/*
 Copyright (C) 2000-2004 Max Berger
 
 This file is part of versitSaxDriver, written for the OpenGroupware.org 
 project (OGo).
 
 OGo is free software; you can redistribute it and/or modify it under
 the terms of the GNU Lesser General Public License as published by the
 Free Software Foundation; either version 2, or (at your option) any
 later version.
 
 OGo is distributed in the hope that it will be useful, but WITHOUT ANY
 WARRANTY; without even the implied warranty of MERCHANTABILITY or
 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
 License for more details.
 
 You should have received a copy of the GNU Lesser General Public
 License along with OGo; see the file COPYING.  If not, write to the
 Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA
 02111-1307, USA.
*/
// $Id$

#include "VersitSaxDriver.h"
#include "common.h"

@implementation VersitSaxDriver

static BOOL doDebug = NO;

+ (void)initialize
{
  NSUserDefaults *ud = [NSUserDefaults standardUserDefaults];
  static BOOL didInit = NO;
  if (didInit) return;
  didInit = YES;
  
  doDebug   = [ud boolForKey:@"OGoDebugVersitSaxDriver"];  
}


+ (NSCharacterSet *)newlineCharacterSet {
  return [NSCharacterSet characterSetWithCharactersInString:@"\x0a\x0d\x85"];
}

- (id)init {
  [VersitSaxDriver initialize];
  if ((self = [super init])) {
    self->prefixURI         = @"";
    self->cardStack         = [[NSMutableArray alloc]      init];
    self->elementList       = [[NSMutableArray alloc]      init];
    self->attributeMapping  = [[NSMutableDictionary alloc] init];
    self->subItemMapping    = [[NSMutableDictionary alloc] init];
  }
  return self;
}

- (void)dealloc {
  [self->contentHandler    release];
  [self->prefixURI         release];
  [self->cardStack         release];
  [self->elementList       release];
  [self->attributeElements release];
  [self->elementMapping    release];
  [self->attributeMapping  release];
  [self->subItemMapping    release];
  [super dealloc];
}

/* accessors */

- (void)setFeature:(NSString *)_name to:(BOOL)_value {
}
- (BOOL)feature:(NSString *)_name {
  return NO;
}

- (void)setProperty:(NSString *)_name to:(id)_value {
}
- (id)property:(NSString *)_name {
  return nil;
}

/* handlers */

- (void)setContentHandler:(id<NSObject,SaxContentHandler>)_handler {
  ASSIGN(self->contentHandler,_handler);
}

- (void)setDTDHandler:(id<NSObject,SaxDTDHandler>)_handler {
  // FIXME
}

- (void)setErrorHandler:(id<NSObject,SaxErrorHandler>)_handler {
  // FIXME
}
- (void)setEntityResolver:(id<NSObject,SaxEntityResolver>)_handler {
  // FIXME
}

- (id<NSObject,SaxContentHandler>)contentHandler {
  return self->contentHandler;
}

- (id<NSObject,SaxDTDHandler>)dtdHandler {
  // FIXME
  return NULL;
}

- (id<NSObject,SaxErrorHandler>)errorHandler {
  // FIXME
  return NULL;
}
- (id<NSObject,SaxEntityResolver>)entityResolver {
  // FIXME
  return NULL;
}

- (void)setPrefixURI:(NSString *)_uri {
  ASSIGNCOPY(self->prefixURI, _uri);
}
- (NSString *)prefixURI {
  return self->prefixURI;
}

- (void)setAttributeElements:(NSSet *)_elements {
  ASSIGNCOPY(self->attributeElements, _elements);
}
- (NSSet *)attributeElements {
  return self->attributeElements;
}

- (void)setElementMapping:(NSDictionary *)_mapping {
  ASSIGNCOPY(self->elementMapping, _mapping);
}
- (NSDictionary *)elementMapping {
  return self->elementMapping;
}

- (void)setAttributeMapping:(NSDictionary *)_mapping {
  [self setAttributeMapping:_mapping forElement:@""];
}

- (void)setAttributeMapping:(NSDictionary *)_mapping 
  forElement:(NSString *)_element 
{
  if (_element==NULL) _element = @"";
  [attributeMapping setObject:_mapping forKey:_element];
}

- (void)setSubItemMapping:(NSArray *)_mapping 
  forElement:(NSString *)_element 
{
  [subItemMapping setObject:_mapping forKey:_element];  
}



