Repurpose into gRPC service

Repurpose repository into a spiritual successor of the previous
binding.  The backend code is retained behind a new gRPC API
defined in protos/radio.proto.  The simpler synchronous gRPC API
had been used for expediency, this may warrant revisiting to
rework into an async or callback API based server instead.  As
well, authentication has been left until some consensus on an
approach can be worked out.

Bug-AGL: SPEC-4665

Signed-off-by: Scott Murray <scott.murray@konsulko.com>
Change-Id: I28b122ce6e0ecfc7504aa08b90394cb1b9e22976
(cherry picked from commit dd23c157bdba1b25bbb50cdb99a60aa597735f43)

1 files changed, 326 insertions, 0 deletions

diff --git a/src/RadioImpl.cc b/src/RadioImpl.cc
new file mode 100644
index 0000000..634f066
--- /dev/null
+++ b/src/RadioImpl.cc
@@ -0,0 +1,326 @@
+// SPDX-License-Identifier: Apache-2.0
+/*
+ * Copyright (C) 2022 Konsulko Group
+ */
+
+#include "RadioImpl.h"
+
+// C backend implementations
+extern "C" {
+#include "radio_impl_null.h"
+#include "radio_impl_rtlsdr.h"
+#include "radio_impl_kingfisher.h"
+#include "radio_impl_tef665x.h"
+}
+
+using grpc::StatusCode;
+using automotivegradelinux::Band;
+using automotivegradelinux::BAND_UNSPECIFIED;
+using automotivegradelinux::BAND_AM;
+using automotivegradelinux::BAND_FM;
+using automotivegradelinux::StereoMode;
+using automotivegradelinux::STEREO_MODE_UNSPECIFIED;
+using automotivegradelinux::STEREO_MODE_MONO;
+using automotivegradelinux::STEREO_MODE_STEREO;
+using automotivegradelinux::ScanDirection;
+using automotivegradelinux::SCAN_DIRECTION_FORWARD;
+using automotivegradelinux::SCAN_DIRECTION_BACKWARD;
+
+RadioImpl::RadioImpl()
+{
+}
+
+bool RadioImpl::Detect()
+{
+	// Probe for radio backends
+	m_radio_impl_ops = &rtlsdr_impl_ops;
+	int rc = m_radio_impl_ops->probe();
+	if(rc != 0) {
+		// Look for Kingfisher Si4689
+		m_radio_impl_ops = &kf_impl_ops;
+		rc = m_radio_impl_ops->probe();
+	}
+#if 0
+	if(rc != 0) {
+		m_radio_impl_ops = &tef665x_impl_ops;
+		rc = m_radio_impl_ops->probe();
+	}
+#endif
+	if (rc != 0) {
+		m_radio_impl_ops = &null_impl_ops;
+		rc = m_radio_impl_ops->probe();
+	}
+	if (rc != 0) {
+		// We don't expect the null implementation to fail probe, but just in case...
+		std::cerr << "No radio device found, exiting" << std::endl;
+		return false;
+	}
+	// Try to initialize detected backend
+	rc = m_radio_impl_ops->init();
+	if(rc < 0) {
+		std::cerr << m_radio_impl_ops->name << " initialization failed" << std::endl;
+		return false;
+	}
+	std::cout << m_radio_impl_ops->name << "found" << std::endl;
+	m_radio_impl_ops->set_frequency_callback(FrequencyCallback, this);
+	m_radio_impl_ops->set_frequency_callback(FrequencyCallback, this);
+#if 0	
+	if(m_radio_impl_ops->set_rds_callback) {
+		m_radio_impl_ops->set_rds_callback(RDSCallback);
+	}
+#endif
+	return true;
+}
+
+Status RadioImpl::GetFrequency(ServerContext* context, const GetFrequencyRequest* request, GetFrequencyResponse* response)
+{
+	response->set_frequency(m_radio_impl_ops->get_frequency());
+	return Status::OK;
+}
+
+Status RadioImpl::SetFrequency(ServerContext* context, const SetFrequencyRequest* request, SetFrequencyResponse* response)
+{
+	radio_band_t band = m_radio_impl_ops->get_band();
+	uint32_t min_frequency = m_radio_impl_ops->get_min_frequency(band);
+	uint32_t max_frequency = m_radio_impl_ops->get_max_frequency(band);
+	uint32_t step = m_radio_impl_ops->get_frequency_step(band);
+
+	uint32_t frequency = request->frequency();
+	if(frequency < min_frequency ||
+	   frequency > max_frequency ||
