import Foundation

/// Persists the last-known playback status per host so the player shows cached
/// values immediately on a cold launch — the first live poll can take several
/// seconds over a flapping link (the dead-LAN endpoint costs a ConnectTimeout),
/// and "Nothing playing" for that window is worse than a slightly-stale state.
public enum PlayerStatusCache {
    public struct Entry: Codable, Sendable, Equatable {
        public var status: PlaybackStatus
        public var capturedAt: Date
        public init(status: PlaybackStatus, capturedAt: Date) {
            self.status = status; self.capturedAt = capturedAt
        }
    }

    static func url() -> URL {
        FileManager.default.homeDirectoryForCurrentUser
            .appendingPathComponent(".local/state/tv-anarchy/player-status.json")
    }

    public static func load() -> [String: Entry] {
        guard let data = try? Data(contentsOf: url()) else { return [:] }
        let dec = JSONDecoder()
        dec.dateDecodingStrategy = .iso8601
        return (try? dec.decode([String: Entry].self, from: data)) ?? [:]
    }

    public static func save(_ map: [String: Entry]) {
        let u = url()
        try? FileManager.default.createDirectory(at: u.deletingLastPathComponent(),
                                                 withIntermediateDirectories: true)
        let enc = JSONEncoder()
        enc.dateEncodingStrategy = .iso8601
        enc.outputFormatting = [.withoutEscapingSlashes]
        guard let data = try? enc.encode(map) else { return }
        try? data.write(to: u, options: .atomic)
    }
}