import Foundation

@MainActor
final class FleetViewModel: ObservableObject {
    struct Row: Equatable, Identifiable {
        let id: UUID
        var instance: Instance
        var status: ConnectionStatus
        var testing: Bool
    }

    @Published var rows: [Row] = []
    @Published var searchText = ""
    @Published var selectedIDs: Set<UUID> = []
    @Published var selectionMode = false
    @Published var isLoading = false
    @Published var errorMessage: String?
    @Published var showingForm = false

    private let repository: any InstanceRepository
    private let probe: ConnectionProbe
    private let credentials: any CredentialStore

    init(
        repository: any InstanceRepository,
        probe: ConnectionProbe,
        credentials: any CredentialStore
    ) {
        self.repository = repository
        self.probe = probe
        self.credentials = credentials
    }

    func refresh() async {
        isLoading = true
        errorMessage = nil
        do {
            let query = InstanceQuery(search: searchText.isEmpty ? nil : searchText)
            let instances = try await repository.list(query)
            rows = instances.map {
                Row(id: $0.id, instance: $0, status: .unknown, testing: true)
            }
            await withTaskGroup(of: Void.self) { group in
                for instance in instances {
                    group.addTask { [probe] in
                        let result = try? await probe.test(instance)
                        await self.applyProbe(instance.id, result)
                    }
                }
            }
        } catch {
            errorMessage = "无法刷新节点列表"
        }
        isLoading = false
    }

    func add(_ input: InstanceInput) async throws {
        let created = try await repository.create(input)
        if let password = input.password, !password.isEmpty {
            try credentials.set(instanceID: created.id, password: password)
        }
        showingForm = false
        await refresh()
    }

    func delete(_ ids: [UUID]) async {
        for id in ids {
            if let row = rows.first(where: { $0.id == id }) {
                do {
                    try await repository.delete(id, expectedRevision: row.instance.configRevision)
                    try credentials.remove(instanceID: id)
                } catch {
                    errorMessage = "删除 \(row.instance.name) 失败"
                }
            }
        }
        selectedIDs.removeAll()
        selectionMode = false
        await refresh()
    }

    private func applyProbe(_ id: UUID, _ result: ConnectionResult?) {
        guard let index = rows.firstIndex(where: { $0.id == id }) else { return }
        rows[index].status = result?.status ?? .unknown
        rows[index].testing = false
    }
}