/*

  * Project:     Libezv

  * File:        AWEzvRendezvousData.h

  *

  * Version:     1.0

  * Author:      Andrew Wellington <proton[at]wiretapped.net>

  *

  * License:

  * Copyright (C) 2004-2005 Andrew Wellington.

  * All rights reserved.

  * 

  * Redistribution and use in source and binary forms, with or without

  * modification, are permitted provided that the following conditions are met:

  * 

  * 1. Redistributions of source code must retain the above copyright notice,

  * this list of conditions and the following disclaimer.

  * 2. 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.

  * 

  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR "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 AUTHOR 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 "AWEzvRendezvousData.h"

 #import "AWEzvSupportRoutines.h"

 #import <AIUtilities/AIStringAdditions.h>

 @implementation AWEzvRendezvousData

 /* subnegotiation that appears at start of rendezvous packet */

 /*                             Reserved version? */

 NSString	*subn = @"subn\x00\x00\x00\x01";

 /* end of subnegotation. significance of value unknown */

 /*                        Reserved unknown       */

 NSString	*endn = @"\x00\x00\x00\x00";

 /* initialization, create our dictionary */

 -(AWEzvRendezvousData *) init 

 {

     if ((self = [super init])) {

 		keys = [[NSMutableDictionary dictionary] retain];

 		serial = 1;

 	}

     return self;

 }

 /* intialise given an NSData containing an announcement */

 -(AWEzvRendezvousData *) initWithData:(NSData *)data {

     UInt32	version;	/* the version of the iChat announcement (?) */

     UInt32	fieldCount;	/* number of fields in the announcement */

     UInt16	fieldLen;	/* length of field being read */

     UInt32	i;		/* read index into data buffer */

     NSString	*fieldName;	/* name of field */

     NSString	*fieldContent;	/* contents of field */

     NSData	*tmpData;	/* temporary data */

     NSRange	range;		/* range for reading of data */

     /* call the standard initialisation */

     self = [self init];

     /* check that the length is ok */

     if ([data length] < ([subn length] + 4 + [endn length])) {

 	AWEzvLog(@"Invalid rendezvous announcement: length %u", [data length]);

 		[self autorelease];

 	return nil;

     }

     /* check version (?) of iChat announcement */

     range.location = 4;

     range.length = 4;

     [data getBytes:&version range:range];

     version = ntohl(version);

     if (version != 1) {

 	AWEzvLog(@"Invalid rendezvous announcement: incorrect version: %u", version);

 		[self autorelease];

 	return nil;

     }

     /* get serial of announcement */

     range.location = 8;

     range.length = 4;

     [data getBytes:&serial range:range];

     serial = ntohl(serial);

     /* get field count of data */

     range.location = 16;

     range.length = 4;

     [data getBytes:&fieldCount range:range];

     fieldCount = ntohl(fieldCount);

     /* read fields from data */

     for (i = [subn length] + 4 + [endn length] + 4; i < [data length];) {

 	int binFlag = 0;

 	/* read length of field name */

 	if ([data length] < i + 2) {

 	    AWEzvLog(@"Invalid rendezvous announcement at field name length");

 		[self autorelease];

 	    return nil;

 	}

 	range.location = i;

 	range.length = 2;

 	[data getBytes:&fieldLen range:range];

 	fieldLen = ntohs(fieldLen);

 	fieldLen = fieldLen & 0x7FFF;

         i = i + 2;

 	/* read field data */

 	if ([data length] < i + fieldLen) {

 	    AWEzvLog(@"Invalid rendezvous announcement at field name");

 		[self autorelease];

 	    return nil;

 	}

         tmpData = [NSData dataWithBytes:[data bytes] + i length:fieldLen];

 	fieldName = [[[NSString alloc] initWithData:tmpData encoding:NSUTF8StringEncoding] autorelease];

 	i = i + fieldLen;

 	/* read length of field data */

 	if ([data length] < i + 2) {

 	    AWEzvLog(@"Invalid rendezvous announcement at field data length");

 		[self autorelease];

 	    return nil;

 	}

 	range.location = i;

 	range.length = 2;

 	[data getBytes:&fieldLen range:range];

 	fieldLen = ntohs(fieldLen);

 	/* most significant bit in fieldLen is a binary data flag */

 	if ((fieldLen & 0x7FFF) != fieldLen)

 	    binFlag = 1;

         fieldLen = fieldLen & 0x7FFF;

 	i = i + 2;

