/*

    File:       CFNetworkHTTPDownload.c

    Contains:   This sample demonstrates how to use CFNetwork to download a url.

    Disclaimer: IMPORTANT:  This Apple software is supplied to you by Apple Computer, Inc.

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                        expressly stated in this notice, no other rights or licenses, express or implied,

                        are granted by Apple herein, including but not limited to any patent rights that

                        may be infringed by your derivative works or by other works in which the Apple

                        Software may be incorporated.

                        The Apple Software is provided by Apple on an "AS IS" basis.  APPLE MAKES NO

                        WARRANTIES, EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION THE IMPLIED

                        WARRANTIES OF NON-INFRINGEMENT, MERCHANTABILITY AND FITNESS FOR A PARTICULAR

                        PURPOSE, REGARDING THE APPLE SOFTWARE OR ITS USE AND OPERATION ALONE OR IN

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                        IN NO EVENT SHALL APPLE BE LIABLE FOR ANY SPECIAL, INDIRECT, INCIDENTAL OR

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    Copyright © 2002 Apple Computer, Inc., All Rights Reserved

        Change History (most recent first):

        6/2003      MK              Updated for Project Builder

*/

#include <Carbon/Carbon.h>

pascal OSStatus DoAppCommandProcess(EventHandlerCallRef nextHandler, EventRef theEvent, void* userData);

static pascal OSErr QuitAppleEventHandler(const AppleEvent *appleEvt, AppleEvent* reply, long refcon);

void DownloadURL( char *url );

static  void    TerminateDownload( CFReadStreamRef stream );

void    SetControlText( WindowRef window, OSType signature, SInt32 id, Size textLen, char *text );

OSStatus    GetControlBySigAndID( WindowRef window, OSType  signature, SInt32 id, ControlRef *control );

EventLoopTimerRef   gNetworkTimeoutTimerRef;

int main( void )

{   

    OSErr           err;

    WindowRef       window;

    IBNibRef        mainNibRef;

    EventTypeSpec   eventType[] = { { kEventClassCommand, kEventCommandProcess} };

    gNetworkTimeoutTimerRef = NULL;

    err = CreateNibReference( CFSTR("CFNetworkHTTPDownload"), &mainNibRef );

    err = AEInstallEventHandler( kCoreEventClass, kAEQuitApplication, NewAEEventHandlerUPP(QuitAppleEventHandler), 0, false );

    if ( err != noErr ) goto Bail;

    err = CreateWindowFromNib( mainNibRef, CFSTR("MainWindow"), &window );

    if ( (err == noErr) && (window != NULL) )

        ShowWindow( window );

    (void) SetMenuBarFromNib( mainNibRef, CFSTR("MenuBar") );

    InstallApplicationEventHandler( NewEventHandlerUPP( DoAppCommandProcess ), GetEventTypeCount(eventType), eventType, NULL, NULL );

    RunApplicationEventLoop();

Bail:

    if ( mainNibRef != NULL )   DisposeNibReference( mainNibRef );

    return( err );

}

// Handle command-process events at the application level

pascal OSStatus DoAppCommandProcess(EventHandlerCallRef nextHandler, EventRef theEvent, void* userData)

{

    #pragma unused (nextHandler, userData)

    HICommand       aCommand;

    ControlRef      control;

    char            url[8 * 1024];                          //  We assume urls will be under 8K in length

    SInt32          dataSize;

    OSStatus        result      = eventNotHandledErr;

    const ControlID     urlControlID    = { 'URLs', 0 };

    GetEventParameter( theEvent, kEventParamDirectObject, typeHICommand, NULL, sizeof(HICommand), NULL, &aCommand );

    switch ( aCommand.commandID )

    {

        case kHICommandOK:          //  Download the URL specified by the text in urlControlID

            GetControlByID( FrontNonFloatingWindow(), &urlControlID, &control );

            result  = GetControlData( control, 0, kControlStaticTextTextTag, sizeof(url), url, &dataSize );

            if ( result == noErr )

            {

                url[dataSize]   = '\0';

                DownloadURL( url );

            }

            break;

        case kHICommandQuit:

            QuitApplicationEventLoop();

            break;

        default:

            break;

    }

    return( result );

}

static pascal   OSErr   QuitAppleEventHandler(const AppleEvent *appleEvt, AppleEvent* reply, long refcon)

{

    #pragma unused ( appleEvt, reply, refcon )

    QuitApplicationEventLoop();

    return( noErr );

}

//  These are the network events we are interested in.

