root/apps/iphone/superbook/trunk/DotTel_SDK/Classes/RecordTxt.m @ 382

//
//  RecordTxt.m
//  DotTel SDK
//
//  Created by Henri Asseily on 9/13/08.
/*
 Copyright (c) 2008-2009, Telnic Ltd. All rights reserved.
 
 Redistribution and use in source and binary forms, with or without modification,
 are permitted provided that the following conditions are met:
 
 Redistributions of source code must retain the above copyright notice, this list of conditions
 and the following disclaimer. Redistributions in binary form must reproduce the above copyright
 notice, this list of conditions and the following disclaimer in the documentation and/or other
 materials provided with the distribution.
 Neither the name of the Telnic Ltd. nor the names of its contributors may be used to endorse or
 promote products derived from this software without specific prior written permission.
 THIS DOCUMENTATION IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS
 OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
 AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
 IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
//

#import "RecordTxt.h"

static NSCharacterSet *trimCharacterSet;

@interface RecordTxt (PrivateMethods)

- (BOOL)parseKeywordsFromRecord:(const ldns_rr *)rr;

- (NSString *)stringFromStringRdf:(const ldns_rdf *)rdf;

@end

@implementation RecordTxt

@synthesize isValid;
@synthesize isHeader;
@synthesize isKeyword;
@synthesize isSystemMessage;
@synthesize expiryDate;

@synthesize primaryDescription;
@synthesize primaryValue;
@synthesize textValue;
@synthesize keysAndValues;

+ (id)recordWithRr:(ldns_rr *)rr {
        NSDate *lookupDate = [[NSDate date] retain];
        self = [RecordTxt recordWithRr:rr date:lookupDate];
        [lookupDate release];
        return self;
}

+ (id)recordWithRr:(ldns_rr *)rr date:(NSDate *)lookupDate {
        self = [[[RecordTxt alloc] initWithRr:rr date:lookupDate] autorelease];
        return self;
}

- (id)init {
        // Never initialize it empty
        self = [super init];
        isValid = NO;
        return self;
}

- (id)initWithRr:(ldns_rr *)rr date:(NSDate *)lookupDate {
        self = [super init];
        trimCharacterSet = [[NSCharacterSet whitespaceCharacterSet] retain];
        isValid = NO;
        isKeyword = NO;

        if (ldns_rr_get_type(rr) != LDNS_RR_TYPE_TXT)
                return self;

        NSTimeInterval ttl = (NSTimeInterval)ldns_rr_ttl(rr);
        expiryDate = [lookupDate addTimeInterval:ttl];
        
        NSString *firstString = [self stringFromStringRdf:ldns_rr_rdf(rr,0)];
        if ([firstString isEqualToString:@".tkw"]) {
                // parse keywords
                isKeyword = YES;
                isValid = [self parseKeywordsFromRecord:rr];
        } else if ([firstString isEqualToString:@".tsm"]) {
                // system message, do nothing
                return self;
        } else if ([firstString isEqualToString:@".tad"]) {
                // advert, do nothing for now
                return self;
        } else {
                // header
                isHeader = YES;
                primaryDescription = [@"" retain];
                primaryValue = NULL;
                // Could have multiple strings in one record, they need to be joined together
                NSMutableArray *stringComponents = [NSMutableArray arrayWithCapacity:2];
                for (NSUInteger i=0; i < ldns_rr_rd_count(rr); i++) {
                        [stringComponents addObject:[self stringFromStringRdf:ldns_rr_rdf(rr,i)]];
                }

                textValue = [stringComponents componentsJoinedByString:@" "];
                isValid = YES;
        }
        
        return self;
}

- (BOOL)parseKeywordsFromRecord:(const ldns_rr *)rr {
        // Keywords always start with ".tkw" followed by the version number.
        // After that, there are any number of pairs of type and value
        // In general there should be a single pair, but compound keywords like addresses
        // will have more. Here we opt to concatenate all the values for these compound keywords
        // and only keep the first type string, discarding all other type strings if they exist
        // However, we also keep a full array of type+value in case the user wants to store that
        // info into the address book.
        
        // Check version
        if ([[self stringFromStringRdf:ldns_rr_rdf(rr,1)] isEqualToString:@"1"]) {
                // Version 1
                keysAndValues = [[NSMutableArray arrayWithCapacity:ldns_rr_rd_count(rr)] retain];
                for (NSUInteger i=2; i < ldns_rr_rd_count(rr); i=i+2) {
                        [keysAndValues addObject:[self stringFromStringRdf:ldns_rr_rdf(rr,i)]];
                        [keysAndValues addObject:[self stringFromStringRdf:ldns_rr_rdf(rr,i+1)]];
                }
                primaryDescription = [LocTelStr([keysAndValues objectAtIndex:0]) retain];
                if ([keysAndValues count] < 3) {        // Only a single primary keyword/value
                        primaryValue = NULL;
                        textValue = [keysAndValues objectAtIndex:1];
                } else {
                        primaryValue = [keysAndValues objectAtIndex:1];
                        NSMutableArray *keyValueComponents = [NSMutableArray arrayWithCapacity:2];
                        for (NSUInteger i=1; i < [keysAndValues count]; i=i+2) {
                                [keyValueComponents addObject:[keysAndValues objectAtIndex:i]];
                        }
                        textValue = [[[keyValueComponents componentsJoinedByString:@" "]
                                                  stringByTrimmingCharactersInSet:trimCharacterSet] retain];
                }
                return TRUE;
        } else {
                // Unknown version
                return FALSE;
        }
}

# pragma mark ------------- Utility functions for parsing record data fields ------------

- (NSString *)stringFromStringRdf:(const ldns_rdf *)rdf {
        NSMutableString *res;
        const uint8_t *data = ldns_rdf_data(rdf);
        uint8_t length = data[0];
        res = [[[NSMutableString alloc] initWithBytes:(const unichar *)(data+1)
                                                                                   length:length
                                                                                 encoding:NSUTF8StringEncoding] autorelease];
        return res;
}

#pragma mark ---- cleanup ----

- (void)dealloc {
        [trimCharacterSet release];
        [super dealloc];
}

@end