// JQCApp.swift
// ------------
// App entry point.

import SwiftUI
import SwiftData
import BackgroundTasks
import UserNotifications

@main
struct JanitorialQCApp: App {

    @StateObject private var auth = AuthManager.shared
    @StateObject private var sync = SyncManager.shared

    init() {
        registerBackgroundTasks()
        requestNotificationPermission()
        // Set delegate so notifications display as banners when the app is in
        // the foreground. Without this iOS silently drops them.
        UNUserNotificationCenter.current().delegate = NotificationDelegate.shared
    }

    var body: some Scene {
        WindowGroup {
            ContentView()
                .environmentObject(auth)
                .environmentObject(sync)
        }
        .modelContainer(for: [
            LocalFacility.self,
            LocalArea.self,
            LocalTemplate.self,
            LocalInspection.self,
            LocalIssue.self,
            PendingPhoto.self,
            SyncQueueEntry.self,
        ], isUndoEnabled: false) { result in
            switch result {
            case .success(let container):
                // Only set the model context here — do NOT await anything.
                // Session restore and sync are triggered by ContentView.task{}
                // which runs on the MainActor inside the SwiftUI lifecycle,
                // guaranteeing isLoading changes are seen by the view immediately.
                SyncManager.shared.modelContext = container.mainContext
            case .failure(let error):
                fatalError("SwiftData container failed: \(error)")
            }
        }
    }

    // ── Local notification permission ─────────────────────────────────────

    private func requestNotificationPermission() {
        UNUserNotificationCenter.current().requestAuthorization(
            options: [.alert, .sound, .badge]
        ) { granted, error in
            if let error { print("[JQC] Notification permission error: \(error)") }
        }
    }

    private func registerBackgroundTasks() {
        BGTaskScheduler.shared.register(
            forTaskWithIdentifier: "com.jqc.sync",
            using: nil
        ) { task in
            guard let processingTask = task as? BGProcessingTask else {
                task.setTaskCompleted(success: false)
                return
            }
            handleBackgroundSync(task: processingTask)
        }
    }

    private func handleBackgroundSync(task: BGProcessingTask) {
        scheduleBackgroundSync()
        let syncTask = Task {
            await SyncManager.shared.triggerSync()
        }
        task.expirationHandler = {
            syncTask.cancel()
        }
        Task {
            await syncTask.value
            task.setTaskCompleted(success: !syncTask.isCancelled)
        }
    }
}

// ── Notification delegate ─────────────────────────────────────────────────────
// Allows local notifications to appear as banners while the app is in the
// foreground. Without this delegate iOS discards them silently.

final class NotificationDelegate: NSObject, UNUserNotificationCenterDelegate {
    static let shared = NotificationDelegate()
    private override init() {}

    func userNotificationCenter(
        _ center: UNUserNotificationCenter,
        willPresent notification: UNNotification,
        withCompletionHandler completionHandler:
            @escaping (UNNotificationPresentationOptions) -> Void
    ) {
        // Show banner + play sound even when the app is active in foreground.
        completionHandler([.banner, .sound])
    }
}

func scheduleBackgroundSync() {
    let request = BGProcessingTaskRequest(identifier: "com.jqc.sync")
    request.requiresNetworkConnectivity = true
    request.requiresExternalPower       = false
    try? BGTaskScheduler.shared.submit(request)
}