/*

Copyright (C) 2016 Apple Inc. All Rights Reserved.

See LICENSE.txt for this sample’s licensing information

Abstract:

Part of Core Audio AUBase Classes

*/

#ifndef __ComponentBase_h__

#define __ComponentBase_h__

#include <new>

#include "CADebugMacros.h"

#include "CAXException.h"

#if !defined(__COREAUDIO_USE_FLAT_INCLUDES__)

    #include <CoreAudio/CoreAudioTypes.h>

    #include <AudioUnit/AudioUnit.h>

    #if !CA_USE_AUDIO_PLUGIN_ONLY

        #include <CoreServices/../Frameworks/CarbonCore.framework/Headers/Components.h>

        #if (MAC_OS_X_VERSION_MAX_ALLOWED <= MAC_OS_X_VERSION_10_5)

            #define AudioComponentInstance          ComponentInstance

            #define AudioComponentDescription       ComponentDescription

            #define AudioComponent                  Component

        #endif

        Handle CMgr_GetComponentInstanceStorage(ComponentInstance aComponentInstance);

        void CMgr_SetComponentInstanceStorage(ComponentInstance aComponentInstance, Handle theStorage);

    #endif

    #if MAC_OS_X_VERSION_MAX_ALLOWED <= MAC_OS_X_VERSION_10_4

        typedef Float32 AudioUnitParameterValue;

    #endif

    #if COREAUDIOTYPES_VERSION < 1051

        typedef Float32 AudioUnitSampleType;

    #endif

    #if !TARGET_OS_WIN32

        #include <pthread.h>

    #endif

    #if TARGET_OS_WIN32

        #include "CAGuard.h"

    #endif

#else

    #include "CoreAudioTypes.h"

    #if !CA_USE_AUDIO_PLUGIN_ONLY

        #include "ComponentManagerDependenciesWin.h"

    #endif

    #include "AudioUnit.h"

    #include "CAGuard.h"

#endif

#ifndef COMPONENT_THROW

    #if VERBOSE_COMPONENT_THROW

        #define COMPONENT_THROW(throw_err) \

            do { DebugMessage(#throw_err); throw static_cast<OSStatus>(throw_err); } while (0)

    #else

        #define COMPONENT_THROW(throw_err) \

            throw static_cast<OSStatus>(throw_err)

    #endif

#endif

#define COMPONENT_CATCH \

    catch (const CAXException &ex) { result = ex.mError; } \

    catch (std::bad_alloc &) { result = kAudio_MemFullError; } \

    catch (OSStatus catch_err) { result = catch_err; } \

    catch (OSErr catch_err) { result = catch_err; } \

    catch (...) { result = -1; }

/*! @class ComponentBase */

class ComponentBase {

public:

    // classic MacErrors

    enum { noErr = 0};

    /*! @ctor ComponentBase */

                ComponentBase(AudioComponentInstance inInstance);

    /*! @dtor ~ComponentBase */

    virtual     ~ComponentBase();

    /*! @method PostConstructor */

    virtual void            PostConstructor();

    /*! @method PreDestructor */

    virtual void            PreDestructor();

#if !CA_USE_AUDIO_PLUGIN_ONLY

    /*! @method Version */

    virtual OSStatus        Version();

    /*! @method ComponentEntryDispatch */

    static OSStatus     ComponentEntryDispatch(ComponentParameters *p, ComponentBase *This);

    /*! GetSelectorForCanDo */

    static SInt16       GetSelectorForCanDo(ComponentParameters *params);

#endif

    /*! @method GetComponentInstance */

    AudioComponentInstance      GetComponentInstance() const { return mComponentInstance; }

    /*! @method GetComponentDescription */

    AudioComponentDescription   GetComponentDescription() const;

    // This global variable is so that new instances know how they were instantiated: via the Component Manager, 

    // or as AudioComponents. It's ugly, but preferable to altering the constructor of every class in the hierarchy.

