import RastrilloNative
import SwiftUI

/// A compact save status for a toolbar or title bar. Silent when saved, but
/// the accessibility element stays present while silent, so the first
/// failure is announced from a region that already exists (estilo
/// savestatus). Entering offline, needs-sign-in and failed is announced; a
/// saving flicker never is.
public struct NativeSyncStatusView: View {
  private let status: SyncStatus
  private let strings: NativeSyncStrings

  public init(status: SyncStatus, strings: NativeSyncStrings = .kit) {
    self.status = status
    self.strings = strings
  }

  public var body: some View {
    let text = strings.text(for: status) ?? ""
    Text(text)
      .font(.callout)
      .fontWeight(status.saveState == .failed ? .semibold : .regular)
      .foregroundStyle(status.saveState == .failed ? AnyShapeStyle(.red) : AnyShapeStyle(.secondary))
      .lineLimit(2)
      .frame(minWidth: 8)
      .accessibilityElement(children: .ignore)
      .accessibilityLabel(text)
      .accessibilityAddTraits(.updatesFrequently)
      .onChange(of: status) { old, new in
        guard new.isAnnounced, !Self.sameKind(old, new), let text = strings.text(for: new) else { return }
        AccessibilityNotification.Announcement(text).post()
      }
  }

  /// A count changing inside the same state is not news.
  static func sameKind(_ a: SyncStatus, _ b: SyncStatus) -> Bool {
    switch (a, b) {
    case (.offline, .offline), (.needsSignIn, .needsSignIn), (.retrying, .retrying): return true
    case (.failed(_, let x), .failed(_, let y)): return x == y
    default: return a == b
    }
  }
}