#!/bin/sh
#
# gen-release
#
# Copyright © 2017-2024 Guillem Jover <guillem@debian.org>
#
# 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.  If not, see <https://www.gnu.org/licenses/>.
#

set -x
set -e
set -u

# Pre-checks.

# Currently requires packages: dpkg-dev, git, schroot and devscripts
# (the latter should eventually be replaced by dpkg tools).
for req in dpkg-parsechangelog git schroot dch debsign dscverify; do
  if ! command -v $req >/dev/null 2>&1; then
    echo "error: missing required command $req" >&2
    exit 1
  fi
done

if [ "$(dpkg-parsechangelog -SSource)" != 'dpkg' ] || ! [ -e .git ]; then
  echo "error: not inside the dpkg git tree" >&2
  exit 1
fi

# Setup.
dist="${1:-unstable}"
relver="${2:-$(dpkg-parsechangelog -SVersion)}"

numjobs="$(nproc)"
checkflags="-j$numjobs AUTHOR_TESTING=1 TEST_PARALLEL=$numjobs"

dircode="$(pwd)"
dirtests="$dircode/tests"
dirbuild="$(mktemp --tmpdir --directory release-dpkg.XXXXXXXX)"

# Update the source chroot.
schroot -c "source:$dist" -- sudo eatmydata apt-get --yes update
schroot -c "source:$dist" -- sudo eatmydata apt-get --yes upgrade

# Setup a clean chroot session.
chroot="$(schroot -c "$dist" -b)"

echo "Release start: $(date -Iseconds)"

cd "$dircode"

schroot -c "$chroot" -r -- sudo eatmydata apt-get --yes build-dep \
  -P pkg.dpkg.author-testing,pkg.dpkg.author-release .

if ! git log --format=tformat:%s -s HEAD~2.. | grep 'po: Regenerate'; then
  # Clean slate.
  git clean -Xdf

  # Update the .pot and .po files.
  echo "$relver" >.dist-version
  schroot -c "$chroot" -r -- ./autogen
  schroot -c "$chroot" -r -- ./configure
  schroot -c "$chroot" -r -- make update-po
  rm -f .dist-version
  git commit -a -m 'po: Regenerate .pot files and merge .po files with them'
fi

if [ -z "$(git tag --list "$relver")" ]; then
  # Finalize the actual release.
  genchangelog='build-aux/gen-changelog'
  sed -i -e "2e$genchangelog" -e '2,3d' debian/changelog
  dch -r -D"$dist"
  git commit -a -m "Release $relver"
  git tag -s "$relver" -m "Release $relver"
elif [ "$(git describe)" != "$relver" ]; then
  echo "error: mismatched tag for $relver not on git HEAD" >&2
  exit 1
fi

# Clean slate.
git clean -Xdf

# Prepare the tarball for distribution.
schroot -c "$chroot" -r -- ./autogen
schroot -c "$chroot" -r -- ./configure
if [ "$dist" = unstable ]; then
  # Generate the CPAN distribution only from main.
  make dist-cpan
fi
# shellcheck disable=SC2086
schroot -c "$chroot" -r -- make $checkflags distcheck

# Prepare for packaged release.
mkdir -p "$dirbuild"
cp "dpkg-$relver.tar.xz" "$dirbuild/"

# Teardown pre-release chroot.
schroot -c "$chroot" -e

cd "$dirbuild"

# Setup a clean chroot session for the dist tarballs.
chroot="$(schroot -c "$dist" -b)"

# Build twice, to make sure we can build ourselves with the new dpkg,
# and to verify that we are building reproducibly.

# Build A and B in a chroot.
for iter in a b; do (
  mkdir -p "build-$iter"
  cd "build-$iter"
  tar xaf "../dpkg-$relver.tar.xz"
  cd "dpkg-$relver"

  schroot -c "$chroot" -r -- sudo eatmydata apt-get --yes build-dep .
  schroot -c "$chroot" -r -- dpkg-buildpackage -us -uc --changes-option=-S

  # Install resulting .debs.
  schroot -c "$chroot" -r -- sudo eatmydata dpkg -iO ../*.deb
) done

# Run functional test-suite.
(
  set -x
  set -e
  set -u

  cd "$dirtests"
  schroot -c "$chroot" -r -- sudo eatmydata apt-get --yes purge pkg-config
  schroot -c "$chroot" -r -- eatmydata make test-clean clean
  schroot -c "$chroot" -r -- eatmydata make test 2>&1 | tee test.log
)

schroot -c "$chroot" -r -- sudo eatmydata apt-get --yes install lintian

# Verify the result.
diff -u build-a/dpkg_*.changes build-b/dpkg_*.changes || true
# Prompt to continue? (.buildinfo will differ)
diff -u build-a/dpkg_*.buildinfo build-b/dpkg_*.buildinfo || true
# Prompt to continue? (Build-Date, Environment will differ).
schroot -c "$chroot" -r -- lintian build-b/*.changes build-b/*.deb

# Teardown chroot.
schroot -c "$chroot" -e

# Sign and verify.
cd "$dirbuild/build-b"
debsign dpkg_"${relver}"_*.changes
dscverify dpkg_"${relver}"_*.changes

ls -l "$(pwd)"

echo "Release process finished (dpkg ${relver}): $(date -Iseconds)"
echo "  Hint: upload to CPAN"
echo "  Hint: update https://www.wikidata.org/wiki/Q305892"