feat: OTA notification handling with ACK/NAK retry logic

android/app/src/main/java/nl/eddydevink/sylda/BleRelayManager.kt

@@ -60,6 +60,16 @@ class BleRelayManager(
     private var espVersion: String? = null
     private var appVersion: String = ""
 
+    interface OtaNotifyCallback {
+        fun onOtaNotify(status: Int, seq: Int)
+    }
+
+    private var otaNotifyCallback: OtaNotifyCallback? = null
+
+    fun setOtaNotifyCallback(callback: OtaNotifyCallback?) {
+        otaNotifyCallback = callback
+    }
+
     init {
         instance = this
     }
@@ -330,6 +340,25 @@ class BleRelayManager(
                 handler.post { callbacks.onStatusChanged(BleStatus.CommError) }
             }
         }
+
+        @SuppressLint("MissingPermission")
+        override fun onCharacteristicChanged(
+            gatt: BluetoothGatt,
+            characteristic: BluetoothGattCharacteristic,
+            value: ByteArray
+        ) {
+            if (characteristic.uuid == OTA_UUID && value.size >= 1) {
+                val status = value[0].toInt() and 0xFF
+                val seq = if (value.size >= 5) {
+                    ((value[1].toInt() and 0xFF) shl 24) or
+                    ((value[2].toInt() and 0xFF) shl 16) or
+                    ((value[3].toInt() and 0xFF) shl 8) or
+                    (value[4].toInt() and 0xFF)
+                } else 0
+                Log.d(TAG, "OTA notify: status=$status seq=$seq")
+                handler.post { otaNotifyCallback?.onOtaNotify(status, seq) }
+            }
+        }
     }
 
     private fun loadState() {

android/app/src/main/java/nl/eddydevink/sylda/OtaManager.kt

@@ -1,13 +1,8 @@
 // SPDX-License-Identifier: GPL-3.0-or-later
 package nl.eddydevink.sylda
 
-import android.annotation.SuppressLint
-import android.bluetooth.BluetoothGatt
-import android.bluetooth.BluetoothGattCallback
-import android.bluetooth.BluetoothGattCharacteristic
 import android.content.Context
 import android.util.Log
-import kotlinx.coroutines.CompletableDeferred
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.delay
 import kotlinx.coroutines.ensureActive
@@ -25,12 +20,13 @@ class OtaManager(
         private const val TAG = "OtaManager"
         private const val OTA_CHUNK_DATA_SIZE = 248
         private const val OTA_CMD_START: Byte = 0x10
-        private const val OTA_CMD_END: Byte = 0x11
         private const val OTA_STATUS_ACK: Byte = 0x00
         private const val OTA_STATUS_COMPLETE: Byte = 0x10
         private const val OTA_STATUS_ERROR: Byte = 0x11
-        private const val OTA_CHUNK_TIMEOUT_MS = 5000L
         private const val OTA_START_TIMEOUT_MS = 10000L
+        private const val OTA_CHUNK_TIMEOUT_MS = 2000L
+        private const val OTA_FINAL_TIMEOUT_MS = 10000L
+        private const val MAX_RETRIES = 3
     }
 
     interface OtaCallback {
@@ -58,6 +54,22 @@ class OtaManager(
         }
 
         val sha256 = MessageDigest.getInstance("SHA-256").digest(fw)
+        var chunkAckReceived = false
+        var chunkNakReceived = false
+        var finalStatusReceived = false
+        var finalStatus = -1
+
+        val notifyCallback = object : BleRelayManager.OtaNotifyCallback {
+            override fun onOtaNotify(status: Int, seq: Int) {
+                when (status) {
+                    0x00 -> chunkAckReceived = true
+                    0x01 -> chunkNakReceived = true
+                    0x10 -> { finalStatusReceived = true; finalStatus = 0x10 }
+                    0x11 -> { finalStatusReceived = true; finalStatus = 0x11 }
+                }
+            }
+        }
+        relayManager.setOtaNotifyCallback(notifyCallback)
 
         try {
             withContext(Dispatchers.Main) { callback.onProgress(0, "OTA starten...") }
@@ -67,12 +79,11 @@ class OtaManager(
             startPacket.putInt(fw.size)
             relayManager.sendOtaData(startPacket.array())
 
