#include <stdio.h>

#include <types.h>

#include <Files.h>

#include <Devices.h>

#include "WhereCDs.h"

/* 

 * use this version of a Control structure for a ReadTOC call

 */

typedef struct {

    struct QElem *qLink;

    short qType;

    short ioTrap;

    Ptr ioCmdAddr;

    ProcPtr ioCompletion;

    OSErr ioResult;

    char *ioNamePtr;

    short ioVRefNum;

    short ioCRefNum;

    short csCode;

    unsigned long   discID;

    char    unused[18];

} CDTOCParam;

enum {

    kReadTOC = 100,

    kDiskIsLocked = 0x80,

    kDiskEjectableFlag = 0x08

};

#define kDriverName "\p.AppleCD"

void main(void);

Boolean DriveIsEjectable(DrvQEl *queueElementPtr);

Boolean DriveIsHardwareLocked(DrvQEl *queueElementPtr);

OSErr IDDisc(short refNum, unsigned long *discID);

void TechNoteCDs(void);

/************************************************************************

 *

 *  Function:   main

 *  

 *  Purpose:    for testing only

 *

 *  Returns:    nothing

 *

 *  Side Effects: prints list of available CD-ROM drives (best guess)

 *

 *  Description: scan drive queue.  Call PBControl with a csCode 100

 *               ReadTOC call. See tech note DV 22 for details.

 *

 ************************************************************************/

void main(void)

{

    OSErr   err;

    short   refNum;

    UInt32  discID = 0L;

    QHdrPtr driveQueuePtr;

    DrvQEl  *queueElementPtr;

    printf("Test of identifying a disc\n"); // initializes toolbox

    driveQueuePtr = GetDrvQHdr();

    queueElementPtr = (DrvQEl *)driveQueuePtr -> qHead;

    do 

    {

        refNum = queueElementPtr->dQRefNum;

        if ( DriveIsEjectable(queueElementPtr) && 

                DriveIsHardwareLocked(queueElementPtr) )

            printf("drive with refNum %d (0x%x) is ejectable and hardware locked\n", 

                        refNum, refNum);

        err = IDDisc(refNum, &discID);      // If we don't get an error from

                                            // calling ReadTOC, assume it's a CD.

        if (!err)

            printf("I think this is a CD-ROM disc.\n");

        queueElementPtr = (DrvQEl *)queueElementPtr->qLink;

    } while (queueElementPtr != nil);

    TechNoteCDs();

    printf("Finished!\n");

}

/************************************************************************

 *

 *  Function:       DriveIsEjectable

 *

 *  Purpose:        determine if drive is ejectable

 *

 *  Returns:        true if ejectable, false if not

 *

 *  Side Effects:   none

 *

 *  Description:    look at the 4 bytes preceeding the drive queue

 *                  element.

 *

 ************************************************************************/

Boolean DriveIsEjectable(DrvQEl *queueElementPtr)

{

    UInt8 * bytePtr;

    bytePtr = (UInt8 *)queueElementPtr;

    bytePtr -= 4;

    return ( (bytePtr[1] & kDiskEjectableFlag) != kDiskEjectableFlag );

}

/************************************************************************

 *

 *  Function:       DriveIsHardwareLocked

 *

 *  Purpose:        determine if drive is HardwareLocked

 *

 *  Returns:        true if HardwareLocked, false if not

 *

 *  Side Effects:   none

 *

 *  Description:    look at the 4 bytes preceeding the drive queue

 *                  element.

 *

 ************************************************************************/

Boolean DriveIsHardwareLocked(DrvQEl *queueElementPtr)

{

    UInt8 * bytePtr;

    bytePtr = (UInt8 *)queueElementPtr;

    bytePtr -= 4;

    return ( (bytePtr[0] & kDiskIsLocked) == kDiskIsLocked );

}

/************************************************************************

 *

 *  Function:       IDDisc

 *

 *  Purpose:        return total time on this disc as unique ID

 *

 *  Returns:        OSErr

 *                  either noErr if everything was okay

 *                  or some parameter error from driver call.

 *

 *  Side Effects:   fills in discID

 *

 *  Description:    call the driver ReadTOC call to get lead-out time.

 *                  Return this time as the unique id for this disc.

 *

 ************************************************************************/

OSErr IDDisc(short refNum, unsigned long *discID)

{

    CDTOCParam  myPB;

    OSErr   result;

    myPB.ioCompletion = 0;

    myPB.ioNamePtr = (char *) 0;

    myPB.ioVRefNum = 0;

    myPB.ioCRefNum = refNum;

    myPB.csCode = kReadTOC;

    myPB.discID = 0x00020000;   /* request lead-out time */

    result = PBControlSync((ParmBlkPtr)&myPB);

    if (result == noErr)

        *discID = myPB.discID >> 8;

    else

        *discID = 0;

    return result;

}

/************************************************************************

 *

 *  Function:       TechNoteCDs 

 *

 *  Purpose:        use the technique in DV 22 to find CD-ROM drives

 *

 *  Returns:        nothing

 *

 *  Side Effects:   prints a list of found CDs

 *

 *  Description:    call the routine documented in DV 22 and print 

 *                  the result

 *

 ************************************************************************/

void TechNoteCDs(void)

{

    UInt8   locations;

    short   i;

    locations = WhereCDs();

    printf("The WhereCDs() procedure reports there are CDs at SCSI IDs: ");

    for (i = 0; i < 7; i++)

        if (locations & (1 << i))

            printf("%d ", i);

    putchar('\n');

}