/*

File: URLDataReceiver.m

Abstract: A Class encapsulating the asynchronous loading functionality of NSURLConnection.

Version: 1.0

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*/

#import "URLDataReceiver.h"

/*!

 * @abstract Status of URLDataReceiver.

 */

enum {

    DRInit = 1,

    DRLoading,

    DRFinished,

    DRCancelled

};

/*!

 * @abstract Private routines.

 */

@interface URLDataReceiver(Private)

- (void)notifyDidFinish;

- (void)setError:(NSError*)error;

@end

@implementation URLDataReceiver

- (id)initWithURL:(NSURL*)aURL delegate:(id)delegate {

    self = [super init];

    if (self == nil) return nil;

    fStatus = DRLoading;

    fURL = [aURL copy];

    fReceived = [NSMutableData new];

    fError = nil;

    fDelegate = delegate;

    fLock = [NSRecursiveLock new];

    fConnection = nil;

    return self;

}

- (void) dealloc {

    //cancel it if we are loading.

    [fLock lock];

    if (fStatus == DRLoading) [self cancel];

    [fLock unlock];

    if (fURL) [fURL release];

    if (fReceived) [fReceived release];

    if (fError) [fError release];

    if (fLock) [fLock release];

    if (fConnection) [fConnection release];

    [super dealloc];

}

- (void)startLoading {

    [fLock lock];

    fStatus = DRLoading;

    fConnection = [[NSURLConnection alloc] 

                    initWithRequest:[NSURLRequest requestWithURL:fURL]

                    delegate:self];

    [fLock unlock];

}

- (void)cancel {

    [fLock lock];

    //return right away if we are not loading.

    if (fStatus != DRLoading) {

        [fLock unlock];

        return;

    }

    fStatus = DRCancelled;

    if (fConnection) [fConnection cancel];

    [fReceived setLength:0];

    [fLock unlock];

}

- (NSData*)receivedData {

    return fReceived;

}

- (NSURL*)url {

    return fURL;

}

- (NSError*)lastError {

    return fError;

}

/////////// NSURLConnection delegate functions //////////////////////////

- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {

    [fLock lock];

    NSAssert(fStatus == DRLoading, @"I should be loadiing.");

    [fReceived appendData:data];

    [fLock unlock];

}

- (void)connection:(NSURLConnection *)connection didFailWithError:(NSError *)error {

    [fLock lock];

    NSAssert(fStatus != DRFinished, @"Why am I here if I already finished.");

    fStatus = DRFinished;

    [fReceived setLength:0];

    [self setError:error];

    [self notifyDidFinish];

    [fLock unlock];

}

- (void)connection:(NSURLConnection *)connection 

                didReceiveAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge {

    [fLock lock];

    NSAssert(fStatus != DRFinished, @"Why am I here if I already finished.");

    [fConnection cancel];

    fStatus = DRFinished;

    [fReceived setLength:0];

    [self setError:nil];

    [self notifyDidFinish];

    [fLock unlock];

}

- (NSURLRequest *)connection:(NSURLConnection *)connection 

                willSendRequest:(NSURLRequest *)request redirectResponse:(NSURLResponse *)redirectResponse {

    return request;

}

- (void)connectionDidFinishLoading:(NSURLConnection *)connection {

    [fLock lock];

    NSAssert(fStatus != DRFinished, @"Why am I here if I already finished.");

    fStatus = DRFinished;

    [self setError:nil];

    [self notifyDidFinish];

    [fLock unlock];

}

/////////////// Private Routines //////////////////

- (void)notifyDidFinish {

    //notify the delegate.

    if (fDelegate && [fDelegate respondsToSelector:@selector(URLDataReceiverDidFinish:)])

        [fDelegate performSelector:@selector(URLDataReceiverDidFinish:) withObject:self];

 }

- (void)setError:(NSError*)error {

    if (fError) [fError release];

    if (error) 

        fError = [error retain];

    else

        fError = nil;

}

@end