#!/bin/sh
# Builds Steward's two Debian packages:
#
#   dist/steward-cli_<version>_<arch>.deb  the CLI, to install anywhere:
#     /usr/bin/steward, its bash completion, and /usr/share/doc/steward-cli/
#     (README, CHANGELOG, the CLI and permissions docs). No scripts:
#     installing it changes nothing else on the machine.
#   dist/steward_<version>_<arch>.deb      the server, which depends on
#     steward-cli of the same version:
#     /usr/bin/stewardd and its bash completion
#     /usr/lib/systemd/system/{steward.service,steward-backup.service,steward-backup.timer}
#     /usr/lib/sysusers.d/steward.conf, /usr/lib/tmpfiles.d/steward.conf
#     /usr/share/doc/steward/ (README, CHANGELOG, docs)
#     Its scripts (deploy/debian) create the steward user and directories and
#     /etc/steward/steward.yaml on the first install, turn on the daily backup
#     timer, restart a running stewardd on upgrades, and stop both on removal.
#     No file in /etc belongs to the package, so an upgrade never asks
#     about configuration files.
#
# Run through 'make deb' (which sets the variables below); needs only
# dpkg-deb, no root and no debhelper.
#
# Variables: DEB_ARCH (Debian architecture, e.g. amd64, arm64, armhf),
# DEB_VERSION, VERSION, LDFLAGS, GOFLAGS, and DEB_MAINTAINER (default: your
# git name and email).
set -eu

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

# Debian architecture -> Go architecture.
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 ;;
s390x) goarch=s390x ;;
*) 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:-Steward packager} <${email:-root@localhost}>"
fi

work=dist/deb/${DEB_VERSION}_${DEB_ARCH}
stage=$work/stage
rm -rf "$work"
# Older packages of this architecture (every development build has its
# own version), so 'apt install ./dist/steward_*_amd64.deb' finds just one.
rm -f dist/steward_*_"$DEB_ARCH".deb dist/steward-cli_*_"$DEB_ARCH".deb
mkdir -p "$stage"

# Binaries for the package's architecture (bin/ holds the host's, which
# also generated the completion scripts).
echo "mkdeb: building for linux/$goarch"
# go reads GOFLAGS (-trimpath) from the environment.
export GOFLAGS
GOOS=linux GOARCH=$goarch GOARM=$goarm CGO_ENABLED=0 go build -ldflags "$LDFLAGS" -o "$work/bin/stewardd" ./cmd/stewardd
GOOS=linux GOARCH=$goarch GOARM=$goarm CGO_ENABLED=0 go build -ldflags "$LDFLAGS" -o "$work/bin/steward" ./cmd/steward

# Everything 'make install' would install, then split in two.
make --no-print-directory install-files DESTDIR="$stage" PREFIX=/usr \
	UNITDIR=/usr/lib/systemd/system STEWARDD_BIN="$work/bin/stewardd" STEWARD_BIN="$work/bin/steward" >/dev/null

cli=$work/steward-cli
srv=$work/steward
mkdir -p "$cli/DEBIAN" "$cli/usr/bin" "$cli/usr/share/bash-completion/completions" "$cli/usr/share/doc/steward-cli/docs"
mv "$stage/usr/bin/steward" "$cli/usr/bin/"
mv "$stage/usr/share/bash-completion/completions/steward" "$cli/usr/share/bash-completion/completions/"
cp "$stage/usr/share/doc/steward/README.md" "$stage/usr/share/doc/steward/CHANGELOG.md" "$cli/usr/share/doc/steward-cli/"
for d in cli permissions; do
	cp "$stage/usr/share/doc/steward/docs/$d.md" "$cli/usr/share/doc/steward-cli/docs/"
done
mv "$stage" "$srv"
mkdir -p "$srv/DEBIAN"
for f in postinst prerm postrm; do
	install -m 0755 "deploy/debian/$f" "$srv/DEBIAN/$f"
done

# Debian's machine-readable copyright file, from LICENSE.
indent() { sed -e 's/^$/./' -e 's/^/ /' "$1"; }
copyright() {
	echo "Format: https://www.debian.org/doc/packaging-manuals/copyright-format/1.0/"
	echo "Upstream-Name: steward"
	echo
	echo "Files: *"
	echo "Copyright: $(sed -n 's/^Copyright (c) //p' LICENSE)"
	echo "License: Expat"
	indent LICENSE
}

# build PACKAGE ROOT: writes the control file and md5sums and builds the .deb.
build() {
	pkg=$1 root=$2 out=dist/${1}_${DEB_VERSION}_${DEB_ARCH}.deb
	copyright > "$root/usr/share/doc/$pkg/copyright"
	rm -f "$root/usr/share/doc/$pkg/LICENSE"
	# Directories 0755 and no group/other write, whatever the build's umask.
	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-$pkg.in" > "$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"
	# Files belong to root in the package, whoever builds it.
	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'
}
build steward-cli "$cli"
build steward "$srv"
rm -rf dist/deb