From 039f1c430abdc5f9fa492e07a375f6b0e5bcf2d1 Mon Sep 17 00:00:00 2001
From: rasputin <ra5pvt1n@proton.me>
Date: Fri, 5 Jun 2026 21:07:52 +0200
Subject: [PATCH] feat: cold start on scanning nfc tag

---
 app/src/main/AndroidManifest.xml              |  20 ++++
 .../bitcointxoko/gudariwallet/MainActivity.kt |  34 ++++--
 .../gudariwallet/ui/WalletScreen.kt           |   2 +-
 .../gudariwallet/ui/nfc/NfcViewModel.kt       | 105 ++++++++++++------
 4 files changed, 116 insertions(+), 45 deletions(-)

diff --git a/app/src/main/AndroidManifest.xml b/app/src/main/AndroidManifest.xml
index 368cc91..d8c9a30 100644
--- a/app/src/main/AndroidManifest.xml
+++ b/app/src/main/AndroidManifest.xml
@@ -44,6 +44,26 @@
                 <data android:scheme="lnurlc" />
                 <data android:scheme="lnurl" />
             </intent-filter>
+            <intent-filter>
+                <action android:name="android.nfc.action.NDEF_DISCOVERED" />
+                <category android:name="android.intent.category.DEFAULT" />
+                <data android:scheme="lightning" />
+            </intent-filter>
+            <intent-filter>
+                <action android:name="android.nfc.action.NDEF_DISCOVERED" />
+                <category android:name="android.intent.category.DEFAULT" />
+                <data android:scheme="lnurl" />
+            </intent-filter>
+            <intent-filter>
+                <action android:name="android.nfc.action.NDEF_DISCOVERED" />
+                <category android:name="android.intent.category.DEFAULT" />
+                <data android:scheme="bitcoin" />
+            </intent-filter>
+            <intent-filter>
+                <action android:name="android.nfc.action.NDEF_DISCOVERED" />
+                <category android:name="android.intent.category.DEFAULT" />
+                <data android:mimeType="text/plain" />
+            </intent-filter>
         </activity>
 
         <activity
diff --git a/app/src/main/java/com/bitcointxoko/gudariwallet/MainActivity.kt b/app/src/main/java/com/bitcointxoko/gudariwallet/MainActivity.kt
index f2300c3..6812cce 100644
--- a/app/src/main/java/com/bitcointxoko/gudariwallet/MainActivity.kt
+++ b/app/src/main/java/com/bitcointxoko/gudariwallet/MainActivity.kt
@@ -4,6 +4,7 @@ import android.Manifest
 import android.app.PendingIntent
 import android.content.ActivityNotFoundException
 import android.content.Intent
+import android.content.IntentFilter
 import android.nfc.NfcAdapter
 import android.nfc.Tag
 import android.os.Build
@@ -54,8 +55,12 @@ class MainActivity : AppCompatActivity() {
     private val nfcPendingIntent: PendingIntent by lazy {
         PendingIntent.getActivity(
             this, 0,
-            Intent(this, javaClass).addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP),
-            PendingIntent.FLAG_MUTABLE
+            Intent(this, javaClass).apply {
+                addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP)
+                // Do NOT add FLAG_ACTIVITY_NEW_TASK — this causes
+                // balDontBringExistingBackgroundTaskStackToFg = true
+            },
+            PendingIntent.FLAG_MUTABLE or PendingIntent.FLAG_UPDATE_CURRENT
         )
     }
 
@@ -102,6 +107,8 @@ class MainActivity : AppCompatActivity() {
         // Initialise NFC adapter (null on devices without NFC — handled gracefully)
         nfcAdapter = NfcAdapter.getDefaultAdapter(this)
 
+        nfcVm.onNfcIntent(intent)
+
         enableEdgeToEdge()
 
         setContent {
@@ -137,13 +144,18 @@ class MainActivity : AppCompatActivity() {
 
     override fun onResume() {
         super.onResume()
-        // Give this activity first pick of all NFC tag intents while foregrounded.
-        // Passing null for techLists and intentFilters means we intercept every tag type.
+        // Restrict to NDEF only — avoids TAG_DISCOVERED BAL blocks for non-NDEF tags
+        val intentFilters = arrayOf(
+            IntentFilter(NfcAdapter.ACTION_NDEF_DISCOVERED).also { f ->
+                try { f.addDataType("*/*") } catch (_: IntentFilter.MalformedMimeTypeException) {}
+            }
+        )
+        val techLists = arrayOf(arrayOf(android.nfc.tech.Ndef::class.java.name))
         nfcAdapter?.enableForegroundDispatch(
             this,
             nfcPendingIntent,
-            null,   // intercept all intent filters
-            null    // intercept all tech lists
+            intentFilters,
+            techLists
         )
     }
 
