feat(install): blacklist packages, and fix the dead VirusTotal button

## Blacklist (#101 parity — InstallerX has this, we did not)

Packages the user chooses never to install. Deliberately not an
InstallRisk: a risk warns and lets you push past it, and a blacklist you
can click through is not a blacklist. The gate lives inside
confirmInstall — the single funnel every install path reaches, so a new
entry point cannot bypass it — and reads a hot StateFlow rather than
DataStore, because that runs on the main thread.

Surfaced everywhere the state matters, which was the gap in the first
attempt:
- Manage: a Blocked badge on the row, in error colours next to the
  neutral System/Split badges, plus a Blocked filter chip. The chips
  generate from AppFilter.entries so the enum entry was enough.
- Install sheet and install dialog: a banner above the footer with the
  Install button disabled, and Unblock right there. Learning something
  is blocked happens when you try to install it; making the user hunt
  through Settings to undo it is the wrong shape.
- Settings → Blocked packages: its own screen, not a collapsed section
  buried between Sync and Advanced. Review-and-remove only — no text
  field, because nobody types com.example.app from memory and a typo
  silently blocks nothing. Adding happens in Manage where the user can
  see what they are blocking.

Blocking is a toggle, so the same row unblocks.

## VirusTotal button did nothing without a key

The VirusTotal card lives inside ApkInfoContent's scroll area, which
only exists when the sheet is expanded. Tapping Scan from the compact
sheet set the state and rendered the result into a composable that was
not on screen — no key, no result, no error, just a dead button.

The button now expands the sheet first. And rather than only reporting
"no API key", both the sheet and the dialog offer the fix: Add API key
opens Settings, Get a free key opens virustotal.com.

Verified on device: the dialog's VirusTotal row shows the no-key message
and opens Settings when tapped.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

Author: nqmgaming

app/src/main/AndroidManifest.xml

@@ -215,6 +215,10 @@
             android:name=".presentation.setting.help.HelpActivity"
             android:exported="false"
             android:theme="@style/Theme.UniversalInstaller" />
+        <activity
+            android:name=".presentation.setting.blacklist.BlacklistActivity"
+            android:exported="false"
+            android:theme="@style/Theme.UniversalInstaller" />
 
         <provider
             android:name="rikka.shizuku.ShizukuProvider"

app/src/main/java/app/pwhs/universalinstaller/domain/manager/InstallBlacklist.kt

@@ -0,0 +1,38 @@
+package app.pwhs.universalinstaller.domain.manager
+
+import androidx.datastore.preferences.core.Preferences
+import androidx.datastore.preferences.core.stringSetPreferencesKey
+
+/**
+ * Package names the user has chosen never to install.
+ *
+ * Deliberately *not* modelled as an [app.pwhs.universalinstaller.presentation.install.dialog.InstallRisk].
+ * A risk is something you warn about and let the user push past — the risk dialog's whole shape is
+ * "here is the problem, Install anyway". A blacklist that can be clicked through is not a
+ * blacklist. This blocks the install outright and the only way forward is to remove the entry.
+ *
+ * The store is a plain `Set<String>` in DataStore rather than a Room table: it is a handful of
+ * package names, read on every install, and a table would mean a migration for no benefit.
+ */
+object InstallBlacklist {
+
+    val KEY: Preferences.Key<Set<String>> = stringSetPreferencesKey("install_blacklist")
+
+    fun read(prefs: Preferences?): Set<String> = prefs?.get(KEY).orEmpty()
+
+    /**
+     * True when [packageName] is blocked.
+     *
+     * Blank package names never match. An APK we failed to parse reports its package as blank or
+     * "Unknown", and blocking every unparseable file because the blacklist happens to be non-empty
+     * would be a nasty surprise.
+     */
+    fun isBlocked(prefs: Preferences?, packageName: String): Boolean =
+        packageName.isNotBlank() && packageName in read(prefs)
+
+    fun add(current: Set<String>, packageName: String): Set<String> =
+        if (packageName.isBlank()) current else current + packageName.trim()
+
+    fun remove(current: Set<String>, packageName: String): Set<String> =
+        current - packageName
+}

