Add Android BLE mesh client and project website

2026-03-16 19:04:20 +00:00
parent 2ad5e03cb7
commit c833fd467d
27 changed files with 1539 additions and 0 deletions
--- a/android/app/src/main/AndroidManifest.xml
+++ b/android/app/src/main/AndroidManifest.xml
@@ -0,0 +1,44 @@
+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android">
+
+    <uses-feature
+        android:name="android.hardware.bluetooth_le"
+        android:required="false" />
+
+    <uses-permission android:name="android.permission.BLUETOOTH" android:maxSdkVersion="30" />
+    <uses-permission android:name="android.permission.BLUETOOTH_ADMIN" android:maxSdkVersion="30" />
+    <uses-permission
+        android:name="android.permission.BLUETOOTH_SCAN"
+        android:usesPermissionFlags="neverForLocation" />
+    <uses-permission android:name="android.permission.BLUETOOTH_CONNECT" />
+    <uses-permission android:name="android.permission.BLUETOOTH_ADVERTISE" />
+    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" android:maxSdkVersion="30" />
+    <uses-permission android:name="android.permission.POST_NOTIFICATIONS" />
+    <uses-permission android:name="android.permission.FOREGROUND_SERVICE" />
+    <uses-permission android:name="android.permission.FOREGROUND_SERVICE_CONNECTED_DEVICE" />
+
+    <application
+        android:allowBackup="true"
+        android:icon="@android:drawable/sym_def_app_icon"
+        android:label="@string/app_name"
+        android:roundIcon="@android:drawable/sym_def_app_icon"
+        android:supportsRtl="true"
+        android:theme="@style/Theme.SchoolMeshMessenger">
+        <activity
+            android:name=".MainActivity"
+            android:exported="true">
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN" />
+
+                <category android:name="android.intent.category.LAUNCHER" />
+            </intent-filter>
+        </activity>
+
+        <service
+            android:name=".mesh.MeshForegroundService"
+            android:enabled="true"
+            android:exported="false"
+            android:foregroundServiceType="connectedDevice" />
+    </application>
+
+</manifest>
--- a/android/app/src/main/java/com/schoolmesh/messenger/MainActivity.kt
+++ b/android/app/src/main/java/com/schoolmesh/messenger/MainActivity.kt
@@ -0,0 +1,165 @@
+package com.schoolmesh.messenger
+
+import android.Manifest
+import android.content.BroadcastReceiver
+import android.content.Context
+import android.content.Intent
+import android.content.IntentFilter
+import android.os.Build
+import android.os.Bundle
+import android.widget.Button
+import android.widget.TextView
+import android.widget.Toast
+import androidx.activity.result.contract.ActivityResultContracts
+import androidx.appcompat.app.AppCompatActivity
+import androidx.core.content.ContextCompat
+import com.schoolmesh.messenger.mesh.MeshForegroundService
+import com.schoolmesh.messenger.mesh.MeshServiceContract
+
+class MainActivity : AppCompatActivity() {
+    private lateinit var statusText: TextView
+    private lateinit var peersText: TextView
+    private lateinit var logsText: TextView
+
+    private val peers = linkedSetOf<String>()
+    private val logs = ArrayDeque<String>()
+
+    private val meshEventReceiver = object : BroadcastReceiver() {
+        override fun onReceive(context: Context?, intent: Intent?) {
+            if (intent?.action != MeshServiceContract.ACTION_EVENT) return
+            val eventType = intent.getStringExtra(MeshServiceContract.EXTRA_EVENT_TYPE) ?: return
+            val value = intent.getStringExtra(MeshServiceContract.EXTRA_EVENT_VALUE) ?: return
+
+            when (eventType) {
+                MeshServiceContract.EVENT_STATUS -> updateStatus(value)
+                MeshServiceContract.EVENT_PEER -> addPeer(value)
+                MeshServiceContract.EVENT_LOG -> appendLog(value)
+            }
+        }
+    }
+
+    private val permissionLauncher = registerForActivityResult(
+        ActivityResultContracts.RequestMultiplePermissions()
+    ) { result ->
+        val allGranted = result.values.all { it }
+        if (allGranted) {
+            startMesh()
+        } else {
+            updateStatus("Нет BLE-разрешений")
+            appendLog("Permissions denied by user")
+            Toast.makeText(this, "Разрешения отклонены", Toast.LENGTH_SHORT).show()
+        }
+    }
+
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        setContentView(R.layout.activity_main)
+
+        statusText = findViewById(R.id.statusText)
+        peersText = findViewById(R.id.peersText)
+        logsText = findViewById(R.id.logsText)
+
+        findViewById<Button>(R.id.btnStartMesh).setOnClickListener {
+            ensurePermissionsAndStart()
+        }
+        findViewById<Button>(R.id.btnStopMesh).setOnClickListener {
+            MeshForegroundService.stop(this)
+            updateStatus("Mesh остановлен")
