feat(app): add the Compose PGP keys screen

One screen for managing keys, choosing the key of a new local store
and importing the key a store needs. Rows show user ID and key ID;
the import keeps the old success, replace and failure dialogs.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

3 files changed, 337 insertions, 0 deletions

diff --git a/app/src/main/java/app/passwordstore/ui/setup/PgpKeysScreen.kt b/app/src/main/java/app/passwordstore/ui/setup/PgpKeysScreen.kt
new file mode 100644
index 00000000..2f060f56
--- /dev/null
+++ b/app/src/main/java/app/passwordstore/ui/setup/PgpKeysScreen.kt
@@ -0,0 +1,331 @@
+/*
+ * Copyright (C) 2026 Danilo M. <danix@danix.xyz>
+ * SPDX-License-Identifier: GPL-3.0-only
+ */
+
+package app.passwordstore.ui.setup
+
+import androidx.activity.compose.BackHandler
+import androidx.activity.compose.rememberLauncherForActivityResult
+import androidx.activity.result.contract.ActivityResultContracts.OpenDocument
+import androidx.compose.foundation.clickable
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.rememberScrollState
+import androidx.compose.foundation.verticalScroll
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.automirrored.filled.ArrowBack
+import androidx.compose.material.icons.filled.Add
+import androidx.compose.material.icons.filled.Delete
+import androidx.compose.material3.ExperimentalMaterial3Api
+import androidx.compose.material3.ExtendedFloatingActionButton
+import androidx.compose.material3.Icon
+import androidx.compose.material3.IconButton
+import androidx.compose.material3.LinearProgressIndicator
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Scaffold
+import androidx.compose.material3.Text
+import androidx.compose.material3.TextButton
+import androidx.compose.material3.TopAppBar
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.text.font.FontFamily
+import androidx.compose.ui.text.style.TextOverflow
+import androidx.compose.ui.unit.dp
+import androidx.hilt.navigation.compose.hiltViewModel
+import androidx.lifecycle.lifecycleScope
+import app.passwordstore.R
+import app.passwordstore.data.repo.PasswordRepository
+import app.passwordstore.ui.compose.GroupedSurface
+import app.passwordstore.ui.compose.theme.SpacingLarge
+import app.passwordstore.ui.compose.theme.SpacingMedium
+import app.passwordstore.ui.main.MainActivity
+import app.passwordstore.util.extensions.commitChange
+import app.passwordstore.util.extensions.snackbar
+import com.github.michaelbull.result.onFailure
+import com.google.android.material.snackbar.Snackbar
+import kotlinx.collections.immutable.ImmutableList
+import kotlinx.coroutines.launch
+import kotlinx.serialization.Serializable
+
+/** What the PGP keys screen is for. */
+@Serializable
+enum class KeysMode {
+  /** Import and delete keys (Settings). */
+  Manage,
+  /** Pick the key a new local store is encrypted for. */
+  Choose,
+  /** A key is needed (after a clone, or by an entry): import it, or go on without. */
+  Need,
+}
+
+/**
+ * The imported [keys] with the import FAB. [mode] decides what a row does (select in
+ * [KeysMode.Choose], delete in [KeysMode.Manage]) and the guidance shown; [recipients] are the
+ * store's `.gpg-id` entries, listed in [KeysMode.Need].
+ */
+@OptIn(ExperimentalMaterial3Api::class)
+@Composable
+fun PgpKeysScreen(
+  mode: KeysMode,
+  keys: ImmutableList<KeyRow>,
+  recipients: ImmutableList<String>,
+  busy: Boolean,
+  onImport: () -> Unit,
+  onSelect: (KeyRow) -> Unit,
+  onDelete: (KeyRow) -> Unit,
+  onLater: () -> Unit,
+  onBack: () -> Unit,
+  modifier: Modifier = Modifier,
+) {
+  var deleting by remember { mutableStateOf<KeyRow?>(null) }
+  Scaffold(
+    modifier = modifier,
+    topBar = {
+      TopAppBar(
+        title = {
+          Text(
+            stringResource(
+              when (mode) {
+                KeysMode.Manage -> R.string.activity_label_pgp_key_manager
+                KeysMode.Choose -> R.string.gpg_key_select
+                KeysMode.Need -> R.string.pref_import_pgp_key_title
+              }
+            )
+          )
+        },
+        navigationIcon = {
+          IconButton(onClick = onBack) {
+            Icon(Icons.AutoMirrored.Filled.ArrowBack, stringResource(R.string.entry_back))
+          }
+        },
+        actions = {
+          if (mode == KeysMode.Need)
+            TextButton(onClick = onLater) { Text(stringResource(R.string.ssh_keygen_later)) }
+        },
+      )
+    },
+    floatingActionButton = {
+      // M3 clears the label's semantics; the FAB takes its description from the icon.