    // It's safe because construction is protected by ComponentInitLocker.

    enum EInstanceType { kComponentMgrInstance, kAudioComponentInstance };

    static EInstanceType sNewInstanceType;

    /*! @method IsPluginObject */

    bool            IsPluginObject () const { return mInstanceType == kAudioComponentInstance; }

    /*! @method IsCMgrObject */

    bool            IsCMgrObject () const { return mInstanceType == kComponentMgrInstance; }

    /*! @method AP_Open */

    static OSStatus AP_Open(void *self, AudioUnit compInstance);

    /*! @method AP_Close */

    static OSStatus AP_Close(void *self);

protected:

    /*! @var mComponentInstance */

    AudioComponentInstance      mComponentInstance;

    EInstanceType               mInstanceType;

};

class ComponentInitLocker 

{

#if TARGET_OS_MAC

public:

    ComponentInitLocker() 

    { 

        pthread_once(&sOnce, InitComponentInitLocker);

        pthread_mutex_lock(&sComponentOpenMutex); 

        mPreviousNewInstanceType = ComponentBase::sNewInstanceType;

    }

    ~ComponentInitLocker() 

    { 

        ComponentBase::sNewInstanceType = mPreviousNewInstanceType;

        pthread_mutex_unlock(&sComponentOpenMutex); 

    }

    // There are situations (11844772) where we need to be able to release the lock early.

    class Unlocker {

    public:

        Unlocker()

        {

            pthread_mutex_unlock(&sComponentOpenMutex);

        }

        ~Unlocker()

        {

            pthread_mutex_lock(&sComponentOpenMutex); 

        }

    };

private:

    static pthread_mutex_t sComponentOpenMutex;

    static pthread_once_t sOnce;

    static void InitComponentInitLocker();

#elif TARGET_OS_WIN32

public:

    bool sNeedsUnlocking;

    ComponentInitLocker() { sNeedsUnlocking = sComponentOpenGuard.Lock(); }

    ~ComponentInitLocker() { if(sNeedsUnlocking) { sComponentOpenGuard.Unlock(); } }

private:

    static CAGuard  sComponentOpenGuard;

#endif

private:

    ComponentBase::EInstanceType    mPreviousNewInstanceType;

};

/*! @class AudioComponentPlugInInstance */ 

struct AudioComponentPlugInInstance {

    AudioComponentPlugInInterface       mPlugInInterface;

    void *                              (*mConstruct)(void *memory, AudioComponentInstance ci);

    void                                (*mDestruct)(void *memory);

    void *                              mPad[2];                // pad to a 16-byte boundary (in either 32 or 64 bit mode)

    UInt32                              mInstanceStorage;       // the ACI implementation object is constructed into this memory

                                                                // this member is just a placeholder. it is aligned to a 16byte boundary

};

/*! @class APFactory */ 

template <class APMethodLookup, class Implementor>

class APFactory {

public:

    static void *Construct(void *memory, AudioComponentInstance compInstance)

    {

        return new(memory) Implementor(compInstance);

    }

    static void Destruct(void *memory)

    {

        ((Implementor *)memory)->~Implementor();

    }

    // This is the AudioComponentFactoryFunction. It returns an AudioComponentPlugInInstance.

    // The actual implementation object is not created until Open().

    static AudioComponentPlugInInterface *Factory(const AudioComponentDescription * /* inDesc */)

    {

        AudioComponentPlugInInstance *acpi = 

                (AudioComponentPlugInInstance *)malloc( offsetof(AudioComponentPlugInInstance, mInstanceStorage) + sizeof(Implementor) );

        acpi->mPlugInInterface.Open = ComponentBase::AP_Open;

        acpi->mPlugInInterface.Close = ComponentBase::AP_Close;

        acpi->mPlugInInterface.Lookup = APMethodLookup::Lookup;

        acpi->mPlugInInterface.reserved = NULL;

        acpi->mConstruct = Construct;

        acpi->mDestruct = Destruct;

        acpi->mPad[0] = NULL;

        acpi->mPad[1] = NULL;

        return (AudioComponentPlugInInterface*)acpi;

    }

    // This is for runtime registration (not for plug-ins loaded from bundles).

    static AudioComponent Register(UInt32 type, UInt32 subtype, UInt32 manuf, CFStringRef name, UInt32 vers, UInt32 flags=0)