+            appendLog("Mesh service stop requested")
+        }
+
+        renderPeers()
+        renderLogs()
+    }
+
+    override fun onStart() {
+        super.onStart()
+        registerMeshReceiver()
+    }
+
+    override fun onStop() {
+        unregisterReceiver(meshEventReceiver)
+        super.onStop()
+    }
+
+    private fun registerMeshReceiver() {
+        val filter = IntentFilter(MeshServiceContract.ACTION_EVENT)
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU) {
+            registerReceiver(meshEventReceiver, filter, RECEIVER_NOT_EXPORTED)
+        } else {
+            @Suppress("DEPRECATION")
+            registerReceiver(meshEventReceiver, filter)
+        }
+    }
+
+    private fun ensurePermissionsAndStart() {
+        val missing = requiredPermissions().filter { permission ->
+            ContextCompat.checkSelfPermission(this, permission) != android.content.pm.PackageManager.PERMISSION_GRANTED
+        }
+        if (missing.isEmpty()) {
+            startMesh()
+        } else {
+            permissionLauncher.launch(missing.toTypedArray())
+        }
+    }
+
+    private fun requiredPermissions(): List<String> {
+        val permissions = mutableListOf<String>()
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.S) {
+            permissions += Manifest.permission.BLUETOOTH_SCAN
+            permissions += Manifest.permission.BLUETOOTH_CONNECT
+            permissions += Manifest.permission.BLUETOOTH_ADVERTISE
+        } else {
+            permissions += Manifest.permission.ACCESS_FINE_LOCATION
+        }
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU) {
+            permissions += Manifest.permission.POST_NOTIFICATIONS
+        }
+        return permissions
+    }
+
+    private fun startMesh() {
+        MeshForegroundService.start(this)
+        updateStatus("Запуск foreground service")
+        appendLog("Mesh service start requested")
+        Toast.makeText(this, "Mesh запускается", Toast.LENGTH_SHORT).show()
+    }
+
+    private fun updateStatus(text: String) {
+        statusText.text = text
+    }
+
+    private fun addPeer(address: String) {
+        if (peers.add(address)) {
+            renderPeers()
+        }
+    }
+
+    private fun appendLog(message: String) {
+        if (logs.size >= MAX_LOG_ENTRIES) {
+            logs.removeFirst()
+        }
+        logs.addLast(message)
+        renderLogs()
+    }
+
+    private fun renderPeers() {
+        peersText.text = if (peers.isEmpty()) {
+            "Узлы не найдены"
+        } else {
+            peers.joinToString(separator = "\n")
+        }
+    }
+
+    private fun renderLogs() {
+        logsText.text = if (logs.isEmpty()) {
+            "Лог пуст"
+        } else {
+            logs.joinToString(separator = "\n")
+        }
+    }
+
+    companion object {
+        private const val MAX_LOG_ENTRIES = 20
+    }
+}
--- a/android/app/src/main/java/com/schoolmesh/messenger/mesh/BleMeshManager.kt
+++ b/android/app/src/main/java/com/schoolmesh/messenger/mesh/BleMeshManager.kt
@@ -0,0 +1,430 @@
+package com.schoolmesh.messenger.mesh
+
+import android.Manifest
+import android.annotation.SuppressLint
+import android.bluetooth.BluetoothAdapter
+import android.bluetooth.BluetoothDevice
+import android.bluetooth.BluetoothGatt
+import android.bluetooth.BluetoothGattCallback
+import android.bluetooth.BluetoothGattCharacteristic
+import android.bluetooth.BluetoothProfile
+import android.bluetooth.BluetoothGattServer
+import android.bluetooth.BluetoothGattServerCallback
+import android.bluetooth.BluetoothGattService
+import android.bluetooth.BluetoothManager
+import android.bluetooth.le.AdvertiseCallback
+import android.bluetooth.le.AdvertiseData
+import android.bluetooth.le.AdvertiseSettings
+import android.bluetooth.le.BluetoothLeAdvertiser
+import android.bluetooth.le.BluetoothLeScanner
+import android.bluetooth.le.ScanCallback
+import android.bluetooth.le.ScanFilter
+import android.bluetooth.le.ScanResult
+import android.bluetooth.le.ScanSettings
+import android.content.Context
+import android.content.pm.PackageManager
+import android.os.Build
+import android.os.ParcelUuid
+import android.util.Log
+import androidx.core.content.ContextCompat
+import java.nio.charset.StandardCharsets
+import java.util.UUID
+import java.util.concurrent.ConcurrentHashMap
+
+class BleMeshManager(
+    private val context: Context,
+    private val onPeerDiscovered: (String) -> Unit = {},
+    private val onStatusChanged: (String) -> Unit = {},
+    private val onError: (String) -> Unit = {},
+    private val onLog: (String) -> Unit = {},
+    private val seenPacketCache: SeenPacketCache = SeenPacketCache()
+) {
+    private val bluetoothManager = context.getSystemService(BluetoothManager::class.java)
+    private val bluetoothAdapter = bluetoothManager?.adapter
+    private val scanner: BluetoothLeScanner?
