#!/bin/sh

set -o nounset
set -o errexit

if [ "$#" != '0' ]
then
	if [ "${1-}" != '-h' ] && [ "${1-}" != '--help' ]
	then
		code='0'
		exec 1>&2
	fi
	cat <<EOF
USAGE: $0

Reads giada.spec from the same directory as the script. Uses the value of
%upstream_source to download the upstream release archive; filters out
non-redistributable files; and writes a distributable tarball to the current
working directory.
EOF
	exit "${code-1}"
fi

OUTDIR="${PWD}"
cd "$(dirname "$0")"
SPEC="${PWD}/giada.spec"

URL="$(
  rpm -E "$(
    awk -F: '
    tolower($0) ~ /^(name|version|summary|url):/ {
      colon = index($0, ":")
      printf("%%global %s %s\n", tolower($1), substr($0, colon + 1))
    }
    ' "${SPEC}"
  )
  $(grep -E '^%global ' "${SPEC}")
  %upstream_source
  " | sed -r -e 's/^[[:blank:]]+//' -e 's/[[:blank:]]$//'
)"
ARCHIVE="$(echo "${URL}" | awk -F / '{ print $NF }')"

cat 1>&2 <<EOF

Downloading:

  URL: ${URL}
  Archive: ${ARCHIVE}

EOF

# Download the archive
tmpdir="$(mktemp --directory)"
trap "rm -rf '${tmpdir}'" INT TERM EXIT
curl \
		--location \
		--proto-redir -all,https \
		--output "${tmpdir}/${ARCHIVE}" \
		"${URL}"

phase() {
cat <<EOF

==============================================================================
$1
==============================================================================

EOF
}

phase 'Extracting upstream archive'
# Extract the archive
xdir="${tmpdir}/x"
mkdir "${xdir}"
tar -C "${xdir}" -xzf "${tmpdir}/${ARCHIVE}"
echo "Extracted ${ARCHIVE} ($(
	stat --format=%s "${tmpdir}/${ARCHIVE}"
) bytes)"


phase 'Filtering upstream archive'
(
	set -o nounset
	set -o errexit

	cd "${xdir}"

	echo '--> Removing VST 3 SDK'
	rm -rf */src/deps/vst3sdk

	echo '--> Removing JUCE'
	rm -rf */src/deps/juce
)

phase 'Writing filtered archive'
FILTERED_ARCHIVE="$(basename "${ARCHIVE}" .tar.gz)-distributable.tar"
tar -C "${xdir}" -c . -f "./${FILTERED_ARCHIVE}"
echo "Wrote ${FILTERED_ARCHIVE} ($(
	stat --format=%s "${FILTERED_ARCHIVE}"
) bytes)"

phase 'Re-compressing filtered archive'
rm -vf "${FILTERED_ARCHIVE}.xz"
# We could re-compress as gzip with pigz almost instantly; xz takes quite a
# while, but saves many megabytes in the source RPM, which is probably worth
# it as long as we are re-compressing anyway.
xz -9ev "${FILTERED_ARCHIVE}"

phase 'Done'
echo "Wrote ${FILTERED_ARCHIVE}.xz ($(
	stat --format=%s "${FILTERED_ARCHIVE}.xz"
) bytes)"