app/src/main/java/app/pwhs/universalinstaller/domain/model/ApkInfo.kt

@@ -40,4 +40,6 @@ data class ApkInfo(
      * a mismatch. See [app.pwhs.universalinstaller.util.SignatureCheck].
      */
     val signatureMismatch: Boolean? = null,
+    /** The user put this package on the never-install list; the Install button is disabled. */
+    val isBlocked: Boolean = false,
 )

app/src/main/java/app/pwhs/universalinstaller/presentation/install/ApkInfoContent.kt

@@ -27,6 +27,7 @@ import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.automirrored.rounded.OpenInNew
 import androidx.compose.material.icons.rounded.Android
 import androidx.compose.material.icons.rounded.Badge
+import androidx.compose.material.icons.rounded.Block
 import androidx.compose.material.icons.rounded.CheckCircle
 import androidx.compose.material.icons.rounded.CloudUpload
 import androidx.compose.material.icons.rounded.Delete
@@ -139,6 +140,7 @@ internal fun ApkInfoContent(
     onToggleAllUsers: (Boolean) -> Unit = {},
     onSelectUserId: (Int?) -> Unit = {},
     startCompact: Boolean = true,
+    onUnblock: (String) -> Unit = {},
 ) {
     val context = LocalContext.current
     val currentMappingProfileId = appProfileMapping[apkInfo.packageName]
@@ -332,6 +334,15 @@ internal fun ApkInfoContent(
                 fileSizeBytes = apkInfo.fileSizeBytes, 
                 sha256 = apkInfo.sha256, 
                 onCheck = onCheckVirusTotal,
+                onOpenSettings = {
+                    context.startActivity(
+                        android.content.Intent(
+                            context,
+                            app.pwhs.universalinstaller.presentation.setting.SettingActivity::class.java,
+                        )
+                    )
+                },
+                onGetKey = { uriHandler.openUri("https://www.virustotal.com/gui/my-apikey") },
                 onOpenLink = {
                     if (apkInfo.vtResult?.status in setOf(VtStatus.CLEAN, VtStatus.MALICIOUS, VtStatus.SUSPICIOUS) && apkInfo.sha256.isNotBlank()) {
                         uriHandler.openUri("https://www.virustotal.com/gui/file/${apkInfo.sha256}/detection")
@@ -347,6 +358,40 @@ internal fun ApkInfoContent(
         Spacer(Modifier.height(16.dp))
       } // end scroll area
 