+        get() = bluetoothAdapter?.bluetoothLeScanner
+    private val advertiser: BluetoothLeAdvertiser?
+        get() = bluetoothAdapter?.bluetoothLeAdvertiser
+
+    private val activeConnections = ConcurrentHashMap<String, BluetoothGatt>()
+    private var gattServer: BluetoothGattServer? = null
+    private var inboundCharacteristic: BluetoothGattCharacteristic? = null
+    private var isRunning = false
+
+    private val localNodeId: String by lazy {
+        bluetoothAdapter?.address ?: "android-${UUID.randomUUID()}"
+    }
+
+    private val scanCallback = object : ScanCallback() {
+        override fun onScanResult(callbackType: Int, result: ScanResult) {
+            val device = result.device ?: return
+            val address = device.address ?: return
+            onPeerDiscovered(address)
+            if (address == localNodeId || activeConnections.containsKey(address)) {
+                return
+            }
+            log("Discovered BLE node: $address")
+            connectToPeer(device)
+        }
+
+        override fun onScanFailed(errorCode: Int) {
+            fail("BLE scan failed: $errorCode")
+        }
+    }
+
+    private val advertiseCallback = object : AdvertiseCallback() {
+        override fun onStartSuccess(settingsInEffect: AdvertiseSettings) {
+            log("BLE advertising started")
+        }
+
+        override fun onStartFailure(errorCode: Int) {
+            fail("BLE advertising failed: $errorCode")
+        }
+    }
+
+    private val gattServerCallback = object : BluetoothGattServerCallback() {
+        override fun onConnectionStateChange(device: BluetoothDevice, status: Int, newState: Int) {
+            log("GATT server connection ${device.address}: state=$newState status=$status")
+        }
+
+        override fun onCharacteristicWriteRequest(
+            device: BluetoothDevice,
+            requestId: Int,
+            characteristic: BluetoothGattCharacteristic,
+            preparedWrite: Boolean,
+            responseNeeded: Boolean,
+            offset: Int,
+            value: ByteArray
+        ) {
+            if (characteristic.uuid != CHARACTERISTIC_PACKET_UUID) {
+                if (responseNeeded) {
+                    gattServer?.sendResponse(device, requestId, BluetoothGatt.GATT_FAILURE, offset, null)
+                }
+                return
+            }
+
+            val rawPacket = value.toString(StandardCharsets.UTF_8)
+            log("Packet received from ${device.address}: $rawPacket")
+            handleIncomingPacket(rawPacket)
+
+            if (responseNeeded) {
+                gattServer?.sendResponse(device, requestId, BluetoothGatt.GATT_SUCCESS, offset, null)
+            }
+        }
+    }
+
+    private inner class MeshGattCallback(
+        private val device: BluetoothDevice
+    ) : BluetoothGattCallback() {
+        override fun onConnectionStateChange(gatt: BluetoothGatt, status: Int, newState: Int) {
+            val address = device.address ?: return
+            if (status != BluetoothGatt.GATT_SUCCESS) {
+                log("GATT client error for $address: status=$status")
+                closeConnection(address)
+                return
+            }
+
+            when (newState) {
+                BluetoothProfile.STATE_CONNECTED -> {
+                    log("Connected to peer $address")
+                    activeConnections[address] = gatt
+                    gatt.discoverServices()
+                }
+
+                BluetoothProfile.STATE_DISCONNECTED -> {
+                    log("Disconnected from peer $address")
+                    closeConnection(address)
+                }
+            }
+        }
+
+        override fun onServicesDiscovered(gatt: BluetoothGatt, status: Int) {
+            if (status != BluetoothGatt.GATT_SUCCESS) {
+                log("Service discovery failed for ${device.address}: $status")
+                return
+            }
+            log("Services discovered for ${device.address}")
+            sendPresence(gatt)
+        }
+
+        override fun onCharacteristicWrite(
+            gatt: BluetoothGatt,
+            characteristic: BluetoothGattCharacteristic,
+            status: Int
+        ) {
+            val address = device.address ?: return
+            if (status == BluetoothGatt.GATT_SUCCESS) {
+                log("Packet sent to $address")
+            } else {