@@ -174,12 +186,20 @@ class MainActivity : AppCompatActivity() {
         }
 
         // NFC tag discovered → hand off to NfcViewModel for reading
-        val tag = intent.getParcelableExtra<Tag>(NfcAdapter.EXTRA_TAG)
+        val tag = intent.getNfcTag()
         if (tag != null) {
             nfcVm.onTagDiscovered(tag)
         }
     }
 
+    private fun Intent.getNfcTag(): Tag? =
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU) {
+            getParcelableExtra(NfcAdapter.EXTRA_TAG, Tag::class.java)
+        } else {
+            @Suppress("DEPRECATION")
+            getParcelableExtra(NfcAdapter.EXTRA_TAG)
+        }
+
     // ── Permission / battery helpers (unchanged) ──────────────────────────────
 
     private fun requestNotificationPermissionIfNeeded() {
diff --git a/app/src/main/java/com/bitcointxoko/gudariwallet/ui/WalletScreen.kt b/app/src/main/java/com/bitcointxoko/gudariwallet/ui/WalletScreen.kt
index a63406c..7a569cf 100644
--- a/app/src/main/java/com/bitcointxoko/gudariwallet/ui/WalletScreen.kt
+++ b/app/src/main/java/com/bitcointxoko/gudariwallet/ui/WalletScreen.kt
@@ -473,8 +473,8 @@ fun WalletScreen(
                         modifier = Modifier
                             .fillMaxWidth()
                             .clickable {
-                                nfcVm.dismissNfcOffer()
                                 vm.scan(offer.raw)
+                                nfcVm.dismissNfcOffer()
                                 navController.navigate(TabItem.Send.route) {
                                     launchSingleTop = true
                                 }
diff --git a/app/src/main/java/com/bitcointxoko/gudariwallet/ui/nfc/NfcViewModel.kt b/app/src/main/java/com/bitcointxoko/gudariwallet/ui/nfc/NfcViewModel.kt
index 3ed09f8..ead6782 100644
--- a/app/src/main/java/com/bitcointxoko/gudariwallet/ui/nfc/NfcViewModel.kt
+++ b/app/src/main/java/com/bitcointxoko/gudariwallet/ui/nfc/NfcViewModel.kt
@@ -1,22 +1,23 @@
 package com.bitcointxoko.gudariwallet.ui.nfc
 
-import android.content.ComponentName
-import android.content.Context
-import android.nfc.NfcAdapter
+import android.content.Intent
 import android.nfc.NdefMessage
 import android.nfc.NdefRecord
+import android.nfc.NfcAdapter
 import android.nfc.Tag
 import android.nfc.tech.IsoDep
 import android.nfc.tech.Ndef
-import android.nfc.tech.NdefFormatable
+import android.os.Build
 import android.util.Log
 import androidx.lifecycle.ViewModel
-import com.bitcointxoko.gudariwallet.ui.nfc.NdefHceService
+import androidx.lifecycle.viewModelScope
 import com.bitcointxoko.gudariwallet.ui.NfcOfferState
 import com.bitcointxoko.gudariwallet.util.SendInputDetector
 import com.bitcointxoko.gudariwallet.util.SendInputType
+import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.launch
 
 private const val TAG = "NfcViewModel"
 
@@ -62,50 +63,80 @@ class NfcViewModel : ViewModel() {
      * recognisable payment URI.
      */
     fun onTagDiscovered(tag: Tag) {
-        Log.d(TAG, "onTagDiscovered: ${tag.id?.toHex()}")
-
-        val text = readNdefText(tag) ?: run {
-            Log.w(TAG, "Could not read NDEF from tag")
-            return
+        Log.d(TAG, "onTagDiscovered: ${tag.id.joinToString("") { "%02X".format(it) }}")
+        viewModelScope.launch(Dispatchers.IO) {   // ← move to IO thread
+            readNdefText(tag)
         }
-
-        Log.d(TAG, "Tag NDEF text: $text")
-        val trimmed = text.trim()
-        val type = SendInputDetector.detect(trimmed)
-        if (type == SendInputType.Unknown) {
-            Log.d(TAG, "Tag content not a recognised payment URI")
-            return
-        }
-
-        _nfcOfferState.value = NfcOfferState.Detected(raw = trimmed, inputType = type)
     }
 