+        // Blocked banner sits above the footer, not in the scroll area: the Install button below
+        // is disabled and the user needs to see why without scrolling back up.
+        if (apkInfo.isBlocked) {
+            Surface(
+                color = MaterialTheme.colorScheme.errorContainer,
+                modifier = Modifier.fillMaxWidth(),
+            ) {
+                Row(
+                    modifier = Modifier.padding(horizontal = 20.dp, vertical = 12.dp),
+                    verticalAlignment = Alignment.CenterVertically,
+                ) {
+                    Icon(
+                        Icons.Rounded.Block,
+                        contentDescription = null,
+                        tint = MaterialTheme.colorScheme.onErrorContainer,
+                        modifier = Modifier.size(18.dp),
+                    )
+                    Spacer(Modifier.width(10.dp))
+                    Text(
+                        text = stringResource(R.string.install_blocked_banner),
+                        style = MaterialTheme.typography.bodySmall,
+                        color = MaterialTheme.colorScheme.onErrorContainer,
+                        modifier = Modifier.weight(1f),
+                    )
+                    TextButton(onClick = { onUnblock(apkInfo.packageName) }) {
+                        Text(
+                            stringResource(R.string.install_blocked_unblock),
+                            color = MaterialTheme.colorScheme.onErrorContainer,
+                        )
+                    }
+                }
+            }
+        }
+
         // Fixed footer — sits outside the scroll so the action row is always on screen.
         // A hairline divider hints there's scrollable content above it when expanded.
         if (isExpanded) {
@@ -387,6 +432,7 @@ internal fun ApkInfoContent(
                         onClick = onInstall,
                         modifier = Modifier.weight(1f),
                         shape = MaterialTheme.shapes.medium,
+                        enabled = !apkInfo.isBlocked,
                         colors = if (isDowngrade) ButtonDefaults.buttonColors(containerColor = MaterialTheme.colorScheme.error) else ButtonDefaults.buttonColors()
                     ) {
                         if (confirmText == null) {
@@ -397,7 +443,14 @@ internal fun ApkInfoContent(
                     }
                 } else {
                     Button(
-                        onClick = onCheckVirusTotal,
+                        onClick = {
+                            // The VirusTotal card lives inside the scroll area, which only exists
+                            // when expanded. Tapping this from the compact sheet used to change
+                            // state with nothing on screen to show it — no key, no result, no
+                            // error, just a dead button. Expand first so the outcome is visible.
+                            if (!isExpanded) isExpanded = true
+                            onCheckVirusTotal()
+                        },
                         modifier = Modifier.weight(1f),
                         shape = MaterialTheme.shapes.medium,
                         enabled = !isScanning
@@ -418,7 +471,8 @@ internal fun ApkInfoContent(
             if (!isScanCompleted) {
                 TextButton(
                     onClick = onInstall,
-                    modifier = Modifier.fillMaxWidth()
+                    modifier = Modifier.fillMaxWidth(),
+                    enabled = !apkInfo.isBlocked,
                 ) {
                     Text(stringResource(R.string.skip_and_install_btn))
                 }
@@ -530,7 +584,15 @@ private fun AbisCard(abis: List<String>) {
 
 @OptIn(ExperimentalMaterial3Api::class)
 @Composable
-private fun VirusTotalCard(vt: VtResult?, fileSizeBytes: Long, sha256: String = "", onCheck: () -> Unit, onOpenLink: () -> Unit = {}) {
+private fun VirusTotalCard(
+    vt: VtResult?,
+    fileSizeBytes: Long,
+    sha256: String = "",
+    onCheck: () -> Unit,
+    onOpenSettings: () -> Unit = {},
+    onGetKey: () -> Unit = {},
+    onOpenLink: () -> Unit = {},
+) {
     val extendedColors = LocalExtendedColors.current
     val status = vt?.status
     val inProgress = status == VtStatus.SCANNING || status == VtStatus.UPLOADING || status == VtStatus.QUEUED || status == VtStatus.ANALYZING
@@ -574,6 +636,32 @@ private fun VirusTotalCard(vt: VtResult?, fileSizeBytes: Long, sha256: String =
                 Spacer(Modifier.height(12.dp))
                 VtBreakdownSection(vt = vt, warningColor = extendedColors.warning)
             }
+            // Telling someone their key is missing is only half an answer — the fix is two
+            // screens away and they are mid-install. Offer both steps here.
+            if (status == VtStatus.NO_API_KEY) {
+                Spacer(Modifier.height(8.dp))
+                Row(horizontalArrangement = Arrangement.spacedBy(8.dp)) {
+                    FilledTonalButton(
+                        onClick = onOpenSettings,
+                        shape = MaterialTheme.shapes.medium,
+                        contentPadding = PaddingValues(horizontal = 12.dp, vertical = 6.dp),
+                    ) {
+                        Text(
+                            stringResource(R.string.apk_info_vt_add_key),
+                            style = MaterialTheme.typography.labelMedium,
+                        )
+                    }
+                    TextButton(
+                        onClick = onGetKey,
+                        contentPadding = PaddingValues(horizontal = 12.dp, vertical = 6.dp),
+                    ) {
+                        Text(
+                            stringResource(R.string.apk_info_vt_get_key),
+                            style = MaterialTheme.typography.labelMedium,
+                        )
+                    }
+                }
+            }
         }
     }
 }

app/src/main/java/app/pwhs/universalinstaller/presentation/install/DialogInstallActivity.kt

