arc: bluetooth: Implement Gatt server request to read/write

components/arc/bluetooth/arc_bluetooth_bridge.cc

Index: components/arc/bluetooth/arc_bluetooth_bridge.cc
diff --git a/components/arc/bluetooth/arc_bluetooth_bridge.cc b/components/arc/bluetooth/arc_bluetooth_bridge.cc
index fdc0a7de6c04afd38d24b03c5f0e77f3e13519cc..7375e5eaeb71765ec0f3ed1da3d13ddc6aa360bc 100644
--- a/components/arc/bluetooth/arc_bluetooth_bridge.cc
+++ b/components/arc/bluetooth/arc_bluetooth_bridge.cc
@@ -9,6 +9,7 @@
 
 #include <iomanip>
 #include <string>
+#include <utility>
 
 #include "base/bind.h"
 #include "base/logging.h"
@@ -292,12 +293,75 @@ void ArcBluetoothBridge::GattDescriptorValueChanged(
   // Placeholder for GATT client functionality
 }
 
+// We will use odd transaction_id for read and even id for write to make sure
+// that it does not overlap and make it easy to determine the transaction type.
+int32_t ArcBluetoothBridge::CreateGattReadTransaction(
+    const GattServerReadCallbacks& callbacks) {
+  static int32_t transaction_id = 1;
+  transaction_id += 2;
+  gatt_server_read_callbacks_[transaction_id] = callbacks;
+  return transaction_id;
+}
+
+int32_t ArcBluetoothBridge::CreateGattWriteTransaction(
+    const GattServerWriteCallbacks& callbacks) {
+  static int32_t transaction_id = 2;
+  transaction_id += 2;
+  gatt_server_write_callbacks_[transaction_id] = callbacks;
+  return transaction_id;
+}
+
+template <class T>
+void ArcBluetoothBridge::OnGattAttributeReadRequest(
+    const BluetoothDevice* device,
+    const T* gatt_obj,
+    int offset,
+    const GattServerReadCallbacks& callbacks) {
+  if (!HasBluetoothInstance())
+    return;
+
+  if (!CheckBluetoothInstanceVersion(kMinBtleNotifyVersion))
+    return;
+
+  int32_t transaction_id = CreateGattReadTransaction(callbacks);
+
+  arc_bridge_service()->bluetooth()->instance()->RequestGattRead(
+      mojom::BluetoothAddress::From(device->GetAddress()), transaction_id,
+      ConvertGattIdentifierToId(gatt_obj->GetIdentifier()), offset,
+      false /*is_long */);
+}
+
+template <class T>
+void ArcBluetoothBridge::OnGattAttributeWriteRequest(
+    const BluetoothDevice* device,
+    const T* gatt_obj,
+    const std::vector<uint8_t>& value,
+    int offset,
+    const GattServerWriteCallbacks& callbacks) {
+  if (!HasBluetoothInstance())
+    return;
+
+  if (!CheckBluetoothInstanceVersion(kMinBtleNotifyVersion))
+    return;
+
+  int32_t transaction_id = CreateGattWriteTransaction(callbacks);
+
+  arc_bridge_service()->bluetooth()->instance()->RequestGattWrite(
+      mojom::BluetoothAddress::From(device->GetAddress()), transaction_id,
+      ConvertGattIdentifierToId(gatt_obj->GetIdentifier()), offset,
+      mojo::Array<uint8_t>::From(value));
+}
+
 void ArcBluetoothBridge::OnCharacteristicReadRequest(
     const BluetoothDevice* device,
     const BluetoothLocalGattCharacteristic* characteristic,
     int offset,
     const ValueCallback& callback,
-    const ErrorCallback& error_callback) {}
+    const ErrorCallback& error_callback) {
+  OnGattAttributeReadRequest<BluetoothLocalGattCharacteristic>(
+      device, characteristic, offset,
+      GattServerReadCallbacks(callback, error_callback));
+}
 
 void ArcBluetoothBridge::OnCharacteristicWriteRequest(
     const BluetoothDevice* device,
@@ -305,14 +369,22 @@ void ArcBluetoothBridge::OnCharacteristicWriteRequest(
     const std::vector<uint8_t>& value,
     int offset,
     const base::Closure& callback,
-    const ErrorCallback& error_callback) {}
+    const ErrorCallback& error_callback) {
+  OnGattAttributeWriteRequest<BluetoothLocalGattCharacteristic>(
+      device, characteristic, value, offset,
+      GattServerWriteCallbacks(callback, error_callback));
+}
 
 void ArcBluetoothBridge::OnDescriptorReadRequest(
     const BluetoothDevice* device,
     const BluetoothLocalGattDescriptor* descriptor,
     int offset,
     const ValueCallback& callback,
-    const ErrorCallback& error_callback) {}
+    const ErrorCallback& error_callback) {
+  OnGattAttributeReadRequest<BluetoothLocalGattDescriptor>(
+      device, descriptor, offset,
+      GattServerReadCallbacks(callback, error_callback));
+}
 
 void ArcBluetoothBridge::OnDescriptorWriteRequest(
     const BluetoothDevice* device,
@@ -320,7 +392,11 @@ void ArcBluetoothBridge::OnDescriptorWriteRequest(
     const std::vector<uint8_t>& value,
     int offset,
     const base::Closure& callback,
-    const ErrorCallback& error_callback) {}
+    const ErrorCallback& error_callback) {
+  OnGattAttributeWriteRequest<BluetoothLocalGattDescriptor>(
+      device, descriptor, value, offset,
+      GattServerWriteCallbacks(callback, error_callback));
+}
 
 void ArcBluetoothBridge::OnNotificationsStart(
     const BluetoothDevice* device,
@@ -1160,7 +1236,26 @@ void ArcBluetoothBridge::SendIndication(
 void ArcBluetoothBridge::SendResponse(int32_t trans_id,
                                       int32_t status,
                                       mojo::Array<uint8_t> value,
-                                      const SendResponseCallback& callback) {}
+                                      const SendResponseCallback& callback) {
+  // We used odd transaction_id for read and even id for write.
+  if (trans_id & 1) {  // read
+    DCHECK(gatt_server_read_callbacks_.find(trans_id) !=
+           gatt_server_read_callbacks_.end());
+    if (status)
+      gatt_server_read_callbacks_[trans_id].error_callback.Run();
+    else
+      gatt_server_read_callbacks_[trans_id].success_callback.Run(
+          value.To<std::vector<uint8_t>>());
+  } else {  // write
+    DCHECK(gatt_server_write_callbacks_.find(trans_id) !=
+           gatt_server_write_callbacks_.end());
+    if (status)
+      gatt_server_write_callbacks_[trans_id].error_callback.Run();
+    else
+      gatt_server_write_callbacks_[trans_id].success_callback.Run();
+  }
+  OnGattOperationDone(callback);
+}
 
 void ArcBluetoothBridge::OnDiscoveryError() {
   LOG(WARNING) << "failed to change discovery state";