/* parsing */

- (NSString *)_mapTagName:(NSString *)_tagName {
  NSString       *ret;
  NSRange        range;
  NSCharacterSet *dotSet;

  if ((ret = [self->elementMapping objectForKey:_tagName]) == nil) {
    //NSLog(@"Unknown Key: %@ in %@",_tagName,self->elementMapping);
    ret = _tagName;

    /* This is to allow parsing of vCards produced by Apple
       Addressbook. AFAIK the .dot notation is a non-standard
       extension */
    dotSet = [NSCharacterSet characterSetWithCharactersInString:@"."];
    range = [_tagName rangeOfCharacterFromSet:dotSet];
    if ((range.location > 0) && (range.location < [_tagName length])) {
      NSString *s;
      
      s = [_tagName substringFromIndex:(range.location + 1)];
      ret = [self _mapTagName:s];
    }
  }
  return ret;
}

- (void)_addAttribute:(NSString *)_attribute value:(NSString *)_value 
  toAttrs:(SaxAttributes *)_attrs
{
  [_attrs addAttribute:_attribute uri:self->prefixURI 
	  rawName:_attribute type:@"CDATA" value:_value];
}

- (void)_addAttribute:(NSString *)_attribute value:(NSString *)_value {
  NSArray *element = [cardStack lastObject];
  SaxAttributes *attrs = [element objectAtIndex:2];
  [self _addAttribute:_attribute value:_value toAttrs:attrs];
}

- (NSString *)_mapAttrName:(NSString *)_attrName forTag:(NSString *)_tagName {
  NSDictionary *map;
  NSString *mappedName;

  map        = [self->attributeMapping objectForKey:_tagName];
  mappedName = [map objectForKey:_attrName];
  if (mappedName == nil) {
    map = [self->attributeMapping objectForKey:[self _mapTagName:_tagName]];
    mappedName = [map objectForKey:_attrName];
  }
  if (mappedName == nil) {
    map = [self->attributeMapping objectForKey:@""];
    mappedName = [map objectForKey:_attrName];
  }
  if (mappedName == nil)
    mappedName = _attrName;
  
  return mappedName;
}

- (void)_parseAttr:(NSString *)_attr 
  forTag:(NSString *)_tagName
  intoAttr:(NSString **)attr_
  intoValue:(NSString **)value_
{
  NSCharacterSet  *equalSign = 
    [NSCharacterSet characterSetWithCharactersInString:@"="];
  NSCharacterSet  *commaSign = 
    [NSCharacterSet characterSetWithCharactersInString:@","];
  NSRange         range;
  NSString        *attrName   = nil;
  NSMutableString *attrValue  = nil;
  NSString        *mappedName = nil;

  
  range = [_attr rangeOfCharacterFromSet:equalSign];
  
  /* Unfortunately this is the only way it works with OSX and libFondation */
  if ((range.location > 0) && (range.location < [_attr length])){
    attrName  = [[_attr substringToIndex:range.location] uppercaseString];
    attrValue = [[_attr substringFromIndex:(range.location + 1)] mutableCopy];
  } 
  else {
    attrName  = @"TYPE";
    attrValue = [[NSMutableString alloc]initWithString:_attr];
  }
  mappedName = [self _mapAttrName:attrName forTag:_tagName];
  
  range = [attrValue rangeOfCharacterFromSet:commaSign];
  while ((range.location > 0) && (range.location < [attrValue length])){
    [attrValue replaceCharactersInRange:range withString:@" "];
    range = [attrValue rangeOfCharacterFromSet:commaSign];
  }

  *attr_ = attrName;
  *value_ = [NSString stringWithString:attrValue];
  [attrValue release];
}

- (id<NSObject,SaxAttributes>)_mapAttrs:(NSArray *)_attrs 
  forTag:(NSString *)_tagName 
{
  SaxAttributes       *retAttrs;
  NSEnumerator        *enu;
  NSString            *curAttr=nil;
  NSString            *mappedAttr=nil;
  NSString            *mappedValue=nil;
  NSString            *oldValue=nil;
  NSMutableDictionary *attributes=[[NSMutableDictionary alloc]init];
  
  if ([_attrs count]==0)
    return NULL;
  
  retAttrs = [[SaxAttributes alloc]init];
  enu = [_attrs objectEnumerator];
  while ((curAttr=[enu nextObject])) {
    [self _parseAttr:curAttr forTag:_tagName
      intoAttr:&mappedAttr intoValue:&mappedValue];
    
    if ((oldValue=[attributes objectForKey:mappedAttr])) {
      [attributes setObject:
        [NSString stringWithFormat:@"%@ %@",oldValue,mappedValue] 
        forKey:mappedAttr];
    }
    else  
      [attributes setObject:mappedValue forKey:mappedAttr];
  }

  enu = [attributes keyEnumerator];
  while ((curAttr=[enu nextObject])) {
    [self _addAttribute:curAttr 
      value:[attributes objectForKey:curAttr] toAttrs:retAttrs];
  }
  
