Xiaomi: Improve sleep parsing

- Some devices send a random int 0, which would prevent sleep stage
  parsing
- Some devices send the details as a file of type summary, but same
  structure
- It is still not stable for all devices

Thanks to @opcode for the parsing logic

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/xiaomi/activity/XiaomiActivityParser.java

@@ -111,13 +111,9 @@ public abstract class XiaomiActivityParser {
 
                 break;
             case ACTIVITY_SLEEP:
-                if (fileId.getDetailType() == XiaomiActivityFileId.DetailType.DETAILS) {
                 return new SleepDetailsParser();
         }
 
-                break;
-        }
-
         return null;
     }
 

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/service/devices/xiaomi/activity/impl/SleepDetailsParser.java

@@ -16,12 +16,12 @@
     along with this program.  If not, see <https://www.gnu.org/licenses/>. */
 package nodomain.freeyourgadget.gadgetbridge.service.devices.xiaomi.activity.impl;
 
-import android.util.Log;
 import android.widget.Toast;
 
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import java.nio.BufferUnderflowException;
 import java.nio.ByteBuffer;
 import java.nio.ByteOrder;
 import java.util.ArrayList;
@@ -48,17 +48,23 @@ public class SleepDetailsParser extends XiaomiActivityParser {
 
     @Override
     public boolean parse(final XiaomiSupport support, final XiaomiActivityFileId fileId, final byte[] bytes) {
-        if (fileId.getVersion() != 2) {
+        // Seems to come both as DetailType.DETAILS (version 2) and DetailType.SUMMARY (version 4)
+        if (fileId.getVersion() < 2 || fileId.getVersion() > 4) {
             LOG.warn("Unknown sleep details version {}", fileId.getVersion());
             return false;
         }
 
         final ByteBuffer buf = ByteBuffer.wrap(bytes).order(ByteOrder.LITTLE_ENDIAN);
-        buf.get(); // header ? 0xF0
+        final byte header = buf.get();
 
         final int isAwake = buf.get() & 0xff; // 0/1 - more correctly this would be !isSleepFinish
         final int bedTime = buf.getInt();
         final int wakeupTime = buf.getInt();
+        int sleepQuality = -1;
+        if (fileId.getVersion() >= 4) {
+            sleepQuality = buf.get() & 0xff;
+        }
+
         LOG.debug("Sleep sample: bedTime: {}, wakeupTime: {}, isAwake: {}", bedTime, wakeupTime, isAwake);
 
         final List<XiaomiSleepTimeSample> summaries = new ArrayList<>();
@@ -68,10 +74,8 @@ public class SleepDetailsParser extends XiaomiActivityParser {
         sample.setWakeupTime(wakeupTime * 1000L);
         sample.setIsAwake(isAwake == 1);
 
-        // SleepAssistItemInfo 2x
-        //  - 0: Heart rate samples
-        //  - 1: Sp02 samples
-        for (int i = 0; i < 2; i++) {
+        // Heart rate samples
+        if ((header & (1 << 4)) != 0) {
             final int unit = buf.getShort(); // Time unit (i.e sample rate)
             final int count = buf.getShort();
             final int firstRecordTime = buf.getInt();
@@ -81,8 +85,40 @@ public class SleepDetailsParser extends XiaomiActivityParser {
             buf.position(buf.position() + count);
         }
 
+        // SpO2 samples
+        if ((header & (1 << 3)) != 0) {
+            final int unit = buf.getShort(); // Time unit (i.e sample rate)
+            final int count = buf.getShort();
+            final int firstRecordTime = buf.getInt();
+
+            // Skip count samples - each sample is a u8
+            //   timestamp of each sample is firstRecordTime + (unit * index)
+            buf.position(buf.position() + count);
+        }
+
+        // snore samples
+        if (fileId.getVersion() >= 3 && (header & (1 << 2)) != 0) {
+            final int unit = buf.getShort(); // Time unit (i.e sample rate)
+            final int count = buf.getShort();
+            final int firstRecordTime = buf.getInt();
+
+            // Skip count samples - each sample is a float
+            //   timestamp of each sample is firstRecordTime + (unit * index)
+            buf.position(buf.position() + count * 4);
+        }
+
         final List<XiaomiSleepStageSample> stages = new ArrayList<>();
 
+        // Do not crash if we face a buffer underflow, as the next parsing is not 100% fool-proof,
+        // and we still want to persist whatever we got so far
+        boolean stagesParseFailed = false;
+        try {
+            // FIXME: Sometimes there's a random zero here..?
+            if (buf.getInt() != 0) {
+                // If it wasn't a zero, rewind
+                buf.position(buf.position() - 4);
+            }
+
             while (buf.remaining() >= 17 && buf.getInt() == 0xFFFCFAFB) {
                 final int headerLen = buf.get() & 0xFF; // this seems to always be 17
 
@@ -139,6 +175,8 @@ public class SleepDetailsParser extends XiaomiActivityParser {
                     sample.setRemSleepDuration(rem_duration);
                     sample.setAwakeDuration(wake_duration);
 
+                    // FIXME: This is an array, but we end up persisting only the last sample, since
+                    // the timestamp is the primary key
                     summaries.add(sample);
                     sample = null;
                 }
@@ -160,7 +198,10 @@ public class SleepDetailsParser extends XiaomiActivityParser {
                     }
                 }
             }
-
+        } catch (final BufferUnderflowException e) {
+            LOG.warn("Buffer underflow while parsing sleep stages...", e);
+            stagesParseFailed = true;
+        }
 
         // save all the samples that we got
         try (DBHandler handler = GBApplication.acquireDB()) {
@@ -169,7 +210,6 @@ public class SleepDetailsParser extends XiaomiActivityParser {
 
             final XiaomiSleepTimeSampleProvider sampleProvider = new XiaomiSleepTimeSampleProvider(gbDevice, session);
 
-
             for (final XiaomiSleepTimeSample summary : summaries) {
                 summary.setDevice(DBHelper.getDevice(gbDevice, session));
                 summary.setUser(DBHelper.getUser(session));
@@ -195,6 +235,9 @@ public class SleepDetailsParser extends XiaomiActivityParser {
             return false;
         }
 
+        if (!stagesParseFailed && !stages.isEmpty()) {
+            LOG.debug("Persisting {} sleep stage samples", stages.size());
+
             // Save the sleep stage samples
             try (DBHandler handler = GBApplication.acquireDB()) {
                 final DaoSession session = handler.getDaoSession();
@@ -215,8 +258,9 @@ public class SleepDetailsParser extends XiaomiActivityParser {
                 LOG.error("Error saving sleep stage samples", e);
                 return false;
             }
+        }
 
-        return true;
+        return stagesParseFailed;
     }
 
     static private int decodeStage(int rawStage) {