+                log("Packet send failed to $address: status=$status")
+            }
+        }
+    }
+
+    fun onPacketReceived(packet: MeshPacket): MeshAction {
+        val isNew = seenPacketCache.markSeen(packet.messageId)
+        if (!isNew) {
+            return MeshAction.DropDuplicate
+        }
+
+        if (packet.isExpired()) {
+            return MeshAction.DropExpired
+        }
+
+        return when (packet.type) {
+            PacketType.ACK -> MeshAction.ConsumeAck(packet.messageId)
+            PacketType.PRESENCE -> MeshAction.ConsumePresence(packet.senderId)
+            PacketType.MESSAGE -> MeshAction.ProcessAndRelay(packet.decrementedTtl())
+        }
+    }
+
+    fun start() {
+        if (isRunning) return
+        if (!hasRequiredRuntimePermissions()) {
+            fail("BLE permissions are missing")
+            return
+        }
+
+        val adapter = bluetoothAdapter
+        if (adapter == null || !adapter.isEnabled) {
+            fail("Bluetooth adapter is unavailable or disabled")
+            return
+        }
+
+        startGattServer()
+        startScanning()
+        startAdvertising()
+        isRunning = true
+        onStatusChanged("Mesh активен, идет discovery и GATT transport")
+        log("BLE mesh manager started with nodeId=$localNodeId")
+    }
+
+    fun stop() {
+        if (!isRunning) return
+
+        runCatching { scanner?.stopScan(scanCallback) }
+            .onFailure { Log.w(TAG, "Failed to stop scan", it) }
+        runCatching { advertiser?.stopAdvertising(advertiseCallback) }
+            .onFailure { Log.w(TAG, "Failed to stop advertising", it) }
+        runCatching { gattServer?.close() }
+            .onFailure { Log.w(TAG, "Failed to close GATT server", it) }
+
+        activeConnections.keys.toList().forEach(::closeConnection)
+        inboundCharacteristic = null
+        gattServer = null
+        isRunning = false
+        onStatusChanged("Mesh остановлен")
+        log("BLE mesh manager stopped")
+    }
+
+    private fun handleIncomingPacket(rawPacket: String) {
+        val packet = runCatching { MeshPacketCodec.decode(rawPacket) }
+            .getOrElse {
+                fail("Packet decode failed: ${it.message}")
+                return
+            }
+
+        when (val action = onPacketReceived(packet)) {
+            MeshAction.DropDuplicate -> log("Duplicate packet dropped: ${packet.messageId}")
+            MeshAction.DropExpired -> log("Expired packet dropped: ${packet.messageId}")
+            is MeshAction.ConsumeAck -> log("ACK consumed: ${action.messageId}")
+            is MeshAction.ConsumePresence -> {
+                onPeerDiscovered(action.senderId)
+                onStatusChanged("Presence from ${action.senderId}")
+                log("Presence consumed from ${action.senderId}")
+            }
+
+            is MeshAction.ProcessAndRelay -> {
+                onStatusChanged("Message from ${packet.senderId}")
+                log("Relaying packet ${packet.messageId}")
+                broadcastPacket(action.packetToRelay)
+                sendAck(packet)
+            }
+        }
+    }
+
+    @SuppressLint("MissingPermission")
+    private fun startGattServer() {
+        val manager = bluetoothManager ?: run {
+            fail("BluetoothManager unavailable")
+            return
+        }
+
+        val server = manager.openGattServer(context, gattServerCallback)
+        if (server == null) {
+            fail("Failed to open GATT server")
+            return
+        }
+
+        val characteristic = BluetoothGattCharacteristic(
+            CHARACTERISTIC_PACKET_UUID,
+            BluetoothGattCharacteristic.PROPERTY_WRITE or BluetoothGattCharacteristic.PROPERTY_WRITE_NO_RESPONSE,
+            BluetoothGattCharacteristic.PERMISSION_WRITE
+        )
+
+        val service = BluetoothGattService(
+            MESH_SERVICE_UUID,
+            BluetoothGattService.SERVICE_TYPE_PRIMARY
+        ).apply {
+            addCharacteristic(characteristic)
+        }
+
+        server.addService(service)
+        gattServer = server
+        inboundCharacteristic = characteristic
+        log("GATT server started")
+    }
+
+    @SuppressLint("MissingPermission")
+    private fun startScanning() {
+        val filter = ScanFilter.Builder()
+            .setServiceUuid(ParcelUuid(MESH_SERVICE_UUID))
+            .build()
+        val settings = ScanSettings.Builder()
