Centralize the calendar conversion to/from byte array.

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/devices/miband/MiBandCoordinator.java

@@ -11,6 +11,7 @@ import org.slf4j.LoggerFactory;
 
 import java.io.IOException;
 import java.util.Calendar;
+import java.util.GregorianCalendar;
 
 import nodomain.freeyourgadget.gadgetbridge.devices.DeviceCoordinator;
 import nodomain.freeyourgadget.gadgetbridge.devices.InstallHandler;
@@ -130,4 +131,40 @@ public class MiBandCoordinator implements DeviceCoordinator {
         SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(GBApplication.getContext());
         return Integer.parseInt(prefs.getString(MiBandConst.PREF_MIBAND_FITNESS_GOAL, "10000"));
     }
+
+    /**
+     * uses the standard algorithm to convert bytes received from the MiBand to a Calendar object
+     * @param value
+     * @return
+     */
+    public static GregorianCalendar rawBytesToCalendar(byte[] value) {
+        GregorianCalendar timestamp = new GregorianCalendar();
+
+        if (value.length == 6) {
+            timestamp.set(Calendar.YEAR, (2000 + value[0]));
+            timestamp.set(Calendar.MONTH, value[1]);
+            timestamp.set(Calendar.DATE, value[2]);
+            timestamp.set(Calendar.HOUR_OF_DAY, value[3]);
+            timestamp.set(Calendar.MINUTE, value[4]);
+            timestamp.set(Calendar.SECOND, value[5]);
+        }
+
+        return timestamp;
+    }
+
+    /**
+     * uses the standard algorithm to convert a Calendar object to a byte array to send to MiBand
+     * @param timestamp
+     * @return
+     */
+    public static byte[] calendarToRawBytes(Calendar timestamp) {
+        return new byte[]{
+                (byte) (timestamp.get(Calendar.YEAR) - 2000),
+                (byte) timestamp.get(Calendar.MONTH),
+                (byte) timestamp.get(Calendar.DATE),
+                (byte) timestamp.get(Calendar.HOUR_OF_DAY),
+                (byte) timestamp.get(Calendar.MINUTE),
+                (byte) timestamp.get(Calendar.SECOND)
+        };
+    }
 }

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/miband/BatteryInfo.java

@@ -1,8 +1,8 @@
 package nodomain.freeyourgadget.gadgetbridge.service.devices.miband;
 
-import java.util.Calendar;
 import java.util.GregorianCalendar;
 
+import nodomain.freeyourgadget.gadgetbridge.devices.miband.MiBandCoordinator;
 import nodomain.freeyourgadget.gadgetbridge.model.BatteryState;
 
 public class BatteryInfo extends AbstractInfo {
@@ -46,12 +46,9 @@ public class BatteryInfo extends AbstractInfo {
         GregorianCalendar lastCharge = new GregorianCalendar();
 
         if (mData.length >= 10) {
-            lastCharge.set(Calendar.YEAR, (2000 + mData[1]));
+            lastCharge = MiBandCoordinator.rawBytesToCalendar(new byte[]{
-            lastCharge.set(Calendar.MONTH, mData[2]);
+                    mData[1], mData[2], mData[3], mData[4], mData[5], mData[6]
-            lastCharge.set(Calendar.DATE, mData[3]);
+            });
-            lastCharge.set(Calendar.HOUR_OF_DAY, mData[4]);
-            lastCharge.set(Calendar.MINUTE, mData[5]);
-            lastCharge.set(Calendar.SECOND, mData[6]);
         }
 
         return lastCharge;

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/miband/MiBandSupport.java

@@ -13,7 +13,6 @@ import org.slf4j.LoggerFactory;
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Arrays;
-import java.util.Calendar;
 import java.util.GregorianCalendar;
 import java.util.UUID;
 
