#import "DAClient.h"

static const CFOptionFlags DAClientNetworkEvents = 
	kCFStreamEventOpenCompleted     |
	kCFStreamEventHasBytesAvailable |
	kCFStreamEventEndEncountered    |
	kCFStreamEventErrorOccurred;

static void
ReadStreamClientCallBack(CFReadStreamRef stream, CFStreamEventType type, 
			 void *clientCallBackInfo) 
{
	// Pass off to the object to handle.
	[((DAClient *)clientCallBackInfo) handleNetworkEvent:type];
}

@implementation DAClient

- (void) informDelegateRequestFinished:(NSData *)data
{
	if ([self delegate] == nil) {
		return;
	}
	if ([[self delegate] respondsToSelector:@selector(requestDidFinish:)]) {
		[[self delegate] requestDidFinish:data];
	} else {
		[NSException raise:NSInternalInconsistencyException
			    format:@"Delegate doesn't respond to requestDidFinish:"];
	}
}

- (BOOL) fetchUrl:(NSURL *)url withMethod:(int)method 
   withParameters:(NSDictionary *)params withDelegate:(id)delegate
{
	CFHTTPMessageRef request;
	CFStreamClientContext ctxt = {0, self, NULL, NULL, NULL};
	NSMutableString *paramString = nil;
	
	// Don't fetch if there is a fetch in progress.
	if (_stream) {
		return NO;
	}
	
	// Make sure we have a url
	if (url == nil) {
		return NO;
	}
		
	if (_data != nil) {
		[_data release];
	}
	_data = [[NSMutableData alloc] initWithCapacity:2048];
	
	[self setDelegate:delegate];

	// build a parameter string
	if (params != nil) {
		paramString = [NSMutableString stringWithCapacity:50];
		id key;
		BOOL firstParam = YES;
		NSEnumerator *enumerator = [params keyEnumerator];
		while ((key = [enumerator nextObject])) {
			id value = [params objectForKey:key];
			if ([key isKindOfClass:[NSString class]] &&
			    [value isKindOfClass:[NSString class]])
			{
				if (firstParam) {
					firstParam = NO;
				} else {
					[paramString appendString:@"&"];
				}
				NSString *paramKey = (NSString *)CFURLCreateStringByAddingPercentEscapes(
					NULL, (CFStringRef)key, NULL, NULL, kCFStringEncodingUTF8);
				NSString *paramValue = (NSString *)CFURLCreateStringByAddingPercentEscapes(
					NULL, (CFStringRef)value, NULL, NULL, kCFStringEncodingUTF8);
				[paramString appendString:paramKey];
				[paramString appendString:@"="];
				[paramString appendString:paramValue];
				[paramKey release];
				[paramValue release];
			}
		}
	}

	// Create a new HTTP request.
	if (method == DAClientMethodGET) {
		// for GET requests, append parameter list to url
		NSURL *tmpURL;
		if (paramString != nil) {
			// This is buggy for certain URLs.
			// It only really works with urls like "http://foo.com/"
			// or "http://foo.com/file.pl"
			NSMutableString *tmpS = [NSMutableString stringWithString:[url absoluteString]];
			[tmpS appendString:@"?"];
			[tmpS appendString:paramString];
			tmpURL = [NSURL URLWithString:tmpS];
		} else {
			tmpURL = url;
		}
		request = CFHTTPMessageCreateRequest(kCFAllocatorDefault, 
						     CFSTR("GET"), (CFURLRef)tmpURL, 
						     kCFHTTPVersion1_1);
	} else if (method == DAClientMethodPOST) {
		request = CFHTTPMessageCreateRequest(kCFAllocatorDefault, 
						     CFSTR("POST"), (CFURLRef)url, 
						     kCFHTTPVersion1_1);
		CFHTTPMessageSetHeaderFieldValue(request, CFSTR("Content-Type"),
				CFSTR("application/x-www-form-urlencoded"));
		// Set the parameters in the body of POST requests
		if (paramString && request) {
			NSData *data = [paramString dataUsingEncoding:NSUTF8StringEncoding];
			CFHTTPMessageSetBody(request, (CFDataRef)data);
		}
	}
	if (!request) {
		return NO;
	}

	// Create the stream for the request.
	_stream = CFReadStreamCreateForHTTPRequest(kCFAllocatorDefault, request);
	
	// Release the request.  The fetch should've retained it if it
	// is performing the fetch.
	CFRelease(request);
	