+            .setScanMode(ScanSettings.SCAN_MODE_LOW_LATENCY)
+            .build()
+        scanner?.startScan(listOf(filter), settings, scanCallback)
+        log("BLE scanning started")
+    }
+
+    @SuppressLint("MissingPermission")
+    private fun startAdvertising() {
+        val settings = AdvertiseSettings.Builder()
+            .setAdvertiseMode(AdvertiseSettings.ADVERTISE_MODE_LOW_LATENCY)
+            .setConnectable(true)
+            .setTimeout(0)
+            .setTxPowerLevel(AdvertiseSettings.ADVERTISE_TX_POWER_HIGH)
+            .build()
+
+        val data = AdvertiseData.Builder()
+            .setIncludeDeviceName(false)
+            .addServiceUuid(ParcelUuid(MESH_SERVICE_UUID))
+            .build()
+
+        advertiser?.startAdvertising(settings, data, advertiseCallback)
+    }
+
+    @SuppressLint("MissingPermission")
+    private fun connectToPeer(device: BluetoothDevice) {
+        val address = device.address ?: return
+        if (activeConnections.containsKey(address)) return
+        log("Connecting to peer $address")
+        val gatt = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
+            device.connectGatt(context, false, MeshGattCallback(device), BluetoothDevice.TRANSPORT_LE)
+        } else {
+            @Suppress("DEPRECATION")
+            device.connectGatt(context, false, MeshGattCallback(device))
+        }
+        if (gatt != null) {
+            activeConnections[address] = gatt
+        }
+    }
+
+    private fun sendPresence(gatt: BluetoothGatt) {
+        val packet = MeshPacket(
+            senderId = localNodeId,
+            targetId = gatt.device.address ?: "broadcast",
+            type = PacketType.PRESENCE,
+            payload = "presence:$localNodeId"
+        )
+        writePacket(gatt, packet)
+    }
+
+    private fun sendAck(packet: MeshPacket) {
+        val ack = MeshPacket(
+            senderId = localNodeId,
+            targetId = packet.senderId,
+            type = PacketType.ACK,
+            payload = packet.messageId
+        )
+        broadcastPacket(ack)
+    }
+
+    private fun broadcastPacket(packet: MeshPacket) {
+        activeConnections.values.forEach { gatt ->
+            writePacket(gatt, packet)
+        }
+    }
+
+    @SuppressLint("MissingPermission")
+    private fun writePacket(gatt: BluetoothGatt, packet: MeshPacket) {
+        val characteristic = gatt
+            .getService(MESH_SERVICE_UUID)
+            ?.getCharacteristic(CHARACTERISTIC_PACKET_UUID)
+
+        if (characteristic == null) {
+            log("Remote characteristic missing on ${gatt.device.address}")
+            return
+        }
+
+        val payload = MeshPacketCodec.encode(packet).toByteArray(StandardCharsets.UTF_8)
+
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU) {
+            gatt.writeCharacteristic(
+                characteristic,
+                payload,
+                BluetoothGattCharacteristic.WRITE_TYPE_DEFAULT
+            )
+        } else {
+            @Suppress("DEPRECATION")
+            characteristic.writeType = BluetoothGattCharacteristic.WRITE_TYPE_DEFAULT
+            @Suppress("DEPRECATION")
+            characteristic.value = payload
+            @Suppress("DEPRECATION")
+            gatt.writeCharacteristic(characteristic)
+        }
+    }
+
+    @SuppressLint("MissingPermission")
+    private fun closeConnection(address: String) {
+        val gatt = activeConnections.remove(address) ?: return
+        runCatching {
+            gatt.disconnect()
+            gatt.close()
+        }.onFailure {
+            Log.w(TAG, "Failed to close connection for $address", it)
+        }
+    }
+
+    private fun hasRequiredRuntimePermissions(): Boolean {
+        val requiredPermissions = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.S) {
+            listOf(
+                Manifest.permission.BLUETOOTH_SCAN,
+                Manifest.permission.BLUETOOTH_CONNECT,
+                Manifest.permission.BLUETOOTH_ADVERTISE
+            )
+        } else {
+            listOf(Manifest.permission.ACCESS_FINE_LOCATION)
+        }
+
+        return requiredPermissions.all { permission ->
+            ContextCompat.checkSelfPermission(context, permission) == PackageManager.PERMISSION_GRANTED
+        }
+    }
+
+    private fun fail(message: String) {
+        Log.e(TAG, message)
+        onError(message)
+        onLog(message)
