/*
    Copyright (C) 2006-2009 Paul Davis
    Some portions Copyright (C) Sophia Poirier.

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

*/

#include <sstream>
#include <errno.h>
#include <string.h>
#include <math.h>
#include <ctype.h>

#include "pbd/transmitter.h"
#include "pbd/xml++.h"
#include "pbd/convert.h"
#include "pbd/whitespace.h"
#include "pbd/pathscanner.h"
#include "pbd/locale_guard.h"

#include <glibmm/threads.h>
#include <glibmm/fileutils.h>
#include <glibmm/miscutils.h>

#include "ardour/ardour.h"
#include "ardour/audioengine.h"
#include "ardour/audio_buffer.h"
#include "ardour/debug.h"
#include "ardour/midi_buffer.h"
#include "ardour/filesystem_paths.h"
#include "ardour/io.h"
#include "ardour/audio_unit.h"
#include "ardour/route.h"
#include "ardour/session.h"
#include "ardour/tempo.h"
#include "ardour/utils.h"

#include "appleutility/CAAudioUnit.h"
#include "appleutility/CAAUParameter.h"

#include <CoreFoundation/CoreFoundation.h>
#include <CoreServices/CoreServices.h>
#include <AudioUnit/AudioUnit.h>
#include <AudioToolbox/AudioUnitUtilities.h>
#ifdef WITH_CARBON
#include <Carbon/Carbon.h>
#endif

#include "i18n.h"

using namespace std;
using namespace PBD;
using namespace ARDOUR;

AUPluginInfo::CachedInfoMap AUPluginInfo::cached_info;

static string preset_search_path = "/Library/Audio/Presets:/Network/Library/Audio/Presets";
static string preset_suffix = ".aupreset";
static bool preset_search_path_initialized = false;

static OSStatus
_render_callback(void *userData,
		 AudioUnitRenderActionFlags *ioActionFlags,
		 const AudioTimeStamp    *inTimeStamp,
		 UInt32       inBusNumber,
		 UInt32       inNumberFrames,
		 AudioBufferList*       ioData)
{
	if (userData) {
		return ((AUPlugin*)userData)->render_callback (ioActionFlags, inTimeStamp, inBusNumber, inNumberFrames, ioData);
	}
	return paramErr;
}

static OSStatus
_get_beat_and_tempo_callback (void*    userData,
                              Float64* outCurrentBeat,
                              Float64* outCurrentTempo)
{
	if (userData) {
		return ((AUPlugin*)userData)->get_beat_and_tempo_callback (outCurrentBeat, outCurrentTempo);
	}

	return paramErr;
}

static OSStatus
_get_musical_time_location_callback (void *     userData,
                                     UInt32 *   outDeltaSampleOffsetToNextBeat,
                                     Float32 *  outTimeSig_Numerator,
                                     UInt32 *   outTimeSig_Denominator,
                                     Float64 *  outCurrentMeasureDownBeat)
{
	if (userData) {
		return ((AUPlugin*)userData)->get_musical_time_location_callback (outDeltaSampleOffsetToNextBeat,
										  outTimeSig_Numerator,
										  outTimeSig_Denominator,
										  outCurrentMeasureDownBeat);
	}
	return paramErr;
}

static OSStatus
_get_transport_state_callback (void*     userData,
			       Boolean*  outIsPlaying,
			       Boolean*  outTransportStateChanged,
			       Float64*  outCurrentSampleInTimeLine,
			       Boolean*  outIsCycling,
			       Float64*  outCycleStartBeat,
			       Float64*  outCycleEndBeat)
{
	if (userData) {
		return ((AUPlugin*)userData)->get_transport_state_callback (
			outIsPlaying, outTransportStateChanged,
			outCurrentSampleInTimeLine, outIsCycling,
			outCycleStartBeat, outCycleEndBeat);
	}
	return paramErr;
}


static int
save_property_list (CFPropertyListRef propertyList, Glib::ustring path)

{
	CFDataRef xmlData;
	int fd;

	// Convert the property list into XML data.

	xmlData = CFPropertyListCreateXMLData( kCFAllocatorDefault, propertyList);

	if (!xmlData) {
		error << _("Could not create XML version of property list") << endmsg;
		return -1;
	}

	// Write the XML data to the file.

	fd = open (path.c_str(), O_WRONLY|O_CREAT|O_EXCL, 0664);
	while (fd < 0) {
		if (errno == EEXIST) {
			error << string_compose (_("Preset file %1 exists; not overwriting"),
			                         path) << endmsg;
		} else {
			error << string_compose (_("Cannot open preset file %1 (%2)"),
			                         path, strerror (errno)) << endmsg;
		}
		CFRelease (xmlData);
		return -1;
	}

	size_t cnt = CFDataGetLength (xmlData);

	if (write (fd, CFDataGetBytePtr (xmlData), cnt) != (ssize_t) cnt) {
		CFRelease (xmlData);
		close (fd);
		return -1;
	}

	close (fd);
	return 0;
}


static CFPropertyListRef
load_property_list (Glib::ustring path)
{
	int fd;
	CFPropertyListRef propertyList = 0;
	CFDataRef         xmlData;
	CFStringRef       errorString;

	// Read the XML file.

	if ((fd = open (path.c_str(), O_RDONLY)) < 0) {
		return propertyList;

	}

	off_t len = lseek (fd, 0, SEEK_END);
	char* buf = new char[len];
	lseek (fd, 0, SEEK_SET);

	if (read (fd, buf, len) != len) {
		delete [] buf;
		close (fd);
		return propertyList;
	}

	close (fd);

	xmlData = CFDataCreateWithBytesNoCopy (kCFAllocatorDefault, (UInt8*) buf, len, kCFAllocatorNull);

	// Reconstitute the dictionary using the XML data.

	propertyList = CFPropertyListCreateFromXMLData( kCFAllocatorDefault,
							xmlData,
							kCFPropertyListImmutable,
							&errorString);

	CFRelease (xmlData);
	delete [] buf;

	return propertyList;
}

//-----------------------------------------------------------------------------
static void
set_preset_name_in_plist (CFPropertyListRef plist, string preset_name)
{
	if (!plist) {
		return;
	}
	CFStringRef pn = CFStringCreateWithCString (kCFAllocatorDefault, preset_name.c_str(), kCFStringEncodingUTF8);

	if (CFGetTypeID (plist) == CFDictionaryGetTypeID()) {
		CFDictionarySetValue ((CFMutableDictionaryRef)plist, CFSTR(kAUPresetNameKey), pn);
	}

	CFRelease (pn);
}

//-----------------------------------------------------------------------------
static std::string
get_preset_name_in_plist (CFPropertyListRef plist)
{
	std::string ret;

	if (!plist) {
		return ret;
	}

	if (CFGetTypeID (plist) == CFDictionaryGetTypeID()) {
		const void *p = CFDictionaryGetValue ((CFMutableDictionaryRef)plist, CFSTR(kAUPresetNameKey));
		if (p) {
			CFStringRef str = (CFStringRef) p;
			int len = CFStringGetLength(str);
			len =  (len * 2) + 1;
			char local_buffer[len];
			if (CFStringGetCString (str, local_buffer, len, kCFStringEncodingUTF8)) {
				ret = local_buffer;
			}
		}
	}
	return ret;
}