  [attributes release];
  
  return [retAttrs autorelease];
}

- (NSArray *)_beginTag:(NSString *)_tagName 
  withAttrs:(id<NSObject,SaxAttributes>)_attrs 
{
  NSArray *tag;
  
  tag = [NSArray arrayWithObjects:@"BEGIN" ,_tagName, _attrs, NULL];
  [self->elementList addObject:tag];
  return tag;
}

- (void)_endTag:(NSString *)_tagName {
  NSArray *tag;
  
  tag = [NSArray arrayWithObjects:@"END",_tagName,NULL];
  [self->elementList addObject:tag];
}

- (void)_addSubItems:(NSArray *)_items withData:(NSString *)_content {
  NSEnumerator *itemEnum, *contentEnum;
  NSString *subTag;
  NSString *subContent;
  
  itemEnum    = [_items objectEnumerator];
  contentEnum = [[_content componentsSeparatedByString:@";"] objectEnumerator];
  
  while ((subTag=[itemEnum nextObject])) {
    subContent = [contentEnum nextObject];
    
    [self _beginTag:subTag withAttrs:nil];
    if ([subContent length]>0) 
      [self->elementList addObject:
        [NSArray arrayWithObjects:@"DATA", subContent, nil]];  
    [self _endTag:subTag];
  }
}

- (void)_dataTag:(NSString *)_tagName 
  withAttrs:(id<NSObject,SaxAttributes>)_attrs 
  andContent:(NSString *)_content 
{
  NSArray *subItems;
  
  if ([self->attributeElements containsObject:_tagName]) {
    [self _addAttribute:_tagName value:_content];
  } 
  else {
    [self _beginTag:_tagName withAttrs:_attrs];
    if ([_content length] > 0) {
      if ((subItems=[self->subItemMapping objectForKey:_tagName])) {
        [self _addSubItems:subItems withData:_content];
      }
      else {
        NSArray *tag;

        tag = [[NSArray alloc] initWithObjects:@"DATA", _content, nil];
        [self->elementList addObject:tag];
        [tag release];
      }
    }
    [self _endTag:_tagName];
  }
}

- (void)_eventsForElements {
  NSEnumerator *enu;
  NSArray  *obj;
  NSString *type;
  NSString *name;
  unichar  *chardata;
  id<NSObject,SaxAttributes> attrs = nil;
  
  enu = [elementList objectEnumerator];
  while ((obj = [enu nextObject])) {
    type = [obj objectAtIndex:0];
    name = [obj objectAtIndex:1];
    attrs = nil;
    
    if ([obj count] > 2) 
      attrs = [obj objectAtIndex:2];
    
    if ([type isEqual:@"BEGIN"]) {
      [self->contentHandler
         startElement:name
         namespace:self->prefixURI
         rawName:name
         attributes:attrs];
    } 
    else if ([type isEqual:@"END"]) {
      [self->contentHandler
        endElement:name
        namespace:self->prefixURI
        rawName:name];  
    } 
    else {
      chardata = malloc(([name length] + 2) * sizeof(unichar));
      [name getCharacters:chardata];
      [self->contentHandler characters:chardata length:[name length]];
      if (chardata) free(chardata);
    }
  }
  [elementList removeAllObjects];
}

- (void)_parseLine:(NSString *)_line {
  NSCharacterSet *colonAndSemicolon;
  NSScanner *theScanner;
  NSString *tagName;
  NSString *tagAttribute;
  NSString *tagValue;
  NSMutableArray *tagAttributes;
  
  colonAndSemicolon = 
    [NSCharacterSet characterSetWithCharactersInString:@":;"];
  theScanner    = [NSScanner scannerWithString:_line];
  tagAttributes = [[NSMutableArray alloc] init];
 
  tagName = @""; 
  [theScanner scanUpToCharactersFromSet:colonAndSemicolon intoString:&tagName];

  while ([theScanner scanString:@";" intoString:NULL]) {
    [theScanner scanUpToCharactersFromSet:colonAndSemicolon 
		intoString:&tagAttribute];
    [tagAttributes addObject:tagAttribute];
  }
  [theScanner scanString:@":" intoString:NULL];
  tagValue = [_line substringFromIndex:[theScanner scanLocation]];
  