//  We set ReadStreamClientCallBack() as the notifier proc to handle these events.

static const CFOptionFlags kNetworkEvents = kCFStreamEventOpenCompleted |

                                            kCFStreamEventHasBytesAvailable |

                                            kCFStreamEventEndEncountered |

                                            kCFStreamEventErrorOccurred;

static void ReadStreamClientCallBack( CFReadStreamRef stream, CFStreamEventType type, void *clientCallBackInfo )

{

    #pragma unused (clientCallBackInfo)

    UInt8       buffer[16 * 1024];              //  Create a 16K buffer

    CFIndex     bytesRead;

        switch ( type )

        {

            case kCFStreamEventHasBytesAvailable:

                    bytesRead = CFReadStreamRead( stream, buffer, sizeof(buffer) );

                    if ( bytesRead > 0 )    // If zero bytes were read, wait for the EOF to come.

                    {

                        SetControlText( ActiveNonFloatingWindow(), 'Sorc', 0, bytesRead, (char*)buffer );

                        SetEventLoopTimerNextFireTime( gNetworkTimeoutTimerRef, kEventDurationSecond * 5 ); //  Still active so reset the timer for another 5 seconds

                    }

                    else if ( bytesRead < 0 )       // Less than zero is an error

                    {

                        TerminateDownload( stream );

                    }

                    else    //  0 assume we are done with the stream

                    {

                        TerminateDownload( stream );

                    }

                break;

            case kCFStreamEventEndEncountered:

                    TerminateDownload( stream );

                break;

            case kCFStreamEventErrorOccurred:

                    SetControlText( ActiveNonFloatingWindow(), 'Sorc', 0, strlen("kCFStreamEventErrorOccurred"), "kCFStreamEventErrorOccurred" );

                    TerminateDownload( stream );

                break;

            default:

                break;

        }

}

//  We set up a one-shot timer to fire in 5 seconds which will terminate the download.  Every time we

//  get some download activity in our notifier, we tickle the timer

static  pascal  void    NetworkTimeoutTimerProc( EventLoopTimerRef inTimer, void *inUserData )

{

    #pragma unused ( inTimer )

    SetControlText( ActiveNonFloatingWindow(), 'Sorc', 0, strlen("Network Timeout - NetworkTimeoutTimerProc"), "Network Timeout - NetworkTimeoutTimerProc" );

    TerminateDownload( (CFReadStreamRef)inUserData );

}

static  void    TerminateDownload( CFReadStreamRef stream )

{   

    SetEventLoopTimerNextFireTime( gNetworkTimeoutTimerRef, kEventDurationForever );    //  Put the timeout timer on hold

    //***   ALWAYS set the stream client (notifier) to NULL if you are releaseing it

    //  otherwise your notifier may be called after you released the stream leaving you with a 

    //  bogus stream within your notifier.

    CFReadStreamSetClient( stream, kCFStreamEventNone, NULL, NULL );

    CFReadStreamUnscheduleFromRunLoop( stream, CFRunLoopGetCurrent(), kCFRunLoopCommonModes );

    CFReadStreamClose( stream );

    CFRelease( stream );

}

//  DownloadURL, downloads the url.  If NULL is passed in, it uses the last urlRef saved as a static.

void    DownloadURL( char *url )

{

    CFStringRef                 rawCFString;

    CFStringRef                 normalizedCFString;

    CFStringRef                 escapedCFString;

    static  CFURLRef            urlRef;

    static  EventLoopTimerUPP   networkTimeoutTimerUPP;

    CFHTTPMessageRef            messageRef      = NULL;

    CFReadStreamRef             readStreamRef   = NULL;

    CFStreamClientContext       ctxt            = { 0, (void*)NULL, NULL, NULL, NULL };

    if ( url != NULL )

    {

        //  If the url doesn't start out with "http", assume the user was lazy and put it in there

        if ( strncmp( url, "http", strlen("http") ) != 0 )

        {

            BlockMoveData( url, url+strlen("http://"), strlen(url)+1 );

            strncpy( url, "http://", strlen("http://") );

        }

        if ( strlen( url ) < 12 )   goto Bail;

        if ( urlRef != NULL ) CFRelease( urlRef );

