#!/bin/bash
# SPDX-License-Identifier: LGPL-2.1-or-later
set -e

if ((NO_BUILD)); then
    exit 0
fi

# shellcheck source=/dev/null
. /usr/lib/os-release

if [ ! -d "pkg/$ID/debian" ]; then
    echo "deb rules not found at pkg/$ID/debian, run mkosi once with -ff to make sure the rules are cloned" >&2
    exit 1
fi

# We transplant the debian/ folder from the deb package sources into the upstream sources.
mount --mkdir --bind "$SRCDIR/pkg/$ID/debian" "$SRCDIR"/debian

# We remove the patches so they don't get applied.
rm -rf "$SRCDIR"/debian/patches/*

# While the build directory can be specified through DH_OPTIONS, the default one is hardcoded everywhere so
# we have to use that. Because it is architecture dependent, we query it using dpkg-architecture first.
DEB_HOST_GNU_TYPE="$(dpkg-architecture --query DEB_HOST_GNU_TYPE)"
mount --mkdir --bind "$BUILDDIR" "$SRCDIR/obj-$DEB_HOST_GNU_TYPE"

if [ -d .git/ ] && [ -z "$(git status --porcelain)" ]; then
    TS="$(git show --no-patch --format=%ct HEAD)"
else
    TS="${SOURCE_DATE_EPOCH:-$(date +%s)}"
fi

# Add a new changelog entry to update the version. We use a fixed date since a dynamic one causes a full
# rebuild every time.
cat >debian/changelog.new <<EOF
systemd ($(cat meson.version)-$(date "+%Y%m%d%H%M%S" --date "@$TS")) UNRELEASED; urgency=low

  * Automatic build from mkosi

 -- systemd test <systemd-devel@lists.freedesktop.org>  $(date --rfc-email --date "@$TS")

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

MKOSI_CFLAGS="-O0"
if ((LLVM)); then
    # TODO: Remove -fno-sanitize-function when https://github.com/systemd/systemd/issues/29972 is fixed.
    MKOSI_CFLAGS="$MKOSI_CFLAGS -shared-libasan -fno-sanitize=function"
fi

MKOSI_LDFLAGS=""
if ((LLVM)) && [[ -n "$SANITIZERS" ]]; then
    MKOSI_LDFLAGS="$MKOSI_LDFLAGS -Wl,-rpath=$(clang --print-file-name="")lib/linux"
fi

MKOSI_MESON_OPTIONS="-D mode=developer -D b_sanitize=${SANITIZERS:-none}"
if ((WIPE)); then
    MKOSI_MESON_OPTIONS="$MKOSI_MESON_OPTIONS --wipe"
fi

# TODO: Drop GENSYMBOLS_LEVEL once https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=986746 is fixed.
build() {
    env \
    CC="$( ((LLVM)) && echo clang || echo gcc)" \
    CXX="$( ((LLVM)) && echo clang++ || echo g++)" \
    CC_LD="$( ((LLVM)) && echo lld)" \
    CXX_LD="$( ((LLVM)) && echo lld)" \
    DEB_BUILD_OPTIONS="$(awk '$1=$1' <<<"\
        $( ((WITH_TESTS)) || echo nocheck) \
        $( ((WITH_DOCS)) || echo nodoc) \
        $( ((WITH_DEBUG)) && echo debug || echo nostrip) \
        $( ! ((MESON_VERBOSE)) && echo terse) \
        optimize=-lto \
        hardening=-fortify \
    ")" \
    DEB_BUILD_PROFILES="$(awk '$1=$1' <<<"\
        $( ((WITH_TESTS)) || echo nocheck) \
        $( ((WITH_DOCS)) || echo nodoc) \
        pkg.systemd.upstream \
    ")" \
    DEB_CFLAGS_APPEND="$MKOSI_CFLAGS $CFLAGS" \
    DEB_CXXFLAGS_APPEND="$MKOSI_CFLAGS $CFLAGS" \
    DEB_LDFLAGS_APPEND="$MKOSI_LDFLAGS $LDFLAGS" \
    DPKG_FORCE="unsafe-io" \
    DPKG_DEB_COMPRESSOR_TYPE="none" \
    DH_MISSING="--fail-missing" \
    CONFFLAGS_UPSTREAM="$MKOSI_MESON_OPTIONS $MESON_OPTIONS" \
    GENSYMBOLS_LEVEL="$( ((LLVM)) && echo 0 || echo 1)" \
        dpkg-buildpackage \
        --no-pre-clean \
        --unsigned-changes \
        --build=binary

    EXIT_STATUS=$?

    # Make sure we don't reconfigure twice.
    MKOSI_MESON_OPTIONS="${MKOSI_MESON_OPTIONS//"--wipe"/}"

    return $EXIT_STATUS
}

if ! build; then
    # debhelper installs files for each package to debian/<package> so we figure out which files were
    # packaged by querying all the package names from debian/control and running find on each of the
    # corresponding package directory in debian/.
    grep "Package:" debian/control |
        sed "s/Package: //" |
        xargs -d '\n' -I {} sh -c "[ -d debian/{} ] && (cd debian/{} && find . ! -type d ! -path "*dh-exec*" -printf '%P\n')" |
        # Remove compression suffix from compressed manpages as the manpages in debian/tmp will be uncompressed.
        sed --regexp-extended 's/([0-9])\.gz$/\1/' |
        sort --unique >/tmp/packaged-files

    # We figure out the installed files by running find on debian/tmp/ which contains the files installed
    # by meson install.
    (cd debian/tmp/ && find . ! -type d ! -path "*dh-exec*" -printf '%P\n') >/tmp/installed-files

    if [ -f debian/not-installed ]; then
        grep --invert-match "^#" debian/not-installed >>/tmp/installed-files
    fi

    sort --unique --output /tmp/installed-files /tmp/installed-files

    # We get all the installed files that were not packaged by finding entries in the installed file that are
    # not in the packaged file.
    comm -23 /tmp/installed-files /tmp/packaged-files > /tmp/unpackaged-files
    # If there are no unpackaged files something else went wrong.
    if [ ! -s /tmp/unpackaged-files ]; then
        exit 1
    fi

    # Otherwise, we append the unpackaged files to the filelist for the systemd package and retry the build.
    cat /tmp/unpackaged-files >>debian/systemd.install
    build
fi

(
    shopt -s nullglob
    cp ../*.deb ../*.ddeb "$PACKAGEDIR"
    cp ../*.deb ../*.ddeb "$OUTPUTDIR"
)