Move app files to root folder

2026-09-14 23:06:11 -04:00 · 2021-09-01 15:24:27 +03:00
parent cd462fd2bb
commit 73befc9e7b
124 changed files with 0 additions and 0 deletions
@@ -0,0 +1,130 @@
+package com.dosse.airpods.pods;
+
+import android.bluetooth.le.ScanCallback;
+import android.bluetooth.le.ScanFilter;
+import android.bluetooth.le.ScanResult;
+import android.os.SystemClock;
+
+import com.dosse.airpods.utils.Logger;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+import java.util.Objects;
+
+/**
+ * TODO: proper javadoc
+ * On a normal OS, we would use the bluetooth address of the device to filter out beacons from other devices.
+ * UNFORTUNATELY, someone at google was so concerned about privacy (yea, as if they give a shit) that he decided it was a good idea to not allow access to the bluetooth address of incoming BLE beacons.
+ * As a result, we have no reliable way to make sure that the beacon comes from YOUR airpods and not the guy sitting next to you on the bus.
+ * What we did to workaround this issue is this:
+ * - When a beacon arrives that looks like a pair of AirPods, look at the other beacons received in the last 10 seconds and get the strongest one
+ * - If the strongest beacon's fake address is the same as this, use this beacon; otherwise use the strongest beacon
+ * - Filter for signals stronger than -60db
+ * - Decode...
+ */
+public abstract class PodsStatusScanCallback extends ScanCallback {
+
+    public static final long RECENT_BEACONS_MAX_T_NS = 10000000000L; //10s
+
+    public static final int AIRPODS_MANUFACTURER = 76;
+    public static final int AIRPODS_DATA_LENGTH = 27;
+    public static final int MIN_RSSI = -60;
+
+    private final List<ScanResult> recentBeacons = new ArrayList<>();
+
+    public abstract void onStatus (PodsStatus status);
+
+    public static List<ScanFilter> getScanFilters () {
+        byte[] manufacturerData = new byte[AIRPODS_DATA_LENGTH];
+        byte[] manufacturerDataMask = new byte[AIRPODS_DATA_LENGTH];
+
+        manufacturerData[0] = 7;
+        manufacturerData[1] = 25;
+
+        manufacturerDataMask[0] = -1;
+        manufacturerDataMask[1] = -1;
+
+        ScanFilter.Builder builder = new ScanFilter.Builder();
+        builder.setManufacturerData(AIRPODS_MANUFACTURER, manufacturerData, manufacturerDataMask);
+
+        return Collections.singletonList(builder.build());
+    }
+
+    @Override
+    public void onBatchScanResults (List<ScanResult> scanResults) {
+        for (ScanResult result : scanResults)
+            onScanResult(-1, result);
+
+        super.onBatchScanResults(scanResults);
+    }
+
+    @Override
+    public void onScanResult (int callbackType, ScanResult result) {
+        try {
+            if (!isAirpodsResult(result))
+                return;
+
+            result.getDevice().getAddress();
+
+            Logger.debug(result.getRssi() + "db");
+            Logger.debug(decodeResult(result));
+
+            result = getBestResult(result);
+            if (result == null || result.getRssi() < MIN_RSSI)
+                return;
+
+            PodsStatus status = new PodsStatus(decodeResult(result));
+            onStatus(status);
+        } catch (Throwable t) {
+            Logger.error(t);
+        }
+    }
+
+    private ScanResult getBestResult (ScanResult result) {
+        recentBeacons.add(result);
+        ScanResult strongestBeacon = null;
+
+        for (int i = 0; i < recentBeacons.size(); i++) {
+            if (SystemClock.elapsedRealtimeNanos() - recentBeacons.get(i).getTimestampNanos() > RECENT_BEACONS_MAX_T_NS) {
+                recentBeacons.remove(i--);
+                continue;
+            }
+
+            if (strongestBeacon == null || strongestBeacon.getRssi() < recentBeacons.get(i).getRssi())
+                strongestBeacon = recentBeacons.get(i);
+        }
+
+        if (strongestBeacon != null && Objects.equals(strongestBeacon.getDevice().getAddress(), result.getDevice().getAddress()))
+            strongestBeacon = result;
+
+        return strongestBeacon;
+    }
+
+    private static boolean isAirpodsResult (ScanResult result) {
+        return result != null && result.getScanRecord() != null && isDataValid(result.getScanRecord().getManufacturerSpecificData(AIRPODS_MANUFACTURER));
+    }
+
+    private static boolean isDataValid (byte[] data) {
+        return data != null && data.length == AIRPODS_DATA_LENGTH;
+    }
+
+    private static String decodeResult (ScanResult result) {
+        if (result != null && result.getScanRecord() != null) {
+            byte[] data = result.getScanRecord().getManufacturerSpecificData(AIRPODS_MANUFACTURER);
+            if (isDataValid(data))
+                return decodeHex(data);
+        }
+        return null;
+    }
+
+    public static String decodeHex (byte[] bArr) {
+        StringBuilder ret = new StringBuilder();
+
+        for (byte b : bArr)
+            ret.append(String.format("%02X", b));
+
+        return ret.toString();
+    }
+
+}