import Async
import Bits
import Fluent
import Authentication
import MongoKitten

/// Authenticatable by `Basic username:password` auth.
public protocol MongoBasicAuthenticatable: Authenticatable {
  /// Key path to the username
  typealias UsernameKey = WritableKeyPath<Self, String>

  /// The key under which the user's username,
  /// email, or other identifing value is stored.
  static var usernameKey: UsernameKey { get }

  /// Key path to the password
  typealias PasswordKey = WritableKeyPath<Self, String>

  /// The key under which the user's password
  /// is stored.
  static var passwordKey: PasswordKey { get }

  /// Authenticates using the supplied credentials, connection, and verifier.
  static func authenticate(using basic: BasicAuthorization, verifier: PasswordVerifier, on collection: MongoKitten.Collection) -> Future<Self?>
}

extension MongoBasicAuthenticatable where Self: Model {
  /// See `BasicAuthenticatable`.
  public static func authenticate(using basic: BasicAuthorization, verifier: PasswordVerifier, on collection: MongoKitten.Collection) -> Future<Self?> {

    return collection.findOne("username" == basic.username).map({ (document) -> (Self?) in

      guard let document = document else {
        return nil
      }

      let user = try document.user()

      guard try verifier.verify(basic.password, created: user.basicPassword) else {
        return nil
      }

      return user as? Self
    })
  }
}

extension MongoBasicAuthenticatable {
  /// Accesses the model's password
  public var basicPassword: String {
    get { return self[keyPath: Self.passwordKey] }
    set { self[keyPath: Self.passwordKey] = newValue }
  }

  /// Accesses the model's username
  public var basicUsername: String {
    get { return self[keyPath: Self.usernameKey] }
    set { self[keyPath: Self.usernameKey] = newValue }
  }
}