+    }
+
+    private fun log(message: String) {
+        Log.d(TAG, message)
+        onLog(message)
+    }
+
+    companion object {
+        private const val TAG = "BleMeshManager"
+        private val MESH_SERVICE_UUID: UUID = UUID.fromString("8fa8f9f0-e755-4c1d-9ac2-4f0a02e07f8b")
+        private val CHARACTERISTIC_PACKET_UUID: UUID =
+            UUID.fromString("f9629b10-9d60-4d95-bc6a-6fdb4d4f5a4a")
+    }
+}
+
+sealed interface MeshAction {
+    data object DropDuplicate : MeshAction
+    data object DropExpired : MeshAction
+    data class ConsumeAck(val messageId: String) : MeshAction
+    data class ConsumePresence(val senderId: String) : MeshAction
+    data class ProcessAndRelay(val packetToRelay: MeshPacket) : MeshAction
+}
--- a/android/app/src/main/java/com/schoolmesh/messenger/mesh/MeshForegroundService.kt
+++ b/android/app/src/main/java/com/schoolmesh/messenger/mesh/MeshForegroundService.kt
@@ -0,0 +1,119 @@
+package com.schoolmesh.messenger.mesh
+
+import android.app.Notification
+import android.app.NotificationChannel
+import android.app.NotificationManager
+import android.app.Service
+import android.content.Context
+import android.content.Intent
+import android.os.Build
+import android.os.IBinder
+import androidx.core.app.NotificationCompat
+import com.schoolmesh.messenger.R
+
+class MeshForegroundService : Service() {
+    private lateinit var bleMeshManager: BleMeshManager
+
+    override fun onCreate() {
+        super.onCreate()
+        createNotificationChannel()
+        bleMeshManager = BleMeshManager(
+            context = applicationContext,
+            onPeerDiscovered = { address ->
+                sendEvent(MeshServiceContract.EVENT_PEER, address)
+                sendEvent(MeshServiceContract.EVENT_LOG, "Peer discovered: $address")
+            },
+            onStatusChanged = { status ->
+                sendEvent(MeshServiceContract.EVENT_STATUS, status)
+                updateNotification(status)
+            },
+            onError = { message ->
+                sendEvent(MeshServiceContract.EVENT_STATUS, "Ошибка: $message")
+                sendEvent(MeshServiceContract.EVENT_LOG, "Error: $message")
+                updateNotification("Ошибка mesh")
+            },
+            onLog = { message ->
+                sendEvent(MeshServiceContract.EVENT_LOG, message)
+            }
+        )
+    }
+
+    override fun onStartCommand(intent: Intent?, flags: Int, startId: Int): Int {
+        when (intent?.action) {
+            MeshServiceContract.ACTION_STOP -> stopMesh()
+            else -> startMesh()
+        }
+        return START_STICKY
+    }
+
+    override fun onDestroy() {
+        bleMeshManager.stop()
+        super.onDestroy()
+    }
+
+    override fun onBind(intent: Intent?): IBinder? = null
+
+    private fun startMesh() {
+        startForeground(NOTIFICATION_ID, buildNotification("Mesh запускается"))
+        bleMeshManager.start()
+    }
+
+    private fun stopMesh() {
+        bleMeshManager.stop()
+        stopForeground(STOP_FOREGROUND_REMOVE)
+        stopSelf()
+    }
+
+    private fun buildNotification(contentText: String): Notification {
+        return NotificationCompat.Builder(this, CHANNEL_ID)
+            .setContentTitle(getString(R.string.notification_title))
+            .setContentText(contentText)
+            .setSmallIcon(android.R.drawable.stat_sys_data_bluetooth)
+            .setOngoing(true)
+            .build()
+    }
+
+    private fun updateNotification(contentText: String) {
+        val notificationManager = getSystemService(NotificationManager::class.java)
+        notificationManager.notify(NOTIFICATION_ID, buildNotification(contentText))
+    }
+
+    private fun createNotificationChannel() {
+        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.O) return
+        val manager = getSystemService(NotificationManager::class.java)
+        val channel = NotificationChannel(
+            CHANNEL_ID,
+            getString(R.string.notification_channel_name),
+            NotificationManager.IMPORTANCE_LOW
+        )
+        manager.createNotificationChannel(channel)
+    }
+
+    private fun sendEvent(type: String, value: String) {
+        sendBroadcast(
+            Intent(MeshServiceContract.ACTION_EVENT)
+                .setPackage(packageName)
+                .putExtra(MeshServiceContract.EXTRA_EVENT_TYPE, type)