+	   (frequency - min_frequency) % step) {
+		//afb_req_reply(request, NULL, "failed", "Invalid frequency");
+		return Status::OK;
+	}
+	m_radio_impl_ops->set_frequency(frequency);
+	return Status::OK;
+}
+
+Status RadioImpl::GetBand(ServerContext* context, const GetBandRequest* request, GetBandResponse* response)
+{
+	Band band = BAND_UNSPECIFIED;
+	radio_band_t impl_band = m_radio_impl_ops->get_band();
+
+	if (impl_band == RADIO_BAND_AM)
+		band = BAND_AM;
+	else if (impl_band == RADIO_BAND_FM)
+		band = BAND_FM;
+	response->set_band(band);
+	return Status::OK;
+}
+
+Status RadioImpl::SetBand(ServerContext* context, const SetBandRequest* request, SetBandResponse* response)
+{
+	radio_band_t impl_band = RADIO_BAND_UNSPECIFIED;
+	if (request->band() == BAND_AM)
+		impl_band = RADIO_BAND_AM;
+	else if (request->band() == BAND_FM)
+		impl_band = RADIO_BAND_FM;
+
+	if (impl_band != RADIO_BAND_UNSPECIFIED) {
+		m_radio_impl_ops->set_band(impl_band);
+	} else {
+		// FIXME: Indicate error
+		return Status::OK;
+	}
+	
+	return Status::OK;
+}
+
+Status RadioImpl::GetBandSupported(ServerContext* context, const GetBandSupportedRequest* request, GetBandSupportedResponse* response)
+{
+	radio_band_t impl_band = RADIO_BAND_UNSPECIFIED;
+	if (request->band() == BAND_AM)
+		impl_band = RADIO_BAND_AM;
+	else if (request->band() == BAND_FM)
+		impl_band = RADIO_BAND_FM;
+
+	if (impl_band != RADIO_BAND_UNSPECIFIED)
+		response->set_supported(m_radio_impl_ops->band_supported(impl_band));
+	else
+		response->set_supported(false);
+
+	return Status::OK;
+}
+
+Status RadioImpl::GetBandParameters(ServerContext* context, const GetBandParametersRequest* request, GetBandParametersResponse* response)
+{
+	radio_band_t impl_band = RADIO_BAND_UNSPECIFIED;
+	if (request->band() == BAND_AM)
+		impl_band = RADIO_BAND_AM;
+	else if (request->band() == BAND_FM)
+		impl_band = RADIO_BAND_FM;
+
+	if (impl_band != RADIO_BAND_UNSPECIFIED) {
+		response->set_min(m_radio_impl_ops->get_min_frequency(impl_band));
+		response->set_max(m_radio_impl_ops->get_max_frequency(impl_band));
+		response->set_step(m_radio_impl_ops->get_frequency_step(impl_band));
+	} else {
+		// FIXME: Indicate error
+		return Status::OK;
+	}
+	return Status::OK;
+}
+
+Status RadioImpl::GetStereoMode(ServerContext* context, const GetStereoModeRequest* request, GetStereoModeResponse* response)
+{
+	StereoMode mode = STEREO_MODE_UNSPECIFIED;
+	radio_stereo_mode_t impl_mode = m_radio_impl_ops->get_stereo_mode();
+
+	if (impl_mode == RADIO_MODE_MONO)
+		mode = STEREO_MODE_MONO;
+	else if (impl_mode == RADIO_MODE_STEREO)
+		mode = STEREO_MODE_STEREO;
+	response->set_mode(mode);
+	return Status::OK;
+}
+
+Status RadioImpl::SetStereoMode(ServerContext* context, const SetStereoModeRequest* request, SetStereoModeResponse* response)
+{
+	radio_stereo_mode_t impl_mode = RADIO_MODE_UNSPECIFIED;
+	if (request->mode() == STEREO_MODE_MONO)
+		impl_mode = RADIO_MODE_MONO;
+	else if (request->mode() == STEREO_MODE_STEREO)
+		impl_mode = RADIO_MODE_STEREO;
+
+	if (impl_mode != RADIO_MODE_UNSPECIFIED) {
+		m_radio_impl_ops->set_stereo_mode(impl_mode);
+	} else {
+		// FIXME: Indicate error
+		return Status::OK;
+	}
+	return Status::OK;
+}
+
+Status RadioImpl::Start(ServerContext* context, const StartRequest* request, StartResponse* response)
+{
+	m_radio_impl_ops->set_output(NULL);
+	m_radio_impl_ops->start();
+	m_playing = true;
+
+	StatusResponse status_response;
+	auto play_status = status_response.mutable_play();
+	play_status->set_playing(true);
