Uncruft iOS 8.0 and OS X 10.10 API diffs

uncruftapidiff.m

//
//  Copyright (c) 2014 Cédric Luthi “0xced”
//
// ./uncruftapidiff https://developer.apple.com/library/prerelease/ios/releasenotes/General/iOS80APIDiffs/index.html iOS8_0APIDiffs.html
// ./uncruftapidiff https://developer.apple.com/library/prerelease/mac/documentation/General/Reference/APIDiffsMacOSX10_10SeedDiff/index.html OSX10_10APIDiffs.html
//

#import <Foundation/Foundation.h>
#import <sysexits.h>

void TerminateIf(BOOL condition, int exitCode, NSString *message)
{
	if (condition)
	{
		fprintf(stderr, "%s\n", [message.description UTF8String]);
		exit(exitCode);
	}
}

@interface NSXMLNode (removeFromParent)

- (void) removeFromParent;

@end

@implementation NSXMLNode (removeFromParent)

- (void) removeFromParent
{
	NSUInteger childIndex = [self.parent.children indexOfObjectIdenticalTo:self];
	
	if ([self.parent isKindOfClass:[NSXMLElement class]] && childIndex != NSNotFound)
		[(NSXMLElement *)self.parent removeChildAtIndex:childIndex];
	else
		TerminateIf(YES, EX_SOFTWARE, @"Trying to remove a non element node");
}

@end

void RemoveNodesMatchingXPath(NSXMLDocument *document, NSString *xpath)
{
	NSError *error;
	NSArray *nodes = [document nodesForXPath:xpath error:&error];
	TerminateIf(nodes == nil, EX_SOFTWARE, error.description);
	
	for (NSXMLNode *node in nodes)
		[node removeFromParent];
}

void RemoveMethodToProperties(NSXMLDocument *document)
{
	NSArray *addedElements = [document nodesForXPath:@"//div[@class='headerFile']/div[@class='added']/div[@class='symbolName']" error:NULL];
	for (NSXMLElement *addedElement in addedElements)
	{
		BOOL removed = NO;
		NSString *addedTitle = [[[addedElement attributeForName:@"title"] stringValue] lowercaseString];
		if ([addedTitle hasPrefix:@"//apple_ref/occ/intfp"] || [addedTitle hasPrefix:@"//apple_ref/occ/instp"])
		{
			NSArray *removedElements = [addedElement.parent.parent nodesForXPath:@"div[@class='removed']/div[@class='symbolName']" error:NULL];
			for (NSXMLElement *removedElement in removedElements)
			{
				NSString *removedTitle = [[[removedElement attributeForName:@"title"] stringValue] lowercaseString];
				for (NSString *inx in @[ @"/intf", @"/inst" ])
				{
					NSString *p = [inx stringByAppendingString:@"p/"];
					NSString *m = [inx stringByAppendingString:@"m/"];
					NSString *getter = [addedTitle stringByReplacingOccurrencesOfString:p withString:m];
					NSString *isgetter = [NSString stringWithFormat:@"/%@/is%@", [getter stringByDeletingLastPathComponent], [getter lastPathComponent]];
					NSString *setter = [NSString stringWithFormat:@"/%@/set%@:", [getter stringByDeletingLastPathComponent], [getter lastPathComponent]];
					if ([getter isEqualToString:removedTitle] || [isgetter isEqualToString:removedTitle] || [setter isEqualToString:removedTitle])
					{
						[removedElement removeFromParent];
						removed = YES;
					}
				}
			}
		}
		if (removed)
			[addedElement removeFromParent];
	}
}

NSXMLElement *ElementWithAttributes(NSString *elementName, NSDictionary *attributes)
{
	NSXMLElement *element = [[NSXMLElement alloc] initWithName:elementName];
	[attributes enumerateKeysAndObjectsUsingBlock:^(id key, id obj, BOOL *stop) {
		NSXMLNode *attribute = [[NSXMLNode alloc] initWithKind:NSXMLAttributeKind];
		attribute.name = key;
		attribute.stringValue = obj;
		[element addAttribute:attribute];
	}];
	return element;
}

void GroupNodesInElementWithAttributes(NSXMLDocument *document, NSString *xpath, NSString *elementName, NSDictionary *attributes)
{
	NSError *error;
	NSArray *nodes = [document nodesForXPath:xpath error:&error];
	TerminateIf(nodes == nil, EX_SOFTWARE, error.description);
	
