import SwiftUI
import IndieBackup
import os

/// The iPhone app's entry point. Two tabs, per the mobile MVP charter: Boards (the whole
/// board → lane → card navigation stack) and Settings (backup/restore).
@main
struct MobileApp: App {

    /// **The app's root model, owned here and nowhere else** — the container home, the one
    /// `NSMetadataQuery` the process runs, and the per-board session cache. `@State` because the
    /// scene owns its lifetime; every screen reaches it through `.environment`, never by
    /// constructing one.
    @State private var boardIndex = BoardIndexStore()

    /// Backup/restore (indie-backup skill), built once `boardIndex.home` resolves to a real
    /// `CloudHome` — see `MobileBackupConfiguration`'s doc comment for why this can't happen at
    /// `@State` init time. Stays `nil` for the lifetime of a run with no iCloud account;
    /// `SettingsTabView` renders the quiet disabled state for exactly that case.
    @State private var backupController: BackupController?

    private static let logger = Logger(subsystem: "dev.rzen.indie.KanbanMobile", category: "backup")

    var body: some Scene {
        WindowGroup {
            RootTabView()
                .environment(boardIndex)
                .environment(\.backupController, backupController)
                .task(id: boardIndex.home) {
                    guard backupController == nil, let home = boardIndex.home else { return }
                    backupController = BackupController(
                        configuration: MobileBackupConfiguration(root: home.documentsURL, index: boardIndex)
                    )
                }
                .onOpenURL { url in
                    // A backup file opened from Files, AirDrop, or a share sheet. Silently
                    // ignored before `backupController` exists — there is no resolved cloud home
                    // to restore into either, at that point.
                    guard url.pathExtension == MobileBackupConfiguration.fileExtension,
                          let backupController
                    else { return }
                    Task {
                        do {
                            try await backupController.restoreBackup(from: url)
                        } catch {
                            Self.logger.error("restore from opened file failed: \(error.localizedDescription, privacy: .public)")
                        }
                    }
                }
        }
    }
}

struct RootTabView: View {
    var body: some View {
        TabView {
            Tab("Boards", systemImage: "rectangle.stack") {
                BoardsTabView()
            }
            Tab("Settings", systemImage: "gearshape") {
                SettingsTabView()
            }
        }
    }
}