@@ -401,6 +401,7 @@ class DialogInstallActivity : ComponentActivity() {
                                 finish()
                             },
                             onMenu = viewModel::dialogShowMenu,
+                            onUnblock = viewModel::unblockPackage,
                             onMenuBack = viewModel::dialogBackToPrepare,
                             onCheckVirusTotal = {
                                 viewModel.scanVirusTotal(this@DialogInstallActivity)

app/src/main/java/app/pwhs/universalinstaller/presentation/install/InstallScreen.kt

@@ -178,6 +178,7 @@ fun InstallScreen(
         onCancel = viewModel::cancelSession,
         onRetry = viewModel::retrySession,
         onDismissSession = viewModel::dismissSession,
+        onUnblock = viewModel::unblockPackage,
         onClearHistory = viewModel::clearHistory,
         onCheckVirusTotal = { viewModel.scanVirusTotal(context) },
         onStartDeviceScan = { viewModel.startDeviceScan(context) },
@@ -249,6 +250,7 @@ private fun InstallUi(
     onCancel: (java.util.UUID) -> Unit = {},
     onRetry: (java.util.UUID) -> Unit = {},
     onDismissSession: (java.util.UUID) -> Unit = {},
+    onUnblock: (String) -> Unit = {},
     onClearHistory: () -> Unit = {},
     onCheckVirusTotal: () -> Unit = {},
     onStartDeviceScan: () -> Unit = {},
@@ -490,6 +492,7 @@ private fun InstallUi(
                 onToggleAllUsers = onToggleAllUsers,
                 onSelectUserId = onSelectUserId,
                 startCompact = true,
+                onUnblock = onUnblock,
             )
         }
     }

app/src/main/java/app/pwhs/universalinstaller/presentation/install/InstallViewModel.kt

@@ -39,6 +39,7 @@ import androidx.work.WorkManager
 import app.pwhs.universalinstaller.presentation.install.dialog.isDowngrade
 import app.pwhs.universalinstaller.util.DhizukuCompat
 import app.pwhs.universalinstaller.presentation.install.controller.DhizukuInstallController
+import app.pwhs.universalinstaller.domain.manager.InstallBlacklist
 import app.pwhs.universalinstaller.util.SignatureCheck
 import app.pwhs.universalinstaller.presentation.setting.PreferencesKeys
 import app.pwhs.core.util.RootShell
@@ -48,6 +49,7 @@ import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.Job
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.SharingStarted
+import kotlinx.coroutines.flow.catch
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.asStateFlow
 import kotlinx.coroutines.flow.combine
@@ -119,6 +121,18 @@ class InstallViewModel(
     private val _batchDetailUri = MutableStateFlow<android.net.Uri?>(null)
     private val _dialogStage = MutableStateFlow<DialogStage>(DialogStage.None)
     private val _mergeSplits = MutableStateFlow(false)
+    /**
+     * Blocked package names, kept hot so [confirmInstall] can check them without suspending.
+     * Empty on a read failure — failing open beats making every install impossible.
+     */
+    private val blacklist: StateFlow<Set<String>> = application.dataStore.data
+        .map { InstallBlacklist.read(it) }
+        .catch { e ->
+            Timber.w(e, "Could not read the install blacklist")
+            emit(emptySet())
+        }
+        .stateIn(viewModelScope, SharingStarted.Eagerly, emptySet())
+
     private val _selectedProfileId = MutableStateFlow<String?>(null)
 
