/*

 * 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