//--------------------------------------------------------------------------
// general implementation for ComponentDescriptionsMatch() and ComponentDescriptionsMatch_Loosely()
// if inIgnoreType is true, then the type code is ignored in the ComponentDescriptions
Boolean ComponentDescriptionsMatch_General(const ComponentDescription * inComponentDescription1, const ComponentDescription * inComponentDescription2, Boolean inIgnoreType);
Boolean ComponentDescriptionsMatch_General(const ComponentDescription * inComponentDescription1, const ComponentDescription * inComponentDescription2, Boolean inIgnoreType)
{
	if ( (inComponentDescription1 == NULL) || (inComponentDescription2 == NULL) )
		return FALSE;

	if ( (inComponentDescription1->componentSubType == inComponentDescription2->componentSubType)
			&& (inComponentDescription1->componentManufacturer == inComponentDescription2->componentManufacturer) )
	{
		// only sub-type and manufacturer IDs need to be equal
		if (inIgnoreType)
			return TRUE;
		// type, sub-type, and manufacturer IDs all need to be equal in order to call this a match
		else if (inComponentDescription1->componentType == inComponentDescription2->componentType)
			return TRUE;
	}

	return FALSE;
}

//--------------------------------------------------------------------------
// general implementation for ComponentAndDescriptionMatch() and ComponentAndDescriptionMatch_Loosely()
// if inIgnoreType is true, then the type code is ignored in the ComponentDescriptions
Boolean ComponentAndDescriptionMatch_General(Component inComponent, const ComponentDescription * inComponentDescription, Boolean inIgnoreType);
Boolean ComponentAndDescriptionMatch_General(Component inComponent, const ComponentDescription * inComponentDescription, Boolean inIgnoreType)
{
	OSErr status;
	ComponentDescription desc;

	if ( (inComponent == NULL) || (inComponentDescription == NULL) )
		return FALSE;

	// get the ComponentDescription of the input Component
	status = GetComponentInfo(inComponent, &desc, NULL, NULL, NULL);
	if (status != noErr)
		return FALSE;

	// check if the Component's ComponentDescription matches the input ComponentDescription
	return ComponentDescriptionsMatch_General(&desc, inComponentDescription, inIgnoreType);
}

//--------------------------------------------------------------------------
// determine if 2 ComponentDescriptions are basically equal
// (by that, I mean that the important identifying values are compared,
// but not the ComponentDescription flags)
Boolean ComponentDescriptionsMatch(const ComponentDescription * inComponentDescription1, const ComponentDescription * inComponentDescription2)
{
	return ComponentDescriptionsMatch_General(inComponentDescription1, inComponentDescription2, FALSE);
}

//--------------------------------------------------------------------------
// determine if 2 ComponentDescriptions have matching sub-type and manufacturer codes
Boolean ComponentDescriptionsMatch_Loose(const ComponentDescription * inComponentDescription1, const ComponentDescription * inComponentDescription2)
{
	return ComponentDescriptionsMatch_General(inComponentDescription1, inComponentDescription2, TRUE);
}

//--------------------------------------------------------------------------
// determine if a ComponentDescription basically matches that of a particular Component
Boolean ComponentAndDescriptionMatch(Component inComponent, const ComponentDescription * inComponentDescription)
{
	return ComponentAndDescriptionMatch_General(inComponent, inComponentDescription, FALSE);
}

//--------------------------------------------------------------------------
// determine if a ComponentDescription matches only the sub-type and manufacturer codes of a particular Component
Boolean ComponentAndDescriptionMatch_Loosely(Component inComponent, const ComponentDescription * inComponentDescription)
{
	return ComponentAndDescriptionMatch_General(inComponent, inComponentDescription, TRUE);
}


AUPlugin::AUPlugin (AudioEngine& engine, Session& session, boost::shared_ptr<CAComponent> _comp)
	: Plugin (engine, session)
	, comp (_comp)
	, unit (new CAAudioUnit)
	, initialized (false)
	, _current_block_size (0)
	, _requires_fixed_size_buffers (false)
	, buffers (0)
	, input_maxbuf (0)
	, input_offset (0)
	, input_buffers (0)
	, frames_processed (0)
	, _parameter_listener (0)
	, _parameter_listener_arg (0)
	, last_transport_rolling (false)
	, last_transport_speed (0.0)
{
	if (!preset_search_path_initialized) {
		Glib::ustring p = Glib::get_home_dir();
		p += "/Library/Audio/Presets:";
		p += preset_search_path;
		preset_search_path = p;
		preset_search_path_initialized = true;
	}

	init ();
}


AUPlugin::AUPlugin (const AUPlugin& other)
	: Plugin (other)
	, comp (other.get_comp())
	, unit (new CAAudioUnit)
	, initialized (false)
	, _current_block_size (0)
	, _last_nframes (0)
	, _requires_fixed_size_buffers (false)
	, buffers (0)
	, input_maxbuf (0)
	, input_offset (0)
	, input_buffers (0)
	, frames_processed (0)
	, _parameter_listener (0)
	, _parameter_listener_arg (0)

{
	init ();
}

AUPlugin::~AUPlugin ()
{
	if (_parameter_listener) {
		AUListenerDispose (_parameter_listener);
		_parameter_listener = 0;
	}
	
	if (unit) {
		DEBUG_TRACE (DEBUG::AudioUnits, "about to call uninitialize in plugin destructor\n");
		unit->Uninitialize ();
	}

	if (buffers) {
		free (buffers);
	}
}

void
AUPlugin::discover_factory_presets ()
{
	CFArrayRef presets;
	UInt32 dataSize;
	Boolean isWritable;
	OSStatus err;

	if ((err = unit->GetPropertyInfo (kAudioUnitProperty_FactoryPresets, kAudioUnitScope_Global, 0, &dataSize, &isWritable)) != 0) {
		DEBUG_TRACE (DEBUG::AudioUnits, "no factory presets for AU\n");
		return;
	}

	assert (dataSize == sizeof (presets));

	if ((err = unit->GetProperty (kAudioUnitProperty_FactoryPresets, kAudioUnitScope_Global, 0, (void*) &presets, &dataSize)) != 0) {
		error << string_compose (_("cannot get factory preset info: errcode %1"), err) << endmsg;
		return;
	}

	if (!presets) {
		return;
	}

	CFIndex cnt = CFArrayGetCount (presets);

	for (CFIndex i = 0; i < cnt; ++i) {
		AUPreset* preset = (AUPreset*) CFArrayGetValueAtIndex (presets, i);

		string name = CFStringRefToStdString (preset->presetName);
		factory_preset_map[name] = preset->presetNumber;
	}

	CFRelease (presets);
}

void
AUPlugin::init ()
{
	OSErr err;

	/* these keep track of *configured* channel set up,
	   not potential set ups.
	*/

	input_channels = -1;
	output_channels = -1;

	try {
		DEBUG_TRACE (DEBUG::AudioUnits, "opening AudioUnit\n");
		err = CAAudioUnit::Open (*(comp.get()), *unit);
	} catch (...) {
		error << _("Exception thrown during AudioUnit plugin loading - plugin ignored") << endmsg;
		throw failed_constructor();
	}

	if (err != noErr) {
		error << _("AudioUnit: Could not convert CAComponent to CAAudioUnit") << endmsg;
		throw failed_constructor ();
	}

	DEBUG_TRACE (DEBUG::AudioUnits, "count global elements\n");
	unit->GetElementCount (kAudioUnitScope_Global, global_elements);
	DEBUG_TRACE (DEBUG::AudioUnits, "count input elements\n");
	unit->GetElementCount (kAudioUnitScope_Input, input_elements);
	DEBUG_TRACE (DEBUG::AudioUnits, "count output elements\n");
	unit->GetElementCount (kAudioUnitScope_Output, output_elements);

	if (input_elements > 0) {
		/* setup render callback: the plugin calls this to get input data 
		 */
		
		AURenderCallbackStruct renderCallbackInfo;
		
		renderCallbackInfo.inputProc = _render_callback;
		renderCallbackInfo.inputProcRefCon = this;
		
		DEBUG_TRACE (DEBUG::AudioUnits, "set render callback in input scope\n");
		if ((err = unit->SetProperty (kAudioUnitProperty_SetRenderCallback, kAudioUnitScope_Input,
					      0, (void*) &renderCallbackInfo, sizeof(renderCallbackInfo))) != 0) {
			error << string_compose (_("cannot install render callback (err = %1)"), err) << endmsg;
			throw failed_constructor();
		}
	}

	/* tell the plugin about tempo/meter/transport callbacks in case it wants them */

	HostCallbackInfo info;
	memset (&info, 0, sizeof (HostCallbackInfo));
	info.hostUserData = this;
	info.beatAndTempoProc = _get_beat_and_tempo_callback;
	info.musicalTimeLocationProc = _get_musical_time_location_callback;
	info.transportStateProc = _get_transport_state_callback;

