import Foundation
import UserNotifications

class NotificationManager: NSObject, UNUserNotificationCenterDelegate {
    static let shared = NotificationManager()

    /// UNUserNotificationCenter requires a valid .app bundle.
    /// When running the bare binary (e.g. via build-test.sh) we skip notifications.
    private var isInsideBundle: Bool {
        return Bundle.main.bundleIdentifier != nil
    }

    private override init() {
        super.init()
        if isInsideBundle {
            UNUserNotificationCenter.current().delegate = self
        }
    }

    func requestPermission() {
        guard isInsideBundle else {
            NSLog("Pommedoro: skipping notification permission (not running from .app bundle)")
            return
        }
        UNUserNotificationCenter.current().requestAuthorization(options: [.alert, .sound]) { granted, error in
            if let error = error {
                NSLog("Pommedoro: notification permission error: \(error.localizedDescription)")
            }
        }
    }

    func postCycleStarted(durationMinutes: Int) {
        guard isInsideBundle else { return }

        let content = UNMutableNotificationContent()
        content.title = "Pommedoro"
        content.body = "Cycle started — \(durationMinutes) minutes"
        content.sound = .default

        let trigger = UNTimeIntervalNotificationTrigger(timeInterval: 1, repeats: false)
        let request = UNNotificationRequest(
            identifier: "pommedoro-cycle-start-\(UUID().uuidString)",
            content: content,
            trigger: trigger
        )

        UNUserNotificationCenter.current().add(request) { error in
            if let error = error {
                NSLog("Pommedoro: failed to post notification: \(error.localizedDescription)")
            }
        }
    }

    func userNotificationCenter(
        _ center: UNUserNotificationCenter,
        willPresent notification: UNNotification,
        withCompletionHandler completionHandler: @escaping (UNNotificationPresentationOptions) -> Void
    ) {
        completionHandler([.banner, .sound])
    }
}