+      ExtendedFloatingActionButton(
+        text = { Text(stringResource(R.string.pref_import_pgp_key_title)) },
+        icon = { Icon(Icons.Filled.Add, stringResource(R.string.pref_import_pgp_key_title)) },
+        onClick = { if (!busy) onImport() },
+      )
+    },
+  ) { padding ->
+    Column(Modifier.padding(padding).fillMaxSize().verticalScroll(rememberScrollState())) {
+      if (busy) LinearProgressIndicator(Modifier.fillMaxWidth())
+      val message =
+        when (mode) {
+          KeysMode.Manage -> null
+          KeysMode.Choose -> R.string.select_gpg_key_message
+          KeysMode.Need -> R.string.pgp_key_needed_message
+        }
+      if (message != null)
+        Text(
+          stringResource(message),
+          Modifier.padding(SpacingLarge),
+          style = MaterialTheme.typography.bodyLarge,
+        )
+      if (mode == KeysMode.Need && recipients.isNotEmpty())
+        GroupedSurface {
+          Column(Modifier.padding(SpacingLarge)) {
+            Text(
+              stringResource(R.string.pgp_key_needed_recipients),
+              style = MaterialTheme.typography.labelMedium,
+              color = MaterialTheme.colorScheme.onSurfaceVariant,
+            )
+            recipients.forEach { Text(it, fontFamily = FontFamily.Monospace) }
+          }
+        }
+      if (keys.isEmpty())
+        Text(
+          stringResource(R.string.pgp_key_manager_no_keys_guidance),
+          Modifier.padding(SpacingLarge),
+          color = MaterialTheme.colorScheme.onSurfaceVariant,
+        )
+      else
+        GroupedSurface {
+          keys.forEach { row ->
+            KeyItem(row = row, mode = mode, onSelect = onSelect, onDelete = { deleting = row })
+          }
+        }
+      // Room for the FAB below the last row.
+      Spacer(Modifier.height(88.dp))
+    }
+  }
+  deleting?.let { row ->
+    SetupDialog(
+      title = stringResource(R.string.pgp_key_manager_delete_confirmation_dialog_title),
+      text = row.userId ?: row.keyId.toString(),
+      confirm = stringResource(R.string.dialog_yes),
+      onConfirm = {
+        deleting = null
+        onDelete(row)
+      },
+      onDismiss = { deleting = null },
+      dismiss = stringResource(R.string.dialog_no),
+    )
+  }
+}
+
+@Composable
+private fun KeyItem(
+  row: KeyRow,
+  mode: KeysMode,
+  onSelect: (KeyRow) -> Unit,
+  onDelete: () -> Unit,
+  modifier: Modifier = Modifier,
+) {
+  Row(
+    modifier
+      .fillMaxWidth()
+      .then(if (mode == KeysMode.Choose) Modifier.clickable { onSelect(row) } else Modifier)
+      .padding(horizontal = SpacingLarge, vertical = SpacingMedium),
+    verticalAlignment = Alignment.CenterVertically,
+  ) {
+    Column(Modifier.weight(1f)) {
+      Text(
+        row.userId ?: row.keyId.toString(),
+        style = MaterialTheme.typography.bodyLarge,
+        maxLines = 1,
+        overflow = TextOverflow.Ellipsis,
+      )
+      if (row.userId != null)
+        Text(
+          row.keyId.toString(),
+          style = MaterialTheme.typography.bodySmall,
+          fontFamily = FontFamily.Monospace,
+          color = MaterialTheme.colorScheme.onSurfaceVariant,
+        )
+    }
+    if (mode == KeysMode.Manage)
+      IconButton(onClick = onDelete) { Icon(Icons.Filled.Delete, stringResource(R.string.delete)) }
+  }
+}
+
+/**
+ * The PGP keys screen: wires [PgpKeysScreen] to the [viewModel], the document picker and the import
+ * dialogs. [onImported] runs after every successful import; [onDone] ends the flow: after an
+ * import, "Later" or back in [KeysMode.Need], after the new store is created in [KeysMode.Choose].
+ * [onClose] leaves the other modes.
+ */
+@Composable
+fun PgpKeysDestination(
+  activity: MainActivity,
+  mode: KeysMode,
+  onClose: () -> Unit,
+  onDone: () -> Unit,
+  onImported: () -> Unit,
+  modifier: Modifier = Modifier,
+  viewModel: PgpKeysViewModel = hiltViewModel(),
+) {
+  val root = PasswordRepository.getRepositoryDirectory()
+  // Read off the main thread, symlink- and size-checked (readGpgId).
+  LaunchedEffect(mode) { if (mode == KeysMode.Need) viewModel.loadRecipients(root) }
+  // A created store moves on from here, also when the screen was recreated in between.
+  val done = viewModel.done
+  LaunchedEffect(done) { if (done) onDone() }
+
+  fun leave() {
+    if (viewModel.busy) return
+    if (mode == KeysMode.Need) onDone() else onClose()
+  }
+  BackHandler(onBack = ::leave)
+
+  val picker =
+    rememberLauncherForActivityResult(OpenDocument()) { uri ->
+      if (uri != null) viewModel.import(uri, activity)
+    }
+
+  // ponytail: a theme or locale change in the middle cancels the commit; the next commit picks up
+  // the new `.gpg-id`, and choosing the key again re-creates nothing that would conflict.
