/*

     File: HTTPServer.m

 Abstract: HTTPServer, HTTPConnection, and HTTPServerRequest classes.

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*/

/*

 File: HTTPServer.m

 Abstract: Implementation for a basic HTTP server Foundation class

*/ 

#import "HTTPServer.h"

@implementation HTTPServer

- (id)init {

    connClass = [HTTPConnection self];

    return self;

}

- (void)dealloc {

    [super dealloc];

}

- (Class)connectionClass {

    return connClass;

}

- (void)setConnectionClass:(Class)value {

    connClass = value;

}

- (NSURL *)documentRoot {

    return docRoot;

}

- (void)setDocumentRoot:(NSURL *)value {

    if (docRoot != value) {

        [docRoot release];

        docRoot = [value copy];

    }

}

// Converts the TCPServer delegate notification into the HTTPServer delegate method.

- (void)handleNewConnectionFromAddress:(NSData *)addr inputStream:(NSInputStream *)istr outputStream:(NSOutputStream *)ostr {

    HTTPConnection *connection = [[connClass alloc] initWithPeerAddress:addr inputStream:istr outputStream:ostr forServer:self];

    [connection setDelegate:[self delegate]];

    if ([self delegate] && [[self delegate] respondsToSelector:@selector(HTTPServer:didMakeNewConnection:)]) { 

        [[self delegate] HTTPServer:self didMakeNewConnection:connection];

    }

    // The connection at this point is turned loose to exist on its

    // own, and not released or autoreleased.  Alternatively, the

    // HTTPServer could keep a list of connections, and HTTPConnection

    // would have to tell the server to delete one at invalidation

    // time.  This would perhaps be more correct and ensure no

    // spurious leaks get reported by the tools, but HTTPServer

    // has nothing further it wants to do with the HTTPConnections,

    // and would just be "owning" the connections for form.

}

@end

@implementation HTTPConnection

- (id)init {

    [self dealloc];

    return nil;

}

- (id)initWithPeerAddress:(NSData *)addr inputStream:(NSInputStream *)istr outputStream:(NSOutputStream *)ostr forServer:(HTTPServer *)serv {

    peerAddress = [addr copy];

    server = serv;

    istream = [istr retain];

    ostream = [ostr retain];

    [istream setDelegate:self];

    [ostream setDelegate:self];

    [istream scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:(id)kCFRunLoopCommonModes];

    [ostream scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:(id)kCFRunLoopCommonModes];

    [istream open];

    [ostream open];

    isValid = YES;

    return self;

}

- (void)dealloc {

    [self invalidate];

    [peerAddress release];

    [super dealloc];

}

- (id)delegate {

    return delegate;

}

- (void)setDelegate:(id)value {

    delegate = value;

}

- (NSData *)peerAddress {

    return peerAddress;

}

- (HTTPServer *)server {

    return server;

}

- (HTTPServerRequest *)nextRequest {

    unsigned idx, cnt = requests ? [requests count] : 0;

    for (idx = 0; idx < cnt; idx++) {

        id obj = [requests objectAtIndex:idx];

        if ([obj response] == nil) {

            return obj;

        }

    }

    return nil;

}

- (BOOL)isValid {

    return isValid;

}

- (void)invalidate {

    if (isValid) {

        isValid = NO;

        [istream close];

        [ostream close];

        [istream release];

        [ostream release];

        istream = nil;

        ostream = nil;

        [ibuffer release];

        [obuffer release];

        ibuffer = nil;

        obuffer = nil;

        [requests release];

        requests = nil;

        [self release];

        // This last line removes the implicit retain the HTTPConnection

        // has on itself, given by the HTTPServer when it abandoned the

        // new connection.

    }

}

// YES return means that a complete request was parsed, and the caller

// should call again as the buffered bytes may have another complete

// request available.

- (BOOL)processIncomingBytes {

    CFHTTPMessageRef working = CFHTTPMessageCreateEmpty(kCFAllocatorDefault, TRUE);

    CFHTTPMessageAppendBytes(working, [ibuffer bytes], [ibuffer length]);

    // This "try and possibly succeed" approach is potentially expensive

    // (lots of bytes being copied around), but the only API available for

    // the server to use, short of doing the parsing itself.

