#!/bin/sh -e

OS="$(cat "${__global}/explorer/os")"

case "${OS}" in
  debian)
    SUPER_USER_GROUP=root
  ;;
  *bsd)
    SUPER_USER_GROUP=wheel
  ;;
  *)
    echo "Your OS '${OS}' is currently not supported." >&2
    exit 1
  ;;
esac

BIN_DIR="/usr/local/bin"
ETC_DIR="/etc"

# Ensure the target bin dir exists
#   Care, we never want to remove it :-D
__directory "${BIN_DIR}" \
	--state "exists" \
	--mode 0755
export require="${require} __directory${BIN_DIR}"

STATE="$(cat "${__object}/parameter/state")"
USER="$(cat "${__object}/parameter/user")"
GROUP="$(cat "${__object}/parameter/group" 2>/dev/null || true)"
if [ -z "${GROUP}" ]; then
	GROUP="${USER}"
fi

SERVICE_NAME="${__object_id}"

BINARY="$(cat "${__object}/parameter/binary" 2>/dev/null || true)"
if [ -z "${BINARY}" ]; then
	BINARY="${SERVICE_NAME}"
fi
EXTRA_BINARIES="$(cat "${__object}/parameter/extra-binary" 2>/dev/null || true)"
# This only makes sense for file archives
if [ -n "${EXTRA_BINARIES}" ] && [ -f "${__object}/parameter/unpack" ]; then
	cat >&2 <<-EOF
	You cannot specify extra binaries without the --unpack argument.
	Make sure that the --url argument points to a file archive.
EOF
fi

SERVICE_EXEC="$(cat "${__object}/parameter/service-exec" 2>/dev/null || true)"
if [ -z "${SERVICE_EXEC}" ]; then
	SERVICE_EXEC="${BIN_DIR}/${BINARY}"
fi
SERVICE_ARGS="$(cat "${__object}/parameter/service-args")"
SERVICE_EXEC="${SERVICE_EXEC} ${SERVICE_ARGS}"

SERVICE_DESCRIPTION="$(cat "${__object}/parameter/service-description" \
	2>/dev/null || true)"
if [ -z "${SERVICE_DESCRIPTION}" ]; then
	SERVICE_DESCRIPTION="cdist-managed '${SERVICE_NAME}' service"
fi

DOWNLOAD_URL="$(cat "${__object}/parameter/url")"
CHECKSUM="$(cat "${__object}/parameter/checksum")"
SHOULD_VERSION="$(cat "${__object}/parameter/version")"

# Create a user for the service if it is not root
if [ "${USER}" != "root" ] && \
		[ ! -f "${__object}/parameter/do-not-manage-user" ]; then
	if [ "${STATE}" = "absent" ]; then
		# When removing, ensure user is not being used
		user_require="__systemd_unit/${SERVICE_NAME}.service"
	fi
	require="${require} ${user_require}" __user "${USER}" \
		--system \
		--state "${STATE}" \
		--home /nonexistent \
		--comment "cdist-managed ${SERVICE_NAME} user"
	# Track dependencies
	service_require="${service_require} __user/${USER}"
fi

# Place config file if necessary
CONFIG_FILE_DEST="${ETC_DIR}/${SERVICE_NAME}.conf"
CONFIG_FILE_SOURCE="$(cat "${__object}/parameter/config-file-source" 2>/dev/null || true)"
if [ "${CONFIG_FILE_SOURCE}" = "-" ]; then
	CONFIG_FILE_SOURCE="${__object}/stdin"
fi
if [ -n "${CONFIG_FILE_SOURCE}" ] && [ "${STATE}" = "present" ]; then
	require="${require} __user/${USER}" __file \
		"${CONFIG_FILE_DEST}" \
		--owner "${USER}" \
		--group "${GROUP}" \
		--mode "0440" \
		--source "${CONFIG_FILE_SOURCE}"
	service_require="${service_require} __file${CONFIG_FILE_DEST}"
fi



INIT="$(cat "${__global}/explorer/init")"
# TODO: Support non-systemd
case "${INIT}" in
	systemd)
		__systemd_unit "${SERVICE_NAME}.service" \
			--source "-" \
			--state "${STATE}" \
			--enablement-state "enabled" <<EOF
[Unit]
Description=${SERVICE_DESCRIPTION}
After=network.target

[Service]
Type=simple

User=${USER}
Group=${GROUP}
ExecStart=${SERVICE_EXEC}
Restart=always

[Install]
WantedBy=multi-user.target
EOF
	service_require="${service_require} __systemd_unit/${SERVICE_NAME}.service"

  ;;
  *)
    echo "Init system ${INIT}' is currently not supported." >&2
    exit 1
  ;;
esac

# Proceed after user and service description have been prepared
export require="${require} ${service_require}"

VERSION_FILE="${BIN_DIR}/.${SERVICE_NAME}.cdist.version"
IS_VERSION="$(cat "${__object}/explorer/explorer-version")"

if [ "${SHOULD_VERSION}" != "${IS_VERSION}" ] && \
		[ "${STATE}" = "present" ]; then
	# We are installing the service and there has been a version change
	# (or it is first-time install)
	TMP_PATH="/tmp/${SERVICE_NAME}-${SHOULD_VERSION}"

	# This is what will stop the service, replace the binaries and
	# start the service again
	perform_service_upgrade="$(cat <<EOF
service ${SERVICE_NAME} stop || true
for bin_file in ${BINARY} ${EXTRA_BINARIES}; do
	bin_path="${TMP_PATH}/\${bin_file}"
	chown root:${SUPER_USER_GROUP} "\${bin_path}"
	chmod 0555 "\${bin_path}"
	cp -af "\${bin_path}" "${BIN_DIR}/\${bin_file}"
done
service ${SERVICE_NAME} start || true
EOF
)"

	if [ -f "${__object}/parameter/unpack" ]; then
		# TODO: Support files other than .tar.gz
		UNPACK_ARGS="$(cat "${__object}/parameter/unpack-args" \
			2>/dev/null || true)"
		# Download packed file
		__download "${TMP_PATH}.tar.gz" \
			--url "${DOWNLOAD_URL}" \
			--download remote \
			--sum "${CHECKSUM}"

		# Unpack file and also perform service upgrade
		# shellcheck disable=SC2086
		require="__download${TMP_PATH}.tar.gz" \
			__unpack "${TMP_PATH}.tar.gz" \
			${UNPACK_ARGS} \
			--destination "${TMP_PATH}"
		version_bump_require="__unpack${TMP_PATH}.tar.gz"
	else
		# Create temp directory
		__directory "${TMP_PATH}"
		# Download binary directoy to the temp directory with the
		# specified binary name
		require="__directory${TMP_PATH}" __download \
			"${TMP_PATH}/${BINARY}" \
			--url "${DOWNLOAD_URL}" \
			--download remote \
			--sum "${CHECKSUM}"
		version_bump_require="__download${TMP_PATH}/${BINARY}"
	fi

	# Perform update of cdist-managed version file
	# And also perform service upgrade
	printf "%s" "${SHOULD_VERSION}" | \
		require="${version_bump_require}" __file \
			"${VERSION_FILE}" \
			--onchange "${perform_service_upgrade}" \
			--source "-"
fi

if [ "${STATE}" = "absent" ]; then
	# Perform cleanup of generated files
	for bin_file in ${BINARY} ${EXTRA_BINARIES}; do
		__file "${BIN_DIR}/${bin_file}" --state "absent"
	done
	__file "${VERSION_FILE}" --state "absent"
	__file "${CONFIG_FILE_DEST}" --state "absent"
fi