	//ignore result of this - don't care if the property isn't supported
	DEBUG_TRACE (DEBUG::AudioUnits, "set host callbacks in global scope\n");
	unit->SetProperty (kAudioUnitProperty_HostCallbacks,
			   kAudioUnitScope_Global,
			   0, //elementID
			   &info,
			   sizeof (HostCallbackInfo));

	if (set_block_size (_session.get_block_size())) {
		error << _("AUPlugin: cannot set processing block size") << endmsg;
		throw failed_constructor();
	}

	create_parameter_listener (AUPlugin::_parameter_change_listener, this, 0.05);
	discover_parameters ();
	discover_factory_presets ();

	// Plugin::setup_controls ();
}

void
AUPlugin::discover_parameters ()
{
	/* discover writable parameters */

	AudioUnitScope scopes[] = {
		kAudioUnitScope_Global,
		kAudioUnitScope_Output,
		kAudioUnitScope_Input
	};

	descriptors.clear ();

	for (uint32_t i = 0; i < sizeof (scopes) / sizeof (scopes[0]); ++i) {

		AUParamInfo param_info (unit->AU(), false, false, scopes[i]);

		for (uint32_t i = 0; i < param_info.NumParams(); ++i) {

			AUParameterDescriptor d;

			d.id = param_info.ParamID (i);

			const CAAUParameter* param = param_info.GetParamInfo (d.id);
			const AudioUnitParameterInfo& info (param->ParamInfo());

			const int len = CFStringGetLength (param->GetName());;
			char local_buffer[len*2];
			Boolean good = CFStringGetCString(param->GetName(),local_buffer,len*2,kCFStringEncodingMacRoman);
			if (!good) {
				d.label = "???";
			} else {
				d.label = local_buffer;
			}

			d.scope = param_info.GetScope ();
			d.element = param_info.GetElement ();

			/* info.units to consider */
			/*
			  kAudioUnitParameterUnit_Generic             = 0
			  kAudioUnitParameterUnit_Indexed             = 1
			  kAudioUnitParameterUnit_Boolean             = 2
			  kAudioUnitParameterUnit_Percent             = 3
			  kAudioUnitParameterUnit_Seconds             = 4
			  kAudioUnitParameterUnit_SampleFrames        = 5
			  kAudioUnitParameterUnit_Phase               = 6
			  kAudioUnitParameterUnit_Rate                = 7
			  kAudioUnitParameterUnit_Hertz               = 8
			  kAudioUnitParameterUnit_Cents               = 9
			  kAudioUnitParameterUnit_RelativeSemiTones   = 10
			  kAudioUnitParameterUnit_MIDINoteNumber      = 11
			  kAudioUnitParameterUnit_MIDIController      = 12
			  kAudioUnitParameterUnit_Decibels            = 13
			  kAudioUnitParameterUnit_LinearGain          = 14
			  kAudioUnitParameterUnit_Degrees             = 15
			  kAudioUnitParameterUnit_EqualPowerCrossfade = 16
			  kAudioUnitParameterUnit_MixerFaderCurve1    = 17
			  kAudioUnitParameterUnit_Pan                 = 18
			  kAudioUnitParameterUnit_Meters              = 19
			  kAudioUnitParameterUnit_AbsoluteCents       = 20
			  kAudioUnitParameterUnit_Octaves             = 21
			  kAudioUnitParameterUnit_BPM                 = 22
			  kAudioUnitParameterUnit_Beats               = 23
			  kAudioUnitParameterUnit_Milliseconds        = 24
			  kAudioUnitParameterUnit_Ratio               = 25
			*/

			/* info.flags to consider */

			/*

			  kAudioUnitParameterFlag_CFNameRelease       = (1L << 4)
			  kAudioUnitParameterFlag_HasClump            = (1L << 20)
			  kAudioUnitParameterFlag_HasName             = (1L << 21)
			  kAudioUnitParameterFlag_DisplayLogarithmic  = (1L << 22)
			  kAudioUnitParameterFlag_IsHighResolution    = (1L << 23)
			  kAudioUnitParameterFlag_NonRealTime         = (1L << 24)
			  kAudioUnitParameterFlag_CanRamp             = (1L << 25)
			  kAudioUnitParameterFlag_ExpertMode          = (1L << 26)
			  kAudioUnitParameterFlag_HasCFNameString     = (1L << 27)
			  kAudioUnitParameterFlag_IsGlobalMeta        = (1L << 28)
			  kAudioUnitParameterFlag_IsElementMeta       = (1L << 29)
			  kAudioUnitParameterFlag_IsReadable          = (1L << 30)
			  kAudioUnitParameterFlag_IsWritable          = (1L << 31)
			*/

			d.lower = info.minValue;
			d.upper = info.maxValue;
			d.default_value = info.defaultValue;

			d.integer_step = (info.unit == kAudioUnitParameterUnit_Indexed);
			d.toggled = (info.unit == kAudioUnitParameterUnit_Boolean) ||
				(d.integer_step && ((d.upper - d.lower) == 1.0));
			d.sr_dependent = (info.unit == kAudioUnitParameterUnit_SampleFrames);
			d.automatable = !d.toggled &&
				!(info.flags & kAudioUnitParameterFlag_NonRealTime) &&
				(info.flags & kAudioUnitParameterFlag_IsWritable);

			d.logarithmic = (info.flags & kAudioUnitParameterFlag_DisplayLogarithmic);
			d.unit = info.unit;

			d.step = 1.0;
			d.smallstep = 0.1;
			d.largestep = 10.0;
			d.min_unbound = 0; // lower is bound
			d.max_unbound = 0; // upper is bound

			descriptors.push_back (d);

			uint32_t last_param = descriptors.size() - 1;
			parameter_map.insert (pair<uint32_t,uint32_t> (d.id, last_param));
			listen_to_parameter (last_param);
		}
	}
}


static unsigned int
four_ints_to_four_byte_literal (unsigned char n[4])
{
	/* this is actually implementation dependent. sigh. this is what gcc
	   and quite a few others do.
	 */
	return ((n[0] << 24) + (n[1] << 16) + (n[2] << 8) + n[3]);
}

std::string
AUPlugin::maybe_fix_broken_au_id (const std::string& id)
{
	if (isdigit (id[0])) {
		return id;
	}

	/* ID format is xxxx-xxxx-xxxx
	   where x maybe \xNN or a printable character.

	   Split at the '-' and and process each part into an integer.
	   Then put it back together.
	*/


	unsigned char nascent[4];
	const char* cstr = id.c_str();
	const char* estr = cstr + id.size();
	uint32_t n[3];
	int in;
	int next_int;
	char short_buf[3];
	stringstream s;

	in = 0;
	next_int = 0;
	short_buf[2] = '\0';

	while (*cstr && next_int < 4) {

		if (*cstr == '\\') {

			if (estr - cstr < 3) {

				/* too close to the end for \xNN parsing: treat as literal characters */

				nascent[in] = *cstr;
				++cstr;
				++in;

			} else {

				if (cstr[1] == 'x' && isxdigit (cstr[2]) && isxdigit (cstr[3])) {

					/* parse \xNN */

					memcpy (short_buf, &cstr[2], 2);
					nascent[in] = strtol (short_buf, NULL, 16);
					cstr += 4;
					++in;

				} else {

					/* treat as literal characters */
					nascent[in] = *cstr;
					++cstr;
					++in;
				}
			}

		} else {

			nascent[in] = *cstr;
			++cstr;
			++in;
		}

		if (in && (in % 4 == 0)) {
			/* nascent is ready */
			n[next_int] = four_ints_to_four_byte_literal (nascent);
			in = 0;
			next_int++;

