import Foundation

/// The episode the player last had and where it got to, kept across launches, so "Resume iPX"
/// (#427) and the widget's button carry on with it when the app was closed and no page is loaded
/// to say what to play.
enum LastPlayed {
    private static let itemKey = "ipx.last.item"
    private static let positionKey = "ipx.last.position"
    static var defaults = UserDefaults.standard

    static var item: Playback.Item? {
        get { defaults.data(forKey: itemKey).flatMap { try? JSONDecoder().decode(Playback.Item.self, from: $0) } }
        set {
            // A different episode starts from where the page put it, not the last one's place.
            if newValue != item { defaults.removeObject(forKey: positionKey) }
            defaults.set(newValue.flatMap { try? JSONEncoder().encode($0) }, forKey: itemKey)
        }
    }

    static var position: Double? {
        get { defaults.object(forKey: positionKey) as? Double }
        set { defaults.set(newValue, forKey: positionKey) }
    }
}