Huami: Fix payload when setting the time

Fixes #2999

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/btle/actions/WriteAction.java

@@ -63,7 +63,7 @@ public class WriteAction extends BtLEAction {
         return false;
     }
 
-    protected final byte[] getValue() {
+    public final byte[] getValue() {
         return value;
     }
 

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/huami/Huami2021Support.java

@@ -745,7 +745,7 @@ public abstract class Huami2021Support extends HuamiSupport {
         buf.put(REMINDERS_CMD_UPDATE);
         buf.put((byte) (position & 0xFF));
 
-        final Calendar cal = Calendar.getInstance();
+        final Calendar cal = createCalendar();
         cal.setTime(reminder.getDate());
 
         int reminderFlags = REMINDER_FLAG_ENABLED | REMINDER_FLAG_TEXT;
@@ -916,7 +916,7 @@ public abstract class Huami2021Support extends HuamiSupport {
         // - Day of week starts at 0
         // Otherwise, the command gets rejected with an "Out of Range" error and init fails.
 
-        final Calendar timestamp = Calendar.getInstance();
+        final Calendar timestamp = createCalendar();
         final byte[] year = fromUint16(timestamp.get(Calendar.YEAR));
 
         final byte[] cmd = {

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/huami/HuamiSupport.java

@@ -276,7 +276,6 @@ import static nodomain.freeyourgadget.gadgetbridge.model.ActivityUser.PREF_USER_
 import static nodomain.freeyourgadget.gadgetbridge.model.ActivityUser.PREF_USER_NAME;
 import static nodomain.freeyourgadget.gadgetbridge.model.ActivityUser.PREF_USER_WEIGHT_KG;
 import static nodomain.freeyourgadget.gadgetbridge.model.ActivityUser.PREF_USER_YEAR_OF_BIRTH;
-import static nodomain.freeyourgadget.gadgetbridge.service.btle.BLETypeConversions.fromUint8;
 import static nodomain.freeyourgadget.gadgetbridge.service.btle.GattCharacteristic.UUID_CHARACTERISTIC_ALERT_LEVEL;
 
 public abstract class HuamiSupport extends AbstractBTLEDeviceSupport implements Huami2021Handler {
@@ -404,20 +403,56 @@ public abstract class HuamiSupport extends AbstractBTLEDeviceSupport implements
         return weatherSpec.windSpeedAsBeaufort() + ""; // cast to string
     }
 
+    /**
+     * Returns the given date/time (calendar) as a byte sequence, suitable for sending to the
+     * Mi Band 2 (or derivative). The band appears to not handle DST offsets, so we simply add this
+     * to the timezone.
+     *
+     * @param calendar
+     * @param precision
+     * @return
+     */
     public byte[] getTimeBytes(Calendar calendar, TimeUnit precision) {
+        byte[] bytes;
         if (precision == TimeUnit.MINUTES) {
-            final byte[] bytes = BLETypeConversions.shortCalendarToRawBytes(calendar);
-            //add nonstandard extension
-            final byte[] tail = new byte[] { 0, BLETypeConversions.mapTimeZone(calendar, BLETypeConversions.TZ_FLAG_INCLUDE_DST_IN_TZ) };
-            return BLETypeConversions.join(bytes, tail);
+            bytes = BLETypeConversions.shortCalendarToRawBytes(calendar);
         } else if (precision == TimeUnit.SECONDS) {
-            final byte[] bytes = BLETypeConversions.calendarToCurrentTime(calendar);
-            //add nonstandard extension, only one byte needed, as format is different from above
-            final byte[] tail = new byte[] { BLETypeConversions.mapTimeZone(calendar, BLETypeConversions.TZ_FLAG_INCLUDE_DST_IN_TZ) };
-            return BLETypeConversions.join(bytes, tail);
+            bytes = calendarToRawBytes(calendar);
         } else {
             throw new IllegalArgumentException("Unsupported precision, only MINUTES and SECONDS are supported till now");
         }
+        byte[] tail = new byte[] { 0, BLETypeConversions.mapTimeZone(calendar, BLETypeConversions.TZ_FLAG_INCLUDE_DST_IN_TZ) };
+        // 0 = adjust reason bitflags? or DST offset?? , timezone
+//        byte[] tail = new byte[] { 0x2 }; // reason
+        byte[] all = BLETypeConversions.join(bytes, tail);
+        return all;
+    }
+
+    /**
+     * Converts a timestamp to the byte sequence to be sent to the current time characteristic
+     *
+     * @param timestamp
+     * @return
+     * @see GattCharacteristic#UUID_CHARACTERISTIC_CURRENT_TIME
+     */
+    public static byte[] calendarToRawBytes(Calendar timestamp) {
+        // MiBand2:
+        // year,year,month,dayofmonth,hour,minute,second,dayofweek,0,0,tz
+
+        byte[] year = BLETypeConversions.fromUint16(timestamp.get(Calendar.YEAR));
+        return new byte[] {
+                year[0],
+                year[1],
+                BLETypeConversions.fromUint8(timestamp.get(Calendar.MONTH) + 1),
+                BLETypeConversions.fromUint8(timestamp.get(Calendar.DATE)),
+                BLETypeConversions.fromUint8(timestamp.get(Calendar.HOUR_OF_DAY)),
+                BLETypeConversions.fromUint8(timestamp.get(Calendar.MINUTE)),
+                BLETypeConversions.fromUint8(timestamp.get(Calendar.SECOND)),
+                BLETypeConversions.dayOfWeekToRawBytes(timestamp),
+                0, // fractions256 (not set)
+                // 0 (DST offset?) Mi2
+                // k (tz) Mi2
+        };
     }
 
     public Calendar fromTimeBytes(byte[] bytes) {
@@ -426,12 +461,19 @@ public abstract class HuamiSupport extends AbstractBTLEDeviceSupport implements
     }
 
     public HuamiSupport setCurrentTimeWithService(TransactionBuilder builder) {
-        GregorianCalendar now = BLETypeConversions.createCalendar();
-        final byte[] bytes = getTimeBytes(now, TimeUnit.MINUTES);
+        final Calendar now = createCalendar();
+        byte[] bytes = getTimeBytes(now, TimeUnit.SECONDS);
         builder.write(getCharacteristic(GattCharacteristic.UUID_CHARACTERISTIC_CURRENT_TIME), bytes);
         return this;
     }
 