			/* swallow space-hyphen-space */

			if (next_int < 3) {
				++cstr;
				++cstr;
				++cstr;
			}
		}
	}

	if (next_int != 3) {
		goto err;
	}

	s << n[0] << '-' << n[1] << '-' << n[2];

	return s.str();

  err:
	return string();
}

string
AUPlugin::unique_id () const
{
	return AUPluginInfo::stringify_descriptor (comp->Desc());
}

const char *
AUPlugin::label () const
{
	return _info->name.c_str();
}

uint32_t
AUPlugin::parameter_count () const
{
	return descriptors.size();
}

float
AUPlugin::default_value (uint32_t port)
{
	if (port < descriptors.size()) {
		return descriptors[port].default_value;
	}

	return 0;
}

framecnt_t
AUPlugin::signal_latency () const
{
	return unit->Latency() * _session.frame_rate();
}

void
AUPlugin::set_parameter (uint32_t which, float val)
{
	if (which >= descriptors.size()) {
		return;
	}

	if (get_parameter(which) == val) {
		return;
	}

	const AUParameterDescriptor& d (descriptors[which]);
	DEBUG_TRACE (DEBUG::AudioUnits, string_compose ("set parameter %1 in scope %2 element %3 to %4\n", d.id, d.scope, d.element, val));
	unit->SetParameter (d.id, d.scope, d.element, val);

	/* tell the world what we did */

	AudioUnitEvent theEvent;

	theEvent.mEventType = kAudioUnitEvent_ParameterValueChange;
	theEvent.mArgument.mParameter.mAudioUnit = unit->AU();
	theEvent.mArgument.mParameter.mParameterID = d.id;
	theEvent.mArgument.mParameter.mScope = d.scope;
	theEvent.mArgument.mParameter.mElement = d.element;

	DEBUG_TRACE (DEBUG::AudioUnits, "notify about parameter change\n");
	AUEventListenerNotify (NULL, NULL, &theEvent);

	Plugin::set_parameter (which, val);
}

float
AUPlugin::get_parameter (uint32_t which) const
{
	float val = 0.0;
	if (which < descriptors.size()) {
		const AUParameterDescriptor& d (descriptors[which]);
		// DEBUG_TRACE (DEBUG::AudioUnits, string_compose ("get value of parameter %1 in scope %2 element %3\n", d.id, d.scope, d.element));
		unit->GetParameter(d.id, d.scope, d.element, val);
	}
	return val;
}

int
AUPlugin::get_parameter_descriptor (uint32_t which, ParameterDescriptor& pd) const
{
	if (which < descriptors.size()) {
		pd = descriptors[which];
		return 0;
	}
	return -1;
}

uint32_t
AUPlugin::nth_parameter (uint32_t which, bool& ok) const
{
	if (which < descriptors.size()) {
		ok = true;
		return which;
	}
	ok = false;
	return 0;
}

void
AUPlugin::activate ()
{
	if (!initialized) {
		OSErr err;
		DEBUG_TRACE (DEBUG::AudioUnits, "call Initialize in activate()\n");
		if ((err = unit->Initialize()) != noErr) {
			error << string_compose (_("AUPlugin: %1 cannot initialize plugin (err = %2)"), name(), err) << endmsg;
		} else {
			frames_processed = 0;
			initialized = true;
		}
	}
}

void
AUPlugin::deactivate ()
{
	DEBUG_TRACE (DEBUG::AudioUnits, "call Uninitialize in deactivate()\n");
	unit->Uninitialize ();
	initialized = false;
}

void
AUPlugin::flush ()
{
	DEBUG_TRACE (DEBUG::AudioUnits, "call Reset in flush()\n");
	unit->GlobalReset ();
}

bool
AUPlugin::requires_fixed_size_buffers() const
{
	return _requires_fixed_size_buffers;
}


int
AUPlugin::set_block_size (pframes_t nframes)
{
	bool was_initialized = initialized;
	UInt32 numFrames = nframes;
	OSErr err;

	if (initialized) {
		deactivate ();
	}

	DEBUG_TRACE (DEBUG::AudioUnits, string_compose ("set MaximumFramesPerSlice in global scope to %1\n", numFrames));
	if ((err = unit->SetProperty (kAudioUnitProperty_MaximumFramesPerSlice, kAudioUnitScope_Global,
				      0, &numFrames, sizeof (numFrames))) != noErr) {
		error << string_compose (_("AU: cannot set max frames (err = %1)"), err) << endmsg;
		return -1;
	}

	if (was_initialized) {
		activate ();
	}

	_current_block_size = nframes;

	return 0;
}

bool
AUPlugin::configure_io (ChanCount in, ChanCount out)
{
	AudioStreamBasicDescription streamFormat;
	bool was_initialized = initialized;
	int32_t audio_in = in.n_audio();
	int32_t audio_out = out.n_audio();

	DEBUG_TRACE (DEBUG::AudioUnits, string_compose ("configure %1 for %2 in %3 out\n", name(), in, out));

	if (initialized) {
		//if we are already running with the requested i/o config, bail out here
		if ( (audio_in==input_channels) && (audio_out==output_channels) ) {
			return 0;
		} else {
			deactivate ();
		}
	}

	streamFormat.mSampleRate = _session.frame_rate();
	streamFormat.mFormatID = kAudioFormatLinearPCM;
	streamFormat.mFormatFlags = kAudioFormatFlagIsFloat|kAudioFormatFlagIsPacked|kAudioFormatFlagIsNonInterleaved;

#ifdef __LITTLE_ENDIAN__
	/* relax */
#else
	streamFormat.mFormatFlags |= kAudioFormatFlagIsBigEndian;
#endif

	streamFormat.mBitsPerChannel = 32;
	streamFormat.mFramesPerPacket = 1;

	/* apple says that for non-interleaved data, these
	   values always refer to a single channel.
	*/
	streamFormat.mBytesPerPacket = 4;
	streamFormat.mBytesPerFrame = 4;

	streamFormat.mChannelsPerFrame = audio_in;

	if (set_input_format (streamFormat) != 0) {
		return -1;
	}

	streamFormat.mChannelsPerFrame = audio_out;

	if (set_output_format (streamFormat) != 0) {
		return -1;
	}

	/* reset plugin info to show currently configured state */
	
	_info->n_inputs = in;
	_info->n_outputs = out;

	if (was_initialized) {
		activate ();
	}

	return 0;
}

ChanCount
AUPlugin::input_streams() const
{
	ChanCount c;

	c.set (DataType::AUDIO, 1);
	c.set (DataType::MIDI, 0);

	if (input_channels < 0) {
		warning << string_compose (_("AUPlugin: %1 input_streams() called without any format set!"), name()) << endmsg;
	} else {
		c.set (DataType::AUDIO, input_channels);
		c.set (DataType::MIDI, _has_midi_input ? 1 : 0);
	}

	return c;
}


ChanCount
AUPlugin::output_streams() const
{
	ChanCount c;

	c.set (DataType::AUDIO, 1);
	c.set (DataType::MIDI, 0);

	if (output_channels < 0) {
		warning << string_compose (_("AUPlugin: %1 output_streams() called without any format set!"), name()) << endmsg;
	} else {
		c.set (DataType::AUDIO, output_channels);
		c.set (DataType::MIDI, _has_midi_output ? 1 : 0);
	}

	return c;
}

bool
AUPlugin::can_support_io_configuration (const ChanCount& in, ChanCount& out)
{
	// Note: We never attempt to multiply-instantiate plugins to meet io configurations.

	int32_t audio_in = in.n_audio();
	int32_t audio_out;
	bool found = false;
	AUPluginInfoPtr pinfo = boost::dynamic_pointer_cast<AUPluginInfo>(get_info());

	/* lets check MIDI first */

	if (in.n_midi() > 0) {
		if (!_has_midi_input) {
			return false;
		}
	}

	vector<pair<int,int> >& io_configs = pinfo->cache.io_configs;

	DEBUG_TRACE (DEBUG::AudioUnits, string_compose ("%1 has %2 IO configurations, looking for %3 in, %4 out\n", 
							name(), io_configs.size(), in, out));

