More bluetooth medium code.

internal/platform/implementation/linux/bluetooth_classic_medium.h

@@ -0,0 +1,99 @@
+#ifndef PLATFORM_IMPL_LINUX_BLUETOOTH_CLASSIC_MEDIUM_H_
+#define PLATFORM_IMPL_LINUX_BLUETOOTH_CLASSIC_MEDIUM_H_
+
+#include <map>
+#include <memory>
+
+#include <systemd/sd-bus.h>
+
+#include "internal/base/observer_list.h"
+#include "internal/platform/implementation/bluetooth_classic.h"
+#include "internal/platform/implementation/linux/bluetooth_classic_device.h"
+
+namespace nearby {
+namespace linux {
+// Container of operations that can be performed over the Bluetooth Classic
+// medium.
+class BluetoothClassicMedium : public api::BluetoothClassicMedium {
+public:
+  BluetoothClassicMedium(absl::string_view adapter);
+  ~BluetoothClassicMedium();
+
+  // https://developer.android.com/reference/android/bluetooth/BluetoothAdapter.html#startDiscovery()
+  //
+  // Returns true once the process of discovery has been initiated.
+  bool StartDiscovery(DiscoveryCallback discovery_callback) override;
+  // https://developer.android.com/reference/android/bluetooth/BluetoothAdapter.html#cancelDiscovery()
+  //
+  // Returns true once discovery is well and truly stopped; after this returns,
+  // there must be no more invocations of the DiscoveryCallback passed in to
+  // StartDiscovery().
+  bool StopDiscovery() override;
+
+  // A combination of
+  // https://developer.android.com/reference/android/bluetooth/BluetoothDevice.html#createInsecureRfcommSocketToServiceRecord
+  // followed by
+  // https://developer.android.com/reference/android/bluetooth/BluetoothSocket.html#connect().
+  //
+  // service_uuid is the canonical textual representation
+  // (https://en.wikipedia.org/wiki/Universally_unique_identifier#Format) of a
+  // type 3 name-based
+  // (https://en.wikipedia.org/wiki/Universally_unique_identifier#Versions_3_and_5_(namespace_name-based))
+  // UUID.
+  //
+  // On success, returns a new BluetoothSocket.
+  // On error, returns nullptr.
+  std::unique_ptr<api::BluetoothSocket>
+  ConnectToService(api::BluetoothDevice &remote_device,
+                   const std::string &service_uuid,
+                   CancellationFlag *cancellation_flag) override;
+
+  // https://developer.android.com/reference/android/bluetooth/BluetoothAdapter.html#listenUsingInsecureRfcommWithServiceRecord
+  //
+  // service_uuid is the canonical textual representation
+  // (https://en.wikipedia.org/wiki/Universally_unique_identifier#Format) of a
+  // type 3 name-based
+  // (https://en.wikipedia.org/wiki/Universally_unique_identifier#Versions_3_and_5_(namespace_name-based))
+  // UUID.
+  //
+  //  Returns nullptr error.
+  std::unique_ptr<api::BluetoothServerSocket>
+  ListenForService(const std::string &service_name,
+                   const std::string &service_uuid) override;
+
+  // https://developer.android.com/reference/android/bluetooth/BluetoothDevice.html#createBond()
+  //
+  // Start the bonding (pairing) process with the remote device.
+  // Return a Bluetooth pairing instance to handle the pairing process with the
+  // remote device.
+  std::unique_ptr<api::BluetoothPairing>
+  CreatePairing(api::BluetoothDevice &remote_device) override;
+
+  api::BluetoothDevice *
+  GetRemoteDevice(const std::string &mac_address) override;
+
+  void AddObserver(Observer *observer) override;
+  void RemoveObserver(Observer *observer) override;
+
+  struct DiscoveryParams {
+    std::string &adapter_object_path;
+    std::map<std::string, std::unique_ptr<BluetoothDevice>> &devices_by_path;
+    ObserverList<Observer> &observers_;
+    BluetoothClassicMedium::DiscoveryCallback cb;
+  };
+
+private:
+  std::string GetDeviceObjectPath(absl::string_view mac_address);
+  
+  sd_bus *system_bus_ = nullptr;
+  sd_bus_slot *system_bus_slot_ = nullptr;
+  std::string adapter_object_path_ = std::string();
+  std::map<std::string, std::unique_ptr<BluetoothDevice>> devices_by_id_;
+  ObserverList<Observer> observers_;
+
+  DiscoveryParams discovery_params_ = {adapter_object_path_, devices_by_id_, observers_};
+};
+} // namespace linux
+} // namespace nearby
+
+#endif