import Foundation

@Observable
final class ContentCache {
    static let shared = ContentCache()

    private var timestamps: [String: Date] = [:]
    private let ttl: TimeInterval = 300 // 5 分钟

    private init() {}

    func isExpired(key: String) -> Bool {
        guard let ts = timestamps[key] else { return true }
        return Date().timeIntervalSince(ts) > ttl
    }

    func markFresh(key: String) {
        timestamps[key] = Date()
    }

    func invalidate(key: String) {
        timestamps[key] = nil
    }
}