	//Ardour expects the plugin to tell it the output
	//configuration but AU plugins can have multiple I/O
	//configurations in most cases. so first lets see
	//if there's a configuration that keeps out==in

	audio_out = audio_in;

	for (vector<pair<int,int> >::iterator i = io_configs.begin(); i != io_configs.end(); ++i) {

		int32_t possible_in = i->first;
		int32_t possible_out = i->second;

		if ((possible_in == audio_in) && (possible_out == audio_out)) {
			DEBUG_TRACE (DEBUG::AudioUnits, string_compose ("\tCHOSEN: %1 in %2 out to match in %3 out %4\n", 
									possible_in, possible_out,
									in, out));

			out.set (DataType::MIDI, 0);
			out.set (DataType::AUDIO, audio_out);

			return 1;
		}
	}

	/* now allow potentially "imprecise" matches */

	audio_out = -1;

	for (vector<pair<int,int> >::iterator i = io_configs.begin(); i != io_configs.end(); ++i) {

		int32_t possible_in = i->first;
		int32_t possible_out = i->second;

		DEBUG_TRACE (DEBUG::AudioUnits, string_compose ("\tpossible in %1 possible out %2\n", possible_in, possible_out));

		if (possible_out == 0) {
			warning << string_compose (_("AU %1 has zero outputs - configuration ignored"), name()) << endmsg;
			/* XXX surely this is just a send? (e.g. AUNetSend) */
			continue;
		}

		if (possible_in == 0) {

			/* instrument plugin, always legal but throws away inputs ...
			*/

			if (possible_out == -1) {
				/* any configuration possible, provide stereo output */
				audio_out = 2;
				found = true;
			} else if (possible_out == -2) {
				/* plugins shouldn't really use (0,-2) but might. 
				   any configuration possible, provide stereo output 
				*/
				audio_out = 2;
				found = true;
			} else if (possible_out < -2) {
				/* explicitly variable number of outputs. 

                                   Since Ardour can handle any configuration,
                                   we have to somehow pick a number. 

                                   We'll use the number of inputs
                                   to the master bus, or 2 if there
                                   is no master bus.
                                */
                                boost::shared_ptr<Route> master = _session.master_out();
                                if (master) {
                                        audio_out = master->input()->n_ports().n_audio();
                                } else {
                                        audio_out = 2;
                                }
				found = true;
			} else {
				/* exact number of outputs */
				audio_out = possible_out;
				found = true;
			}
		}

		if (possible_in == -1) {

			/* wildcard for input */

			if (possible_out == -1) {
				/* out much match in */
				audio_out = audio_in;
				found = true;
			} else if (possible_out == -2) {
				/* any configuration possible, pick matching */
				audio_out = audio_in;
				found = true;
			} else if (possible_out < -2) {
				/* explicitly variable number of outputs, pick maximum */
				audio_out = -possible_out;
				found = true;
			} else {
				/* exact number of outputs */
				audio_out = possible_out;
				found = true;
			}
		}

		if (possible_in == -2) {

			if (possible_out == -1) {
				/* any configuration possible, pick matching */
				audio_out = audio_in;
				found = true;
			} else if (possible_out == -2) {
				/* plugins shouldn't really use (-2,-2) but might. 
				   interpret as (-1,-1).
				*/
				audio_out = audio_in;
				found = true;
			} else if (possible_out < -2) {
				/* explicitly variable number of outputs, pick maximum */
				audio_out = -possible_out;
				found = true;
			} else {
				/* exact number of outputs */
				audio_out = possible_out;
				found = true;
			}
		}

		if (possible_in < -2) {

			/* explicit variable number of inputs */

			if (audio_in > -possible_in) {
				/* request is too large */
			}


			if (possible_out == -1) {
				/* any output configuration possible, provide stereo out */
				audio_out = 2;
				found = true;
			} else if (possible_out == -2) {
				/* plugins shouldn't really use (<-2,-2) but might. 
				   interpret as (<-2,-1): any configuration possible, provide stereo output 
				*/
				audio_out = 2;
				found = true;
			} else if (possible_out < -2) {
				/* explicitly variable number of outputs. 

                                   Since Ardour can handle any configuration,
                                   we have to somehow pick a number. 

                                   We'll use the number of inputs
                                   to the master bus, or 2 if there
                                   is no master bus.
                                */
                                boost::shared_ptr<Route> master = _session.master_out();
                                if (master) {
                                        audio_out = master->input()->n_ports().n_audio();
                                } else {
                                        audio_out = 2;
                                }
				found = true;
			} else {
				/* exact number of outputs */
				audio_out = possible_out;
				found = true;
			}
		}

		if (possible_in && (possible_in == audio_in)) {

			/* exact number of inputs ... must match obviously */

			if (possible_out == -1) {
				/* any output configuration possible, provide stereo output */
				audio_out = 2;
				found = true;
			} else if (possible_out == -2) {
				/* plugins shouldn't really use (>0,-2) but might. 
				   interpret as (>0,-1): 
				   any output configuration possible, provide stereo output
				*/
				audio_out = 2;
				found = true;
			} else if (possible_out < -2) {
				/* explicitly variable number of outputs, pick maximum */
				audio_out = -possible_out;
				found = true;
			} else {
				/* exact number of outputs */
				audio_out = possible_out;
				found = true;
			}
		}

		if (found) {
			break;
		}

	}

	if (found) {
		DEBUG_TRACE (DEBUG::AudioUnits, string_compose ("\tCHOSEN: in %1 out %2\n", in, out));
	} else {
		DEBUG_TRACE (DEBUG::AudioUnits, string_compose ("\tFAIL: no io configs match %1\n", in));
		return false;
	}

	out.set (DataType::MIDI, 0);
	out.set (DataType::AUDIO, audio_out);

	return true;
}

int
AUPlugin::set_input_format (AudioStreamBasicDescription& fmt)
{
	return set_stream_format (kAudioUnitScope_Input, input_elements, fmt);
}

int
AUPlugin::set_output_format (AudioStreamBasicDescription& fmt)
{
	if (set_stream_format (kAudioUnitScope_Output, output_elements, fmt) != 0) {
		return -1;
	}

	if (buffers) {
		free (buffers);
		buffers = 0;
	}

	buffers = (AudioBufferList *) malloc (offsetof(AudioBufferList, mBuffers) +
					      fmt.mChannelsPerFrame * sizeof(::AudioBuffer));

	return 0;
}

int
AUPlugin::set_stream_format (int scope, uint32_t cnt, AudioStreamBasicDescription& fmt)
{
	OSErr result;

	for (uint32_t i = 0; i < cnt; ++i) {
		DEBUG_TRACE (DEBUG::AudioUnits, string_compose ("set stream format for %1, scope = %2 element %3\n",
								(scope == kAudioUnitScope_Input ? "input" : "output"),
								scope, cnt));
		if ((result = unit->SetFormat (scope, i, fmt)) != 0) {
			error << string_compose (_("AUPlugin: could not set stream format for %1/%2 (err = %3)"),
						 (scope == kAudioUnitScope_Input ? "input" : "output"), i, result) << endmsg;
			return -1;
		}
	}

	if (scope == kAudioUnitScope_Input) {
		input_channels = fmt.mChannelsPerFrame;
	} else {
		output_channels = fmt.mChannelsPerFrame;
	}

	return 0;
}

OSStatus
AUPlugin::render_callback(AudioUnitRenderActionFlags*,
			  const AudioTimeStamp*,
			  UInt32,
			  UInt32       inNumberFrames,
			  AudioBufferList*       ioData)
{
	/* not much to do with audio - the data is already in the buffers given to us in connect_and_run() */

	// DEBUG_TRACE (DEBUG::AudioUnits, string_compose ("%1: render callback, frames %2 bufs %3\n",
        // name(), inNumberFrames, ioData->mNumberBuffers));

	if (input_maxbuf == 0) {
		error << _("AUPlugin: render callback called illegally!") << endmsg;
		return kAudioUnitErr_CannotDoInCurrentContext;
	}
	uint32_t limit = min ((uint32_t) ioData->mNumberBuffers, input_maxbuf);

	for (uint32_t i = 0; i < limit; ++i) {
		ioData->mBuffers[i].mNumberChannels = 1;
		ioData->mBuffers[i].mDataByteSize = sizeof (Sample) * inNumberFrames;

