feat(app,android,ios): ask before forgetting matches or downloading a whole show

- Turning metadata off or switching provider forgets every stored answer,
  including matches chosen by hand. The desktop now asks first and says
  how many hand-picked matches go. The phones' settings dialog says so
  above Save.
- Forgetting a hand-picked match on the desktop, and any match on the
  phones, is asked about first.
- Downloading a season, a show, or everything from a library tile asks
  first, with the episode count and their size.
- Android confirmations that delete something use an error-toned text
  button rather than the filled accent, which read as the safe choice.

android/app/src/main/java/io/narl/protonstream/ui/Common.kt

@@ -10,6 +10,7 @@ import androidx.compose.foundation.layout.PaddingValues
 import androidx.compose.foundation.layout.RowScope
 import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.foundation.layout.padding
+import androidx.compose.material3.AlertDialog
 import androidx.compose.material3.ExperimentalMaterial3Api
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.Text
@@ -17,7 +18,10 @@ import androidx.compose.material3.TopAppBar
 import androidx.compose.material3.TopAppBarColors
 import androidx.compose.material3.TopAppBarDefaults
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
 import androidx.compose.runtime.staticCompositionLocalOf
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
@@ -25,9 +29,11 @@ import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.input.nestedscroll.nestedScroll
 import androidx.compose.ui.text.style.TextAlign
 import androidx.compose.ui.unit.dp
+import io.narl.protonstream.download.DownloadCoordinator
 import io.narl.protonstream.download.RetainedDownload
 import io.narl.protonstream.settings.SettingsStore
 import io.narl.protonstream.ui.theme.AccentButton
+import io.narl.protonstream.ui.theme.TonalButton
 import uniffi.pstr_android.EpisodeRecord
 
 /**
@@ -141,6 +147,45 @@ internal fun formatBytes(bytes: ULong): String {
     }
 }
 
+/**
+ * Download episodes, asking first when it is more than one: a season or a
+ * show is tens of gigabytes, and one tap should not fill a phone. The
+ * question says how many and how big. Call it in composition; it draws the
+ * dialog where it is called and returns what starts the download.
+ */
+@Composable
+internal fun rememberDownload(): (List<EpisodeRecord>, String) -> Unit {
+    val context = LocalContext.current
+    var asking by remember { mutableStateOf<Pair<List<EpisodeRecord>, String>?>(null) }
+    asking?.let { (episodes, what) ->
+        val bytes = episodes.sumOf { it.size ?: 0uL }
+        AlertDialog(
+            onDismissRequest = { asking = null },
+            title = { Text("Download ${episodes.size} episodes of $what?") },
+            text = {
+                Text(
+                    "They are kept on this device for watching without a connection" +
+                        (if (bytes > 0uL) " — about ${formatBytes(bytes)}" else "") +
+                        ". Delete them from Downloads.",
+                )
+            },
+            confirmButton = {
+                AccentButton(onClick = {
+                    asking = null
+                    DownloadCoordinator.enqueue(context, episodes)
+                }) { Text("Download") }
+            },
+            dismissButton = { TonalButton(onClick = { asking = null }) { Text("Cancel") } },
+        )
+    }
+    return remember(context) {
+        { episodes, what ->
+            val wanted = episodes.filterNot(EpisodeRecord::offline)
+            if (wanted.size > 1) asking = wanted to what else DownloadCoordinator.enqueue(context, wanted)
+        }
+    }
+}
+
 /**
  * One line under a download that has not finished: "Running · 120.0 MiB of
  * 1.2 GiB · 2.4 MiB/s", or "Queued" while it waits for a slot — or, given a

android/app/src/main/java/io/narl/protonstream/ui/DownloadsScreen.kt

@@ -40,7 +40,7 @@ import androidx.work.WorkManager
 import io.narl.protonstream.download.DownloadCoordinator
 import io.narl.protonstream.download.DownloadStateStore
 import io.narl.protonstream.download.RetainedDownload
-import io.narl.protonstream.ui.theme.AccentButton
+import io.narl.protonstream.ui.theme.DangerButton
 import io.narl.protonstream.ui.theme.AccentProgress
 import io.narl.protonstream.ui.theme.TonalButton
 import uniffi.pstr_android.OfflineRecord
@@ -138,7 +138,7 @@ internal fun DownloadsScreen(
                 )
             },
             confirmButton = {
-                AccentButton(onClick = {
+                DangerButton(onClick = {
                     deleting = null
                     onRemove(file)
                 }) { Text("Delete") }