+    /** Cold-start path: Android already parsed the NDEF message into the intent.
+     *  No tag connection needed — avoids "Tag is out of date" SecurityException. */
+    fun onNfcIntent(intent: Intent) {
+        if (intent.action != NfcAdapter.ACTION_NDEF_DISCOVERED &&
+            intent.action != NfcAdapter.ACTION_TAG_DISCOVERED) return
+
+        // Android attaches the parsed NDEF messages directly to the intent
+        val rawMessages = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU) {
+            intent.getParcelableArrayExtra(NfcAdapter.EXTRA_NDEF_MESSAGES, NdefMessage::class.java)
+        } else {
+            @Suppress("DEPRECATION")
+            intent.getParcelableArrayExtra(NfcAdapter.EXTRA_NDEF_MESSAGES)
+        }
+
+        if (rawMessages != null && rawMessages.isNotEmpty()) {
+            val message = rawMessages[0] as NdefMessage
+            val uri = extractUri(message)
+            if (uri != null) {
+                Log.d(TAG, "onNfcIntent (cold-start): uri=$uri")
+                _nfcOfferState.value = NfcOfferState.Detected(uri, SendInputDetector.detect(uri))
+                return
+            }
+        }
+
+        // Fallback: no NDEF messages in intent, try connecting to tag
+        val tag = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU) {
+            intent.getParcelableExtra(NfcAdapter.EXTRA_TAG, Tag::class.java)
+        } else {
+            @Suppress("DEPRECATION")
+            intent.getParcelableExtra<Tag>(NfcAdapter.EXTRA_TAG)
+        }
+        if (tag != null) {
+            viewModelScope.launch(Dispatchers.IO) {
+                readNdefText(tag)
+            }
+        }
+    }
+
+
     fun dismissNfcOffer() {
         _nfcOfferState.value = NfcOfferState.None
     }
 
     // ── NDEF reading ─────────────────────────────────────────────────────────
 
-    private fun readNdefText(tag: Tag): String? {
-        // Try standard NDEF first (covers Type 1–5 tags, NTAG21x, etc.)
-        Ndef.get(tag)?.use { ndef ->
-            ndef.connect()
-            val msg = ndef.ndefMessage ?: ndef.cachedNdefMessage ?: return null
-            return extractUri(msg)
+    private fun readNdefText(tag: Tag) {
+        val uri = try {
+            Ndef.get(tag)?.use { ndef ->
+                ndef.connect()
+                val msg = ndef.ndefMessage ?: ndef.cachedNdefMessage ?: return
+                extractUri(msg)
+            } ?: IsoDep.get(tag)?.use { isoDep ->
+                isoDep.connect()
+                isoDep.timeout = 3000
+                val msg = readNdefFromIsoDep(isoDep) ?: return
+                extractUri(msg)
+            }
+        } catch (e: Exception) {
+            Log.e(TAG, "readNdefText error: ${e.message}")
+            null
         }
-
-        // Try NdefFormatable (blank tags — nothing to read)
-        // Try IsoDep last (Type 4 / ISO-DEP tags like Bolt Cards)
-        IsoDep.get(tag)?.use { isoDep ->
-            isoDep.connect()
-            isoDep.timeout = 3000
-            val msg = readNdefFromIsoDep(isoDep) ?: return null
-            return extractUri(msg)
+        if (uri != null) {
+            Log.d(TAG, "readNdefText: uri=$uri")
+            _nfcOfferState.value = NfcOfferState.Detected(uri, SendInputDetector.detect(uri))
+        } else {
+            Log.w(TAG, "readNdefText: no URI found in tag")
         }
-
-        return null
     }
-
     /**
      * Reads an NDEF message from an ISO-DEP (Type 4) tag by replaying the
      * same APDU sequence our HCE service responds to.