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 endpoint = "endpoint"
    static let model = "model"
    static let prompt = "prompt"
    static let destination = "destination"
    static let shortcut = "shortcut"
  }

  private let defaults: UserDefaults

  @Published var endpoint: String { didSet { defaults.set(endpoint, forKey: Key.endpoint) } }
  @Published var model: String { didSet { defaults.set(model, forKey: Key.model) } }
  @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
    endpoint = defaults.string(forKey: Key.endpoint) ?? ""
    model = defaults.string(forKey: Key.model) ?? ""
    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 apiKey: String {
    get { KeychainStore.read() }
    set { KeychainStore.write(newValue) }
  }
}