+                .putExtra(MeshServiceContract.EXTRA_EVENT_VALUE, value)
+        )
+    }
+
+    companion object {
+        private const val CHANNEL_ID = "mesh_status"
+        private const val NOTIFICATION_ID = 1001
+
+        fun start(context: Context) {
+            val intent = Intent(context, MeshForegroundService::class.java).apply {
+                action = MeshServiceContract.ACTION_START
+            }
+            androidx.core.content.ContextCompat.startForegroundService(context, intent)
+        }
+
+        fun stop(context: Context) {
+            val intent = Intent(context, MeshForegroundService::class.java).apply {
+                action = MeshServiceContract.ACTION_STOP
+            }
+            context.startService(intent)
+        }
+    }
+}
--- a/android/app/src/main/java/com/schoolmesh/messenger/mesh/MeshPacket.kt
+++ b/android/app/src/main/java/com/schoolmesh/messenger/mesh/MeshPacket.kt
@@ -0,0 +1,21 @@
+package com.schoolmesh.messenger.mesh
+
+import java.util.UUID
+
+data class MeshPacket(
+    val messageId: String = UUID.randomUUID().toString(),
+    val senderId: String,
+    val targetId: String,
+    val ttl: Int = DEFAULT_TTL,
+    val timestamp: Long = System.currentTimeMillis(),
+    val type: PacketType,
+    val payload: String
+) {
+    fun isExpired(): Boolean = ttl <= 0
+
+    fun decrementedTtl(): MeshPacket = copy(ttl = ttl - 1)
+
+    companion object {
+        const val DEFAULT_TTL = 6
+    }
+}
--- a/android/app/src/main/java/com/schoolmesh/messenger/mesh/MeshPacketCodec.kt
+++ b/android/app/src/main/java/com/schoolmesh/messenger/mesh/MeshPacketCodec.kt
@@ -0,0 +1,30 @@
+package com.schoolmesh.messenger.mesh
+
+import org.json.JSONObject
+
+object MeshPacketCodec {
+    fun encode(packet: MeshPacket): String {
+        return JSONObject()
+            .put("messageId", packet.messageId)
+            .put("senderId", packet.senderId)
+            .put("targetId", packet.targetId)
+            .put("ttl", packet.ttl)
+            .put("timestamp", packet.timestamp)
+            .put("type", packet.type.name)
+            .put("payload", packet.payload)
+            .toString()
+    }
+
+    fun decode(raw: String): MeshPacket {
+        val json = JSONObject(raw)
+        return MeshPacket(
+            messageId = json.getString("messageId"),
+            senderId = json.getString("senderId"),
+            targetId = json.getString("targetId"),
+            ttl = json.getInt("ttl"),
+            timestamp = json.getLong("timestamp"),
+            type = PacketType.valueOf(json.getString("type")),
+            payload = json.getString("payload")
+        )
+    }
+}
--- a/android/app/src/main/java/com/schoolmesh/messenger/mesh/MeshServiceContract.kt
+++ b/android/app/src/main/java/com/schoolmesh/messenger/mesh/MeshServiceContract.kt
@@ -0,0 +1,14 @@
+package com.schoolmesh.messenger.mesh
+
+object MeshServiceContract {
+    const val ACTION_START = "com.schoolmesh.messenger.mesh.START"
+    const val ACTION_STOP = "com.schoolmesh.messenger.mesh.STOP"
+    const val ACTION_EVENT = "com.schoolmesh.messenger.mesh.EVENT"
+
+    const val EXTRA_EVENT_TYPE = "event_type"
+    const val EXTRA_EVENT_VALUE = "event_value"
+
+    const val EVENT_STATUS = "status"
+    const val EVENT_PEER = "peer"
+    const val EVENT_LOG = "log"
+}
--- a/android/app/src/main/java/com/schoolmesh/messenger/mesh/PacketType.kt
+++ b/android/app/src/main/java/com/schoolmesh/messenger/mesh/PacketType.kt
@@ -0,0 +1,7 @@
+package com.schoolmesh.messenger.mesh
+
+enum class PacketType {
+    MESSAGE,
+    ACK,
+    PRESENCE
+}
--- a/android/app/src/main/java/com/schoolmesh/messenger/mesh/SeenPacketCache.kt
+++ b/android/app/src/main/java/com/schoolmesh/messenger/mesh/SeenPacketCache.kt
@@ -0,0 +1,21 @@
+package com.schoolmesh.messenger.mesh
+
+class SeenPacketCache(
+    private val maxSize: Int = 512
+) {
+    private val packetIds = LinkedHashSet<String>()
+
+    @Synchronized
+    fun markSeen(packetId: String): Boolean {
+        if (packetIds.contains(packetId)) return false
+
+        packetIds.add(packetId)
+        if (packetIds.size > maxSize) {
+            val oldest = packetIds.firstOrNull()
+            if (oldest != null) {
+                packetIds.remove(oldest)
+            }
+        }
+        return true
+    }
+}
--- a/android/app/src/main/res/layout/activity_main.xml
+++ b/android/app/src/main/res/layout/activity_main.xml
