//
//  KSHTMLWriter.m
//
//  Copyright (c) 2010, Mike Abdullah and Karelia Software
//  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.
//  
//  THIS SOFTWARE 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 MIKE ABDULLAH OR KARELIA SOFTWARE 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 "KSHTMLWriter.h"

#import "KSXMLAttributes.h"


NSString *KSHTMLWriterDocTypeHTML_4_01_Strict = @"HTML PUBLIC \"-//W3C//DTD HTML 4.01//EN\" \"http://www.w3.org/TR/html4/strict.dtd\"";
NSString *KSHTMLWriterDocTypeHTML_4_01_Transitional = @"HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\" \"http://www.w3.org/TR/html4/loose.dtd\"";
NSString *KSHTMLWriterDocTypeHTML_4_01_Frameset = @"HTML PUBLIC \"-//W3C//DTD HTML 4.01 Frameset//EN\" \"http://www.w3.org/TR/html4/frameset.dtd\"";
NSString *KSHTMLWriterDocTypeXHTML_1_0_Strict = @"html PUBLIC \"-//W3C//DTD XHTML 1.0 Strict//EN\" \"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd\"";
NSString *KSHTMLWriterDocTypeXHTML_1_0_Transitional = @"html PUBLIC \"-//W3C//DTD XHTML 1.0 Transitional//EN\" \"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd\"";
NSString *KSHTMLWriterDocTypeXHTML_1_0_Frameset = @"html PUBLIC \"-//W3C//DTD XHTML 1.0 Frameset//EN\" \"http://www.w3.org/TR/xhtml1/DTD/xhtml1-frameset.dtd\"";
NSString *KSHTMLWriterDocTypeXHTML_1_1 = @"html PUBLIC \"-//W3C//DTD XHTML 1.1//EN\" \"http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd\"";
NSString *KSHTMLWriterDocTypeHTML_5 = @"html";


@interface KSHTMLWriter ()
@property(nonatomic, copy, readwrite) NSString *docType;
@end


@implementation KSHTMLWriter

#pragma mark Creating an HTML Writer

- (id)initWithOutputWriter:(id <KSWriter>)output;
{
  self = [super initWithOutputWriter:output];
  if (self != nil) {
    [self setDocType:KSHTMLWriterDocTypeHTML_5];
    _IDs = [[NSMutableSet alloc] init];
    _classNames = [[NSMutableArray alloc] init];
  }  
  return self;
}

- (id)initWithOutputWriter:(id <KSWriter>)output docType:(NSString *)docType encoding:(NSStringEncoding)encoding;
{
  if (self = [self initWithOutputWriter:output encoding:encoding])
  {
    [self setDocType:docType];
  }
  
  return self;
}


#pragma mark DTD

- (void)startDocumentWithDocType:(NSString *)docType encoding:(NSStringEncoding)encoding;
{
  [self setDocType:docType];
  [super startDocumentWithDocType:docType encoding:encoding];
}

@synthesize docType = _docType;
- (void)setDocType:(NSString *)docType;
{
  docType = [docType copy];
   _docType = docType;
  
  _isXHTML = [[self class] isDocTypeXHTML:docType];
}

- (BOOL)isXHTML; { return _isXHTML; }

+ (BOOL)isDocTypeXHTML:(NSString *)docType;
{
  BOOL result = !([docType isEqualToString:KSHTMLWriterDocTypeHTML_4_01_Strict] ||
                  [docType isEqualToString:KSHTMLWriterDocTypeHTML_4_01_Transitional] ||
                  [docType isEqualToString:KSHTMLWriterDocTypeHTML_4_01_Frameset]);
  return result;
}

#pragma mark CSS Class Name

- (NSString *)currentElementClassName;
{
  NSString *result = nil;
  if ([_classNames count])
  {
    result = [_classNames componentsJoinedByString:@" "];
  }
  return result;
}

- (void)pushClassName:(NSString *)className;
{
#ifdef DEBUG
  if ([_classNames containsObject:className])
  {
    NSLog(@"Adding class \"%@\" to an element twice", className);
  }
#endif
  
  [_classNames addObject:className];
}

- (void)pushAttribute:(NSString *)attribute value:(id)value;
{
  if ([attribute isEqualToString:@"class"])
  {
    return [self pushClassName:value];
  }
  
  // Keep track of IDs in use
  if ([attribute isEqualToString:@"id"]) [_IDs addObject:value];
  [super pushAttribute:attribute value:value];
}

- (KSXMLAttributes *)currentAttributes;
{
  KSXMLAttributes *result = [super currentAttributes];
  
  // Add in buffered class info
  NSString *class = [self currentElementClassName];
  if (class) [result addAttribute:@"class" value:class];
  
  return result;
}

- (BOOL)hasCurrentAttributes;
{
  return ([super hasCurrentAttributes] || [_classNames count]);
}

#pragma mark HTML Fragments

- (void)writeHTMLString:(NSString *)html;
{
  [self writeString:html];
}

- (void)writeHTMLFormat:(NSString *)format , ...
{
	va_list argList;
	va_start(argList, format);
	NSString *aString = [[NSString alloc] initWithFormat:format arguments:argList];
	va_end(argList);
	