+    /**
+     * Allow for the calendar to be overridden to a fixed date, for tests.
+     */
+    protected Calendar createCalendar() {
+        return BLETypeConversions.createCalendar();
+    }
+
     /**
      * Last action of initialization sequence. Sets the device to initialized.
      * It is only invoked if all other actions were successfully run, so the device

app/src/test/java/nodomain/freeyourgadget/gadgetbridge/service/devices/huami/Huami2021SupportTest.java

@@ -0,0 +1,71 @@
+/*  Copyright (C) 2022 José Rebelo
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.huami;
+
+import android.bluetooth.BluetoothGattCharacteristic;
+import android.content.Context;
+import android.net.Uri;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.io.IOException;
+import java.time.Instant;
+import java.time.ZoneId;
+import java.time.ZonedDateTime;
+import java.util.Calendar;
+import java.util.GregorianCalendar;
+import java.util.UUID;
+
+import nodomain.freeyourgadget.gadgetbridge.devices.huami.HuamiFWHelper;
+import nodomain.freeyourgadget.gadgetbridge.service.btle.TransactionBuilder;
+import nodomain.freeyourgadget.gadgetbridge.service.btle.actions.WriteAction;
+
+public class Huami2021SupportTest {
+    @Test
+    public void testSetCurrentTimeWithService() {
+        final Huami2021Support support = createSupport();
+
+        final TransactionBuilder testTransactionBuilder = new TransactionBuilder("test");
+        support.setCurrentTimeWithService(testTransactionBuilder);
+        final WriteAction action = (WriteAction) testTransactionBuilder.getTransaction().getActions().get(0);
+
+        Assert.assertArrayEquals(new byte[]{-26, 7, 12, 15, 20, 38, 53, 4, 0, 8, 4}, action.getValue());
+    }
+
+    private Huami2021Support createSupport() {
+        return new Huami2021Support() {
+            @Override
+            public BluetoothGattCharacteristic getCharacteristic(final UUID uuid) {
+                return new BluetoothGattCharacteristic(null, 0, 0);
+            }
+
+            @Override
+            public HuamiFWHelper createFWHelper(final Uri uri, final Context context) throws IOException {
+                return null;
+            }
+
+            @Override
+            public Calendar createCalendar() {
+                // 2022-12-15 20:38:53 GMT+1
+                final Instant instant = Instant.ofEpochMilli(1671133133000L);
+                final ZonedDateTime zdt = ZonedDateTime.ofInstant(instant, ZoneId.of("Europe/Paris"));
+                return GregorianCalendar.from(zdt);
+            }
+        };
+    }
+}

app/src/test/java/nodomain/freeyourgadget/gadgetbridge/service/devices/huami/HuamiSupportTest.java

@@ -0,0 +1,71 @@
+/*  Copyright (C) 2022 José Rebelo
+
+    This file is part of Gadgetbridge.
+
+    Gadgetbridge is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Gadgetbridge is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
+package nodomain.freeyourgadget.gadgetbridge.service.devices.huami;
+
+import android.bluetooth.BluetoothGattCharacteristic;
+import android.content.Context;
+import android.net.Uri;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.io.IOException;
+import java.time.Instant;
+import java.time.ZoneId;
+import java.time.ZonedDateTime;
+import java.util.Calendar;
+import java.util.GregorianCalendar;
+import java.util.UUID;
+
+import nodomain.freeyourgadget.gadgetbridge.devices.huami.HuamiFWHelper;
+import nodomain.freeyourgadget.gadgetbridge.service.btle.TransactionBuilder;
+import nodomain.freeyourgadget.gadgetbridge.service.btle.actions.WriteAction;
+
+public class HuamiSupportTest {
+    @Test
+    public void testSetCurrentTimeWithService() {
+        final TransactionBuilder testTransactionBuilder = new TransactionBuilder("test");
+        final HuamiSupport huamiSupport = createSupport();
+
+        huamiSupport.setCurrentTimeWithService(testTransactionBuilder);
+        final WriteAction action = (WriteAction) testTransactionBuilder.getTransaction().getActions().get(0);
+
+        Assert.assertArrayEquals(new byte[]{-26, 7, 12, 15, 20, 38, 53, 4, 0, 0, 4}, action.getValue());
+    }
+
+    private HuamiSupport createSupport() {
+        return new HuamiSupport() {
+            @Override
+            public BluetoothGattCharacteristic getCharacteristic(final UUID uuid) {
+                return new BluetoothGattCharacteristic(null, 0, 0);
+            }
+
+            @Override
+            public HuamiFWHelper createFWHelper(final Uri uri, final Context context) throws IOException {
+                return null;
+            }
+
+            @Override
+            public Calendar createCalendar() {
+                // 2022-12-15 20:38:53 GMT+1
+                final Instant instant = Instant.ofEpochMilli(1671133133000L);
+                final ZonedDateTime zdt = ZonedDateTime.ofInstant(instant, ZoneId.of("Europe/Paris"));
+                return GregorianCalendar.from(zdt);
+            }
+        };
+    }
+}