREAM_DISTRIBUTIONS="bullseye bullseye-updates bullseye-proposed-updates"
		DOWNSTREAM_DISTRIBUTION="engywuck-backports"
		DOWNSTREAM_MIRROR="https://apt.progress-linux.org/packages"
		DOWNSTREAM_TAG="progress"
		;;

	fuchur)
		UPSTREAM_DISTRIBUTIONS="bullseye bullseye-updates bullseye-proposed-updates"
		DOWNSTREAM_DISTRIBUTION="fuchur"
		DOWNSTREAM_MIRROR="https://apt.progress-linux.org/packages"
		DOWNSTREAM_TAG="progress"
		;;

	fuchur-backports)
		UPSTREAM_DISTRIBUTIONS="sid experimental"
		DOWNSTREAM_DISTRIBUTION="fuchur-backports"
		DOWNSTREAM_MIRROR="https://apt.progress-linux.org/packages"
		DOWNSTREAM_TAG="progress"
		;;

	buster)
		UPSTREAM_DISTRIBUTIONS="buster buster-updates buster-proposed-updates"
		DOWNSTREAM_DISTRIBUTION="buster"
		DOWNSTREAM_MIRROR="https://apt.bfh.science/packages"
		DOWNSTREAM_TAG="bfh"
		;;

	buster-backports)
		UPSTREAM_DISTRIBUTIONS="sid experimental"
		DOWNSTREAM_DISTRIBUTION="buster-backports"
		DOWNSTREAM_MIRROR="https://apt.bfh.science/packages"
		DOWNSTREAM_TAG="bfh"
		;;
esac

UPSTREAM_SECTIONS="main contrib non-free"
UPSTREAM_MIRROR="http://debian.ethz.ch/debian"

DOWNSTREAM_SECTIONS="main contrib non-free"

Download_downstream_sources ()
{
	# Download downstream sources
#	if [ -e "downstream.${MODE}.sources" ] && [ "$(( $(stat -c %Y downstream.${MODE}.sources) + ( 4 * 3600 ) ))" -lt "$(date +%s)" ]
#	then
#		# file is older than 4 hours
		rm -f "downstream.${MODE}.sources"
#	fi

	if [ ! -e "downstream.${MODE}.sources" ]
	then
		for SECTION in ${DOWNSTREAM_SECTIONS}
		do
			wget -q -O - "${DOWNSTREAM_MIRROR}/dists/${DOWNSTREAM_DISTRIBUTION}/${SECTION}/source/Sources.xz" | xz -d >> "downstream.${MODE}.sources"
		done
	fi
}

Download_upstream_sources ()
{
	# Download upstream sources
	if [ -e "upstream.${MODE}.sources" ] && [ "$(( $(stat -c %Y upstream.${MODE}.sources) + ( 4 * 3600 ) ))" -lt "$(date +%s)" ]
	then
		# file is older than 4 hours
		rm -f "upstream.${MODE}.sources"
	fi

	if [ ! -e "upstream.${MODE}.sources" ]
	then
		for DISTRIBUTION in ${UPSTREAM_DISTRIBUTIONS}
		do
			case "${DISTRIBUTION}" in
				*-*)
					;;

				*)
					if wget -q -O /dev/null "http://security.debian.org/dists/${DISTRIBUTION}/updates/Release"
					then
						for SECTION in ${UPSTREAM_SECTIONS}
						do
							wget -q -O - "http://security.debian.org/dists/${DISTRIBUTION}/updates/${SECTION}/source/Sources.xz" | xz -d >> "upstream.${MODE}.sources"
						done
					fi
					;;
			esac

			for SECTION in ${UPSTREAM_SECTIONS}
			do
				wget -q -O - "${UPSTREAM_MIRROR}/dists/${DISTRIBUTION}/${SECTION}/source/Sources.xz" | xz -d >> "upstream.${MODE}.sources"
			done
		done
	fi
}

Download_downstream_sources
Download_upstream_sources

# Process downstream sources
DOWNSTREAM_PACKAGES="$(awk '/^Package: / { print $2 }' downstream.${MODE}.sources | sort -u)"

echo "################################################################################"
echo "${DOWNSTREAM_DISTRIBUTION}"
echo "################################################################################"

echo -n "Comparing versions... "

for PACKAGE in ${DOWNSTREAM_PACKAGES}
do
	DOWNSTREAM_VERSION="$(sed -n "/^Package: ${PACKAGE}$/,/^Version:/p" downstream.${MODE}.sources | awk '/^Version: / { print $2 }')"
	UPSTREAM_VERSION="$(sed -n "/^Package: ${PACKAGE}$/,/^Version:/p" upstream.${MODE}.sources | awk '/^Version: / { print $2 }' | sort -rV | head -n1)"

	if echo ${UPSTREAM_VERSION} | grep -qs '-'
	then
		# package is non-native
		DOWNSTREAM="$(echo ${DOWNSTREAM_VERSION} | sed -e "s|~${DOWNSTREAM_TAG}.*||" -e "s|${DOWNSTREAM_TAG}.*||")"
	else
		# package is native
		DOWNSTREAM="$(echo ${DOWNSTREAM_VERSION} | sed -e "s|-0.0~${DOWNSTREAM_TAG}.*||" -e "s|-0.*${DOWNSTREAM_TAG}.*||")"
	fi

	if grep -qs "^${PACKAGE} ${UPSTREAM_VERSION}$" ignore.txt
	then
		continue
	fi

	if [ -z "${UPSTREAM_VERSION}" ] && grep -qs "^${PACKAGE} ${DOWNSTREAM_VERSION}$" ignore.txt
	then
		continue
	fi

	if [ -z "${UPSTREAM_VERSION}" ]
	then
		echo "${BLUE}${PACKAGE}${NORMAL} '!${DOWNSTREAM_VERSION}'"
		continue
	fi

	# comparing versions
	if dpkg --compare-versions ${UPSTREAM_VERSION} eq ${DOWNSTREAM}
	then
		echo -n "."
	elif dpkg --compare-versions ${UPSTREAM_VERSION} gt ${DOWNSTREAM}
	then
		echo "${RED}${PACKAGE}${NORMAL} '${UPSTREAM_VERSION} >> ${DOWNSTREAM_VERSION}'"
	elif dpkg --compare-versions ${UPSTREAM_VERSION} lt ${DOWNSTREAM}
	then
		echo "${YELLOW}${PACKAGE}${NORMAL} '${UPSTREAM_VERSION} << ${DOWNSTREAM_VERSION}'"
	else
		echo "${PACKAGE}: internal error"
	fi
done

echo " done."