/*

    File:       DNSSDService.h

    Contains:   Represents a Bonjour service found by the low-level DNS-SD API.

    Written by: DTS

    Copyright:  Copyright (c) 2011 Apple Inc. All Rights Reserved.

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*/

#import <Foundation/Foundation.h>

// forward declarations

@protocol DNSSDServiceDelegate;

#pragma mark * DNSSDService

// DNSSDService represents a service discovered on the network.  You can use it to 

// resolve that service, and get a DNS name and port to connect to.

@interface DNSSDService : NSObject <NSCopying>

- (id)initWithDomain:(NSString *)domain type:(NSString *)type name:(NSString *)name;

    // In most cases you don't need to construct a DNSSDService object because you get it 

    // back from a DNSSDBrowser.  However, if you do need to construct one, it's fine to 

    // do so by calling this method.

    //

    // domain, type and name must not be nil or the empty string.  type must be of the 

    // form "_foo._tcp." or "_foo._udp." (possibly without the trailing dot, see below).

    // 

    // domain and type should include the trailing dot; if they don't, one is added 

    // and that change is reflected in the domain and type properties.

    // 

    // domain and type must not include a leading dot.

// DNSSDService implements -isEqual: based on a comparison of the domain, type and name, and  

// it implements -hash correspondingly.  This allows you to use DNSSDService objects in sets, 

// as dictionary keys, and so on.

//

// IMPORTANT: This uses case-sensitive comparison.  In general DNS is case insensitive. 

// DNS-SD will always pass you services with a consistent case, so using case sensitive 

// comparison here is not a problem.  You might run into problems, however, if you do 

// odd things like manually create a DNSSDService with the domain set to "LOCAL." instead 

// of "local.".

// 

// DNSSDService also implements NSCopying.  When you copy a service, the copy has the same 

// domain, type and name as the original.  However, the copy does not bring across any of 

// the resolution state.  Specifically:

//

// o If the original was resolving, the copy is not.

//

// o If the original had successfully resolved (and thus has resolvedHost and resolvedPort set), 

//   these results are not present in the copy.

//

// However, because the domain, type and name are copied, and these are the only things 

// considered by -isEqual: and -hash, DNSSDService can be used as a dictionary key.

// properties that are set up by the init method

@property (copy,   readonly ) NSString * domain;

@property (copy,   readonly ) NSString * type;

@property (copy,   readonly ) NSString * name;

// properties that you can change any time

@property (assign, readwrite) id<DNSSDServiceDelegate> delegate;

- (void)startResolve;

    // Starts a resolve.  Starting a resolve on a service that is currently resolving 

    // is a no-op.  If the resolve does not complete within 30 seconds, it will fail 

    // with a time out.

- (void)stop;

    // Stops a resolve.  Stopping a resolve on a service that is not resolving is a no-op.

// properties that are set up once the resolve completes

@property (copy,   readonly ) NSString * resolvedHost;

@property (assign, readonly ) NSUInteger resolvedPort;

@end

@protocol DNSSDServiceDelegate <NSObject>

// All delegate methods are called on the main thread.

@optional

- (void)dnssdServiceWillResolve:(DNSSDService *)service;

    // Called before the service starts resolving.

- (void)dnssdServiceDidResolveAddress:(DNSSDService *)service;

    // Called when the service successfully resolves.  The resolve will be stopped 

    // immediately after this delegate method returns.

- (void)dnssdService:(DNSSDService *)service didNotResolve:(NSError *)error;

    // Called when the service fails to resolve.  The resolve will be stopped 

    // immediately after this delegate method returns.

- (void)dnssdServiceDidStop:(DNSSDService *)service;

    // Called when a resolve stops (except if you call -stop on it).

@end