        //  We first create a CFString in a standard URL format, for instance spaces, " ", become "%20" within the string

        //  To do this we normalize the URL first, then create the escaped equivalent

        rawCFString     = CFStringCreateWithCString( NULL, url, CFStringGetSystemEncoding() );                                      if ( rawCFString == NULL ) goto Bail;

        normalizedCFString  = CFURLCreateStringByReplacingPercentEscapes( NULL, rawCFString, CFSTR("") );                           if ( normalizedCFString == NULL ) goto Bail;

        escapedCFString = CFURLCreateStringByAddingPercentEscapes( NULL, normalizedCFString, NULL, NULL, kCFStringEncodingUTF8 );   if ( escapedCFString == NULL ) goto Bail;

        urlRef= CFURLCreateWithString( kCFAllocatorDefault, escapedCFString, NULL );

        CFRelease( rawCFString );

        CFRelease( normalizedCFString );

        CFRelease( escapedCFString );

        if ( urlRef == NULL ) goto Bail;

    }

    messageRef = CFHTTPMessageCreateRequest( kCFAllocatorDefault, CFSTR("GET"), urlRef, kCFHTTPVersion1_1 );

    if ( messageRef == NULL ) goto Bail;

    // Create the stream for the request.

    readStreamRef   = CFReadStreamCreateForHTTPRequest( kCFAllocatorDefault, messageRef );

    if ( readStreamRef == NULL ) goto Bail;

    //  There are times when a server checks the User-Agent to match a well known browser.  This is what Safari used at the time the sample was written

    //CFHTTPMessageSetHeaderFieldValue( messageRef, CFSTR("User-Agent"), CFSTR("Mozilla/5.0 (Macintosh; U; PPC Mac OS X; en-us) AppleWebKit/125.5.5 (KHTML, like Gecko) Safari/125")); 

    if ( CFReadStreamSetProperty(readStreamRef, kCFStreamPropertyHTTPShouldAutoredirect, kCFBooleanTrue) == false )

        goto Bail;

    // Set the client notifier

    if ( CFReadStreamSetClient( readStreamRef, kNetworkEvents, ReadStreamClientCallBack, &ctxt ) == false )

        goto Bail;

    // Schedule the stream

    CFReadStreamScheduleWithRunLoop( readStreamRef, CFRunLoopGetCurrent(), kCFRunLoopCommonModes );

    // Start the HTTP connection

    if ( CFReadStreamOpen( readStreamRef ) == false )

        goto Bail;

    //  Set up a watch dog timer to terminate the download after 5 seconds

    if ( networkTimeoutTimerUPP == NULL )   networkTimeoutTimerUPP  = NewEventLoopTimerUPP( NetworkTimeoutTimerProc );

    if ( gNetworkTimeoutTimerRef != NULL ) RemoveEventLoopTimer( gNetworkTimeoutTimerRef );

    InstallEventLoopTimer( GetCurrentEventLoop(), kEventDurationSecond * 5, 0, networkTimeoutTimerUPP, (void*)readStreamRef, &gNetworkTimeoutTimerRef );

    if ( messageRef != NULL ) CFRelease( messageRef );

            return;

Bail:

    if ( messageRef != NULL ) CFRelease( messageRef );

    if ( readStreamRef != NULL )

    {

        CFReadStreamSetClient( readStreamRef, kCFStreamEventNone, NULL, NULL );

        CFReadStreamUnscheduleFromRunLoop( readStreamRef, CFRunLoopGetCurrent(), kCFRunLoopCommonModes );

        CFReadStreamClose( readStreamRef );

        CFRelease( readStreamRef );

    }

    return;

}

void    SetControlText( WindowRef window, OSType signature, SInt32 id, Size textLen, char *text )

{

    ControlRef      control;

    GetControlBySigAndID( window, signature, id, &control );

    if ( control == NULL ) goto Bail;

    (void) SetControlData( control, 0, kControlStaticTextTextTag, textLen, text );

    Draw1Control( control );

Bail:

    return;

}

OSStatus    GetControlBySigAndID( WindowRef window, OSType  signature, SInt32 id, ControlRef *control )

{

    ControlID   controlID;

    controlID.id        = id;

    controlID.signature = signature;

    return( GetControlByID( window, &controlID, control ) );

}