 	/* read field data */

 	if ([data length] < i + fieldLen) {

 	    AWEzvLog(@"Invalid rendezvous announcement at field data");

 		[self autorelease];

 	    return nil;

 	}

         if (!binFlag) {

             tmpData = [NSData dataWithBytes:[data bytes] + i length:fieldLen];

             fieldContent = [[[NSString alloc] initWithData:tmpData encoding:NSUTF8StringEncoding] autorelease];

         } else {

 			fieldContent = [[[NSString alloc] initWithBytes:[data bytes] + i length:fieldLen encoding:NSUTF8StringEncoding] autorelease];

         }

         i = i + fieldLen;

 	/* save field information */

 	[self setField:fieldName content:fieldContent];

     }

     /* return initialised object */

     return self;

 }

 /* intialise rendezvous data with a plist of the data */

 -(AWEzvRendezvousData *) initWithPlist:(NSString *)plist {

     id		extracted;	/* extracted data from plist */

     NSData	*xmlData;	/* XML data in NSData form */

     NSString	*error;		/* error from conversion of plist */

     NSPropertyListFormat format;/* something we can point at for the format pointer */

     error = [NSString string];

     /* create XML data */

     xmlData = [NSData dataWithBytes:[plist UTF8String] length:[plist length]];

     /* extract plist from XML data */

     format = NSPropertyListXMLFormat_v1_0;

     extracted = [NSPropertyListSerialization

 		    propertyListFromData:xmlData

 		    mutabilityOption:NSPropertyListImmutable

 		    format:&format

 		    errorDescription:&error];

     /* check if there was an error in extraction */

     if (extracted == nil) {

 	AWEzvLog(@"Unable to extract XML into plist");

 		[self autorelease];

 	return nil;

     }

     /* make sure it's an NSData, or reponds to getBytes:range: */

     if (![extracted respondsToSelector:@selector(getBytes:range:)]) {

 	AWEzvLog(@"Extracted object from XML is not an NSData");

 		[self autorelease];

 	return nil;  

     }

     /* pass it to another initialiser */

     return [self initWithData:extracted];

 }

 /* initialise object with a dictionary */

 - (AWEzvRendezvousData *)initWithDictionary:(NSDictionary *)dictionary 

 {

     if ((self = [super init])) {

 		keys = [dictionary retain];

 		serial++;

 	}	

     return self;

 }

 /* initialise object with an AV TXT record */

 - (AWEzvRendezvousData *)initWithAVTxt:(NSString *)txt {

     NSArray *attribs;

     NSString *key;

     self = [self init];

     attribs = [txt componentsSeparatedByString:@"\001"];

     for (key in attribs) {

 	NSRange range;

 	range = [key rangeOfString:@"="];

 	if (range.location != NSNotFound) {

 	    [self setField:[key substringToIndex:range.location]

 		   content:[key substringFromIndex:range.location+1]];

 	}

     }

     return self;

 }

 - (AWEzvRendezvousData *) initWithTXTRecordRef:(const unsigned char *) txtRecord length:(uint16_t)len{

 	self = [self init];

 	DNSServiceErrorType txtRecordError;

 	int i, numKeys;

 	numKeys = TXTRecordGetCount(len, txtRecord);

 	for (i=0; i<numKeys; i++) {

 		char key[256];

 		uint8_t valLen;

 		const void *value;

 		txtRecordError = TXTRecordGetItemAtIndex (

 			/* length */ len,

 			/* txtrecord */ txtRecord,

 			/* index */ i,

 			/* keybuffer length */ sizeof(key), 

 		    /* key buffer */ key,

 			/* valueLength */ &valLen,

 			/* value pointer */ &value );

 		if (txtRecordError == kDNSServiceErr_NoError) {

 			NSString *keyString = NULL;

 			NSString *data = NULL;

 			keyString = [NSString stringWithUTF8String: key];

 			if (value) {

 				data = [[[NSString alloc] initWithBytes: value length: valLen encoding: NSUTF8StringEncoding] autorelease];

 			}

 			if (data != NULL && keyString != NULL) {

 				[self setField:keyString content:data];

 			} else {

 				AWEzvLog(@"Creating TXTRecord: No data and No key");

 			}

 			/* AWEzvLog(@"key:%@ value=%@", keyString, data); */

 		} else {

 			AWEzvLog(@"Error reading txt keys");

