import Combine
import Foundation

enum TranscriptDestination: String, CaseIterable, Identifiable {
  case cursor
  case clipboard

  var id: Self { self }

  var label: String {
    switch self {
    case .cursor: "Type at cursor"
    case .clipboard: "Copy to clipboard"
    }
  }
}

@MainActor
final class AppSettings: ObservableObject {
  private enum Key {
    static let hostedEndpoint = "endpoint"
    static let hostedModel = "model"
    static let localEndpoint = "local_endpoint"
    static let localModel = "local_model"
    static let hostedFirst = "hosted_first"
    static let prompt = "prompt"
    static let destination = "destination"
    static let shortcut = "shortcut"
  }

  private let defaults: UserDefaults

  @Published var hostedEndpoint: String {
    didSet { defaults.set(hostedEndpoint, forKey: Key.hostedEndpoint) }
  }
  @Published var hostedModel: String {
    didSet { defaults.set(hostedModel, forKey: Key.hostedModel) }
  }
  @Published var localEndpoint: String {
    didSet { defaults.set(localEndpoint, forKey: Key.localEndpoint) }
  }
  @Published var localModel: String {
    didSet { defaults.set(localModel, forKey: Key.localModel) }
  }
  @Published var hostedFirst: Bool {
    didSet { defaults.set(hostedFirst, forKey: Key.hostedFirst) }
  }
  @Published var prompt: String { didSet { defaults.set(prompt, forKey: Key.prompt) } }
  @Published var destination: TranscriptDestination {
    didSet { defaults.set(destination.rawValue, forKey: Key.destination) }
  }
  @Published var shortcut: HotkeyShortcut {
    didSet {
      if let data = try? JSONEncoder().encode(shortcut) {
        defaults.set(data, forKey: Key.shortcut)
      }
    }
  }

  init(defaults: UserDefaults = .standard) {
    self.defaults = defaults
    hostedEndpoint = defaults.string(forKey: Key.hostedEndpoint) ?? ""
    hostedModel = defaults.string(forKey: Key.hostedModel) ?? ""
    localEndpoint = defaults.string(forKey: Key.localEndpoint) ?? "http://localhost:8080"
    localModel = defaults.string(forKey: Key.localModel) ?? ""
    hostedFirst = defaults.object(forKey: Key.hostedFirst) as? Bool ?? true
    prompt = defaults.string(forKey: Key.prompt) ?? ""
    destination =
      TranscriptDestination(
        rawValue: defaults.string(forKey: Key.destination) ?? ""
      ) ?? .cursor
    if let data = defaults.data(forKey: Key.shortcut),
      let saved = try? JSONDecoder().decode(HotkeyShortcut.self, from: data)
    {
      shortcut = saved
    } else {
      shortcut = .defaultShortcut
    }
  }

  var hostedKey: String {
    get { KeychainStore.read(.hosted) }
    set { KeychainStore.write(newValue, account: .hosted) }
  }

  var localKey: String {
    get { KeychainStore.read(.local) }
    set { KeychainStore.write(newValue, account: .local) }
  }
}