@@ -0,0 +1,101 @@
+<?xml version="1.0" encoding="utf-8"?>
+<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent"
+    tools:context=".MainActivity">
+
+    <LinearLayout
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:orientation="vertical"
+        android:padding="24dp">
+
+        <TextView
+            android:id="@+id/titleText"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:text="School Mesh Messenger"
+            android:textAppearance="@style/TextAppearance.Material3.HeadlineMedium" />
+
+        <TextView
+            android:id="@+id/subtitleText"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="12dp"
+            android:text="Debug-экран BLE mesh: foreground service, найденные узлы и журнал событий." />
+
+        <LinearLayout
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="24dp"
+            android:orientation="horizontal">
+
+            <Button
+                android:id="@+id/btnStartMesh"
+                android:layout_width="0dp"
+                android:layout_height="wrap_content"
+                android:layout_weight="1"
+                android:text="Запустить mesh" />
+
+            <Button
+                android:id="@+id/btnStopMesh"
+                android:layout_width="0dp"
+                android:layout_height="wrap_content"
+                android:layout_marginStart="12dp"
+                android:layout_weight="1"
+                android:text="Остановить mesh" />
+        </LinearLayout>
+
+        <TextView
+            android:id="@+id/statusLabel"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="24dp"
+            android:text="Статус"
+            android:textStyle="bold" />
+
+        <TextView
+            android:id="@+id/statusText"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="8dp"
+            android:text="Ожидание запуска" />
+
+        <TextView
+            android:id="@+id/peersLabel"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="24dp"
+            android:text="Найденные узлы"
+            android:textStyle="bold" />
+
+        <TextView
+            android:id="@+id/peersText"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="8dp"
+            android:background="#EAF3F7"
+            android:padding="12dp"
+            android:text="Узлы не найдены" />
+
+        <TextView
+            android:id="@+id/logsLabel"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="24dp"
+            android:text="Журнал событий"
+            android:textStyle="bold" />
+
+        <TextView
+            android:id="@+id/logsText"
+            android:layout_width="match_parent"
+            android:layout_height="wrap_content"
+            android:layout_marginTop="8dp"
+            android:background="#101820"
+            android:padding="12dp"
+            android:text="Лог пуст"
+            android:textColor="#EAF7F2"
+            android:textIsSelectable="true" />
+    </LinearLayout>
+</ScrollView>
--- a/android/app/src/main/res/values/colors.xml
+++ b/android/app/src/main/res/values/colors.xml
@@ -0,0 +1,5 @@
+<resources>
+    <color name="teal_primary">#1E6E54</color>
+    <color name="teal_container">#A4F3D5</color>
+    <color name="blue_secondary">#1150B4</color>
+</resources>
--- a/android/app/src/main/res/values/strings.xml
+++ b/android/app/src/main/res/values/strings.xml
@@ -0,0 +1,5 @@
+<resources>
+    <string name="app_name">School Mesh Messenger</string>
+    <string name="notification_title">School Mesh Messenger</string>
+    <string name="notification_channel_name">Mesh status</string>
+</resources>
--- a/android/app/src/main/res/values/themes.xml
+++ b/android/app/src/main/res/values/themes.xml
@@ -0,0 +1,7 @@
+<resources xmlns:tools="http://schemas.android.com/tools">
+    <style name="Theme.SchoolMeshMessenger" parent="Theme.Material3.DayNight.NoActionBar">
+        <item name="colorPrimary">#1E6E54</item>
+        <item name="colorPrimaryContainer">#A4F3D5</item>
+        <item name="colorSecondary">#1150B4</item>
+    </style>
+</resources>
--- a/android/app/src/main/res/xml/backup_rules.xml
+++ b/android/app/src/main/res/xml/backup_rules.xml
@@ -0,0 +1,2 @@
+<?xml version="1.0" encoding="utf-8"?>
+<full-backup-content />
--- a/android/app/src/main/res/xml/data_extraction_rules.xml
+++ b/android/app/src/main/res/xml/data_extraction_rules.xml
@@ -0,0 +1,2 @@
+<?xml version="1.0" encoding="utf-8"?>
+<data-extraction-rules />