		/* we don't use the channel mapping because audiounits are
		   never replicated. one plugin instance uses all channels/buffers
		   passed to PluginInsert::connect_and_run()
		*/

		ioData->mBuffers[i].mData = input_buffers->get_audio (i).data (cb_offset + input_offset);
	}

	cb_offset += inNumberFrames;

	return noErr;
}

int
AUPlugin::connect_and_run (BufferSet& bufs, ChanMapping in_map, ChanMapping out_map, pframes_t nframes, framecnt_t offset)
{
	Plugin::connect_and_run (bufs, in_map, out_map, nframes, offset);

	AudioUnitRenderActionFlags flags = 0;
	AudioTimeStamp ts;
	OSErr err;

	if (requires_fixed_size_buffers() && (nframes != _last_nframes)) {
		unit->GlobalReset();
		_last_nframes = nframes;
	}

	DEBUG_TRACE (DEBUG::AudioUnits, string_compose ("%1 in %2 out %3 MIDI %4 bufs %5 (available %6)\n",
							name(), input_channels, output_channels, _has_midi_input,
							bufs.count(), bufs.available()));

	/* the apparent number of buffers matches our input configuration, but we know that the bufferset
	   has the capacity to handle our outputs.
	*/

	assert (bufs.available() >= ChanCount (DataType::AUDIO, output_channels));

	input_buffers = &bufs;
	input_maxbuf = bufs.count().n_audio(); // number of input audio buffers
	input_offset = offset;
	cb_offset = 0;

	buffers->mNumberBuffers = output_channels;

	for (int32_t i = 0; i < output_channels; ++i) {
		buffers->mBuffers[i].mNumberChannels = 1;
		buffers->mBuffers[i].mDataByteSize = nframes * sizeof (Sample);
		/* setting this to 0 indicates to the AU that it can provide buffers here
		   if necessary. if it can process in-place, it will use the buffers provided
		   as input by ::render_callback() above. 
                   
                   a non-null values tells the plugin to render into the buffer pointed
                   at by the value.
		*/
		buffers->mBuffers[i].mData = 0;
	}

	if (_has_midi_input) {

		uint32_t nmidi = bufs.count().n_midi();

		for (uint32_t i = 0; i < nmidi; ++i) {
			
			/* one MIDI port/buffer only */
			
			MidiBuffer& m = bufs.get_midi (i);
			
			for (MidiBuffer::iterator i = m.begin(); i != m.end(); ++i) {
				Evoral::MIDIEvent<framepos_t> ev (*i);
				
				if (ev.is_channel_event()) {
					const uint8_t* b = ev.buffer();
					DEBUG_TRACE (DEBUG::AudioUnits, string_compose ("%1: MIDI event %2\n", name(), ev));
					unit->MIDIEvent (b[0], b[1], b[2], ev.time());
				}

				/* XXX need to handle sysex and other message types */
			}
		}
	}

	/* does this really mean anything ? 
	 */

	ts.mSampleTime = frames_processed;
	ts.mFlags = kAudioTimeStampSampleTimeValid;

	DEBUG_TRACE (DEBUG::AudioUnits, string_compose ("%1 render flags=%2 time=%3 nframes=%4 buffers=%5\n",
                                                        name(), flags, frames_processed, nframes, buffers->mNumberBuffers));

	if ((err = unit->Render (&flags, &ts, 0, nframes, buffers)) == noErr) {

		input_maxbuf = 0;
		frames_processed += nframes;

		DEBUG_TRACE (DEBUG::AudioUnits, string_compose ("%1 rendered %2 buffers of %3\n",
								name(), buffers->mNumberBuffers, output_channels));

		int32_t limit = min ((int32_t) buffers->mNumberBuffers, output_channels);
		int32_t i;

		for (i = 0; i < limit; ++i) {
			Sample* expected_buffer_address= bufs.get_audio (i).data (offset);
			if (expected_buffer_address != buffers->mBuffers[i].mData) {
				/* plugin provided its own buffer for output so copy it back to where we want it
				 */
				memcpy (expected_buffer_address, buffers->mBuffers[i].mData, nframes * sizeof (Sample));
			}
		}

		/* now silence any buffers that were passed in but the that the plugin
		   did not fill/touch/use.
		*/

		for (;i < output_channels; ++i) {
			memset (bufs.get_audio (i).data (offset), 0, nframes * sizeof (Sample));
		}

		return 0;
	}

	error << string_compose (_("AU: render error for %1, status = %2"), name(), err) << endmsg;
	return -1;
}

OSStatus
AUPlugin::get_beat_and_tempo_callback (Float64* outCurrentBeat,
				       Float64* outCurrentTempo)
{
	TempoMap& tmap (_session.tempo_map());

	DEBUG_TRACE (DEBUG::AudioUnits, "AU calls ardour beat&tempo callback\n");

	/* more than 1 meter or more than 1 tempo means that a simplistic computation
	   (and interpretation) of a beat position will be incorrect. So refuse to
	   offer the value.
	*/

	if (tmap.n_tempos() > 1 || tmap.n_meters() > 1) {
		return kAudioUnitErr_CannotDoInCurrentContext;
	}

	Timecode::BBT_Time bbt;
	TempoMetric metric = tmap.metric_at (_session.transport_frame() + input_offset);
	tmap.bbt_time (_session.transport_frame() + input_offset, bbt);

	if (outCurrentBeat) {
		float beat;
		beat = metric.meter().divisions_per_bar() * bbt.bars;
		beat += bbt.beats;
		beat += bbt.ticks / Timecode::BBT_Time::ticks_per_beat;
		*outCurrentBeat = beat;
	}

	if (outCurrentTempo) {
		*outCurrentTempo = floor (metric.tempo().beats_per_minute());
	}

	return noErr;

}

OSStatus
AUPlugin::get_musical_time_location_callback (UInt32*   outDeltaSampleOffsetToNextBeat,
					      Float32*  outTimeSig_Numerator,
					      UInt32*   outTimeSig_Denominator,
					      Float64*  outCurrentMeasureDownBeat)
{
	TempoMap& tmap (_session.tempo_map());

	DEBUG_TRACE (DEBUG::AudioUnits, "AU calls ardour music time location callback\n");

	/* more than 1 meter or more than 1 tempo means that a simplistic computation
	   (and interpretation) of a beat position will be incorrect. So refuse to
	   offer the value.
	*/

	if (tmap.n_tempos() > 1 || tmap.n_meters() > 1) {
		return kAudioUnitErr_CannotDoInCurrentContext;
	}

	Timecode::BBT_Time bbt;
	TempoMetric metric = tmap.metric_at (_session.transport_frame() + input_offset);
	tmap.bbt_time (_session.transport_frame() + input_offset, bbt);

	if (outDeltaSampleOffsetToNextBeat) {
		if (bbt.ticks == 0) {
			/* on the beat */
			*outDeltaSampleOffsetToNextBeat = 0;
		} else {
			*outDeltaSampleOffsetToNextBeat = (UInt32) 
				floor (((Timecode::BBT_Time::ticks_per_beat - bbt.ticks)/Timecode::BBT_Time::ticks_per_beat) * // fraction of a beat to next beat
				       metric.tempo().frames_per_beat (_session.frame_rate())); // frames per beat
		}
	}

	if (outTimeSig_Numerator) {
		*outTimeSig_Numerator = (UInt32) lrintf (metric.meter().divisions_per_bar());
	}
	if (outTimeSig_Denominator) {
		*outTimeSig_Denominator = (UInt32) lrintf (metric.meter().note_divisor());
	}

	if (outCurrentMeasureDownBeat) {

		/* beat for the start of the bar.
		   1|1|0 -> 1
		   2|1|0 -> 1 + divisions_per_bar
		   3|1|0 -> 1 + (2 * divisions_per_bar)
		   etc.
		*/

		*outCurrentMeasureDownBeat = 1 + metric.meter().divisions_per_bar() * (bbt.bars - 1);
	}

	return noErr;
}

OSStatus
AUPlugin::get_transport_state_callback (Boolean*  outIsPlaying,
					Boolean*  outTransportStateChanged,
					Float64*  outCurrentSampleInTimeLine,
					Boolean*  outIsCycling,
					Float64*  outCycleStartBeat,
					Float64*  outCycleEndBeat)
{
	bool rolling;
	float speed;

