import Foundation
import Observation

@MainActor
@Observable
final class LeadFileViewModel {
    private(set) var url: URL?
    private(set) var message: LocalizedStringResource?
    private(set) var needsLogin = false
    private(set) var allowsRetry = true
    private var generation = 0

    func load(using download: () async throws -> URL) async {
        generation += 1
        let request = generation
        url = nil
        message = nil
        needsLogin = false
        allowsRetry = true
        do {
            let result = try await download()
            try Task.checkCancellation()
            guard request == generation else { return }
            url = result
        } catch is CancellationError {
        } catch {
            guard request == generation, !Task.isCancelled else { return }
            message = error.leadFileMessage
            needsLogin = error as? LeadError == .unauthorized
            allowsRetry = (error as? LeadError)?.allowsRetry ?? true
        }
    }
}