text: // AFNetworkReachabilityManager.h
  // Copyright (c) 2011–2015 Alamofire Software Foundation (http://alamofire.org/)
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  // furnished to do so, subject to the following conditions:
  //
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  // all copies or substantial portions of the Software.
  //
  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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  // THE SOFTWARE.
  
  #import <Foundation/Foundation.h>
  #import <SystemConfiguration/SystemConfiguration.h>
  
  #ifndef NS_DESIGNATED_INITIALIZER
  #if __has_attribute(objc_designated_initializer)
  #define NS_DESIGNATED_INITIALIZER __attribute__((objc_designated_initializer))
  #else
  #define NS_DESIGNATED_INITIALIZER
  #endif
  #endif
  
  typedef NS_ENUM(NSInteger, SeckenAFNetworkReachabilityStatus) {
      SCAFNetworkReachabilityStatusUnknown          = -1,
      SCAFNetworkReachabilityStatusNotReachable     = 0,
      SCAFNetworkReachabilityStatusReachableViaWWAN = 1,
      SCAFNetworkReachabilityStatusReachableViaWiFi = 2,
  };
  
  /**
   `AFNetworkReachabilityManager` monitors the reachability of domains, and addresses for both WWAN and WiFi network interfaces.
  
   Reachability can be used to determine background information about why a network operation failed, or to trigger a network operation retrying when a connection is established. It should not be used to prevent a user from initiating a network request, as it's possible that an initial request may be required to establish reachability.
  
   See Apple's Reachability Sample Code (https://developer.apple.com/library/ios/samplecode/reachability/)
  
   @warning Instances of `AFNetworkReachabilityManager` must be started with `-startMonitoring` before reachability status can be determined.
   */
  @interface SeckenAFNetworkReachabilityManager : NSObject
  
  /**
   The current network reachability status.
   */
  @property (readonly, nonatomic, assign) SeckenAFNetworkReachabilityStatus networkReachabilityStatus;
  
  /**
   Whether or not the network is currently reachable.
   */
  @property (readonly, nonatomic, assign, getter = isReachable) BOOL reachable;
  
  /**
   Whether or not the network is currently reachable via WWAN.
   */
  @property (readonly, nonatomic, assign, getter = isReachableViaWWAN) BOOL reachableViaWWAN;
  
  /**
   Whether or not the network is currently reachable via WiFi.
   */
  @property (readonly, nonatomic, assign, getter = isReachableViaWiFi) BOOL reachableViaWiFi;
  
  ///---------------------
  /// @name Initialization
  ///---------------------
  
  /**
   Returns the shared network reachability manager.
   */
  + (instancetype)sharedManager;
  
  /**
   Creates and returns a network reachability manager for the specified domain.
  
   @param domain The domain used to evaluate network reachability.
  
   @return An initialized network reachability manager, actively monitoring the specified domain.
   */
  + (instancetype)managerForDomain:(NSString *)domain;
  
  /**
   Creates and returns a network reachability manager for the socket address.
  
   @param address The socket address (`sockaddr_in`) used to evaluate network reachability.
  
   @return An initialized network reachability manager, actively monitoring the specified socket address.
   */
  + (instancetype)managerForAddress:(const void *)address;
  
  /**
   Initializes an instance of a network reachability manager from the specified reachability object.
  
   @param reachability The reachability object to monitor.
  
   @return An initialized network reachability manager, actively monitoring the specified reachability.
   */
  - (instancetype)initWithReachability:(SCNetworkReachabilityRef)reachability NS_DESIGNATED_INITIALIZER;
  
  ///--------------------------------------------------
  /// @name Starting & Stopping Reachability Monitoring
  ///--------------------------------------------------
  
  /**
   Starts monitoring for changes in network reachability status.
   */
  - (void)startMonitoring;
  
  /**
   Stops monitoring for changes in network reachability status.
   */
  - (void)stopMonitoring;
  
  ///-------------------------------------------------
  /// @name Getting Localized Reachability Description
  ///-------------------------------------------------
  
  /**
   Returns a localized string representation of the current network reachability status.
   */
  - (NSString *)localizedNetworkReachabilityStatusString;
  
  ///---------------------------------------------------
  /// @name Setting Network Reachability Change Callback
  ///---------------------------------------------------
  
  /**
   Sets a callback to be executed when the network availability of the `baseURL` host changes.
  
   @param block A block object to be executed when the network availability of the `baseURL` host changes.. This block has no return value and takes a single argument which represents the various reachability states from the device to the `baseURL`.
   */
  - (void)setReachabilityStatusChangeBlock:(void (^)(SeckenAFNetworkReachabilityStatus status))block;
  
  @end
  
  ///----------------
  /// @name Constants
  ///----------------
  
  /**
   ## Network Reachability
  
   The following constants are provided by `AFNetworkReachabilityManager` as possible network reachability statuses.
  
   enum {
   AFNetworkReachabilityStatusUnknown,
   AFNetworkReachabilityStatusNotReachable,
   AFNetworkReachabilityStatusReachableViaWWAN,
   AFNetworkReachabilityStatusReachableViaWiFi,
   }
  
   `AFNetworkReachabilityStatusUnknown`
   The `baseURL` host reachability is not known.
  
   `AFNetworkReachabilityStatusNotReachable`
   The `baseURL` host cannot be reached.
  
   `AFNetworkReachabilityStatusReachableViaWWAN`
   The `baseURL` host can be reached via a cellular connection, such as EDGE or GPRS.
  
   `AFNetworkReachabilityStatusReachableViaWiFi`
   The `baseURL` host can be reached via a Wi-Fi connection.
  
   ### Keys for Notification UserInfo Dictionary
  
   Strings that are used as keys in a `userInfo` dictionary in a network reachability status change notification.
  
   `AFNetworkingReachabilityNotificationStatusItem`
   A key in the userInfo dictionary in a `AFNetworkingReachabilityDidChangeNotification` notification.
   The corresponding value is an `NSNumber` object representing the `AFNetworkReachabilityStatus` value for the current reachability status.
   */
  
  ///--------------------
  /// @name Notifications
  ///--------------------
  
  /**
   Posted when network reachability changes.
   This notification assigns no notification object. The `userInfo` dictionary contains an `NSNumber` object under the `AFNetworkingReachabilityNotificationStatusItem` key, representing the `AFNetworkReachabilityStatus` value for the current network reachability.
  
   @warning In order for network reachability to be monitored, include the `SystemConfiguration` framework in the active target's "Link Binary With Library" build phase, and add `#import <SystemConfiguration/SystemConfiguration.h>` to the header prefix of the project (`Prefix.pch`).
   */
  extern NSString * const SeckenAFNetworkingReachabilityDidChangeNotification;
  extern NSString * const SeckenAFNetworkingReachabilityNotificationStatusItem;
  
  ///--------------------
  /// @name Functions
  ///--------------------
  
  /**
   Returns a localized string representation of an `AFNetworkReachabilityStatus` value.
   */
  extern NSString * SeckenAFStringFromNetworkReachabilityStatus(SeckenAFNetworkReachabilityStatus status);
  