Add BluetoothUtils::FromNumber and ToNumber

The implementation is compatible with Windows interpretation of 64 bit MAC addresses.

PiperOrigin-RevId: 531355253

internal/platform/bluetooth_utils.cc

@@ -49,7 +49,6 @@ ByteArray BluetoothUtils::FromString(absl::string_view bluetooth_mac_address) {
   if (bt_mac_address.length() != kBluetoothMacAddressLength * 2) {
     return ByteArray();
   }
-
   // Convert to bytes. If MAC Address bytes are unset, return a null byte array.
   auto bt_mac_address_string(absl::HexStringToBytes(bt_mac_address));
   auto bt_mac_address_bytes =
@@ -70,4 +69,27 @@ bool BluetoothUtils::IsBluetoothMacAddressUnset(
   return true;
 }
 
+std::string BluetoothUtils::FromNumber(std::uint64_t address) {
+  // Gets byte `index` from `address`.
+  auto b = [&](int index) {
+    return (std::uint8_t)(address >> (56 - 8 * index));
+  };
+  return absl::StrFormat("%02X:%02X:%02X:%02X:%02X:%02X", b(2), b(3), b(4),
+                         b(5), b(6), b(7));
+}
+
+std::uint64_t BluetoothUtils::ToNumber(std::string address) {
+  ByteArray binary = FromString(address);
+  if (binary.size() != kBluetoothMacAddressLength) {
+    return 0;
+  }
+  std::uint64_t result = 0;
+  for (char ch : binary.AsStringView()) {
+    result <<= 8;
+    result |= static_cast<uint8_t>(ch);
+  }
+
+  return result;
+}
+
 }  // namespace nearby

internal/platform/bluetooth_utils.h

@@ -34,6 +34,14 @@ class BluetoothUtils {
   // e.g. "AC:37:43:BC:A9:28" -> {-84, 55, 67, -68, -87, 40}.
   static ByteArray FromString(absl::string_view bluetooth_mac_address);
 
+  // Converts a MAC address from binary to canonical format.
+  // Example: 0xF1F2F3F4F5F6 -> "F1:F2:F3:F4:F5:F6"
+  static std::string FromNumber(std::uint64_t address);
+
+  // Converts a MAC address from canonical format to binary
+  // Example: "F1:F2:F3:F4:F5:F6" ->0xF1F2F3F4F5F6
+  static std::uint64_t ToNumber(std::string address);
+
   // Checks if a Bluetooth MAC address is zero for every byte.
   static bool IsBluetoothMacAddressUnset(
       const ByteArray& bluetooth_mac_address);

internal/platform/bluetooth_utils_test.cc

@@ -84,4 +84,16 @@ TEST(BluetoothUtilsTest, InvalidStringReturnsEmptyByteArray) {
   EXPECT_TRUE(bytes_result.Empty());
 }
 
+TEST(BluetoothUtilsTest, FromNumber) {
+  EXPECT_EQ(BluetoothUtils::FromNumber(0xF1F2F3F4F5F6), "F1:F2:F3:F4:F5:F6");
+}
+
+TEST(BluetoothUtilsTest, ToNumber) {
+  EXPECT_EQ(BluetoothUtils::ToNumber("F1:F2:F3:F4:F5:F6"), 0xF1F2F3F4F5F6);
+}
+
+TEST(BluetoothUtilsTest, ToNumberInvalidString) {
+  EXPECT_EQ(BluetoothUtils::ToNumber("22:00:11:33:77:aa::bb::99"), 0);
+}
+
 }  // namespace nearby