//  main.c
//
//  Lisp Metadata Importer
//
//  Created by John Wiseman on 9/1/05.
//  Copyright 2005 John Wiseman.
//
//  Licensed under the MIT license--see the accompanying LICENSE.txt
//  file.

#include <CoreFoundation/CoreFoundation.h>
#include <CoreFoundation/CFPlugInCOM.h>
#include <CoreServices/CoreServices.h>

// Constants


#define PLUGIN_ID "12C869B3-3D4B-4DED-B156-5D55D1C64354"

//
// Below is the generic glue code for all plug-ins.
//
// You should not have to modify this code aside from changing
// names if you decide to change the names defined in the Info.plist
//


// -----------------------------------------------------------------------------
//	typedefs
// -----------------------------------------------------------------------------

// The import function to be implemented in GetMetadataForFile.c
Boolean GetMetadataForFile(void *thisInterface, 
                           CFMutableDictionaryRef attributes, 
                           CFStringRef contentTypeUTI,
                           CFStringRef pathToFile);

// The layout for an instance of MetaDataImporterPlugIn 
typedef struct __MetadataImporterPluginType
{
    MDImporterInterfaceStruct *conduitInterface;
    CFUUIDRef                 factoryID;
    UInt32                    refCount;
} MetadataImporterPluginType;

// -----------------------------------------------------------------------------
//	prototypes
// -----------------------------------------------------------------------------
//	Forward declaration for the IUnknown implementation.
//

MetadataImporterPluginType  *AllocMetadataImporterPluginType(CFUUIDRef inFactoryID);
void                      DeallocMetadataImporterPluginType(MetadataImporterPluginType *thisInstance);
HRESULT                   MetadataImporterQueryInterface(void *thisInstance,REFIID iid,LPVOID *ppv);
void                     *MetadataImporterPluginFactory(CFAllocatorRef allocator,CFUUIDRef typeID);
ULONG                     MetadataImporterPluginAddRef(void *thisInstance);
ULONG                     MetadataImporterPluginRelease(void *thisInstance);
// -----------------------------------------------------------------------------
//	testInterfaceFtbl	definition
// -----------------------------------------------------------------------------
//	The TestInterface function table.
//

static MDImporterInterfaceStruct testInterfaceFtbl = {
    NULL,
    MetadataImporterQueryInterface,
    MetadataImporterPluginAddRef,
    MetadataImporterPluginRelease,
    GetMetadataForFile
};


// -----------------------------------------------------------------------------
//	AllocMetadataImporterPluginType
// -----------------------------------------------------------------------------
//	Utility function that allocates a new instance.
//      You can do some initial setup for the importer here if you wish
//      like allocating globals etc...
//
MetadataImporterPluginType *AllocMetadataImporterPluginType(CFUUIDRef inFactoryID)
{
    MetadataImporterPluginType *theNewInstance;
    
    theNewInstance = (MetadataImporterPluginType *)malloc(sizeof(MetadataImporterPluginType));
    memset(theNewInstance,0,sizeof(MetadataImporterPluginType));
    
    /* Point to the function table */
    theNewInstance->conduitInterface = &testInterfaceFtbl;
    
    /*  Retain and keep an open instance refcount for each factory. */
    theNewInstance->factoryID = CFRetain(inFactoryID);
    CFPlugInAddInstanceForFactory(inFactoryID);
    
    /* This function returns the IUnknown interface so set the refCount to one. */
    theNewInstance->refCount = 1;
    return theNewInstance;
}

// -----------------------------------------------------------------------------
//	DeallocPython_Metadata_ImporterMDImporterPluginType
// -----------------------------------------------------------------------------
//	Utility function that deallocates the instance when
//	the refCount goes to zero.
//      In the current implementation importer interfaces are never deallocated
//      but implement this as this might change in the future
//
void DeallocMetadataImporterPluginType(MetadataImporterPluginType *thisInstance)
{
    CFUUIDRef theFactoryID;
    
    theFactoryID = thisInstance->factoryID;
    free(thisInstance);
    if (theFactoryID){
        CFPlugInRemoveInstanceForFactory(theFactoryID);
        CFRelease(theFactoryID);
    }
}

// -----------------------------------------------------------------------------
//	MetadataImporterQueryInterface
// -----------------------------------------------------------------------------
//	Implementation of the IUnknown QueryInterface function.
//
HRESULT MetadataImporterQueryInterface(void *thisInstance,REFIID iid,LPVOID *ppv)
{
    CFUUIDRef interfaceID;
    
    interfaceID = CFUUIDCreateFromUUIDBytes(kCFAllocatorDefault,iid);
    
    if (CFEqual(interfaceID,kMDImporterInterfaceID)){
        /* If the Right interface was requested, bump the ref count,
         * set the ppv parameter equal to the instance, and
         * return good status.
         */
        ((MetadataImporterPluginType*)thisInstance)->conduitInterface->AddRef(thisInstance);
        *ppv = thisInstance;
        CFRelease(interfaceID);
        return S_OK;
    }else{
        if (CFEqual(interfaceID,IUnknownUUID)){
            /* If the IUnknown interface was requested, same as above. */
            ((MetadataImporterPluginType*)thisInstance )->conduitInterface->AddRef(thisInstance);
            *ppv = thisInstance;
            CFRelease(interfaceID);
            return S_OK;
        }else{
            /* Requested interface unknown, bail with error. */
            *ppv = NULL;
            CFRelease(interfaceID);
            return E_NOINTERFACE;
        }
    }
}

// -----------------------------------------------------------------------------
//	MetadataImporterPluginAddRef
// -----------------------------------------------------------------------------
//	Implementation of reference counting for this type. Whenever an interface
//	is requested, bump the refCount for the instance. NOTE: returning the
//	refcount is a convention but is not required so don't rely on it.
//
ULONG MetadataImporterPluginAddRef(void *thisInstance)
{
    ((MetadataImporterPluginType *)thisInstance )->refCount += 1;
    return ((MetadataImporterPluginType*) thisInstance)->refCount;
}

// -----------------------------------------------------------------------------
// SampleCMPluginRelease
// -----------------------------------------------------------------------------
//	When an interface is released, decrement the refCount.
//	If the refCount goes to zero, deallocate the instance.
//
ULONG MetadataImporterPluginRelease(void *thisInstance)
{
    ((MetadataImporterPluginType*)thisInstance)->refCount -= 1;
    if (((MetadataImporterPluginType*)thisInstance)->refCount == 0){
        DeallocMetadataImporterPluginType((MetadataImporterPluginType*)thisInstance );
        return 0;
    }else{
        return ((MetadataImporterPluginType*) thisInstance )->refCount;
    }
}

// -----------------------------------------------------------------------------
//	Python_Metadata_ImporterMDImporterPluginFactory
// -----------------------------------------------------------------------------
//	Implementation of the factory function for this type.
//
void *MetadataImporterPluginFactory(CFAllocatorRef allocator,CFUUIDRef typeID)
{
    MetadataImporterPluginType *result;
    CFUUIDRef                 uuid;
    
    
    /* If correct type is being requested, allocate an
     * instance of TestType and return the IUnknown interface.
     */
    if (CFEqual(typeID,kMDImporterTypeID)){
        uuid = CFUUIDCreateFromString(kCFAllocatorDefault,CFSTR(PLUGIN_ID));
        result = AllocMetadataImporterPluginType(uuid);
        CFRelease(uuid);
        return result;
    }
    /* If the requested type is incorrect, return NULL. */
    return NULL;
}