import Foundation

/// 已保存的主机（连接目标）。
/// 注：`password` 暂存本地 JSON 仅供 demo；产品化后应移入 Keychain（未签名时 SecItem 不可用，见 HANDOFF）。
struct SavedHost: Identifiable, Codable, Equatable {
    var id: UUID = UUID()
    var name: String
    var host: String
    var port: Int = 22
    var username: String
    var password: String = ""
    /// 登录后引导 mosh 承载会话。
    var useMosh: Bool = false

    var addressLine: String { "\(username)@\(host):\(port)" }
}

/// 主机列表持久化（Application Support 下 JSON）。凭据不入仓库；此文件只在设备本地。
@MainActor
final class HostStore: ObservableObject {
    @Published private(set) var hosts: [SavedHost] = []

    private let url: URL

    init() {
        let base = FileManager.default.urls(for: .applicationSupportDirectory, in: .userDomainMask)[0]
        try? FileManager.default.createDirectory(at: base, withIntermediateDirectories: true)
        url = base.appendingPathComponent("hosts.json")
        load()
    }

    func add(_ host: SavedHost) {
        hosts.append(host)
        save()
    }

    func update(_ host: SavedHost) {
        guard let i = hosts.firstIndex(where: { $0.id == host.id }) else { return }
        hosts[i] = host
        save()
    }

    func remove(_ host: SavedHost) {
        hosts.removeAll { $0.id == host.id }
        save()
    }

    private func load() {
        guard let data = try? Data(contentsOf: url),
              let decoded = try? JSONDecoder().decode([SavedHost].self, from: data) else { return }
        hosts = decoded
    }

    private func save() {
        guard let data = try? JSONEncoder().encode(hosts) else { return }
        try? data.write(to: url, options: .atomic)
    }
}