  [self writeHTMLString:aString];
}

#pragma mark General

- (void)startElement:(NSString *)tagName className:(NSString *)className;
{
  [self startElement:tagName idName:nil className:className];
}

- (void)startElement:(NSString *)tagName idName:(NSString *)idName className:(NSString *)className;
{
  if (idName) [self pushAttribute:@"id" value:idName];
  if (className) [self pushAttribute:@"class" value:className];
  
  [self startElement:tagName];
}

- (BOOL)isIDValid:(NSString *)anID; // NO if the ID has already been used
{
  BOOL result = ![_IDs containsObject:anID];
  return result;
}

#pragma mark Line Break

- (void)writeLineBreak;
{
  [self startElement:@"br"];
  [self endElement];
}

#pragma mark Higher-level Tag Writing

- (void)startAnchorElementWithHref:(NSString *)href title:(NSString *)titleString target:(NSString *)targetString rel:(NSString *)relString;
{
	if (href) [self pushAttribute:@"href" value:href];
	if (targetString) [self pushAttribute:@"target" value:targetString];
	if (titleString) [self pushAttribute:@"title" value:titleString];
	if (relString) [self pushAttribute:@"rel" value:relString];
	
  [self startElement:@"a"];
}

- (void)writeImageWithSrc:(NSString *)src
                      alt:(NSString *)alt
                    width:(id)width
                   height:(id)height;
{
  [self pushAttribute:@"src" value:src];
  [self pushAttribute:@"alt" value:alt];
  if (width) [self pushAttribute:@"width" value:width];
  if (height) [self pushAttribute:@"height" value:height];
  
  [self startElement:@"img"];
  [self endElement];
}

#pragma mark Link

- (void)writeLinkWithHref:(NSString *)href
                     type:(NSString *)type
                      rel:(NSString *)rel
                    title:(NSString *)title
                    media:(NSString *)media;
{
  if (rel) [self pushAttribute:@"rel" value:rel];
  if (!type) type = @"text/css";  [self pushAttribute:@"type" value:type];
  [self pushAttribute:@"href" value:href];
  if (title) [self pushAttribute:@"title" value:title];
  if (media) [self pushAttribute:@"media" value:media];
  
  [self startElement:@"link"];
  [self endElement];
}

- (void)writeLinkToStylesheet:(NSString *)href
                        title:(NSString *)title
                        media:(NSString *)media;
{
  [self writeLinkWithHref:href type:nil rel:@"stylesheet" title:title media:media];
}

#pragma mark Scripts

- (void)writeJavascriptWithSrc:(NSString *)src encoding:(NSStringEncoding)encoding;
{
  // According to the HTML spec, charset only needs to be specified if the script is a different encoding to the document
  NSString *charset = nil;
  if (encoding != [self encoding])
  {
    charset = (__bridge NSString *)CFStringConvertEncodingToIANACharSetName(CFStringConvertNSStringEncodingToEncoding(encoding));
  }
  
  [self writeJavascriptWithSrc:src charset:charset];
}

- (void)writeJavascriptWithSrc:(NSString *)src charset:(NSString *)charset;	// src may be nil
{    
  if (charset) [self pushAttribute:@"charset" value:charset];
  [self startJavascriptElementWithSrc:src];
  [self endElement];
}

- (void)writeJavascript:(NSString *)script useCDATA:(BOOL)useCDATA;
{
  [self startJavascriptElementWithSrc:nil];
  
  if (useCDATA) [self startJavascriptCDATA];
  [self writeString:script];
  if (useCDATA) [self endJavascriptCDATA];
  
  [self endElement];
}

- (void)startJavascriptElementWithSrc:(NSString *)src;  // src may be nil
{
  // HTML5 doesn't need the script type specified, but older doc types do for standards-compliance
  if (![[self docType] isEqualToString:KSHTMLWriterDocTypeHTML_5])
  {
    [self pushAttribute:@"type" value:@"text/javascript"];
  }
  
  // Script
  if (src)
	{
		[self pushAttribute:@"src" value:src];
	}
  
  [self startElement:@"script"];
  
  // Embedded scripts should start on their own line for clarity
  if (!src)
  {
    [self writeString:@"\n"];
    [self stopWritingInline];
  }
}

- (void)startJavascriptCDATA;
{
  [self writeString:@"\n/* "];
  [self startCDATA];
  [self writeString:@" */"];
}

- (void)endJavascriptCDATA;
{
  [self writeString:@"\n/* "];
  [self endCDATA];
  [self writeString:@" */\n"];
}

#pragma mark Param

- (void)writeParamElementWithName:(NSString *)name value:(NSString *)value;
{
	if (name) [self pushAttribute:@"name" value:name];
	if (value) [self pushAttribute:@"value" value:value];
  [self startElement:@"param"];
  [self endElement];
}

#pragma mark Style

- (void)writeStyleElementWithCSSString:(NSString *)css;
{
  [self startStyleElementWithType:@"text/css"];
  [self writeString:css]; // browsers don't expect styles to be XML escaped
  [self endElement];
}