  //NSLog (@"%@ %@ %@",tagName,tagAttributes, tagValue);
  
  tagName = [tagName uppercaseString];
  
  if ([tagName isEqual:@"BEGIN"]) {
    id obj;

    obj = [self _beginTag:[self _mapTagName:tagValue] 
                withAttrs:[[[SaxAttributes alloc] init] autorelease]];
    [self->cardStack addObject:obj];
  } 
  else if ([tagName isEqual:@"END"]) {
    [self _endTag:[self _mapTagName:tagValue]];
    [self->cardStack removeLastObject];
    if ([self->cardStack count]==0) [self _eventsForElements];
  }
  else {
    [self _dataTag:[self _mapTagName:tagName] 
	  withAttrs:[self _mapAttrs:tagAttributes forTag:tagName] 
	  andContent:tagValue];
  }
  
  [tagAttributes release];
}

- (void)_parseString:(NSString *)_stringData {
  int     position;
  BOOL    newline = NO;
  unichar c;
  int     lineLength = 1024;
  unichar *currentLine;
  int     linePos = 0;

  currentLine = malloc( (lineLength + 1 ) * (sizeof(unichar)));
  
  [self->contentHandler startDocument];
  [self->contentHandler startPrefixMapping:@"" uri:self->prefixURI];
  
  for (position = 0; position < [_stringData length]; position++) {
    c = [_stringData characterAtIndex:position];
    
    if ([[VersitSaxDriver newlineCharacterSet] characterIsMember:c]) {
      newline = YES;
      continue;
    }

    if (newline) {
        if ([[NSCharacterSet whitespaceCharacterSet]characterIsMember:c]) {
          // unfold
        } 
	else {
          NSString *line;
          
          line = [[NSString alloc] initWithCharacters:currentLine 
                                   length:linePos];
          [self _parseLine:line];
          [line release];
          currentLine[0] = c;
          linePos = 1;
        }
        newline = NO;
    } 
    else {
        currentLine[linePos] = c;
        linePos++;
        if (linePos >= lineLength) {
          lineLength += 1024;
          currentLine = realloc(currentLine, 
				( lineLength + 2 ) * (sizeof(unichar)));
        }
    }
  }
  [self _parseLine:[NSString stringWithCharacters:currentLine length:linePos]];
  if (currentLine) free(currentLine);
  
  [self->contentHandler endPrefixMapping:@""];
  [self->contentHandler endDocument];
}

- (void)parseFromSource:(id)_source {
  if (doDebug)
    NSLog(@"%s: parse: %@", __PRETTY_FUNCTION__, _source);
  
  if ([_source isKindOfClass:[NSURL class]]) {
    if (doDebug) 
      NSLog(@"%s: trying to load URL...",__PRETTY_FUNCTION__);
    _source = [_source resourceDataUsingCache:NO];
  }
  
  if ([_source isKindOfClass:[NSData class]]) {
    // FIXME: Data is not always utf-8.....
    if (doDebug) 
      NSLog(@"%s: trying to decode data...",__PRETTY_FUNCTION__);
    _source = [[[NSString alloc]
		 initWithData:_source encoding:NSUTF8StringEncoding]
		 autorelease];
  }
  
  if ([_source isKindOfClass:[NSString class]]) {
    if (doDebug) 
      NSLog(@"%s: trying to parse string...",__PRETTY_FUNCTION__);
    [self _parseString:_source];
  } 
  else {
    if (doDebug) 
      NSLog(@"%s: unrecognizable source: %@", __PRETTY_FUNCTION__,_source);
    // FIXME: Return Error
  }
}

- (void)parseFromSource:(id)_source systemId:(NSString *)_sysId {
  [self parseFromSource:_source];
}

- (void)parseFromSystemId:(NSString *)_sysId {
  NSURL *url;
  
  if ((url = [NSURL URLWithString:_sysId]))
    [self parseFromSource:url systemId:_sysId];
}

/* debugging */

- (BOOL)isDebuggingEnabled {
  return doDebug;
}

@end /* VersitSaxDriver */