NetworkError.swift

import Foundation

public enum NetworkError: Error {
  case invalidRequestURL
  case missingContentType(response: Response)
  case invalidParameter
  case noDataInResponse
  case noResponseReceived
  case unacceptableStatusCode(statusCode: Int, response: Response)
  case unacceptableContentType(contentType: String, response: Response)
  case jsonArraySerializationFailed(response: Response)
  case jsonDictionarySerializationFailed(response: Response)
  case stringSerializationFailed(encoding: UInt, response: Response)

  public var reason: String {
    var text: String

    switch self {
    case .invalidRequestURL:
      text = "Invalid request URL"
    case .missingContentType:
      text = "Response content type was missing"
    case .invalidParameter:
      text = "Parameter is not convertible to NSData"
    case .noDataInResponse:
      text = "No data in response"
    case .noResponseReceived:
      text = "No response received"
    case .unacceptableStatusCode(let statusCode, _):
      text = "Response status code \(statusCode) was unacceptable"
    case .unacceptableContentType(let contentType, _):
      text = "Response content type \(contentType) was unacceptable"
    case .jsonArraySerializationFailed:
      text = "No JSON array in response data"
    case .jsonDictionarySerializationFailed:
      text = "No JSON dictionary in response data"
    case .stringSerializationFailed(let encoding, _):
      text = "String could not be serialized with encoding: \(encoding)"
    }

    return NSLocalizedString(text, comment: "")
  }
}

// MARK: - Hashable

extension NetworkError: Hashable {
  public var hashValue: Int {
    return reason.hashValue
  }
}

// MARK: - Equatable

public func == (lhs: NetworkError, rhs: NetworkError) -> Bool {
  return lhs.reason == rhs.reason
}

// MARK: - NSError

extension NSError {
  var isOffline: Bool {
    return Int32(code) == CFNetworkErrors.cfurlErrorNotConnectedToInternet.rawValue
  }
}