    // HTTPConnection does not handle the chunked transfer encoding

    // described in the HTTP spec.  And if there is no Content-Length

    // header, then the request is the remainder of the stream bytes.

    if (CFHTTPMessageIsHeaderComplete(working)) {

        NSString *contentLengthValue = [(NSString *)CFHTTPMessageCopyHeaderFieldValue(working, (CFStringRef)@"Content-Length") autorelease];

        unsigned contentLength = contentLengthValue ? [contentLengthValue intValue] : 0;

        NSData *body = [(NSData *)CFHTTPMessageCopyBody(working) autorelease];

        unsigned bodyLength = [body length];

        if (contentLength <= bodyLength) {

            NSData *newBody = [NSData dataWithBytes:[body bytes] length:contentLength];

            [ibuffer setLength:0];

            [ibuffer appendBytes:([body bytes] + contentLength) length:(bodyLength - contentLength)];

            CFHTTPMessageSetBody(working, (CFDataRef)newBody);

        } else {

            CFRelease(working);

            return NO;

        }

    } else {

        return NO;

    }

    HTTPServerRequest *request = [[HTTPServerRequest alloc] initWithRequest:working connection:self];

    if (!requests) {

        requests = [[NSMutableArray alloc] init];

    }

    [requests addObject:request];

    if (delegate && [delegate respondsToSelector:@selector(HTTPConnection:didReceiveRequest:)]) { 

        [delegate HTTPConnection:self didReceiveRequest:request];

    } else {

        [self performDefaultRequestHandling:request];

    }

    CFRelease(working);

    return YES;

}

- (void)processOutgoingBytes {

    // The HTTP headers, then the body if any, then the response stream get

    // written out, in that order.  The Content-Length: header is assumed to 

    // be properly set in the response.  Outgoing responses are processed in 

    // the order the requests were received (required by HTTP).

    // Write as many bytes as possible, from buffered bytes, response

    // headers and body, and response stream.

    if (![ostream hasSpaceAvailable]) {

        return;

    }

    unsigned olen = [obuffer length];

    if (0 < olen) {

        int writ = [ostream write:[obuffer bytes] maxLength:olen];

        // buffer any unwritten bytes for later writing

        if (writ < olen) {

            memmove([obuffer mutableBytes], [obuffer mutableBytes] + writ, olen - writ);

            [obuffer setLength:olen - writ];

            return;

        }

        [obuffer setLength:0];

    }

    unsigned cnt = requests ? [requests count] : 0;

    HTTPServerRequest *req = (0 < cnt) ? [requests objectAtIndex:0] : nil;

    CFHTTPMessageRef cfresp = req ? [req response] : NULL;

    if (!cfresp) return;

    if (!obuffer) {

        obuffer = [[NSMutableData alloc] init];

    }

    if (!firstResponseDone) {

        firstResponseDone = YES;

        NSData *serialized = [(NSData *)CFHTTPMessageCopySerializedMessage(cfresp) autorelease];

        unsigned olen = [serialized length];

        if (0 < olen) {

            int writ = [ostream write:[serialized bytes] maxLength:olen];

            if (writ < olen) {

                // buffer any unwritten bytes for later writing

                [obuffer setLength:(olen - writ)];

                memmove([obuffer mutableBytes], [serialized bytes] + writ, olen - writ);

                return;

            }

        }

    }

    NSInputStream *respStream = [req responseBodyStream];

    if (respStream) {

        if ([respStream streamStatus] == NSStreamStatusNotOpen) {

            [respStream open];

        }

        // read some bytes from the stream into our local buffer

        [obuffer setLength:16 * 1024];

        int read = [respStream read:[obuffer mutableBytes] maxLength:[obuffer length]];

        [obuffer setLength:read];

    }

    if (0 == [obuffer length]) {

        // When we get to this point with an empty buffer, then the 

        // processing of the response is done. If the input stream

        // is closed or at EOF, then no more requests are coming in.

        if (delegate && [delegate respondsToSelector:@selector(HTTPConnection:didSendResponse:)]) { 

            [delegate HTTPConnection:self didSendResponse:req];

        }

        [requests removeObjectAtIndex:0];

        firstResponseDone = NO;

        if ([istream streamStatus] == NSStreamStatusAtEnd && [requests count] == 0) {

            [self invalidate];

        }

        return;

    }

    olen = [obuffer length];

    if (0 < olen) {

        int writ = [ostream write:[obuffer bytes] maxLength:olen];

        // buffer any unwritten bytes for later writing

        if (writ < olen) {

            memmove([obuffer mutableBytes], [obuffer mutableBytes] + writ, olen - writ);

        }

        [obuffer setLength:olen - writ];