android/app/src/main/java/io/narl/protonstream/ui/LibraryScreen.kt

@@ -35,8 +35,6 @@ import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.setValue
 import androidx.compose.ui.graphics.vector.ImageVector
-import androidx.compose.ui.platform.LocalContext
-import io.narl.protonstream.download.DownloadCoordinator
 import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.Column
@@ -126,7 +124,7 @@ internal fun LibraryScreen(
     onArrange: (LibrarySort, Boolean) -> Unit = { _, _ -> },
     onAddShare: () -> Unit = {},
 ) {
-    val context = LocalContext.current
+    val download = rememberDownload()
     // What a long press opened a menu for: a title, or a Continue watching card.
     var menuFor by remember { mutableStateOf<TitleRecord?>(null) }
     var menuResume by remember { mutableStateOf<Resumable?>(null) }
@@ -218,7 +216,7 @@ internal fun LibraryScreen(
                 onResume(title, nextUpIndex(playlist, title.continueIndex))
             }
             MenuRow(Icons.Default.Info, "Open") { onTitle(title) }
-            MenuRow(Icons.Default.Download, "Download all") { DownloadCoordinator.enqueue(context, playlist) }
+            MenuRow(Icons.Default.Download, "Download all") { download(playlist, title.displayName) }
             MenuRow(
                 if (allWatched) Icons.Outlined.CheckCircle else Icons.Default.CheckCircle,
                 if (allWatched) "Mark unwatched" else "Mark watched",

android/app/src/main/java/io/narl/protonstream/ui/SettingsScreen.kt

@@ -65,6 +65,7 @@ import kotlinx.coroutines.withContext
 import io.narl.protonstream.download.DownloadCoordinator
 import io.narl.protonstream.native.NativeRuntime
 import io.narl.protonstream.ui.theme.AccentButton
+import io.narl.protonstream.ui.theme.DangerButton
 import io.narl.protonstream.ui.theme.AppearanceState
 import io.narl.protonstream.ui.theme.EdgedButton
 import io.narl.protonstream.ui.theme.TonalButton
@@ -316,7 +317,7 @@ internal fun SettingsScreen(
                 )
             },
             confirmButton = {
-                AccentButton(onClick = { confirmDelete = false; onRemoveAllOffline() }) { Text("Delete") }
+                DangerButton(onClick = { confirmDelete = false; onRemoveAllOffline() }) { Text("Delete") }
             },
             dismissButton = { TonalButton(onClick = { confirmDelete = false }) { Text("Cancel") } },
         )
@@ -419,6 +420,7 @@ private fun MetadataSettingsDialog(
     var refusal by remember { mutableStateOf<String?>(null) }
     val scope = rememberCoroutineScope()
     val needsKey = enabled && provider == MetadataProvider.TMDB && !current.ready && apiKey.isBlank()
+    val forgets = current.enabled && (!enabled || provider != current.provider)
     AlertDialog(
         onDismissRequest = { if (!saving) onDismiss() },
         properties = DialogProperties(securePolicy = SecureFlagPolicy.SecureOn),
@@ -450,6 +452,16 @@ private fun MetadataSettingsDialog(
                     )
                 }
                 if (needsKey) Text("Enter a TMDB API key to save.", color = MaterialTheme.colorScheme.error)
+                // Said before Save rather than after: what is forgotten
+                // includes matches chosen by hand, which no look-up redoes.
+                if (forgets) {
+                    Text(
+                        "Saving forgets every poster, description and match stored now, " +
+                            "including ones you chose by hand.",
+                        color = MaterialTheme.colorScheme.error,
+                        style = MaterialTheme.typography.bodySmall,
+                    )
+                }
                 refusal?.let { Text(it, color = MaterialTheme.colorScheme.error) }
             }
         },

android/app/src/main/java/io/narl/protonstream/ui/SharesScreen.kt

@@ -38,6 +38,7 @@ import androidx.compose.ui.window.DialogProperties
 import androidx.compose.ui.window.SecureFlagPolicy
 import androidx.compose.ui.unit.dp
 import io.narl.protonstream.ui.theme.AccentButton
+import io.narl.protonstream.ui.theme.DangerButton
 import io.narl.protonstream.ui.theme.TonalButton
 import uniffi.pstr_android.AccountState
 import uniffi.pstr_android.ShareRecord
@@ -158,7 +159,7 @@ internal fun SharesScreen(
                 )
             },
             confirmButton = {
-                AccentButton(onClick = { removing = null; onRemove(share.id) }) { Text("Remove") }
+                DangerButton(onClick = { removing = null; onRemove(share.id) }) { Text("Remove") }
             },
             dismissButton = { TonalButton(onClick = { removing = null }) { Text("Cancel") } },
         )