	DEBUG_TRACE (DEBUG::AudioUnits, "AU calls ardour transport state callback\n");

	rolling = _session.transport_rolling();
	speed = _session.transport_speed ();

	if (outIsPlaying) {
		*outIsPlaying = _session.transport_rolling();
	}

	if (outTransportStateChanged) {
		if (rolling != last_transport_rolling) {
			*outTransportStateChanged = true;
		} else if (speed != last_transport_speed) {
			*outTransportStateChanged = true;
		} else {
			*outTransportStateChanged = false;
		}
	}

	if (outCurrentSampleInTimeLine) {
		/* this assumes that the AU can only call this host callback from render context,
		   where input_offset is valid.
		*/
		*outCurrentSampleInTimeLine = _session.transport_frame() + input_offset;
	}

	if (outIsCycling) {
		Location* loc = _session.locations()->auto_loop_location();

		*outIsCycling = (loc && _session.transport_rolling() && _session.get_play_loop());

		if (*outIsCycling) {

			if (outCycleStartBeat || outCycleEndBeat) {

				TempoMap& tmap (_session.tempo_map());

				/* more than 1 meter means that a simplistic computation (and interpretation) of
				   a beat position will be incorrect. so refuse to offer the value.
				*/

				if (tmap.n_meters() > 1) {
					return kAudioUnitErr_CannotDoInCurrentContext;
				}

				Timecode::BBT_Time bbt;

				if (outCycleStartBeat) {
					TempoMetric metric = tmap.metric_at (loc->start() + input_offset);
					_session.tempo_map().bbt_time (loc->start(), bbt);

					float beat;
					beat = metric.meter().divisions_per_bar() * bbt.bars;
					beat += bbt.beats;
					beat += bbt.ticks / Timecode::BBT_Time::ticks_per_beat;

					*outCycleStartBeat = beat;
				}

				if (outCycleEndBeat) {
					TempoMetric metric = tmap.metric_at (loc->end() + input_offset);
					_session.tempo_map().bbt_time (loc->end(), bbt);

					float beat;
					beat = metric.meter().divisions_per_bar() * bbt.bars;
					beat += bbt.beats;
					beat += bbt.ticks / Timecode::BBT_Time::ticks_per_beat;

					*outCycleEndBeat = beat;
				}
			}
		}
	}

	last_transport_rolling = rolling;
	last_transport_speed = speed;

	return noErr;
}

set<Evoral::Parameter>
AUPlugin::automatable() const
{
	set<Evoral::Parameter> automates;

	for (uint32_t i = 0; i < descriptors.size(); ++i) {
		if (descriptors[i].automatable) {
			automates.insert (automates.end(), Evoral::Parameter (PluginAutomation, 0, i));
		}
	}

	return automates;
}

string
AUPlugin::describe_parameter (Evoral::Parameter param)
{
	if (param.type() == PluginAutomation && param.id() < parameter_count()) {
		return descriptors[param.id()].label;
	} else {
		return "??";
	}
}

void
AUPlugin::print_parameter (uint32_t /*param*/, char* /*buf*/, uint32_t /*len*/) const
{
	// NameValue stuff here
}

bool
AUPlugin::parameter_is_audio (uint32_t) const
{
	return false;
}

bool
AUPlugin::parameter_is_control (uint32_t) const
{
	return true;
}

bool
AUPlugin::parameter_is_input (uint32_t) const
{
	return false;
}

bool
AUPlugin::parameter_is_output (uint32_t) const
{
	return false;
}

void
AUPlugin::add_state (XMLNode* root) const
{
	LocaleGuard lg (X_("POSIX"));
	CFDataRef xmlData;
	CFPropertyListRef propertyList;

	DEBUG_TRACE (DEBUG::AudioUnits, "get preset state\n");
	if (unit->GetAUPreset (propertyList) != noErr) {
		return;
	}

	// Convert the property list into XML data.

	xmlData = CFPropertyListCreateXMLData( kCFAllocatorDefault, propertyList);

	if (!xmlData) {
		error << _("Could not create XML version of property list") << endmsg;
		return;
	}

	/* re-parse XML bytes to create a libxml++ XMLTree that we can merge into
	   our state node. GACK!
	*/

	XMLTree t;

	if (t.read_buffer (string ((const char*) CFDataGetBytePtr (xmlData), CFDataGetLength (xmlData)))) {
		if (t.root()) {
			root->add_child_copy (*t.root());
		}
	}

	CFRelease (xmlData);
	CFRelease (propertyList);
}

int
AUPlugin::set_state(const XMLNode& node, int version)
{
	int ret = -1;
	CFPropertyListRef propertyList;
	LocaleGuard lg (X_("POSIX"));

	if (node.name() != state_node_name()) {
		error << _("Bad node sent to AUPlugin::set_state") << endmsg;
		return -1;
	}

#ifndef NO_PLUGIN_STATE
	if (node.children().empty()) {
		return -1;
	}

	XMLNode* top = node.children().front();
	XMLNode* copy = new XMLNode (*top);

	XMLTree t;
	t.set_root (copy);

	const string& xml = t.write_buffer ();
	CFDataRef xmlData = CFDataCreateWithBytesNoCopy (kCFAllocatorDefault, (UInt8*) xml.data(), xml.length(), kCFAllocatorNull);
	CFStringRef errorString;

	propertyList = CFPropertyListCreateFromXMLData( kCFAllocatorDefault,
							xmlData,
							kCFPropertyListImmutable,
							&errorString);

	CFRelease (xmlData);

	if (propertyList) {
		DEBUG_TRACE (DEBUG::AudioUnits, "set preset\n");
		if (unit->SetAUPreset (propertyList) == noErr) {
			ret = 0;

			/* tell the world */

			AudioUnitParameter changedUnit;
			changedUnit.mAudioUnit = unit->AU();
			changedUnit.mParameterID = kAUParameterListener_AnyParameter;
			AUParameterListenerNotify (NULL, NULL, &changedUnit);
		}
		CFRelease (propertyList);
	}
#endif

	Plugin::set_state (node, version);
	return ret;
}

bool
AUPlugin::load_preset (PresetRecord r)
{
	Plugin::load_preset (r);

	bool ret = false;
	CFPropertyListRef propertyList;
	Glib::ustring path;
	UserPresetMap::iterator ux;
	FactoryPresetMap::iterator fx;

	/* look first in "user" presets */

	if ((ux = user_preset_map.find (r.label)) != user_preset_map.end()) {

		if ((propertyList = load_property_list (ux->second)) != 0) {
			DEBUG_TRACE (DEBUG::AudioUnits, "set preset from user presets\n");
			if (unit->SetAUPreset (propertyList) == noErr) {
				ret = true;

				/* tell the world */

				AudioUnitParameter changedUnit;
				changedUnit.mAudioUnit = unit->AU();
				changedUnit.mParameterID = kAUParameterListener_AnyParameter;
				AUParameterListenerNotify (NULL, NULL, &changedUnit);
			}
			CFRelease(propertyList);
		}

	} else if ((fx = factory_preset_map.find (r.label)) != factory_preset_map.end()) {

		AUPreset preset;

		preset.presetNumber = fx->second;
		preset.presetName = CFStringCreateWithCString (kCFAllocatorDefault, fx->first.c_str(), kCFStringEncodingUTF8);

		DEBUG_TRACE (DEBUG::AudioUnits, "set preset from factory presets\n");

		if (unit->SetPresentPreset (preset) == 0) {
			ret = true;

			/* tell the world */

			AudioUnitParameter changedUnit;
			changedUnit.mAudioUnit = unit->AU();
			changedUnit.mParameterID = kAUParameterListener_AnyParameter;
			AUParameterListenerNotify (NULL, NULL, &changedUnit);
		}
	}

	return ret;
}

void
AUPlugin::do_remove_preset (std::string) 
{
}

string
AUPlugin::do_save_preset (string preset_name)
{
	CFPropertyListRef propertyList;
	vector<Glib::ustring> v;
	Glib::ustring user_preset_path;

	std::string m = maker();
	std::string n = name();

	strip_whitespace_edges (m);
	strip_whitespace_edges (n);

	v.push_back (Glib::get_home_dir());
	v.push_back ("Library");
	v.push_back ("Audio");
	v.push_back ("Presets");
	v.push_back (m);
	v.push_back (n);

	user_preset_path = Glib::build_filename (v);

	if (g_mkdir_with_parents (user_preset_path.c_str(), 0775) < 0) {
		error << string_compose (_("Cannot create user plugin presets folder (%1)"), user_preset_path) << endmsg;
		return string();
	}

