Show soundtrack covers and edit alternative names (#49)

Covers: statistics cards show the soundtrack's cover on the left, and the
statistics popup shows it large. Until it arrives, and without a cover, the
soundtrack's initials stand in. Covers load only for cards on or near the
screen, three at a time, and are cached in covers/ next to the settings
(CoverCache), downloaded again only when cover_modified changes. The index and
file handling are shared with CharacterCache in a new FileCache.

Alternative names: the popup shows them and has an editor (add, remove, save)
that sends PUT /soundtracks/{uuid}/alternative-names. The statistics search and
the Search popup find soundtracks by them; Search shows the matching name after
the real one. Search now loads /soundtracks, falling back to the plain list.

The API types are regenerated from the server's spec, with a SoundtrackCover
theme style in every theme.

Closes #49

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

popups/soundtrack_stats_popup.gd

@@ -1,27 +1,173 @@
 class_name SoundtrackStatsPopup
 extends BasePopup
-## Shows a soundtrack's play statistics and every song in it, most played first.
-## Opened by clicking a card in the statistics view.
+## Shows a soundtrack's cover, play statistics and alternative names, and every song in
+## it, most played first. Opened by clicking a card in the statistics view.
+##
+## Edit names opens an editor for the alternative names in place of the song list. Saving
+## sends them to the server, which search then finds the soundtrack by.
+
+## Emitted when the alternative names of [param soundtrack] have been saved.
+signal alternative_names_changed(soundtrack: Soundtrack)
+
+## The covers on disk, shared with the statistics view. No cover is shown without it.
+var covers: CoverCache
+## The soundtrack shown.
+var soundtrack: SoundtrackWithSongs
+
+# The names in the editor, saved only when Save is pressed
+var _edited_names: Array[String] = []
 
 @onready var title_label: Label = %TitleLabel
 @onready var summary_label: Label = %SummaryLabel
+@onready var cover_picture: TextureRect = %CoverPicture
+@onready var cover_placeholder: Label = %CoverPlaceholder
+@onready var names_label: Label = %NamesLabel
+@onready var edit_names_button: Button = %EditNamesButton
+@onready var song_scroll: ScrollContainer = %ScrollContainer
 @onready var song_list: VBoxContainer = %SongList
+@onready var names_editor: VBoxContainer = %NamesEditor
+@onready var editor_names: VBoxContainer = %EditorNames
+@onready var new_name_field: LineEdit = %NewNameField
+@onready var add_name_button: Button = %AddNameButton
+@onready var editor_status: Label = %EditorStatus
+@onready var save_names_button: Button = %SaveNamesButton
+@onready var cancel_names_button: Button = %CancelNamesButton
 
 
-## Shows [param soundtrack] and opens the popup.
-func show_soundtrack(soundtrack: SoundtrackWithSongs) -> void:
-	title_label.text = soundtrack.soundtrack_name
-	var summary: PackedStringArray = [SoundtrackCard.played_text(soundtrack.soundtrack_played)]
-	var last_played: String = SoundtrackCard.last_played_text(soundtrack.soundtrack_last_played)
+func _ready() -> void:
+	edit_names_button.pressed.connect(edit_names)
+	add_name_button.pressed.connect(add_name)
+	new_name_field.text_submitted.connect(func(_text: String) -> void: add_name())
+	save_names_button.pressed.connect(save_names)
+	cancel_names_button.pressed.connect(stop_editing)
+
+
+## Shows [param shown] and opens the popup.
+func show_soundtrack(shown: SoundtrackWithSongs) -> void:
+	soundtrack = shown
+	stop_editing()
+	title_label.text = shown.soundtrack_name
+	var summary: PackedStringArray = [SoundtrackCard.played_text(shown.soundtrack_played)]
+	var last_played: String = SoundtrackCard.last_played_text(shown.soundtrack_last_played)
 	if !last_played.is_empty():
 		summary.append(last_played)
-	summary.append("%d %s" % [soundtrack.songs.size(),
-			"song" if soundtrack.songs.size() == 1 else "songs"])
+	summary.append("%d %s" % [shown.songs.size(),
+			"song" if shown.songs.size() == 1 else "songs"])
 	summary_label.text = " · ".join(summary)
+	_show_names()
+
+	cover_placeholder.text = SoundtrackCard.initials(shown.soundtrack_name)
+	_show_cover(null)
+	if covers != null:
+		covers.fetch_cover(shown.soundtrack_uuid, shown.cover_modified,
+				_show_cover_of.bind(shown.soundtrack_uuid))
 