android/app/src/main/java/io/narl/protonstream/ui/TitleScreen.kt

@@ -70,6 +70,7 @@ import io.narl.protonstream.download.DownloadStateStore
 import io.narl.protonstream.download.RetainedDownload
 import io.narl.protonstream.native.NativeRuntime
 import io.narl.protonstream.ui.theme.AccentButton
+import io.narl.protonstream.ui.theme.DangerButton
 import io.narl.protonstream.ui.theme.AccentProgress
 import io.narl.protonstream.ui.theme.EdgedButton
 import io.narl.protonstream.ui.theme.QuietButton
@@ -106,6 +107,7 @@ internal fun TitleScreen(
     onOpenTitle: (TitleRecord) -> Unit = {},
 ) {
     val context = LocalContext.current
+    val download = rememberDownload()
     var showMatch by remember(title.key) { mutableStateOf(false) }
     var overviewOpen by remember(title.key) { mutableStateOf(false) }
 
@@ -270,7 +272,7 @@ internal fun TitleScreen(
                             }
                         }
                         TitleAction(Icons.Default.Download, "Download", Modifier.weight(1f)) {
-                            DownloadCoordinator.enqueue(context, playlist)
+                            download(playlist, title.displayName)
                         }
                         TitleAction(Icons.Default.Edit, "Match", Modifier.weight(1f)) { showMatch = true }
                         // The provider's own page for this title: where a viewer goes
@@ -367,7 +369,7 @@ internal fun TitleScreen(
                                 contentDescription = "Mark ${it.label} ${if (seen) "unwatched" else "watched"}",
                             )
                         }
-                        IconButton(onClick = { DownloadCoordinator.enqueue(context, it.episodes) }) {
+                        IconButton(onClick = { download(it.episodes, "${title.displayName} ${it.label}") }) {
                             Icon(Icons.Default.Download, contentDescription = "Download ${it.label}")
                         }
                     }
@@ -671,7 +673,33 @@ internal fun ChangeMatchDialog(
     // Choosing fetches the entry's episodes too, which is a few requests.
     var choosing by remember { mutableStateOf(false) }
     var options by remember { mutableStateOf<List<MatchRecord>>(emptyList()) }
+    var confirmForget by remember { mutableStateOf(false) }
     val scope = rememberCoroutineScope()
+    if (confirmForget) {
+        // Asked, because a match chosen by hand is work the next look-up
+        // does not redo: it decides again on its own.
+        AlertDialog(
+            onDismissRequest = { confirmForget = false },
+            title = { Text("Forget this match?") },
+            text = {
+                Text(
+                    "Its poster, description and episode names go, and the next look-up " +
+                        "matches it again on its own. A match you chose by hand is lost.",
+                )
+            },
+            confirmButton = {
+                DangerButton(onClick = {
+                    confirmForget = false
+                    scope.launch {
+                        runCatching { withContext(Dispatchers.IO) { NativeRuntime.engine().forgetMatch(title.key) } }
+                            .onSuccess { onChanged() }.onFailure(onError)
+                    }
+                }) { Text("Forget") }
+            },
+            dismissButton = { TonalButton(onClick = { confirmForget = false }) { Text("Cancel") } },
+        )
+        return
+    }
     AlertDialog(
         onDismissRequest = onDismiss,
         title = { Text("Change match") },
@@ -720,12 +748,7 @@ internal fun ChangeMatchDialog(
             }
         },
         confirmButton = {
-            QuietButton(onClick = {
-                scope.launch {
-                    runCatching { withContext(Dispatchers.IO) { NativeRuntime.engine().forgetMatch(title.key) } }
-                        .onSuccess { onChanged() }.onFailure(onError)
-                }
-            }) { Text("Forget match") }
+            QuietButton(onClick = { confirmForget = true }) { Text("Forget match") }
         },
         dismissButton = { TonalButton(onClick = onDismiss) { Text("Close") } },
     )

android/app/src/main/java/io/narl/protonstream/ui/theme/Accent.kt

@@ -142,6 +142,28 @@ internal fun QuietButton(
     content = content,
 )
 
+/**
+ * The yes of a confirmation that deletes or forgets something.
+ *
+ * Not [AccentButton]: the filled accent is this app's "go on", and a dialog
+ * whose most inviting button is the one that loses something reads as the
+ * safe choice. Error-toned text instead, as Material's own guidance has it.
+ */
+@Composable
+internal fun DangerButton(
+    onClick: () -> Unit,
+    modifier: Modifier = Modifier,
+    enabled: Boolean = true,
+    content: @Composable RowScope.() -> Unit,
+) = TextButton(
+    onClick = onClick,
+    modifier = modifier,
+    enabled = enabled,
+    shape = MaterialTheme.shapes.small,
+    colors = ButtonDefaults.textButtonColors(contentColor = MaterialTheme.colorScheme.error),
+    content = content,
+)
+
 /**
  * How far along something is, drawn in the accent.
  *