#ifndef INCLUDED_PORTAUDIO_MEMFUNCALLBACKSTREAM_HXX
#define INCLUDED_PORTAUDIO_MEMFUNCALLBACKSTREAM_HXX

// ---------------------------------------------------------------------------------------

#include "portaudio.h"

#include "portaudiocpp/CallbackStream.hxx"
#include "portaudiocpp/CallbackInterface.hxx"
#include "portaudiocpp/StreamParameters.hxx"
#include "portaudiocpp/Exception.hxx"
#include "portaudiocpp/InterfaceCallbackStream.hxx"

// ---------------------------------------------------------------------------------------

namespace portaudio
{


    //////
    /// @brief Callback stream using a class's member function as a callback. Template argument T is the type of the
    /// class of which a member function is going to be used.
    ///
    /// Example usage:
    /// @verbatim MemFunCallback<MyClass> stream = MemFunCallbackStream(parameters, *this, &MyClass::myCallbackFunction); @endverbatim
    //////
    template<typename T>
    class MemFunCallbackStream : public CallbackStream
    {
    public:
        typedef int (T::*CallbackFunPtr)(const void *, void *, unsigned long, const PaStreamCallbackTimeInfo *,
            PaStreamCallbackFlags);

        // -------------------------------------------------------------------------------

        MemFunCallbackStream()
        {
        }

        MemFunCallbackStream(const StreamParameters &parameters, T &instance, CallbackFunPtr memFun) : adapter_(instance, memFun)
        {
            open(parameters);
        }

        ~MemFunCallbackStream()
        {
            close();
        }

        void open(const StreamParameters &parameters, T &instance, CallbackFunPtr memFun)
        {
            // XXX: need to check if already open?

            adapter_.init(instance, memFun);
            open(parameters);
        }

    private:
        MemFunCallbackStream(const MemFunCallbackStream &); // non-copyable
        MemFunCallbackStream &operator=(const MemFunCallbackStream &); // non-copyable

        //////
        /// @brief Inner class which adapts a member function callback to a CallbackInterface compliant
        /// class (so it can be adapted using the paCallbackAdapter function).
        //////
        class MemFunToCallbackInterfaceAdapter : public CallbackInterface
        {
        public:
            MemFunToCallbackInterfaceAdapter() {}
            MemFunToCallbackInterfaceAdapter(T &instance, CallbackFunPtr memFun) : instance_(&instance), memFun_(memFun) {}

            void init(T &instance, CallbackFunPtr memFun)
            {
                instance_ = &instance;
                memFun_ = memFun;
            }

            int paCallbackFun(const void *inputBuffer, void *outputBuffer, unsigned long numFrames,
                const PaStreamCallbackTimeInfo *timeInfo, PaStreamCallbackFlags statusFlags)
            {
                return (instance_->*memFun_)(inputBuffer, outputBuffer, numFrames, timeInfo, statusFlags);
            }

        private:
            T *instance_;
            CallbackFunPtr memFun_;
        };

        MemFunToCallbackInterfaceAdapter adapter_;

        void open(const StreamParameters &parameters)
        {
            PaError err = Pa_OpenStream(&stream_, parameters.inputParameters().paStreamParameters(), parameters.outputParameters().paStreamParameters(),
                parameters.sampleRate(), parameters.framesPerBuffer(), parameters.flags(), &impl::callbackInterfaceToPaCallbackAdapter,
                static_cast<void *>(&adapter_));

            if (err != paNoError)
                throw PaException(err);
        }
    };


} // portaudio

// ---------------------------------------------------------------------------------------

#endif // INCLUDED_PORTAUDIO_MEMFUNCALLBACKSTREAM_HXX