 	Settings.delete_children(song_list)
-	var songs: Array[SongInfoForStats] = SoundtrackCard.songs_by_plays(soundtrack.songs)
+	var songs: Array[SongInfoForStats] = SoundtrackCard.songs_by_plays(shown.songs)
 	for row: int in songs.size():
 		song_list.add_child(ListRow.create(SoundtrackCard.song_text(songs[row]), row,
 				&"TextLarge"))
 	open()
+
+
+## Opens the editor for the alternative names, in place of the song list.
+func edit_names() -> void:
+	_edited_names.assign(soundtrack.alternative_names)
+	new_name_field.text = ""
+	editor_status.visible = false
+	_show_edited_names()
+	names_editor.visible = true
+	song_scroll.visible = false
+	edit_names_button.disabled = true
+	new_name_field.grab_focus()
+
+
+## Closes the editor without saving.
+func stop_editing() -> void:
+	names_editor.visible = false
+	song_scroll.visible = true
+	edit_names_button.disabled = false
+	_set_saving(false)
+
+
+## Adds the name in the field to the edited names, unless it is empty, the soundtrack's
+## own name or already there.
+func add_name() -> void:
+	var new_name: String = new_name_field.text.strip_edges()
+	if new_name.is_empty() || new_name.to_lower() == soundtrack.soundtrack_name.to_lower() \
+			|| _edited_names.any(func(name: String) -> bool:
+				return name.to_lower() == new_name.to_lower()):
+		return
+	_edited_names.append(new_name)
+	new_name_field.text = ""
+	_show_edited_names()
+
+
+## Takes [param removed] out of the edited names.
+func remove_name(removed: String) -> void:
+	_edited_names.erase(removed)
+	_show_edited_names()
+
+
+## Sends the edited names to the server. The editor closes when they are saved.
+func save_names() -> void:
+	# A name typed but not added yet is meant to be saved too
+	add_name()
+	_set_saving(true)
+	MusicServerClient.set_alternative_names(soundtrack.soundtrack_uuid, _edited_names,
+			_on_names_saved, _on_names_not_saved)
+
+
+func _on_names_saved(updated: Soundtrack) -> void:
+	soundtrack.alternative_names = updated.alternative_names
+	_show_names()
+	stop_editing()
+	alternative_names_changed.emit(updated)
+
+
+func _on_names_not_saved() -> void:
+	_set_saving(false)
+	editor_status.text = "Could not save the names. Try again."
+	editor_status.visible = true
+
+
+func _set_saving(saving: bool) -> void:
+	save_names_button.disabled = saving
+	cancel_names_button.disabled = saving
+	save_names_button.text = "Saving…" if saving else "Save"
+
+
+func _show_names() -> void:
+	var names: Array[String] = soundtrack.alternative_names
+	names_label.text = ", ".join(names) if !names.is_empty() else "No other names yet"
+
+
+func _show_edited_names() -> void:
+	Settings.delete_children(editor_names)
+	for row: int in _edited_names.size():
+		var line: HBoxContainer = HBoxContainer.new()
+		var label: Label = Label.new()
+		label.text = _edited_names[row]
+		label.size_flags_horizontal = Control.SIZE_EXPAND_FILL
+		label.text_overrun_behavior = TextServer.OVERRUN_TRIM_ELLIPSIS
+		line.add_child(label)
+		var remove: Button = Button.new()
+		remove.text = "Remove"
+		remove.focus_mode = Control.FOCUS_NONE
+		remove.pressed.connect(remove_name.bind(_edited_names[row]))
+		line.add_child(remove)
+		var list_row: PanelContainer = PanelContainer.new()
+		list_row.theme_type_variation = &"ListRowOdd" if row % 2 != 0 else &"ListRowEven"
+		list_row.add_child(line)
+		editor_names.add_child(list_row)
+
+
+func _show_cover(cover: Image) -> void:
+	cover_picture.texture = ImageTexture.create_from_image(cover) if cover != null else null
+	cover_placeholder.visible = cover == null
+
+
+# Covers arrive later; one for a soundtrack no longer shown is left out
+func _show_cover_of(cover: Image, uuid: String) -> void:
+	if soundtrack != null && soundtrack.soundtrack_uuid == uuid:
+		_show_cover(cover)