- (void)startStyleElementWithType:(NSString *)type;
{
  if (type) [self pushAttribute:@"type" value:type];
  [self startElement:@"style"];
}

#pragma mark Elements Stack

- (BOOL)topElementIsList;
{
  NSString *tagName = [self topElement];
  BOOL result = ([tagName isEqualToString:@"ul"] ||
                 [tagName isEqualToString:@"ol"]);
  return result;
}

#pragma mark (X)HTML

- (BOOL)elementCanBeEmpty:(NSString *)tagName;
{
  if ([tagName isEqualToString:@"br"] ||
      [tagName isEqualToString:@"img"] ||
      [tagName isEqualToString:@"hr"] ||
      [tagName isEqualToString:@"meta"] ||
      [tagName isEqualToString:@"link"] ||
      [tagName isEqualToString:@"input"] ||
      [tagName isEqualToString:@"base"] ||
      [tagName isEqualToString:@"basefont"] ||
      [tagName isEqualToString:@"param"] ||
      [tagName isEqualToString:@"area"] ||
      [tagName isEqualToString:@"source"]) return YES;
  
  return NO;
}

- (BOOL)canWriteElementInline:(NSString *)tagName;
{
  switch ([tagName length])
  {
    case 1:
      if ([tagName isEqualToString:@"a"] ||
          [tagName isEqualToString:@"b"] ||
          [tagName isEqualToString:@"i"] ||
          [tagName isEqualToString:@"u"] ||
          [tagName isEqualToString:@"q"]) return YES;
      break;
      
    case 2:
      if ([tagName isEqualToString:@"br"] ||
          [tagName isEqualToString:@"em"] ||
          [tagName isEqualToString:@"tt"]) return YES;
      break;
      
    case 3:
      if ([tagName isEqualToString:@"img"] ||
          [tagName isEqualToString:@"sup"] ||
          [tagName isEqualToString:@"sub"] ||
          [tagName isEqualToString:@"big"] ||
          [tagName isEqualToString:@"del"] ||
          [tagName isEqualToString:@"ins"] ||
          [tagName isEqualToString:@"dfn"] ||
          [tagName isEqualToString:@"map"] ||
          [tagName isEqualToString:@"var"] ||
          [tagName isEqualToString:@"bdo"] ||
          [tagName isEqualToString:@"kbd"]) return YES;
      break;
      
    case 4:
      if ([tagName isEqualToString:@"span"] ||
          [tagName isEqualToString:@"font"] ||
          [tagName isEqualToString:@"abbr"] ||
          [tagName isEqualToString:@"cite"] ||
          [tagName isEqualToString:@"code"] ||
          [tagName isEqualToString:@"samp"]) return YES;
      break;
      
    case 5:
      if ([tagName isEqualToString:@"small"] ||
          [tagName isEqualToString:@"input"] ||
          [tagName isEqualToString:@"label"]) return YES;
      break;
      
    case 6:
      if ([tagName isEqualToString:@"strong"] ||
          [tagName isEqualToString:@"select"] ||
          [tagName isEqualToString:@"button"] ||
          [tagName isEqualToString:@"object"] ||
          [tagName isEqualToString:@"applet"] ||
          [tagName isEqualToString:@"script"]) return YES;
      break;
      
    case 7:
      if ([tagName isEqualToString:@"acronym"]) return YES;
      break;
      
    case 8:
      if ([tagName isEqualToString:@"textarea"]) return YES;
      break;
  }
  
  return [super canWriteElementInline:tagName];
}

- (BOOL)validateElement:(NSString *)element;
{
  if (![super validateElement:element]) return NO;
  
  // Lists can only contain list items
  if ([self topElementIsList])
  {
    return [element isEqualToString:@"li"];
  }
  else
  {
    return YES;
  }
}

- (NSString *)validateAttribute:(NSString *)name value:(NSString *)value ofElement:(NSString *)element;
{
  NSString *result = [super validateAttribute:name value:value ofElement:element];
  if (!result) return nil;
  
  // value is only allowed as a list item attribute when in an ordered list
  if ([element isEqualToString:@"li"] && [name isEqualToString:@"value"])
  {
    if (![[self topElement] isEqualToString:@"ol"]) result = nil;
  }
  
  return result;
}

#pragma mark Element Primitives

- (void)startElement:(NSString *)elementName writeInline:(BOOL)writeInline; // for more control
{
  NSAssert1([elementName isEqualToString:[elementName lowercaseString]], @"Attempt to start non-lowercase element: %@", elementName);
  
  
  // Add in any pre-written classes
  NSString *class = [self currentElementClassName];
  if (class)
  {
    [_classNames removeAllObjects];
    [super pushAttribute:@"class" value:class];
  }
  
  [super startElement:elementName writeInline:writeInline];
}

- (void)closeEmptyElementTag;               //   />    OR    >    depending on -isXHTML
{
  if ([self isXHTML])
  {
    [super closeEmptyElementTag];
  }
  else
  {
    [self writeString:@">"];
  }
}

@end