#!/bin/sh

set -e

bendir=/home/vorlon/devel/canonical/ubuntu-transition-tracker-configs/monitor/ongoing

dry_run=false
no_update=false

while [ $# -gt 0 ]; do
        case $1 in
                --dry-run)
                        dry_run=:
                        ;;
		--no-update)
			no_update=:
			;;
                *)
                        echo "Unknown argument: $1"
                        exit 1
                        ;;
        esac
        shift
done

rename_package() {
	oldpkg="$1"
	newpkg="$2"
	if [ -z "$1" ] || [ -z "$2" ]; then
		echo "Error: rename_package called with args '$@'"
		return 1
	fi

	# warning: sed can be hazardous to your mental health.
	sed -i -e"s/\([ |,=/]\)$oldpkg\([ |,:]\|$\)/\1$newpkg\2/g" \
		debian/control debian/control.in debian/rules
	if sed -n -e"/^Package:[[:space:]]*$newpkg[[:space:]]*\$/,/^Package:/p" debian/control \
	   | grep -q Conflicts:
	then
		sed -i -e"/^Package:[[:space:]]*$newpkg[[:space:]]*\$/,/^Package:/ { s/^Conflicts:/& $oldpkg,/; }" \
			debian/control debian/control.in
	else
		sed -i -e"/^Package:[[:space:]]*$newpkg[[:space:]]*\$/,/^Package:/ { /^Description:/i\\" \
		    -e "Conflicts: $oldpkg" -e '}' \
			debian/control debian/control.in
	fi
	if sed -n -e"/^Package:[[:space:]]*$newpkg[[:space:]]*\$/,/^Package:/p" debian/control \
	   | grep -q Replaces:
	then
		sed -i -e"/^Package:[[:space:]]*$newpkg[[:space:]]*\$/,/^Package:/ { s/^Replaces:/& $oldpkg,/; }" \
			debian/control debian/control.in
	else
		sed -i -e"/^Package:[[:space:]]*$newpkg[[:space:]]*\$/,/^Package:/ { /^Description:/i\\" \
		    -e "Replaces: $oldpkg" -e '}' \
			debian/control debian/control.in
	fi
	for dh_old in debian/$oldpkg.*; do
		if [ -e "$dh_old" ]; then
			dh_new=$(echo $dh_old | sed -e"s/$oldpkg/$newpkg/")
			mv -v $dh_old $dh_new
			sed -i -e"s/\(^\|[ |,/]\)$oldpkg\([ |,:/]\|$\)/\1$newpkg\2/g" $dh_new
		fi
	done
	echo "# G++5 ABI transition" >> debian/$newpkg.lintian-overrides
	echo "$newpkg: package-name-doesnt-match-sonames ${oldpkg}" >> debian/$newpkg.lintian-overrides

}

if ! $no_update; then
	echo '========== Downloading Debian build logs =========='
	wget -q --mirror -nH --cut-dirs=3 -np -R '*index.html*' -P "debian-build-logs" \
		https://people.debian.org/~doko/logs/gcc5-20150701/
fi

echo '=============== Rebuilding packages ==============='
for F in debian-build-logs/*.log
do
	srcpkg=$(basename ${F%%_*})
	echo "Source package: $srcpkg"
	if [ -e blacklist.txt ] && grep -q "^$srcpkg\$" blacklist.txt
	then
		echo "  package blacklisted; skipping"
		continue
	fi

	if ! binpkgs=$(awk '/===== BEGIN GCC CXX11 symbols/ { print $6 }' $F | grep -v DEBIAN/symbols | sort -u)
	then
		echo "Error: no binary packages found in log for $srcpkg"
		continue
	fi
	if nonnumpkgs=$(echo "$binpkgs" | grep -v '[0-9]$'); then
		echo "Skipping non-numeric bin packages: $nonnumpkgs"
	fi
	if ! binpkgs=$(echo "$binpkgs" | grep '[0-9]$'); then
		continue
	fi
	binpkgs=$(echo $binpkgs)

	# Find the most recent available source package known to us and check
	# its binaries.  Better done with launchpadlib, but requires switching
	# to python (which is probably sensible anyway, but grep-dctrl)
	# But it can definitely give a wrong answer relative to pull-lp-source.
	# hopefully sort's -V comparison gives us the right answer in most cases
	latestver=$(apt-cache showsrc "$srcpkg" | grep-dctrl -n -FPackage -X "$srcpkg" -sVersion -n | sort -V | tail -n1)
	latestbinlist=$(apt-cache showsrc "$srcpkg" | grep-dctrl -FPackage -X "$srcpkg" -a -FVersion -X "$latestver" -sBinary -n)
	rename_needed=false
	for binpkg in $binpkgs; do
		if echo $latestbinlist | grep -q "\(^\| \)$binpkg\(, \|$\)"; then
			echo "$binpkg still present in latest source, update needed."
			rename_needed=:
			break
		fi
	done
	if ! $rename_needed; then
		echo "$srcpkg has already been transitioned (old binaries: $binpkgs; current binaries: $latestbinlist)"
		continue
	fi

	echo "Rebuilding $srcpkg"
	if $dry_run; then
		continue
	fi

	pull-lp-source $srcpkg
	build_failed=false
	(cd ${srcpkg}-*
	 dch 'Rename library packages for g++5 ABI transition.'

	 for binpkg in $binpkgs; do
		# FIXME: we should also handle dbg packages of the same name.
		newpkg=${binpkg}v5
		rename_package "$binpkg" "$newpkg"
		case $latestbinlist in
			*${binpkg}-dbg*)
				rename_package "${binpkg}-dbg" "${newpkg}-dbg"
				;;
			*) ;;
		esac
	 done
	 update-maintainer
	 dch -r -D wily ''
	 sudo mk-build-deps -i -r -t 'apt-get --no-install-recommends -y'
	 debuild -S
	) || build_failed=:

	if $build_failed; then
		rm -r ${srcpkg}[-_]*
		continue
	fi

	fname="$bendir/${srcpkg}-g++5.ben"
	affected=
	good=
	bad=
	for binpkg in $binpkgs; do
		oldpkg=$(echo $binpkg | sed -e's/\+/\\+/g')
		newpkg=${oldpkg}v5
		affected="$affected${affected:+|}$oldpkg|$newpkg"
		good="$good${good:+|}$newpkg"
		bad="$bad${bad:+|}$oldpkg"
		case $latestbinlist in
			*${binpkg}-dbg*)
				oldpkg=$(echo $binpkg | sed -e's/\+/\\+/g')-dbg
				newpkg=${oldpkg}v5-dbg
				affected="$affected${affected:+|}$oldpkg|$newpkg"
				good="$good${good:+|}$newpkg"
				bad="$bad${bad:+|}$oldpkg"
				;;
			*) ;;
		esac
	done
	echo 'title = "'"$srcpkg g++5 ABI transition"'";' > $fname
	echo "is_affected = .depends ~ /(^| )($affected)\s*([,(:]|$)/;" >> $fname
	echo "is_good = .depends ~ /(^| )($good)\s*([,(:]|$)/;" >> $fname
	echo "is_bad = .depends ~ /(^| )($bad)\s*([,(:]|$)/;" >> $fname
	(cd $bendir; bzr add $(basename $fname))

	if [ -n "$(find ${srcpkg}-*/debian -maxdepth 1 -name '*.symbols*' -print)" ]
	then
		echo "Error: package $srcpkg uses symbols files, needs manual attention."
		exit 1
	fi

	dput ${srcpkg}*_source.changes
	rm -r ${srcpkg}[-_]*
done