#!/bin/bash
# Prepare systemd source package in current directory for testing an upstream
# commit, branch, or PR, without Debian patches. This replaces everything
# except the debian/ directory with an upstream checkout.
# NEVER run this in your actual packaging work directory! This is only meant
# for upstream CI.
#
# Author: Martin Pitt <martin.pitt@ubuntu.com>

set -eu
test -x debian/rules
case "${DEB_BUILD_PROFILES:-}" in
    *pkg.systemd.upstream*) ;;
    *)
        echo "Not in upstream testing mode. Do *not* run this script unless you know what you are doing." >&2
        exit 1
esac
if [ -n "${UPSTREAM_PULL_REQUEST:-}" ]; then
    FETCH="git fetch -fu origin refs/pull/$UPSTREAM_PULL_REQUEST/head:pr"
    CO='git checkout pr'
    DESC="PR #$UPSTREAM_PULL_REQUEST"
elif [ -n "${UPSTREAM_HEAD:-}" ]; then
    FETCH=''
    CO="git checkout $UPSTREAM_HEAD"
    DESC="$UPSTREAM_HEAD"
else
    echo "WARNING: $0: Neither UPSTREAM_PULL_REQUEST nor UPSTREAM_HEAD set, ignoring" >&2
    exit 0
fi

DUMMY_USER_NAME="Merge dummy user"
DUMMY_USER_EMAIL="invalid@example.com"

UPSTREAM_REPO="${UPSTREAM_REPO:-https://github.com/systemd/systemd.git}"
BRANCH_NAME=$(git rev-parse --abbrev-ref HEAD)

# Use git, if in a git repo
if [ -d .git ]; then
    # make sure user.name/user.email are set, git commit wants them
    git config --get user.name || git config user.name "$DUMMY_USER_NAME"
    git config --get user.email || git config user.email "$DUMMY_USER_EMAIL"
fi

mkdir -p debian/tmp
(cd debian/tmp
 git clone "${UPSTREAM_REPO}" upstream || (rm -rf upstream; sleep 60; git clone "${UPSTREAM_REPO}" upstream)
 cd upstream
 $FETCH
 $CO
 git config user.email "$DUMMY_USER_EMAIL"
 git config user.name "$DUMMY_USER_NAME"
 if  [ -n "${UPSTREAM_PULL_REQUEST:-}" ] && [ "${UPSTREAM_REPO}" != "https://github.com/systemd/systemd-stable.git" ]; then
     git rebase main || git rebase --abort
 fi
)
if [ -f debian/tmp/upstream/meson.version ]; then
    UPSTREAM_VER=$(cat debian/tmp/upstream/meson.version)
else
    UPSTREAM_VER=$(cd debian/tmp/upstream; git describe | sed 's/^v//;s/-/./g')
fi

# If we are on a stable branch, check out the corresponding packaging branch. For some settings like
# build dependencies it is already too late, but this is mostly relevant for the dh_install files and
# the tests.
if [ -d .git ] && echo "$UPSTREAM_VER" | grep -q '\.'; then
    git checkout "ci/v${UPSTREAM_VER%%.*}-stable"
fi

if [ -n "${KEEP_DEBIAN_PATCHES:-}" ]; then
        # set up pq branch if it does not exist
        if [ "$BRANCH_NAME" = HEAD ]; then
                echo "ERROR: $0 must be started from a branch when using KEEP_DEBIAN_PATCHES" >&2
                exit 1
        fi
        ( gbp pq import 2> /dev/null && gbp pq switch ) || true
        if ! git branch --contains "$BRANCH_NAME" | grep -q patch-queue/"$BRANCH_NAME"; then
                echo "ERROR: patch-queue/$BRANCH_NAME exists but it is not rebased, please rebase it." >&2
                exit 1
        fi
fi

# switch to native instead of quilt
echo '3.0 (native)' > debian/source/format

# drop our patches
rm -rf debian/patches

# disable tests which are not for upstream
[ -n "${KEEP_DEBIAN_TESTS:-}" ] || sed -i '/# NOUPSTREAM/ q' debian/tests/control

# create new git commit with debian/ changes
if [ -d .git ] && [ -n "$(git status --short debian)" ]; then
    git add debian
    git commit -n -m "checkout-upstream: edit debian/ files for upstream testing"
fi

# clean out original upstream sources
find . -mindepth 1 -maxdepth 1 -name debian -o -name .git -prune -o -print0 | xargs -0n1 rm -rf

# These options changes are only needed for the upstream CI, and we don't want to pollute d/rules with them.
# Also we want to ensure running on an older branch (e.g.: for the systemd-stable repository) doesn't break.
if grep -q default-timeout-sec debian/tmp/upstream/meson_options.txt; then
    sed -i "s/option('default-timeout-sec', type : 'integer', value : 90/option('default-timeout-sec', type : 'integer', value : 180/" debian/tmp/upstream/meson_options.txt
fi
if grep -q log-trace debian/tmp/upstream/meson_options.txt; then
    sed -i "s/option('log-trace', type : 'boolean', value : false/option('log-trace', type : 'boolean', value : true/" debian/tmp/upstream/meson_options.txt
fi

# replace with checkout
mv debian/tmp/upstream/* .
rm -rf debian/tmp

# create new git commit with upstream code
if [ -d .git ] && [ -n "$(git status --short)" ] ; then
    git add .
    git commit -n -m "checkout-upstream: replace with upstream code at version ${UPSTREAM_VER}"
fi

# import Debian patches which apply cleanly
if [ -n "${KEEP_DEBIAN_PATCHES:-}" ]; then
    for c in $(git log "$BRANCH_NAME"..patch-queue/"$BRANCH_NAME" --format='%H' --reverse); do
        if ! git cherry-pick "$c"; then
            git cherry-pick --abort
            git reset --hard
            git clean -dxf
        fi
    done
fi

if [ -z "${UPSTREAM_KEEP_CHANGELOG:-}" ] ; then
    # craft changelog
    cat << EOF > debian/changelog.new
systemd (${UPSTREAM_VER}.0) UNRELEASED; urgency=low

  * Automatic build from upstream $DESC

 -- systemd test <pkg-systemd-maintainers@lists.alioth.debian.org>  $(date -R)

EOF
    cat debian/changelog >> debian/changelog.new
    mv debian/changelog.new debian/changelog

    # create new git commit with changelog entry
    if [ -d .git ] ; then
        git add debian
        git commit -n -m "checkout-upstream: update changelog to version ${UPSTREAM_VER}.0"
    fi
fi