SwaggerApiResponseHandler.swift

extension SwaggerClientAPI {
  private enum HeadersKeys: String {
    case authorization = "Authorization"
  }
  class func setBearer(_ token: String) {
    SwaggerClientAPI.customHeaders = [HeadersKeys.authorization.rawValue: "Bearer \(token)"]
  }
  class func clearBearer() {
    SwaggerClientAPI.customHeaders.removeValue(forKey: HeadersKeys.authorization.rawValue)
  }
}

/// A handler for swagger style responses
class SwaggerApiResponseHandler {
  class func handleResponse<ResponseType>(_ response: (successResponse: ResponseType?, failure: Error?),
                                            success: ((ResponseType) -> Void),
                                            failure: (Error) -> Void) {
    if let error = response.failure {
      handleError(error: error) { outputError in
        failure(outputError)
      }
    } else {
      if let successResponse = response.successResponse {
        success(successResponse)
      } else {
        let error = NSError(domain: "SwaggerApiResponseHandler::handleResponse", code: -2, userInfo: [NSLocalizedDescriptionKey: "server.error.generic".localized])
        failure(error)
      }
    }
  }
  
  class func unwrapResponse<ResponseType>(_ response: (successResponse: ResponseType?, failure: Error?)) throws -> ResponseType {
    if let error = response.failure {
      try unwrapError(error: error)
    } else {
      if let successResponse = response.successResponse {
        return successResponse
      }
    }
    let error = NSError(domain: "SwaggerApiResponseHandler::unwrapResponse", code: -2, userInfo: [NSLocalizedDescriptionKey: "server.error.generic".localized])
    throw error
  }
  
  class func unwrapError(error: Error) throws {
    // Try extract internal error from returned error
    switch error {
    case let errorResponse as ErrorResponse:
      switch errorResponse {
      /// code, data, error. in future we can handle different codes. now when internet connection is interrupted error contains info about it, data is empty and code is 500
      case .error(_, let data, let error):
        if let data = data,
          let serverError = try? JSONDecoder().decode(ErrorBase.self, from: data) {
          throw NSError(domain: "SwaggerApiResponseHandler::unwrapError", code: serverError.errorCode, userInfo: [NSLocalizedDescriptionKey: serverError.failReason ?? ""])
        } else {
          throw error
        }
      }
    // if web service returned error
    default:
      throw error
    }
  }
  
  fileprivate class func handleError(error: Error, failure: (Error) -> Void) {
    // Try extract internal error from returned error
    switch error {
    case let errorResponse as ErrorResponse:
      switch errorResponse {
      /// code, data, error. in future we can handle different codes. now when internet connection is interrupted error contains info about it, data is empty and code is 500
      case .error(_, let data, let error):
        if let data = data,
          let serverError = try? JSONDecoder().decode(ErrorBase.self, from: data) {
          failure(NSError(domain: "SwaggerApiResponseHandler::handleError", code: serverError.errorCode, userInfo: [NSLocalizedDescriptionKey: serverError.failReason ?? ""]))
        } else {
          failure(error)
        }
        break
      }
      break
    // if web service returned error
    default:
      failure(error)
      break
    }
  }
}