relam_storage_context.swift

/* Storage config options */
public enum ConfigurationType {
  case basic(url: String?)
  case inMemory(identifier: String?)
    
  var associated: String? {
    get {
      switch self {
        case .basic(let url): return url
        case .inMemory(let identifier): return identifier
      }
    }
  }
}

class RealmStorageContext: StorageContext {
  var realm: Realm?
  required init(configuration: ConfigurationType = .basic(url: nil)) throws {
    var rmConfig = Realm.Configuration()
    rmConfig.readOnly = true
    switch configuration {
      case .basic:
      rmConfig = Realm.Configuration.defaultConfiguration
      if let url = configuration.associated {
        rmConfig.fileURL = NSURL(string: url) as URL?
      }
      case .inMemory:
        rmConfig = Realm.Configuration()
        if let identifier = configuration.associated {
          rmConfig.inMemoryIdentifier = identifier
        } else {
          throw RealmStorageError.inMemoryIdentifierMissing
        }
    }
    try self.realm = Realm(configuration: rmConfig)
  }
}