@@ -429,14 +428,14 @@ public class MiBandSupport extends AbstractBTLEDeviceSupport {
      * @param builder
      */
     private MiBandSupport setCurrentTime(TransactionBuilder builder) {
-        Calendar now = GregorianCalendar.getInstance();
+        byte[] nowBytes = MiBandCoordinator.calendarToRawBytes(GregorianCalendar.getInstance());
         byte[] time = new byte[]{
-                (byte) (now.get(Calendar.YEAR) - 2000),
+                nowBytes[0],
-                (byte) now.get(Calendar.MONTH),
+                nowBytes[1],
-                (byte) now.get(Calendar.DATE),
+                nowBytes[2],
-                (byte) now.get(Calendar.HOUR_OF_DAY),
+                nowBytes[3],
-                (byte) now.get(Calendar.MINUTE),
+                nowBytes[4],
-                (byte) now.get(Calendar.SECOND),
+                nowBytes[5],
                 (byte) 0x0f,
                 (byte) 0x0f,
                 (byte) 0x0f,
@@ -685,17 +684,18 @@ public class MiBandSupport extends AbstractBTLEDeviceSupport {
      * @param characteristic
      */
     private void queueAlarm(Alarm alarm, TransactionBuilder builder, BluetoothGattCharacteristic characteristic) {
-        Calendar alarmCal = alarm.getAlarmCal();
+        byte[] alarmCalBytes = MiBandCoordinator.calendarToRawBytes(alarm.getAlarmCal());
+
         byte[] alarmMessage = new byte[]{
                 (byte) MiBandService.COMMAND_SET_TIMER,
                 (byte) alarm.getIndex(),
                 (byte) (alarm.isEnabled() ? 1 : 0),
-                (byte) (alarmCal.get(Calendar.YEAR) - 2000),
+                alarmCalBytes[0],
-                (byte) alarmCal.get(Calendar.MONTH),
+                alarmCalBytes[1],
-                (byte) alarmCal.get(Calendar.DATE),
+                alarmCalBytes[2],
-                (byte) alarmCal.get(Calendar.HOUR_OF_DAY),
+                alarmCalBytes[3],
-                (byte) alarmCal.get(Calendar.MINUTE),
+                alarmCalBytes[4],
-                (byte) alarmCal.get(Calendar.SECOND),
+                alarmCalBytes[5],
                 (byte) (alarm.isSmartWakeup() ? 30 : 0),
                 (byte) alarm.getRepetitionMask()
         };

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/miband/operations/FetchActivityOperation.java

@@ -19,6 +19,7 @@ import nodomain.freeyourgadget.gadgetbridge.GBApplication;
 import nodomain.freeyourgadget.gadgetbridge.R;
 import nodomain.freeyourgadget.gadgetbridge.database.DBHandler;
 import nodomain.freeyourgadget.gadgetbridge.devices.SampleProvider;
+import nodomain.freeyourgadget.gadgetbridge.devices.miband.MiBandCoordinator;
 import nodomain.freeyourgadget.gadgetbridge.devices.miband.MiBandService;
 import nodomain.freeyourgadget.gadgetbridge.service.btle.AbstractBTLEOperation;
 import nodomain.freeyourgadget.gadgetbridge.service.btle.TransactionBuilder;
@@ -224,14 +225,15 @@ public class FetchActivityOperation extends AbstractBTLEOperation<MiBandSupport>
      * @param bytesTransferred
      */
     private void sendAckDataTransfer(Calendar time, int bytesTransferred) {
+        byte[] ackTime = MiBandCoordinator.calendarToRawBytes(time);
         byte[] ack = new byte[]{
                 MiBandService.COMMAND_CONFIRM_ACTIVITY_DATA_TRANSFER_COMPLETE,
-                (byte) (time.get(Calendar.YEAR) - 2000),
+                ackTime[0],
-                (byte) time.get(Calendar.MONTH),
+                ackTime[1],
-                (byte) time.get(Calendar.DATE),
+                ackTime[2],
-                (byte) time.get(Calendar.HOUR_OF_DAY),
+                ackTime[3],
-                (byte) time.get(Calendar.MINUTE),
+                ackTime[4],
-                (byte) time.get(Calendar.SECOND),
+                ackTime[5],
                 (byte) (bytesTransferred & 0xff),
                 (byte) (0xff & (bytesTransferred >> 8))
         };