    {

        AudioComponentDescription desc = { type, subtype, manuf, flags, 0 };

        return AudioComponentRegister(&desc, name, vers, Factory); 

    }

};

#if !CA_USE_AUDIO_PLUGIN_ONLY

/*! @class ComponentEntryPoint 

 *  @discussion This is only used for a component manager version

*/

template <class Class>

class ComponentEntryPoint {

public:

    /*! @method Dispatch */

    static OSStatus Dispatch(ComponentParameters *params, Class *obj)

    {

        OSStatus result = noErr;

        try {

            if (params->what == kComponentOpenSelect) {

                // solve a host of initialization thread safety issues.

                ComponentInitLocker lock;

                ComponentBase::sNewInstanceType = ComponentBase::kComponentMgrInstance;

                ComponentInstance ci = (ComponentInstance)(params->params[0]);

                Class *This = new Class((AudioComponentInstance)ci);

                This->PostConstructor();    // allows base class to do additional initialization

                                            // once the derived class is fully constructed

                CMgr_SetComponentInstanceStorage(ci, (Handle)This);

            } else

                result = Class::ComponentEntryDispatch(params, obj);

        }

        COMPONENT_CATCH

        return result;

    }

    /*! @method Register */

    static Component Register(OSType compType, OSType subType, OSType manufacturer)

    {

        ComponentDescription    description = {compType, subType, manufacturer, 0, 0};

        Component   component = RegisterComponent(&description, (ComponentRoutineUPP) Dispatch, registerComponentGlobal, NULL, NULL, NULL);

        if (component != NULL) {

            SetDefaultComponent(component, defaultComponentAnyFlagsAnyManufacturerAnySubType);

        }

        return component;

    }

};

// NOTE: The Carbon Component Manager is deprecated in Mountain Lion (10.8).

// This macro should not be used with new audio components.

// It is only for backwards compatibility with Lion and Snow Leopard.

// This macro registers both an Audio Component plugin and a Carbon Component Manager version.

#define AUDIOCOMPONENT_ENTRY(FactoryType, Class) \

    extern "C" OSStatus Class##Entry(ComponentParameters *params, Class *obj); \

    extern "C" OSStatus Class##Entry(ComponentParameters *params, Class *obj) { \

        return ComponentEntryPoint<Class>::Dispatch(params, obj); \

    } \

    extern "C" void * Class##Factory(const AudioComponentDescription *inDesc); \

    extern "C" void * Class##Factory(const AudioComponentDescription *inDesc) { \

        return FactoryType<Class>::Factory(inDesc); \

    }

    // the only component we still support are the carbon based view components

    // you should be using this macro now to exclusively register those types

#define VIEW_COMPONENT_ENTRY(Class) \

    extern "C" OSStatus Class##Entry(ComponentParameters *params, Class *obj); \

    extern "C" OSStatus Class##Entry(ComponentParameters *params, Class *obj) { \

        return ComponentEntryPoint<Class>::Dispatch(params, obj); \

    }

    /*! @class ComponentRegistrar */

template <class Class, OSType Type, OSType Subtype, OSType Manufacturer>

class ComponentRegistrar {

public:

    /*! @ctor ComponentRegistrar */

    ComponentRegistrar() { ComponentEntryPoint<Class>::Register(Type, Subtype, Manufacturer); }

};

#define COMPONENT_REGISTER(Class,Type,Subtype,Manufacturer) \

    static ComponentRegistrar<Class, Type, Subtype, Manufacturer>   gRegistrar##Class

#else

#define COMPONENT_ENTRY(Class)

#define COMPONENT_REGISTER(Class)

// This macro is used to generate the Entry Point for a given Audio Component.

// You should be using this macro now.

#define AUDIOCOMPONENT_ENTRY(FactoryType, Class) \

    extern "C" void * Class##Factory(const AudioComponentDescription *inDesc); \

    extern "C" void * Class##Factory(const AudioComponentDescription *inDesc) { \

        return FactoryType<Class>::Factory(inDesc); \

    }

#endif // !CA_USE_AUDIO_PLUGIN_ONLY

#endif // __ComponentBase_h__