 		}

 	}

 //	// kind of a hack: munge txtRecord so it's human-readable

 //	if ( len > 0) {

 //		char	*readableText = (char*) malloc( len);

 //		if ( readableText != nil) {

 //			ByteCount   index, subStrLen;

 //			memcpy( readableText, txtRecord, len);

 //			for ( index=0; index < len - 1; index += subStrLen + 1) {

 //				subStrLen = readableText[ index];

 //				readableText[ index] = '\n';

 //			}

 //			//NSLog(@"%@\n\n",[NSString stringWithCString:&readableText[1] length:len - 1]);

 //			free( readableText);

 //		}

 //	}

 	return self;

 }

 /* deallocate, destroy our dictionary */

 - (void)dealloc

 {

 	[keys release];

 	[super dealloc];

 }

 /* sets a field in the rendezvous data structures */

 -(void) setField:(NSString *)fieldName content:(NSObject *)content {

     if (content == nil || fieldName == nil)

         return;

     [keys setObject:content forKey:fieldName];

     serial++;

 }

 /* delete a field in the rendezvous data structure */

 -(void) deleteField:(NSString *)fieldName {

     if ([keys objectForKey:fieldName] != nil)

         [keys removeObjectForKey:fieldName];

 }

 /* get a field from the rendezvous data structure */

 -(NSString *) getField:(NSString *)fieldName {

     return [[[keys objectForKey:fieldName] copy] autorelease];

 }

 /* return if a field exists */

 -(BOOL) fieldExists:(NSString *)fieldName {

     return [keys objectForKey:fieldName] != nil;

 }

 /* return the serial number of the data */

 -(UInt32) serial {

     return serial;

 }

 /* return the dictionary */

 -(NSDictionary *)dictionary {

     return [[keys copy] autorelease];

 }

 /*

  * Generate data to be placed in the protocolSpecificInformation (TXT record)

  * of the rendezvous announcement. This is data shouldn't be used directly, but

  * should be used indirectly via dataAsDNSTXT or dataAsPackedPString

  */

 -(NSString *) data {

     NSMutableData   *data;		/* binary representation of rendezvous data */

     NSData	    *xmlData;		/* data converted to an XML plist */

     NSMutableString *infoData;		/* XML plist as a string */

     NSString *key;			/* strings used when manipulating data */

     id value;				/* value for data field */

     NSString	    *error;		/* error from creation of plist */

     UInt32	    keycount;		/* a 32-bit integer, count of keys in data */

     UInt16	    fieldlen;		/* a 16-bit integer, length of field being added to data */

     UInt16	    fieldlenBE;		/* fieldlen as converted to network byte order */

     UInt32      serialBE = htonl(serial); /* serial as converted to network byte order */

     /* allocate NSData to create data in */

     data = [[NSMutableData alloc] init];

     [data autorelease];

     /* add the subnegotiation string */

     [data appendBytes:[subn UTF8String] length:[subn length]];

     [data appendBytes:&serialBE length:4];

     [data appendBytes:[endn UTF8String] length:[endn length]];

     /* add a field containing the number of fields for the rest of the data */

     keycount = [keys count] + 1; /* +1 for slumming field */

     keycount = htonl(keycount);

     [data appendBytes:&keycount length:4];

     /* loop through fields to be added and add them to data */

 		for (key in keys) {	    

         /* add length of field name, then field name */

 		const char *field;

 		field = [key UTF8String];

 		fieldlen = strlen(field);

 		fieldlenBE = htons(fieldlen);

 		[data appendBytes:&fieldlenBE length:2];

 		[data appendBytes:field length:fieldlen];

         /* add length of field data, then field data */

         value = [keys objectForKey:key];

         if ([value isKindOfClass: [NSData class]]) {

 			field = [value bytes];

 			fieldlen = [(NSData *)value length];

             fieldlen = fieldlen | ~0x7FFF;

 		} else {

 			field = [value UTF8String];

 			fieldlen = strlen(field);

 		}

 		fieldlenBE = htons(fieldlen);

         [data appendBytes:&fieldlenBE length:2];

         if ([value isKindOfClass: [NSData class]]) {

 			fieldlen = [(NSData *)value length];

 		}

 		[data appendBytes:field length:fieldlen];

 	}

     /* we're slumming it in iChat-land */

     key = @"slumming";

     fieldlen = [key length];

     fieldlenBE = htons(fieldlen);

     [data appendBytes:&fieldlenBE length:2];

