fix(android,ios): the player names the episode, not its file

The header under the episode's numbering showed `Episode::detail`, which
falls back to the file name — `[Judas] Chainsaw Man - S01E01.mkv` on a
phone, where the desktop shows `Dog & Chainsaw`. It now shows the
provider's name for the episode, else the one the file name gave it, and
nothing rather than the file name: the release group's tag is no caption,
and it is what a screenshot of the player would carry away.

android/app/src/main/java/io/narl/protonstream/playback/PlayerScreen.kt

@@ -97,6 +97,7 @@ import androidx.core.view.WindowInsetsCompat
 import androidx.core.view.WindowInsetsControllerCompat
 import io.narl.protonstream.settings.SettingsStore
 import io.narl.protonstream.native.NativeRuntime
+import io.narl.protonstream.ui.shownName
 import io.narl.protonstream.ui.theme.AccentButton
 import io.narl.protonstream.ui.theme.AccentTrack
 import io.narl.protonstream.ui.theme.EdgedButton
@@ -567,8 +568,11 @@ fun PlayerScreen(
                         overflow = TextOverflow.Ellipsis,
                         style = MaterialTheme.typography.titleMedium,
                     )
+                    // The episode's name, never its file name: a release
+                    // group's tag is no caption, and it is what a screenshot
+                    // of the player would carry away.
                     Text(
-                        listOfNotNull(title.displayName, episode.detail.takeIf(String::isNotBlank))
+                        listOfNotNull(title.displayName, episode.shownName())
                             .joinToString("  •  "),
                         color = Color.White.copy(alpha = 0.7f),
                         maxLines = 1,

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

@@ -221,6 +221,13 @@ internal fun rememberQueueReason(key: Any?): String? {
     }
 }
 
+/**
+ * The episode's own name: the provider's, else the one the filename gave it.
+ * `null` rather than the filename, which is a release group's tag and the
+ * episode's numbering again.
+ */
+internal fun EpisodeRecord.shownName(): String? = providerName ?: detail.takeIf { it != name && it.isNotBlank() }
+
 /**
  * What an episode row is headed with: "1. Mother and Children".
  *
@@ -229,7 +236,7 @@ internal fun rememberQueueReason(key: Any?): String? {
  * of `[Group] Show - S01E01.mkv` is forty rows that differ in two characters.
  */
 internal fun EpisodeRecord.heading(position: Int): String {
-    val named = providerName ?: detail.takeIf { it != name }
+    val named = shownName()
     val number = number?.toInt()
     return when {
         named != null && number != null -> "$number. $named"

android/app/src/test/java/io/narl/protonstream/ui/EpisodeNameTest.kt

@@ -0,0 +1,24 @@
+package io.narl.protonstream.ui
+
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertNull
+import org.junit.Test
+import uniffi.pstr_android.EpisodeRecord
+
+class EpisodeNameTest {
+    private fun episode(name: String, detail: String, providerName: String? = null) = EpisodeRecord(
+        shareId = "s", volumeId = "v", linkId = "l", name = name, label = "S01E01", detail = detail,
+        season = 1u, number = 1u, size = null, progress = null, resumeAt = null,
+        watched = false, offline = false, providerName = providerName, providerOverview = null, stillUrl = null,
+        airDate = null, lastPlayed = 0,
+    )
+
+    @Test
+    fun `the player captions an episode with its name and never its filename`() {
+        val file = "[Group] Show - S01E01.mkv"
+        assertEquals("Dog & Chainsaw", episode(file, file, providerName = "Dog & Chainsaw").shownName())
+        assertEquals("Winter Is Coming", episode(file, "Winter Is Coming").shownName())
+        assertNull(episode(file, file).shownName())
+        assertNull(episode(file, "").shownName())
+    }
+}

ios/ProtonStream/Player/PlayerView.swift

@@ -210,7 +210,9 @@ struct PlayerView: View {
             // thing a viewer who has just woken the controls is checking.
             VStack(alignment: .leading, spacing: 0) {
                 Text(host.episode?.label ?? "").textStyle(.titleMedium).foregroundStyle(.white).lineLimit(1)
-                Text([host.title?.displayName, host.episode?.detail].compactMap { $0 }.filter { !$0.isEmpty }.joined(separator: "  •  "))
+                // The episode's name, never its file name: a release group's
+                // tag is no caption, and it is what a screenshot would carry away.
+                Text([host.title?.displayName, host.episode?.shownName].compactMap { $0 }.filter { !$0.isEmpty }.joined(separator: "  •  "))
                     .textStyle(.bodySmall).foregroundStyle(.white.opacity(0.7)).lineLimit(1)
             }
             .frame(maxWidth: .infinity, alignment: .leading)

ios/ProtonStream/UI/Common.swift

@@ -342,12 +342,19 @@ func downloadStatusLine(_ download: RetainedDownload, waitingFor: String? = nil)
 }
 
 extension EpisodeRecord {
+    /// The episode's own name: the provider's, else the one the filename gave
+    /// it. `nil` rather than the filename, which is a release group's tag and
+    /// the episode's numbering again.
+    var shownName: String? {
+        providerName ?? (detail != name && !detail.isEmpty ? detail : nil)
+    }
+
     /// What an episode row is headed with: "1. Mother and Children".
     ///
     /// The provider's name for the episode, else the name the filename gave it,
     /// else "Episode 1". The bare filename only when none of those exist.
     func heading(_ position: Int) -> String {
-        let named = providerName ?? (detail != name ? detail : nil)
+        let named = shownName
         switch (named, number) {
         case let (named?, number?): return "\(number). \(named)"
         case let (named?, nil): return named

ios/ProtonStreamTests/UiLogicTests.swift

@@ -171,6 +171,18 @@ final class CommonTests: XCTestCase {
         XCTAssertEqual(bare.heading(0), "Episode 4")
     }
 
+    func testThePlayerCaptionsAnEpisodeWithItsNameAndNeverItsFilename() {
+        var named = episode("e")
+        named.providerName = "Dog & Chainsaw"
+        XCTAssertEqual(named.shownName, "Dog & Chainsaw")
+        var bare = episode("e")
+        bare.name = "[Group] Show - S01E01.mkv"
+        bare.detail = bare.name
+        XCTAssertNil(bare.shownName)
+        bare.detail = ""
+        XCTAssertNil(bare.shownName)
+    }
+
     func testEpisodesAreNumberedBySeasonThenByPlaceInTheList() {
         var numbered = episode("e", number: 38)
         numbered.season = 3