Implement FastPairClient to provides APIs to the FastPair backend OAuth/un-OAuth API

PiperOrigin-RevId: 543807725

fastpair/server_access/fast_pair_client_impl.h

@@ -0,0 +1,87 @@
+// Copyright 2023 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef THIRD_PARTY_NEARBY_FASTPAIR_SERVER_ACCESS_FAST_PAIR_CLIENT_IMPL_H_
+#define THIRD_PARTY_NEARBY_FASTPAIR_SERVER_ACCESS_FAST_PAIR_CLIENT_IMPL_H_
+
+#include <memory>
+#include <optional>
+#include <string>
+#include <utility>
+#include <vector>
+
+#include "absl/strings/string_view.h"
+#include "fastpair/server_access/fast_pair_client.h"
+#include "fastpair/server_access/fast_pair_http_notifier.h"
+#include "internal/account/account_manager.h"
+#include "internal/auth/authentication_manager.h"
+#include "internal/network/http_client.h"
+#include "internal/network/url.h"
+#include "internal/platform/device_info.h"
+
+namespace nearby {
+namespace fastpair {
+// An implementation of FastPairClient that fetches access tokens and makes
+// HTTP request to FastPair backend.
+class FastPairClientImpl : public FastPairClient {
+ public:
+  // Query strings of the request.
+  using QueryParameters = std::vector<std::pair<std::string, std::string>>;
+
+  FastPairClientImpl(auth::AuthenticationManager* authentication_manager,
+                     AccountManager* account_manager,
+                     std::unique_ptr<network::HttpClient> http_client,
+                     FastPairHttpNotifier* notifier, DeviceInfo* device_info);
+  FastPairClientImpl(FastPairClientImpl&) = delete;
+  FastPairClientImpl& operator=(FastPairClientImpl&) = delete;
+  ~FastPairClientImpl() override = default;
+
+  // Gets an observed device.
+  absl::StatusOr<proto::GetObservedDeviceResponse> GetObservedDevice(
+      const proto::GetObservedDeviceRequest& request) override;
+
+  // Reads the user's devices.
+  absl::StatusOr<proto::UserReadDevicesResponse> UserReadDevices(
+      const proto::UserReadDevicesRequest& request) override;
+
+  // Writes a new device to a user's account.
+  absl::StatusOr<proto::UserWriteDeviceResponse> UserWriteDevice(
+      const proto::UserWriteDeviceRequest& request) override;
+
+  // Deletes an existing device from a user's account.
+  absl::StatusOr<proto::UserDeleteDeviceResponse> UserDeleteDevice(
+      const proto::UserDeleteDeviceRequest& request) override;
+
+ private:
+  enum class RequestType { kGet, kPost, kDelete };
+  network::HttpRequestMethod GetRequestMethod(
+      FastPairClientImpl::RequestType request_type) const;
+  // Fetches access token for a logged in user.
+  absl::StatusOr<std::string> GetAccessToken();
+  network::HttpRequest CreateHttpRequest(
+      std::optional<absl::string_view> access_token, network::Url url,
+      RequestType request_type,
+      std::optional<QueryParameters> request_as_query_parameters,
+      std::optional<std::string> body);
+
+  auth::AuthenticationManager* authentication_manager_ = nullptr;
+  AccountManager* account_manager_ = nullptr;
+  std::unique_ptr<network::HttpClient> http_client_;
+  FastPairHttpNotifier* notifier_ = nullptr;
+  DeviceInfo* device_info_ = nullptr;
+};
+}  // namespace fastpair
+}  // namespace nearby
+
+#endif  // THIRD_PARTY_NEARBY_FASTPAIR_SERVER_ACCESS_FAST_PAIR_CLIENT_IMPL_H_