import Foundation

/// Persisted "what we've already notified about", so the background poller
/// only fires a notification when something actually changes:
/// - a PR that wasn't there before → "new PR"
/// - a PR whose CI aggregate status changed → "CI status changed"
struct NotificationState: Codable {
    /// PR ids (repo.fullName#number) we've already announced as new.
    var announcedNewPRs: Set<String> = []
    /// PR id → last notified CI status string ("success"/"failure"/"running"/etc).
    var ciStatusByPR: [String: String] = [:]

    private static let url: URL = {
        let dir = FileManager.default.urls(for: .cachesDirectory, in: .userDomainMask)[0]
        return dir.appendingPathComponent("notification-state.json")
    }()

    func save() {
        guard let data = try? JSONEncoder().encode(self) else { return }
        try? data.write(to: Self.url)
    }

    static func load() -> NotificationState {
        guard let data = try? Data(contentsOf: url),
              let state = try? JSONDecoder().decode(NotificationState.self, from: data) else {
            return NotificationState()
        }
        return state
    }
}