	// Make sure it succeeded.
	if (!_stream) {
		return NO;
	}
	
	// Set the client. Make it call ReadStreamClientCallBack()
	if (!CFReadStreamSetClient(_stream, DAClientNetworkEvents, ReadStreamClientCallBack, &ctxt)) {
		CFRelease(_stream);
		_stream = NULL;
		return NO;
	}
	
	// Schedule the stream
	CFReadStreamScheduleWithRunLoop(_stream, CFRunLoopGetCurrent(), kCFRunLoopCommonModes);
	
	// Start the HTTP connection
	if (!CFReadStreamOpen(_stream)) {
		CFReadStreamSetClient(_stream, 0, NULL, NULL);
		CFReadStreamUnscheduleFromRunLoop(_stream, CFRunLoopGetCurrent(), kCFRunLoopCommonModes);
		CFRelease(_stream);
		_stream = NULL;
		return NO;
	}
	
	return YES;
}

- (void) cancelPending
{
	CFReadStreamSetClient(_stream, 0, NULL, NULL);
	CFReadStreamUnscheduleFromRunLoop(_stream, CFRunLoopGetCurrent(), kCFRunLoopCommonModes);
	CFReadStreamClose(_stream);
	CFRelease(_stream);
	_stream = NULL;
}

- (void) handleNetworkEvent:(CFStreamEventType)type 
{	
	// Dispatch the stream events.
	switch (type) {
		case kCFStreamEventHasBytesAvailable:
			[self handleBytesAvailable];
			break;			
		case kCFStreamEventEndEncountered:
			[self handleStreamComplete];
			break;
		case kCFStreamEventErrorOccurred:
			[self handleStreamError];
			break;
		default:
			break;
	}
}

- (void) handleBytesAvailable 
{
	UInt8 buffer[2048];
	CFIndex bytesRead = CFReadStreamRead(_stream, buffer, sizeof(buffer));
	
	// Less than zero is an error
	if (bytesRead < 0) {
		[self handleStreamError];
	// If zero bytes were read, wait for the EOF to come.
	} else if (bytesRead) {
		// This would not work for binary data!  Build a string to add
		// to the results.
		[_data appendBytes:(void *)buffer length:(unsigned)bytesRead];
	}
}

- (void) handleStreamComplete 
{
	// Don't need the stream any more, and indicate complete.
	CFReadStreamSetClient(_stream, 0, NULL, NULL);
	CFReadStreamUnscheduleFromRunLoop(_stream, CFRunLoopGetCurrent(), kCFRunLoopCommonModes);
	CFReadStreamClose(_stream);
	CFRelease(_stream);
	_stream = NULL;
	[self informDelegateRequestFinished:(NSData *)_data];
}

- (void) handleStreamError 
{
	CFStreamError error = CFReadStreamGetError(_stream);
	if (error.error != 0) {
		if (error.domain == kCFStreamErrorDomainPOSIX) {
			NSLog(@"posix errno: %d", error.error);
		} else if (error.domain == kCFStreamErrorDomainMacOSStatus) {
			OSStatus macError = (OSStatus)error.error;
			NSLog(@"os error: %d", macError);
		} else if (error.domain == kCFStreamErrorDomainHTTP) {
			NSLog(@"http error domain");
		} else if (error.domain == kCFStreamErrorDomainMach) {
			NSLog(@"mach error domain");
		} else if (error.domain == kCFStreamErrorDomainNetDB) {
			NSLog(@"netdb error domain");
		} else if (error.domain == kCFStreamErrorDomainCustom) {
			NSLog(@"custom error domain");
		} else if (error.domain == kCFStreamErrorDomainSystemConfiguration) {
			NSLog(@"system configuration error domain");
		}
		NSLog(@"error %d domain %d", error.error, error.domain);
	}
	CFReadStreamSetClient(_stream, 0, NULL, NULL);
	CFReadStreamUnscheduleFromRunLoop(_stream, CFRunLoopGetCurrent(), kCFRunLoopCommonModes);
	CFReadStreamClose(_stream);
	CFRelease(_stream);
	_stream = NULL;
	[self informDelegateRequestFinished:nil];
}

- (id) delegate
{
	return _delegate;
}
- (void) setDelegate:(id)newDelegate
{
	// Note that we DO NOT retain this. This is to avoid circular refs.
	_delegate = newDelegate;
}

- (void) dealloc
{
	[_data release];
	[super dealloc];
}

@end