+	SendStatusResponse(status_response);
+	
+	return Status::OK;
+}
+
+Status RadioImpl::Stop(ServerContext* context, const StopRequest* request, StopResponse* response)
+{
+	m_radio_impl_ops->stop();
+	m_playing = false;
+
+	StatusResponse status_response;
+	auto play_status = status_response.mutable_play();
+	play_status->set_playing(false);
+	SendStatusResponse(status_response);
+
+	return Status::OK;
+}
+
+Status RadioImpl::ScanStart(ServerContext* context, const ScanStartRequest* request, ScanStartResponse* response)
+{
+	radio_scan_direction_t impl_direction = RADIO_SCAN_UNSPECIFIED;
+	if (request->direction() == SCAN_DIRECTION_FORWARD)
+		impl_direction = RADIO_SCAN_FORWARD;
+	else if (request->direction() == SCAN_DIRECTION_BACKWARD)
+		impl_direction = RADIO_SCAN_BACKWARD;
+
+	if (impl_direction != RADIO_SCAN_UNSPECIFIED) {
+		m_radio_impl_ops->scan_start(impl_direction, ScanCallback, this);
+	} else {
+		// FIXME: Indicate error
+		return Status::OK;
+	}
+
+	return Status::OK;
+}
+
+Status RadioImpl::ScanStop(ServerContext* context, const ScanStopRequest* request, ScanStopResponse* response)
+{
+	m_radio_impl_ops->scan_stop();
+	return Status::OK;
+}
+
+Status RadioImpl::GetRDS(ServerContext* context, const GetRDSRequest* request, GetRDSResponse* response)
+{
+	return Status::OK;
+}
+
+Status RadioImpl::GetQuality(ServerContext* context, const GetQualityRequest* request, GetQualityResponse* response)
+{
+	return Status::OK;
+}
+
+Status RadioImpl::SetAlternativeFrequency(ServerContext* context, const SetAlternativeFrequencyRequest* request, SetAlternativeFrequencyResponse* response)
+{
+	return Status::OK;
+}
+
+Status RadioImpl::GetStatusEvents(ServerContext* context, const StatusRequest* request, ServerWriter<StatusResponse>* writer)
+{
+	// Save client information
+	m_clients_mutex.lock();
+	m_clients.push_back(std::pair(context, writer));
+	m_clients_mutex.unlock();
+
+	// For now block until client disconnect / server shutdown
+	// A switch to the async or callback server APIs might be more elegant than
+        // holding the thread like this, and may be worth investigating at some point.
+	std::unique_lock lock(m_done_mutex);
+	m_done_cv.wait(lock, [context, this]{ return (context->IsCancelled() || m_done); });
+
+	return Status::OK;
+}
+
+void RadioImpl::SendStatusResponse(StatusResponse &response)
+{
+	const std::lock_guard<std::mutex> lock(m_clients_mutex);
+
+	if (m_clients.empty())
+		return;
+
+	auto it = m_clients.begin();
+	while (it != m_clients.end()) {
+		if (it->first->IsCancelled()) {
+			// Client has gone away, remove from list
+			std::cout << "Removing cancelled RPC client!" << std::endl;
+			it = m_clients.erase(it);
+
+			// We're not exiting, but wake up blocked client RPC handlers so
+			// the canceled one will clean exit.
+			// Note that in practice this means the client RPC handler thread
+			// sticks around until the next status event is sent.
+			m_done_cv.notify_all();
+
+			continue;
+		} else {
+			it->second->Write(response);
+			++it;
+		}
+	}
+}
+
+
+void RadioImpl::HandleFrequencyEvent(uint32_t frequency)
+{
+	StatusResponse response;
+	auto frequency_status = response.mutable_frequency();
+	frequency_status->set_frequency(frequency);
+	SendStatusResponse(response);
+}
+
+void RadioImpl::HandleScanEvent(uint32_t frequency)
+{
+	StatusResponse response;
+	auto scan_status = response.mutable_scan();
+	scan_status->set_station_found(frequency);
+	SendStatusResponse(response);
+}
+
+void RadioImpl::HandleRDSEvent(void *rds_data)
+{
+	// TODO
+}
+