+  fun choose(row: KeyRow) {
+    if (viewModel.busy) return
+    viewModel.busy = true
+    activity.lifecycleScope.launch {
+      try {
+        val error = viewModel.createStore(root, row)
+        if (error != null) {
+          activity.snackbar(
+            message = activity.getString(R.string.store_create_failed, error),
+            length = Snackbar.LENGTH_LONG,
+          )
+        } else {
+          // A failed commit is reported like any git error; the store exists either way, and
+          // the next commit picks up the `.gpg-id`.
+          activity
+            .commitChange(
+              activity.getString(R.string.git_commit_gpg_id, activity.getString(R.string.app_name))
+            )
+            .onFailure { activity.promptOnErrorHandler(it) }
+          viewModel.markDone()
+        }
+      } finally {
+        viewModel.busy = false
+      }
+    }
+  }
+
+  Box(modifier) {
+    PgpKeysScreen(
+      mode = mode,
+      keys = viewModel.keys,
+      recipients = viewModel.recipients,
+      busy = viewModel.busy,
+      onImport = { picker.launch(arrayOf("*/*")) },
+      onSelect = ::choose,
+      onDelete = viewModel::deleteKey,
+      onLater = onDone,
+      onBack = ::leave,
+    )
+    when (val result = viewModel.importResult) {
+      null -> Unit
+      is KeyImport.Imported -> {
+        fun accept() {
+          viewModel.dismissImport()
+          onImported()
+          if (mode == KeysMode.Need) onDone()
+        }
+        SetupDialog(
+          title = stringResource(R.string.pgp_key_import_succeeded),
+          text = stringResource(R.string.pgp_key_import_succeeded_message, result.keyId),
+          confirm = stringResource(R.string.dialog_ok),
+          onConfirm = ::accept,
+          onDismiss = ::accept,
+        )
+      }
+      KeyImport.Exists ->
+        SetupDialog(
+          title = stringResource(R.string.pgp_key_import_failed),
+          text = stringResource(R.string.pgp_key_import_failed_replace_message),
+          confirm = stringResource(R.string.dialog_yes),
+          onConfirm = viewModel::replace,
+          onDismiss = viewModel::dismissImport,
+          dismiss = stringResource(R.string.dialog_no),
+        )
+      is KeyImport.Failed ->
+        SetupDialog(
+          title = stringResource(R.string.pgp_key_import_failed),
+          text = result.message.orEmpty(),
+          confirm = stringResource(R.string.dialog_ok),
+          onConfirm = viewModel::dismissImport,
+          onDismiss = viewModel::dismissImport,
+        )
+    }
+  }
+}
diff --git a/app/src/main/res/values-it/strings.xml b/app/src/main/res/values-it/strings.xml
index 50d89f4b..050623b7 100644
--- a/app/src/main/res/values-it/strings.xml
+++ b/app/src/main/res/values-it/strings.xml
@@ -375,6 +375,9 @@
   <string name="connection_mode_none">Nessuna</string>
   <string name="ssh_key_manage">Gestisci</string>
   <string name="ssh_key_public_hint">Fornisci questa chiave pubblica al tuo server Git.</string>
+  <string name="pgp_key_needed_message">Importa la chiave privata per cui è cifrato questo archivio, così le sue voci si possono leggere e salvare.</string>
+  <string name="pgp_key_needed_recipients">Destinatari dell\'archivio</string>
+  <string name="store_create_failed">Impossibile creare l\'archivio: %1$s</string>
   <string name="git_clone_delete_failed">Impossibile svuotare la cartella dell\'archivio, la clonazione non è partita.</string>
   <string name="pgp_key_import_too_large">Il file supera 1 MiB: non è una chiave PGP.</string>
   <string name="pgp_key_import_downgrade">Una chiave privata con questo ID è già importata. La sola chiave pubblica non può sostituirla: elimina prima la chiave privata, se vuoi davvero farlo.</string>
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index 812a33e5..055e0593 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -410,6 +410,9 @@
   <string name="connection_mode_none">None</string>
   <string name="ssh_key_manage">Manage</string>
   <string name="ssh_key_public_hint">Provide this public key to your Git server.</string>
+  <string name="pgp_key_needed_message">Import the private key this store is encrypted for, so its entries can be read and saved.</string>
+  <string name="pgp_key_needed_recipients">Store recipients</string>
+  <string name="store_create_failed">Could not create the store: %1$s</string>
   <string name="git_clone_delete_failed">Could not empty the store folder, so the clone did not start.</string>
   <string name="pgp_key_import_too_large">The file is larger than 1 MiB: not a PGP key.</string>
   <string name="pgp_key_import_downgrade">A private key with this ID is already imported. Its public key alone cannot replace it: delete the private key first if you really want to.</string>