+            try {
                 withTimeout(OTA_START_TIMEOUT_MS) {
                     while (true) { delay(100); ensureActive() }
                 }
-        } catch (e: kotlinx.coroutines.TimeoutCancellationException) {
+            } catch (_: kotlinx.coroutines.TimeoutCancellationException) {}
-            // timeout is expected — ESP doesn't ACK OTA_START, just begins
-        }
 
             val totalChunks = (fw.size + OTA_CHUNK_DATA_SIZE - 1) / OTA_CHUNK_DATA_SIZE
             var seq = 0
@@ -86,25 +97,79 @@ class OtaManager(
                 packet.putInt(seq)
                 packet.put(fw, offset, chunkSize)
 
-            relayManager.sendOtaData(packet.array())
+                chunkAckReceived = false
-            Log.d(TAG, "Sent chunk $seq ($chunkSize bytes)")
+                chunkNakReceived = false
+                var retries = 0
 
-            val pct = ((offset.toFloat() / fw.size.toFloat()) * 100).toInt().coerceAtMost(99)
+                while (retries < MAX_RETRIES) {
+                    relayManager.sendOtaData(packet.array())
+                    Log.d(TAG, "Sent chunk $seq/$totalChunks ($chunkSize bytes) attempt ${retries + 1}")
+
+                    try {
+                        withTimeout(OTA_CHUNK_TIMEOUT_MS) {
+                            while (!chunkAckReceived && !chunkNakReceived) {
+                                delay(50)
+                                ensureActive()
+                            }
+                        }
+                    } catch (_: kotlinx.coroutines.TimeoutCancellationException) {
+                        Log.w(TAG, "Timeout waiting for ACK/NAK on chunk $seq")
+                    }
+
+                    if (chunkAckReceived) break
+                    retries++
+                    Log.w(TAG, "Chunk $seq NAK/timeout, retry $retries/$MAX_RETRIES")
+                }
+
+                if (!chunkAckReceived) {
+                    relayManager.setOtaNotifyCallback(null)
+                    withContext(Dispatchers.Main) { callback.onError("OTA mislukt: chunk $seq geen ACK na $MAX_RETRIES pogingen") }
+                    return@withContext false
+                }
+
+                val pct = ((offset.toFloat() / fw.size.toFloat()) * 99).toInt().coerceAtMost(99)
                 withContext(Dispatchers.Main) {
                     callback.onProgress(pct, "OTA bezig: ${seq + 1}/$totalChunks")
                 }
 
                 offset += chunkSize
                 seq++
-            delay(50)
             }
 
             withContext(Dispatchers.Main) { callback.onProgress(99, "Hash verifiëren...") }
 
+            finalStatusReceived = false
             relayManager.sendOtaData(sha256)
 
-        withContext(Dispatchers.Main) { callback.onProgress(100, "Herstart...") }
+            try {
-        withContext(Dispatchers.Main) { callback.onComplete() }
+                withTimeout(OTA_FINAL_TIMEOUT_MS) {
+                    while (!finalStatusReceived) {
+                        delay(100)
+                        ensureActive()
+                    }
+                }
+            } catch (_: kotlinx.coroutines.TimeoutCancellationException) {
+                Log.w(TAG, "Timeout waiting for final OTA status")
+            }
+
+            relayManager.setOtaNotifyCallback(null)
+
+            if (finalStatus == 0x10) {
+                withContext(Dispatchers.Main) {
+                    callback.onProgress(100, "Herstart...")
+                    callback.onComplete()
+                }
                 true
+            } else {
+                withContext(Dispatchers.Main) {
+                    callback.onError("OTA mislukt: ESP SHA256 verificatie fout")
+                }
+                false
+            }
+        } catch (e: Exception) {
+            relayManager.setOtaNotifyCallback(null)
+            withContext(Dispatchers.Main) { callback.onError("OTA fout: ${e.message}") }
+            false
+        }
     }
 }