     [data appendBytes:[key UTF8String] length:[key length]];

     value = @"1";

     fieldlen = [(NSData *)value length];

     fieldlenBE = htons(fieldlen);

     [data appendBytes:&fieldlenBE length:2];

     [data appendBytes:[value UTF8String] length:[(NSData *)value length]];

     /* create XML plist of data and convert to string */

     xmlData = [NSPropertyListSerialization dataFromPropertyList:data

     				    format:NSPropertyListXMLFormat_v1_0

     				    errorDescription:&error];

     infoData = [[NSMutableString alloc] initWithData:xmlData encoding:NSUTF8StringEncoding];

     [infoData autorelease];

     /* and now we have the rendezvous data to return to the caller, the copy

        converts it to immutable */

     return [[infoData copy] autorelease];

 }

 /* 

  * Converts data: to a format appropriate for passing to service registration.

  * We add an ASCII 1 character every 255 characters for pascal string separation

  */

 -(NSString *)dataAsDNSTXT {

     NSMutableString	*infoData = [[[self data] mutableCopy] autorelease]; /* data to be done */

     unsigned long	i;	/* loop counter */

     /* add the character \001 when we exceed 255 characters, required to allow announcement

     to be longer than 255 characters */

     for (i = 255; i < [infoData length]; i += 255)

     {

 	[infoData insertString:@"\001" atIndex:i];

     }

     /* return a copy so it is immutable */

     return [[infoData copy] autorelease];

 }

 /* ichat AV style TXT record */

 -(NSString *)avDataAsDNSTXT {

     NSMutableString *infoData = [NSMutableString string];

     id value;

     NSString	    *key;

     [infoData appendString:@"\001txtvers=1"];

     [infoData appendString:@"\001version=1"];

     /* enumerate through fields for announcement */    

 		for (key in keys) {	    

 	[infoData appendString:@"\001"];	

 	[infoData appendString:key];

 	[infoData appendString:@"="];

 	value = [keys objectForKey:key];

 	if ([value isKindOfClass: [NSData class]]) {

 	    /* convert binary to hex */

 	    char *hexdata = (char *)malloc([(NSData *)value length] * 2 + 1);

 	    int i;

 	    for (i = 0; i < 20; i++) {

 		sprintf(hexdata + (i*2), "%.2x", ((unsigned char *)[(NSData *)value bytes])[i]);

 	    }

 	    hexdata[[(NSData *)value length] * 2] = '\0';

 	    [infoData appendString:[NSString stringWithUTF8String:hexdata]];

 	} else {

 	    [infoData appendString:value];

 	}

     }

     return infoData;

 }

 -(TXTRecordRef)dataAsTXTRecordRef {

 	//AWEzvLog(@"dataAsTXTRecordRef called");

 	TXTRecordRef txtRecord;

 	DNSServiceErrorType txtRecordError;

 	id value;

 	const char *valueToSet;

 	uint8_t valueSize;

 	TXTRecordCreate(/* TXTRecordRef */ &txtRecord, /* buffer length */ 0, /* buffer */ NULL);

 	/* Enumerate through keys setting the txtrecordvalue */

 	for (NSString *key in [keys keyEnumerator]) {		

 		value = [keys objectForKey:key];

 		 //AWEzvLog(@"key=%@ value=%@", key, value);

 		if ([value isKindOfClass: [NSData class]]) {

 		    /* convert binary to hex */

 		    char *hexdata = (char *)malloc([(NSData *)value length] * 2 + 1);

 		    int i;

 		    for (i = 0; i < 20; i++) {

 			sprintf(hexdata + (i*2), "%.2x", ((unsigned char *)[(NSData *)value bytes])[i]);

 		    }

 		    hexdata[[(NSData *)value length] * 2] = '\0';

 			valueToSet = [[NSString stringWithUTF8String:hexdata] UTF8String];

 			valueSize = strlen(valueToSet);

 			free(hexdata);

 		} else {

 		    valueToSet = [value UTF8String];

 			valueSize = strlen(valueToSet);

 		}

 		txtRecordError = TXTRecordSetValue (

 			/* TXTRecord */ &txtRecord,

 			/* key */ [key UTF8String],

 			/* size, may be zero */ valueSize,

 			/* value, may be null */ valueToSet);

 		if ((txtRecordError == kDNSServiceErr_Invalid) &&

 			[value isKindOfClass:[NSString class]]) {

 			/* kDNSServiceErr_Invalid may be returned if:

 			 *	1. Invalid characters were included (per documentation)

 			 *	2. The length of the value is >= 250 characters (at least for the msg key)

 			 *

 			 * So: First, try stripping out any non-ASCII characters, as I'm not sure what might consitute an

 			 * "illegal character" in a field which requests UTF8.

