Da Fit: Add time sync

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/devices/dafit/DaFitConstants.java

@@ -16,6 +16,10 @@
     along with this program.  If not, see <http://www.gnu.org/licenses/>. */
 package nodomain.freeyourgadget.gadgetbridge.devices.dafit;
 
+import java.text.ParseException;
+import java.text.SimpleDateFormat;
+import java.util.Date;
+import java.util.TimeZone;
 import java.util.UUID;
 
 import nodomain.freeyourgadget.gadgetbridge.model.NotificationType;
@@ -255,4 +259,33 @@ public class DaFitConstants {
     public static final byte TRAINING_TYPE_TENNIS = 9;
     public static final byte TRAINING_TYPE_RUGBY = 10;
     public static final byte TRAINING_TYPE_GOLF = 11;
+
+    // The watch stores all dates in GMT+8 time zone with seconds resolution
+    // These helper functions convert between the watch time representation and local system representation
+
+    public static int LocalTimeToWatchTime(Date localTime)
+    {
+        SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSS");
+        simpleDateFormat.setTimeZone(TimeZone.getDefault());
+        String format = simpleDateFormat.format(localTime);
+        simpleDateFormat.setTimeZone(TimeZone.getTimeZone("GMT+8"));
+        try {
+            return (int)(simpleDateFormat.parse(format).getTime() / 1000);
+        } catch (ParseException e) {
+            throw new IllegalArgumentException(e);
+        }
+    }
+
+    public static Date WatchTimeToLocalTime(int watchTime)
+    {
+        SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSS");
+        simpleDateFormat.setTimeZone(TimeZone.getTimeZone("GMT+8"));
+        String format = simpleDateFormat.format(new Date((long)watchTime * 1000));
+        simpleDateFormat.setTimeZone(TimeZone.getDefault());
+        try {
+            return simpleDateFormat.parse(format);
+        } catch (ParseException e) {
+            throw new IllegalArgumentException(e);
+        }
+    }
 }

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/dafit/DaFitDeviceSupport.java

@@ -27,7 +27,9 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import java.io.IOException;
+import java.nio.ByteBuffer;
 import java.util.ArrayList;
+import java.util.Date;
 import java.util.Objects;
 import java.util.UUID;
 
@@ -102,6 +104,7 @@ public class DaFitDeviceSupport extends AbstractBTLEDeviceSupport {
         builder.add(new SetDeviceStateAction(getDevice(), GBDevice.State.INITIALIZING, getContext()));
         builder.notify(getCharacteristic(DaFitConstants.UUID_CHARACTERISTIC_DATA_IN), true);
         deviceInfoProfile.requestDeviceInfo(builder);
+        setTime(builder);
         batteryInfoProfile.requestBatteryInfo(builder);
         batteryInfoProfile.enableNotify(builder);
         builder.add(new SetDeviceStateAction(getDevice(), GBDevice.State.INITIALIZED, getContext()));
@@ -197,9 +200,22 @@ public class DaFitDeviceSupport extends AbstractBTLEDeviceSupport {
         // not supported :(
     }
 
+    private void setTime(TransactionBuilder builder) {
+        ByteBuffer buffer = ByteBuffer.allocate(5);
+        buffer.putInt(DaFitConstants.LocalTimeToWatchTime(new Date())); // The watch is hardcoded to GMT+8 internally...
+        buffer.put((byte)8); // I guess this means GMT+8 but changing it has no effect at all (it was hardcoded in the original app too)
+        sendPacket(builder, DaFitPacketOut.buildPacket(DaFitConstants.CMD_SYNC_TIME, buffer.array()));
+    }
+
     @Override
     public void onSetTime() {
-        // TODO
+        try {
+            TransactionBuilder builder = performInitialized("onSetTime");
+            setTime(builder);
+            builder.queue(getQueue());
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
     }
 
     @Override