    }

}

- (void)stream:(NSStream *)stream handleEvent:(NSStreamEvent)streamEvent {

    switch(streamEvent) {

    case NSStreamEventHasBytesAvailable:;

        uint8_t buf[16 * 1024];

        uint8_t *buffer = NULL;

        unsigned int len = 0;

        if (![istream getBuffer:&buffer length:&len]) {

            int amount = [istream read:buf maxLength:sizeof(buf)];

            buffer = buf;

            len = amount;

        }

        if (0 < len) {

            if (!ibuffer) {

                ibuffer = [[NSMutableData alloc] init];

            }

            [ibuffer appendBytes:buffer length:len];

        }

        do {} while ([self processIncomingBytes]);

        break;

    case NSStreamEventHasSpaceAvailable:;

        [self processOutgoingBytes];

        break;

    case NSStreamEventEndEncountered:;

        [self processIncomingBytes];

        if (stream == ostream) {

            // When the output stream is closed, no more writing will succeed and

            // will abandon the processing of any pending requests and further

            // incoming bytes.

            [self invalidate];

        }

        break;

    case NSStreamEventErrorOccurred:;

        NSLog(@"HTTPServer stream error: %@", [stream streamError]);

        break;

    default:

        break;

    }

}

- (void)performDefaultRequestHandling:(HTTPServerRequest *)mess {

    CFHTTPMessageRef request = [mess request];

    NSString *vers = [(id)CFHTTPMessageCopyVersion(request) autorelease];

    if (!vers || ![vers isEqual:(id)kCFHTTPVersion1_1]) {

        CFHTTPMessageRef response = CFHTTPMessageCreateResponse(kCFAllocatorDefault, 505, NULL, (CFStringRef)vers); // Version Not Supported

        [mess setResponse:response];

        CFRelease(response);

        return;

    }

    NSString *method = [(id)CFHTTPMessageCopyRequestMethod(request) autorelease];

    if (!method) {

        CFHTTPMessageRef response = CFHTTPMessageCreateResponse(kCFAllocatorDefault, 400, NULL, kCFHTTPVersion1_1); // Bad Request

        [mess setResponse:response];

        CFRelease(response);

        return;

    }

    if ([method isEqual:@"GET"] || [method isEqual:@"HEAD"]) {

        NSURL *uri = [(NSURL *)CFHTTPMessageCopyRequestURL(request) autorelease];

        NSURL *url = [NSURL URLWithString:[uri path] relativeToURL:[server documentRoot]];

        NSData *data = [NSData dataWithContentsOfURL:url];

        if (!data) {

            CFHTTPMessageRef response = CFHTTPMessageCreateResponse(kCFAllocatorDefault, 404, NULL, kCFHTTPVersion1_1); // Not Found

            [mess setResponse:response];

            CFRelease(response);

            return;

        }

        CFHTTPMessageRef response = CFHTTPMessageCreateResponse(kCFAllocatorDefault, 200, NULL, kCFHTTPVersion1_1); // OK

        CFHTTPMessageSetHeaderFieldValue(response, (CFStringRef)@"Content-Length", (CFStringRef)[NSString stringWithFormat:@"%d", [data length]]);

        if ([method isEqual:@"GET"]) {

            CFHTTPMessageSetBody(response, (CFDataRef)data);

        }

        [mess setResponse:response];

        CFRelease(response);

        return;

    }

    CFHTTPMessageRef response = CFHTTPMessageCreateResponse(kCFAllocatorDefault, 405, NULL, kCFHTTPVersion1_1); // Method Not Allowed

    [mess setResponse:response];

    CFRelease(response);

}

@end

@implementation HTTPServerRequest

- (id)init {

    [self dealloc];

    return nil;

}

- (id)initWithRequest:(CFHTTPMessageRef)req connection:(HTTPConnection *)conn {

    connection = conn;

    request = (CFHTTPMessageRef)CFRetain(req);

    return self;

}

- (void)dealloc {

    if (request) CFRelease(request);

    if (response) CFRelease(response);

    [responseStream release];

    [super dealloc];

}

- (HTTPConnection *)connection {

    return connection;

}

- (CFHTTPMessageRef)request {

    return request;

}

- (CFHTTPMessageRef)response {

    return response;

}

- (void)setResponse:(CFHTTPMessageRef)value {

    if (value != response) {

        if (response) CFRelease(response);

        response = (CFHTTPMessageRef)CFRetain(value);

        if (response) {

            // check to see if the response can now be sent out

            [connection processOutgoingBytes];

        }

    }

}

- (NSInputStream *)responseBodyStream {

    return responseStream;

}

- (void)setResponseBodyStream:(NSInputStream *)value {

    if (value != responseStream) {

        [responseStream release];

        responseStream = [value retain];

    }

}

@end