import Foundation

@MainActor
final class DeviceViewModel: ObservableObject {
    @Published var snapshot: DeviceSnapshot?
    @Published var isLoading = false
    @Published var errorMessage: String?
    @Published private(set) var connectionStatus: ConnectionStatus = .unknown

    let instance: Instance
    private let service: DeviceService
    private let probe: ConnectionProbe?

    init(instance: Instance, service: DeviceService, probe: ConnectionProbe? = nil) {
        self.instance = instance
        self.service = service
        self.probe = probe
    }

    func refresh() async {
        isLoading = true
        errorMessage = nil
        do {
            snapshot = try await service.snapshot(instance)
        } catch DeviceServiceError.unauthorized, UpstreamError.unauthorized {
            errorMessage = "需要实例密码登录后才能读取设备数据。"
        } catch let error as UpstreamError {
            errorMessage = ErrorMessage.describe(error, nodeName: instance.name)
        } catch {
            errorMessage = "节点无响应，请确认地址可访问、设备已开机且端口未被拦截。"
        }
        guard let probe else {
            connectionStatus = .offline
            isLoading = false
            return
        }
        let result = try? await probe.test(instance)
        connectionStatus = result?.status ?? .offline
        isLoading = false
    }
}