/*

    File:       QCFHostResolver.h

    Contains:   A Cocoa-style wrapper around CFHost.

    Written by: DTS

    Copyright:  Copyright (c) 2012 Apple Inc. All Rights Reserved.

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*/

#import <Foundation/Foundation.h>

/*

    You can use the object to map from a DNS name to a set of addresses or from a 

    address to a set of DNS names.  To do this:

    1. create the QCFHostResolver object with the info you have

    2. set a delegate

    3. call -start

    4. wait for -hostResolverDidFinish: to be called

    5. extract the information you need from the resolvedXxx properties

*/

@protocol QCFHostResolverDelegate;

@interface QCFHostResolver : NSObject

- (id)initWithName:(NSString *)name;

    // Initialise the object for name-to-address translation.

- (id)initWithAddress:(NSData *)address;

    // Initialise the object for address-to-name translation based on a (struct sockaddr) 

    // embedded in an NSData object.

- (id)initWithAddressString:(NSString *)addressString;

    // Initialise the object for address-to-name translation based on an address string.

// properties set up by the various -init routines

@property (nonatomic, copy,   readonly ) NSString *     name;

@property (nonatomic, copy,   readonly ) NSData *       address;

@property (nonatomic, copy,   readonly ) NSString *     addressString;

// properties you can set at any time

@property (nonatomic, weak,   readwrite) id<QCFHostResolverDelegate> delegate;

- (void)start;

    // Starts the resolution process.

    // 

    // It's not safe to call this is if the resolve is running.

- (void)cancel;

    // Cancels a resolve.  It's safe to call this redundantly.

// properties that are set when resolution completes

@property (nonatomic, copy,   readonly ) NSError *      error;

@property (nonatomic, copy,   readonly ) NSArray *      resolvedAddresses;          // of NSData, each containing a (struct sockaddr)

@property (nonatomic, copy,   readonly ) NSArray *      resolvedAddressStrings;     // of NSString

@property (nonatomic, copy,   readonly ) NSArray *      resolvedNames;              // of NSString

@end

@protocol QCFHostResolverDelegate <NSObject>

@optional

- (void)hostResolverDidFinish:(QCFHostResolver *)resolver;

    // Called when resolution completes succesfully.  Either the resolvedAddress[es|Strings] 

    // or the resolvedNames properties will contain meaningful results depending on whether 

    // the object was initialised for name-to-address or address-to-name translation.

- (void)hostResolver:(QCFHostResolver *)resolver didFailWithError:(NSError *)error;

    // Called when resolution fails.  The error parameter reflects the value in the error 

    // property

@end