#!/bin/sh
# Builds Guard's Debian package, dist/guard_<version>_<arch>.deb:
#
#   /usr/bin/guard and its bash completion
#   /usr/lib/systemd/system/guard.service, /usr/lib/sysusers.d/guard.conf
#   /usr/share/doc/guard/ (README, CHANGELOG, docs)
#
# Its scripts (deploy/debian) create the guard user and an example
# /etc/guard/guard.yaml on the first install, restart a running guard on
# upgrades, and stop it on removal. No file in /etc belongs to the
# package, so an upgrade never asks about configuration files.
#
# Run through 'make deb'; needs only dpkg-deb, no root and no debhelper.
set -eu

: "${DEB_ARCH:?}" "${DEB_VERSION:?}" "${VERSION:?}" "${LDFLAGS:?}"
GOFLAGS=${GOFLAGS:-}

goarm=
case "$DEB_ARCH" in
amd64) goarch=amd64 ;;
arm64) goarch=arm64 ;;
armhf) goarch=arm goarm=7 ;;
i386) goarch=386 ;;
ppc64el) goarch=ppc64le ;;
riscv64) goarch=riscv64 ;;
*) echo "mkdeb: unsupported architecture $DEB_ARCH" >&2; exit 1 ;;
esac

if [ -z "${DEB_MAINTAINER:-}" ]; then
	name=$(git config user.name 2>/dev/null || true)
	email=$(git config user.email 2>/dev/null || true)
	DEB_MAINTAINER="${name:-Guard packager} <${email:-root@localhost}>"
fi

work=dist/deb/${DEB_VERSION}_${DEB_ARCH}
root=$work/guard
rm -rf "$work"
rm -f dist/guard_*_"$DEB_ARCH".deb
mkdir -p "$root"

echo "mkdeb: building for linux/$goarch"
export GOFLAGS
GOOS=linux GOARCH=$goarch GOARM=$goarm CGO_ENABLED=0 go build -ldflags "$LDFLAGS" -o "$work/bin/guard" ./cmd/guard
make --no-print-directory install-files DESTDIR="$root" PREFIX=/usr UNITDIR=/usr/lib/systemd/system GUARD_BIN="$work/bin/guard" >/dev/null
mkdir -p "$root/DEBIAN"
for f in postinst prerm postrm; do
	install -m 0755 "deploy/debian/$f" "$root/DEBIAN/$f"
done

indent() { sed -e 's/^$/./' -e 's/^/ /' "$1"; }
{
	echo "Format: https://www.debian.org/doc/packaging-manuals/copyright-format/1.0/"
	echo "Upstream-Name: guard"
	echo
	echo "Files: *"
	echo "Copyright: $(sed -n 's/^Copyright (c) //p' LICENSE)"
	echo "License: Expat"
	indent LICENSE
} > "$root/usr/share/doc/guard/copyright"
rm -f "$root/usr/share/doc/guard/LICENSE"
find "$root" -type d -exec chmod 0755 {} +
chmod -R go-w "$root"
size=$(du -sk --exclude=DEBIAN "$root" | cut -f1)
sed -e "s/@VERSION@/$DEB_VERSION/g" -e "s/@ARCH@/$DEB_ARCH/" -e "s/@SIZE@/$size/" \
	-e "s|@MAINTAINER@|$DEB_MAINTAINER|" deploy/debian/control.in > "$root/DEBIAN/control"
(cd "$root" && find . -path ./DEBIAN -prune -o -type f -print | sed 's|^\./||' | sort | xargs md5sum) > "$root/DEBIAN/md5sums"
chmod 0644 "$root/DEBIAN/control" "$root/DEBIAN/md5sums"
out=dist/guard_${DEB_VERSION}_${DEB_ARCH}.deb
dpkg-deb --root-owner-group -Zxz --build "$root" "$out" >/dev/null
echo "mkdeb: wrote $out"
dpkg-deb --info "$out" | sed -n 's/^ \(Package\|Version\|Architecture\|Installed-Size\|Depends\):/  \1:/p'
rm -rf dist/deb