#!/bin/bash
#
# shellcheck disable=SC2035,SC2046,SC2086
#
# Prepare the environment for building a desktop environment.
set -e
# Ensure we're running as root.
if [ $EUID -ne 0 ]; then
  echo "Error: Must be run as root." >&2
  exit 1
fi
# Setup the environment.
export MASSOS="$PWD"/massos-rootfs
# Ensure stage1 has been run first.
if [ ! -d "$MASSOS" ]; then
  echo "Error: You must run stage1.sh and stage2.sh first!" >&2
  exit 1
fi
# Ensure the specified desktop environment is valid.
if [ -z "$1" ]; then
  echo "Error: Specify the desktop environment ('stage3/README' for info)." >&2
  exit 1
fi
if [ ! -d "stage3/$1" ]; then
  echo "Error: '$1' is not a valid or supported desktop environment." >&2
  echo "The desktop environment must have a directory in 'stage3/'." >&2
  echo "Alternatively, pass 'nodesktop' if you want a core only build." >&2
  echo "See 'stage3/README' for more information." >&2
  exit 1
fi
if [ ! -e "stage3/$1/stage3-$1.sh" ]; then
  echo "Stage 3 directory for '$1' was found, but there is no Stage 3" >&2
  echo "build script inside it." >&2
  exit 1
fi
if [ ! -e "stage3/$1/source-urls" ]; then
  echo "Stage 3 directory and build script for '$1' was found, but there" >&2
  echo "is no source-urls file." >&2
  exit 1
fi
if [ "$1" != "nodesktop" ] && [ ! -e "stage3/$1/builtins" ]; then
  echo "Stage 3 directory and build script for '$1' was found, but there" >&2
  echo "is no builtins file." >&2
  exit 1
fi
# Download source URls for Stage 3.
echo "Downloading sources for '$1' (Stage 3)..."
mkdir -p stage3/sources; pushd stage3/sources
set +e
wget -nc --continue --input-file=../"$1"/source-urls
STATUS=$?
# Ensure everything downloaded successfully.
if [ $STATUS -ne 0 ]; then
  echo -e "\nOne or more Stage 3 source download(s) failed." >&2
  echo "Consider checking the above output and try re-running '$0 $1'." >&2
  exit $STATUS
fi
set -e
popd
# Put Stage 3 files into the system.
echo "Starting Stage 3 build for '$1'..."
mkdir -p "$MASSOS"/root/mbs/{extras,work}
## Build script, sources and patches.
mv stage3/sources "$MASSOS"/root/mbs
cp stage3/"$1"/stage3-"$1".sh "$MASSOS"/root/mbs/build-stage3.sh
if [ -d stage3/"$1"/patches ]; then
  cp -r stage3/"$1"/patches "$MASSOS"/root/mbs
fi
## Builtins.
if [ -e stage3/"$1"/builtins ]; then
  install -Dm644 stage3/"$1"/builtins "$MASSOS"/usr/share/massos/builtins.d/"$1"
fi
## /etc/skel, if present.
if [ -d stage3/"$1"/skel ]; then
  cp -r stage3/"$1"/skel/. "$MASSOS"/etc/skel/.
  cp -r stage3/"$1"/skel/. "$MASSOS"/root/.
  chown -R root:root "$MASSOS"/etc/skel
  chown -R root:root "$MASSOS"/root
fi
## systemd units.
if [ -d stage3/"$1"/systemd-units ]; then
  cp -r stage3/"$1"/systemd-units/* "$MASSOS"/usr/lib/systemd/system
  chown -R root:root "$MASSOS"/usr/lib/systemd/system
fi
## extra-package-licenses, if present.
if [ -d stage3/"$1"/extra-package-licenses ]; then
  cp -r stage3/"$1"/extra-package-licenses "$MASSOS"/root/mbs/extras
fi
## build environment file.
cp build.env "${MASSOS}"/root/mbs
# Re-enter the chroot and continue the build.
utils/programs/mass-chroot "$MASSOS" /root/mbs/build-stage3.sh
# Put in finalize.sh and finish the build.
echo "Finalizing the build..."
cp finalize.sh "$MASSOS"/root/mbs
utils/programs/mass-chroot "$MASSOS" /root/mbs/finalize.sh
# Install preupgrade and postupgrade.
cp utils/{pre,post}upgrade{,_ng} "$MASSOS"/tmp
# Install Live CD cleanup script for osinstallgui.
install -t "$MASSOS"/tmp -m755 utils/livecd-cleanup.sh
# Strip executables and libraries to free up space.
# Use --strip-unneeded on binaries and shared libraries.
# Use --strip-debug on object files and static libraries.
# Do NOT strip .efi executables as it will remove their secure boot signatures!
printf "Stripping binaries and libraries... "
find "$MASSOS"/usr/{bin,lib,libexec,sbin} -type f ! -name \*.a ! -name \*.o ! -name \*.mod ! -name \*.module ! -name \*.ko\* ! -name \*.efi\* -exec strip --strip-unneeded {} ';' &>/dev/null || true
find "$MASSOS"/usr/lib -type f \( -name \*.a -o -name \*.o -o -name \*.mod -o -name \*.module \) -exec strip --strip-debug {} ';' &>/dev/null || true
echo "Done!"
# Generate list of distribution-provided files, for 'upgrade-massos' utility.
find "$MASSOS"/{boot,etc,usr,var} -type d,f,l -printf "%y:%p\n" | sed "s|$MASSOS||" > "$MASSOS"/usr/share/massos/.distfiles
# Finish the MassOS system.
outfile="massos-$(cat "$MASSOS"/etc/massos-release)-rootfs-x86_64-$1.tar"
printf "Creating %s..." "$outfile"
cd "$MASSOS"
tar -cpf ../"$outfile" *
cd ..
echo "Done!"
echo "Compressing $outfile with ZSTD (using $(nproc) threads)... "
zstd --ultra -22 -T$(nproc) --rm "$outfile"
echo "Successfully created $outfile.zst."
b2sum "$outfile.zst" > "$outfile.zst.b2"
echo "Wrote Blake-2 checksum to $outfile.zst.b2."
# Change ownership of rootfs to top-level directory owner if possible.
chown -v "$(stat -c "%U:%G" .)" "$outfile.zst" "$outfile.zst.b2" || true
# Clean up.
rm -rf "$MASSOS"
# Finishing message.
echo
echo "We know it took time, but the build has finally finished successfully!"
echo "If you want to create a Live ISO file for your build, use the script"
echo "'./create-livecd.sh'."
# Send a notification to the system if supported.
if notify-send --version &>/dev/null; then
  notify-send -i "$PWD"/logo/massos-logo.png "MassOS Build System" "The Stage 3 build has finished successfully." &>/dev/null || true
fi