     /**
@@ -404,6 +418,21 @@ class InstallViewModel(
             ).show()
             return
         }
+        // Blacklist gate. Deliberately inside confirmInstall rather than at each caller: this is
+        // the single funnel every install path reaches, so a new entry point cannot bypass it.
+        // Reads the cached set, not DataStore — this runs on the main thread.
+        val blockedPackage = apkInfo?.packageName.orEmpty()
+        if (blockedPackage.isNotBlank() && blockedPackage in blacklist.value) {
+            Timber.w("Install of $blockedPackage blocked by the user's blacklist")
+            android.widget.Toast.makeText(
+                application,
+                application.getString(R.string.install_blocked_by_blacklist, blockedPackage),
+                android.widget.Toast.LENGTH_LONG,
+            ).show()
+            dismissPendingInstall()
+            return
+        }
+
         val fn = pendingFileName ?: return
         val originalUri = pendingOriginalUri
         val obbEntries = pendingObbEntries
@@ -1547,6 +1576,24 @@ class InstallViewModel(
         }
     }
 
+    /**
+     * Take a package off the never-install list from the install screen itself.
+     *
+     * Reachable here as well as in Settings on purpose: the moment the user learns something is
+     * blocked is when they try to install it, and making them hunt through Settings to undo a
+     * decision they are questioning right now is the wrong shape.
+     */
+    fun unblockPackage(packageName: String) {
+        if (packageName.isBlank()) return
+        viewModelScope.launch {
+            application.dataStore.edit { p ->
+                p[InstallBlacklist.KEY] = InstallBlacklist.remove(InstallBlacklist.read(p), packageName)
+            }
+            // Repaint the sheet that is on screen right now.
+            _pendingApkInfo.value = _pendingApkInfo.value?.copy(isBlocked = false)
+        }
+    }
+
     fun dismissSession(id: UUID) {
         viewModelScope.launch {
             activeController().dismiss(id)
@@ -2131,6 +2178,7 @@ class InstallViewModel(
             supportedAbis = supportedAbis.distinct(),
             splitEntries = splitEntries,
             signatureMismatch = signatureMismatch,
+            isBlocked = ackpinePackageName in blacklist.value,
         )
     }
 

app/src/main/java/app/pwhs/universalinstaller/presentation/install/dialog/DialogGenerator.kt

@@ -40,6 +40,7 @@ fun generateDialogParams(
     onInstall: () -> Unit,
     onCancel: () -> Unit,
     onMenu: () -> Unit,
+    onUnblock: (String) -> Unit = {},
     onMenuBack: () -> Unit,
     onCheckVirusTotal: () -> Unit,
     onRemoveObb: (AttachedObb) -> Unit,
@@ -122,6 +123,7 @@ fun generateDialogParams(
                             onInstall = onInstall,
                             onMenu = onMenu,
                             onCancel = onCancel,
+                            onUnblock = onUnblock,
                         )
                     }
                 )

app/src/main/java/app/pwhs/universalinstaller/presentation/install/dialog/DialogMenuContent.kt

@@ -565,12 +565,23 @@ private fun androidx.compose.foundation.lazy.LazyListScope.securityTab(
                 )
             },
             onClick = {
-                if (vtResult?.status in listOf(VtStatus.CLEAN, VtStatus.MALICIOUS, VtStatus.SUSPICIOUS)) {
-                    if (apkInfo.sha256.isNotBlank()) {
-                        uriHandler.openUri("https://www.virustotal.com/gui/file/${apkInfo.sha256}/detection")
+                when {
+                    vtResult?.status in listOf(VtStatus.CLEAN, VtStatus.MALICIOUS, VtStatus.SUSPICIOUS) -> {
+                        if (apkInfo.sha256.isNotBlank()) {
+                            uriHandler.openUri("https://www.virustotal.com/gui/file/${apkInfo.sha256}/detection")
+                        }
+                    }
+                    // Without a key, tapping Check only rewrites the same "no key" line the user
+                    // is already reading. Send them where the key is entered instead.
+                    vtResult?.status == VtStatus.NO_API_KEY -> {
+                        context.startActivity(
+                            android.content.Intent(
+                                context,
+                                app.pwhs.universalinstaller.presentation.setting.SettingActivity::class.java,
+                            ).addFlags(android.content.Intent.FLAG_ACTIVITY_NEW_TASK)
+                        )
                     }
-                } else {
-                    onCheckVirusTotal()
+                    else -> onCheckVirusTotal()
                 }
             },
         )