 			 *

 			 * Then, if that still fails, truncate the string to 248 characters (248,249,250 are the ellipsis).

 			 */

 			valueToSet = [[value dataUsingEncoding:NSASCIIStringEncoding allowLossyConversion:YES] bytes];

 			valueSize = strlen(valueToSet);

 			txtRecordError = TXTRecordSetValue (

 												/* TXTRecord */ &txtRecord,

 												/* key */ [key UTF8String],

 												/* size, may be zero */ valueSize,

 												/* value, may be null */ valueToSet);

 			if (txtRecordError == kDNSServiceErr_Invalid) {

 				valueToSet = [[value stringWithEllipsisByTruncatingToLength:248] UTF8String];

 				valueSize = strlen(valueToSet);

 				txtRecordError = TXTRecordSetValue (

 													/* TXTRecord */ &txtRecord,

 													/* key */ [key UTF8String],

 													/* size, may be zero */ valueSize,

 													/* value, may be null */ valueToSet);				

 			}

 		}

 		if (txtRecordError != kDNSServiceErr_NoError) {

 			if (txtRecordError == kDNSServiceErr_Invalid) {

 				AWEzvLog(@"Error setting TXTRecord of key=%@ and value=%s: Value contains illegal characters", key, valueToSet);

 			} else if (txtRecordError == kDNSServiceErr_NoMemory) {

 				AWEzvLog(@"Error setting TXTRecord of key=%@ and value=%s: Exceeded available storage", key, valueToSet);

 			} else {

 				AWEzvLog(@"Error setting TXTRecord of key=%@ and value=%s: Error is %i", key, valueToSet, txtRecordError);

 			}

 		}

 	}

 	return txtRecord;

 }

 /*

  * Converts data: to packed PString format as required by the low level rendezvous

  * functions when passing an opaque RData structure

  */

 -(NSData *) dataAsPackedPString {

     NSString		*origdata = [self data];	/* original data */

     NSMutableData	*data = [NSMutableData data];	/* modified data to return */

     unsigned char	pstring[256];			/* pascal string under construction */

     unsigned long	i;				/* loop counter */

     /* initialise pstring */

     pstring[0] = 0;

     /* create strings */

     for (i = 0; i < [origdata length]; i++) {

 	pstring[0]++;

 	pstring[pstring[0]] = [origdata characterAtIndex:i];

 	if (pstring[0] == 254 || i == [origdata length] - 1) {

 	    [data appendBytes:(char *)&pstring length:pstring[0] + 1];

 	    pstring[0] = 0;

 	}

     }

     /* return copy so it is immutable */

     return [[data copy] autorelease];

 }

 /* ichat AV style TXT record */

 -(NSData *)avDataAsPackedPString {

     NSMutableString *infoData = [NSMutableString string];

     id value;

     NSString	    *key;

     const char *data;

     [infoData appendString:@"\x09txtvers=1"];

     [infoData appendString:@"\x09version=1"];

     /* enumerate through fields for announcement */    

 		for (key in keys) {

 		/* convert binary to hex */

 		char *hexdata;

 		int i;

 		value = [keys objectForKey:key];

 		if ([value isKindOfClass:[NSData class]]) {

 			hexdata = (char *)malloc([(NSData *)value length] * 2 + 1);

 			for (i = 0; i < 20; i++) {

 				sprintf(hexdata + (i*2), "%.2x", ((unsigned char *)[(NSData *)value bytes])[i]);

 			}

 			hexdata[[(NSData *)value length] * 2] = '\0';

 			[infoData appendFormat:@"%c", ([(NSData *)value length] * 2 + [key length] + 1)];

 			[infoData appendString:key];

 			[infoData appendString:@"="];

 			[infoData appendString:[NSString stringWithUTF8String:hexdata]];

 			free(hexdata);

 		} else {

 			const char *val = [(NSString *)value UTF8String];

 			int len = strlen(val);

 			[infoData appendFormat:@"%c", len + [key length] + 1];

 			[infoData appendString:key];

 			[infoData appendString:@"="];

 			[infoData appendString:value];

 		}

     }

 	data = [infoData UTF8String];

 	return [NSData dataWithBytes:data length:strlen(data)];

 }

 @end