	NSXMLElement *parent;
	NSXMLElement *element = ElementWithAttributes(elementName, attributes);
	NSUInteger idx = NSNotFound;
	for (NSXMLNode *node in nodes)
	{
		if (idx == NSNotFound)
		{
			parent = (NSXMLElement *)node.parent;
			idx = [parent.children indexOfObjectIdenticalTo:node];
		}
		[node removeFromParent];
		[element addChild:node];
	}
	
	[parent insertChild:element atIndex:idx];
}

int main(int argc, const char * argv[])
{
	@autoreleasepool
	{
		TerminateIf(argc != 3, EX_USAGE, [NSString stringWithFormat:@"Usage: %@ input output", [@(argv[0]) lastPathComponent]]);
		
		NSString *input = @(argv[1]);
		NSURL *inputURL = [input hasPrefix:@"http"] ? [NSURL URLWithString:input] : [NSURL fileURLWithPath:input];
		NSString *output = @(argv[2]);
		NSURL *outputURL = [NSURL fileURLWithPath:output];
		
		NSError *error;
		NSData *inputData = [NSData dataWithContentsOfURL:inputURL options:NSDataReadingMapped error:&error];
		TerminateIf(inputData == nil, EX_NOINPUT, error.description);
		
		NSXMLDocument *document = [[NSXMLDocument alloc] initWithData:inputData options:NSXMLDocumentTidyHTML error:&error];
		TerminateIf(document == nil, EX_DATAERR, error.description);
		
		RemoveNodesMatchingXPath(document, @"//div[@class='modified']");
		RemoveNodesMatchingXPath(document, @"//div[@class='headerName']/(span[@class='added']|span[@class='removed'])/span[@class='diffStatus']");
		RemoveMethodToProperties(document);
		RemoveNodesMatchingXPath(document, @"//div[@class='added' and count(*)=0]");
		RemoveNodesMatchingXPath(document, @"//div[@class='removed' and count(*)=0]");
		RemoveNodesMatchingXPath(document, @"//div[@class='headerFile' and count(div)=1]");
		
		NSArray *emptyFrameworkNodes = [document nodesForXPath:@"//h2[following-sibling::*[1][self::h2]][not(span)]" error:&error];
		TerminateIf(emptyFrameworkNodes == nil, EX_SOFTWARE, error.description);
		for (NSXMLElement *emptyFrameworkNode in emptyFrameworkNodes)
		{
			NSXMLElement *div = ElementWithAttributes(@"div", @{ @"class": @"nochange" });
			div.stringValue = @"No changes";
			NSUInteger idx = [emptyFrameworkNode.parent.children indexOfObjectIdenticalTo:emptyFrameworkNode];
			[(NSXMLElement *)emptyFrameworkNode.parent insertChild:div atIndex:idx + 1];
		}
		
		// `header`, `nav` and `article` elements are stripped during tidying
		GroupNodesInElementWithAttributes(document, @"//(div[@id='title']|ul[@id='headerButtons'])", @"header", @{ @"id": @"header" });
		GroupNodesInElementWithAttributes(document, @"//ul[@id='toc']", @"nav", @{ @"id": @"tocContainer", @"tabindex": @"7" });
		GroupNodesInElementWithAttributes(document, @"//nav/following-sibling::div", @"article", @{ @"id": @"contents" });
		
		NSXMLElement *head = [[document nodesForXPath:@"//head" error:NULL] firstObject];
		[head insertChild:ElementWithAttributes(@"meta", @{ @"http-equiv": @"Content-Type", @"content": @"text/html; charset=UTF-8" }) atIndex:0];
		if (![inputURL isFileURL])
			[head insertChild:ElementWithAttributes(@"base", @{ @"href": [[inputURL URLByDeletingLastPathComponent] absoluteString] }) atIndex:0];
		
		NSData *outputData = [document XMLDataWithOptions:NSXMLDocumentIncludeContentTypeDeclaration];
		BOOL success = [outputData writeToURL:outputURL options:NSDataWritingAtomic error:&error];
		TerminateIf(!success, EX_CANTCREAT, error.description);
	}
	
	return EX_OK;
}