	DEBUG_TRACE (DEBUG::AudioUnits, "get current preset\n");
	if (unit->GetAUPreset (propertyList) != noErr) {
		return string();
	}

	// add the actual preset name */

	v.push_back (preset_name + preset_suffix);

	// rebuild

	user_preset_path = Glib::build_filename (v);

	set_preset_name_in_plist (propertyList, preset_name);

	if (save_property_list (propertyList, user_preset_path)) {
		error << string_compose (_("Saving plugin state to %1 failed"), user_preset_path) << endmsg;
		return string();
	}

	CFRelease(propertyList);

	return string ("file:///") + user_preset_path;
}

//-----------------------------------------------------------------------------
// this is just a little helper function used by GetAUComponentDescriptionFromPresetFile()
static SInt32
GetDictionarySInt32Value(CFDictionaryRef inAUStateDictionary, CFStringRef inDictionaryKey, Boolean * outSuccess)
{
	CFNumberRef cfNumber;
	SInt32 numberValue = 0;
	Boolean dummySuccess;

	if (outSuccess == NULL)
		outSuccess = &dummySuccess;
	if ( (inAUStateDictionary == NULL) || (inDictionaryKey == NULL) )
	{
		*outSuccess = FALSE;
		return 0;
	}

	cfNumber = (CFNumberRef) CFDictionaryGetValue(inAUStateDictionary, inDictionaryKey);
	if (cfNumber == NULL)
	{
		*outSuccess = FALSE;
		return 0;
	}
	*outSuccess = CFNumberGetValue(cfNumber, kCFNumberSInt32Type, &numberValue);
	if (*outSuccess)
		return numberValue;
	else
		return 0;
}

static OSStatus
GetAUComponentDescriptionFromStateData(CFPropertyListRef inAUStateData, ComponentDescription * outComponentDescription)
{
	CFDictionaryRef auStateDictionary;
	ComponentDescription tempDesc = {0,0,0,0,0};
	SInt32 versionValue;
	Boolean gotValue;

	if ( (inAUStateData == NULL) || (outComponentDescription == NULL) )
		return paramErr;

	// the property list for AU state data must be of the dictionary type
	if (CFGetTypeID(inAUStateData) != CFDictionaryGetTypeID()) {
		return kAudioUnitErr_InvalidPropertyValue;
	}

	auStateDictionary = (CFDictionaryRef)inAUStateData;

	// first check to make sure that the version of the AU state data is one that we know understand
	// XXX should I really do this?  later versions would probably still hold these ID keys, right?
	versionValue = GetDictionarySInt32Value(auStateDictionary, CFSTR(kAUPresetVersionKey), &gotValue);

	if (!gotValue) {
		return kAudioUnitErr_InvalidPropertyValue;
	}
#define kCurrentSavedStateVersion 0
	if (versionValue != kCurrentSavedStateVersion) {
		return kAudioUnitErr_InvalidPropertyValue;
	}

	// grab the ComponentDescription values from the AU state data
	tempDesc.componentType = (OSType) GetDictionarySInt32Value(auStateDictionary, CFSTR(kAUPresetTypeKey), NULL);
	tempDesc.componentSubType = (OSType) GetDictionarySInt32Value(auStateDictionary, CFSTR(kAUPresetSubtypeKey), NULL);
	tempDesc.componentManufacturer = (OSType) GetDictionarySInt32Value(auStateDictionary, CFSTR(kAUPresetManufacturerKey), NULL);
	// zero values are illegit for specific ComponentDescriptions, so zero for any value means that there was an error
	if ( (tempDesc.componentType == 0) || (tempDesc.componentSubType == 0) || (tempDesc.componentManufacturer == 0) )
		return kAudioUnitErr_InvalidPropertyValue;

	*outComponentDescription = tempDesc;
	return noErr;
}


static bool au_preset_filter (const string& str, void* arg)
{
	/* Not a dotfile, has a prefix before a period, suffix is aupreset */

	bool ret;

	ret = (str[0] != '.' && str.length() > 9 && str.find (preset_suffix) == (str.length() - preset_suffix.length()));

	if (ret && arg) {

		/* check the preset file path name against this plugin
		   ID. The idea is that all preset files for this plugin
		   include "<manufacturer>/<plugin-name>" in their path.
		*/

		Plugin* p = (Plugin *) arg;
		string match = p->maker();
		match += '/';
		match += p->name();

		ret = str.find (match) != string::npos;

		if (ret == false) {
			string m = p->maker ();
			string n = p->name ();
			strip_whitespace_edges (m);
			strip_whitespace_edges (n);
			match = m;
			match += '/';
			match += n;

			ret = str.find (match) != string::npos;
		}
	}

	return ret;
}

bool
check_and_get_preset_name (Component component, const string& pathstr, string& preset_name)
{
	OSStatus status;
	CFPropertyListRef plist;
	ComponentDescription presetDesc;
	bool ret = false;

	plist = load_property_list (pathstr);

	if (!plist) {
		return ret;
	}

	// get the ComponentDescription from the AU preset file

	status = GetAUComponentDescriptionFromStateData(plist, &presetDesc);

	if (status == noErr) {
		if (ComponentAndDescriptionMatch_Loosely(component, &presetDesc)) {

			/* try to get the preset name from the property list */

			if (CFGetTypeID(plist) == CFDictionaryGetTypeID()) {

				const void* psk = CFDictionaryGetValue ((CFMutableDictionaryRef)plist, CFSTR(kAUPresetNameKey));

				if (psk) {

					const char* p = CFStringGetCStringPtr ((CFStringRef) psk, kCFStringEncodingUTF8);

					if (!p) {
						char buf[PATH_MAX+1];

						if (CFStringGetCString ((CFStringRef)psk, buf, sizeof (buf), kCFStringEncodingUTF8)) {
							preset_name = buf;
						}
					}
				}
			}
		}
	}

	CFRelease (plist);

	return true;
}

std::string
AUPlugin::current_preset() const
{
	string preset_name;

	CFPropertyListRef propertyList;

	DEBUG_TRACE (DEBUG::AudioUnits, "get current preset for current_preset()\n");
	if (unit->GetAUPreset (propertyList) == noErr) {
		preset_name = get_preset_name_in_plist (propertyList);
		CFRelease(propertyList);
	}

	return preset_name;
}

void
AUPlugin::find_presets ()
{
	vector<string*>* preset_files;
	PathScanner scanner;

	user_preset_map.clear ();

	preset_files = scanner (preset_search_path, au_preset_filter, this, true, true, -1, true);

	if (!preset_files) {
		return;
	}

	for (vector<string*>::iterator x = preset_files->begin(); x != preset_files->end(); ++x) {

		string path = *(*x);
		string preset_name;

		/* make an initial guess at the preset name using the path */

		preset_name = Glib::path_get_basename (path);
		preset_name = preset_name.substr (0, preset_name.find_last_of ('.'));

		/* check that this preset file really matches this plugin
		   and potentially get the "real" preset name from
		   within the file.
		*/

		if (check_and_get_preset_name (get_comp()->Comp(), path, preset_name)) {
			user_preset_map[preset_name] = path;
		}

		delete *x;
	}

	delete preset_files;

	/* now fill the vector<string> with the names we have */

	for (UserPresetMap::iterator i = user_preset_map.begin(); i != user_preset_map.end(); ++i) {
		_presets.insert (make_pair (i->second, Plugin::PresetRecord (i->second, i->first)));
	}

	/* add factory presets */

	for (FactoryPresetMap::iterator i = factory_preset_map.begin(); i != factory_preset_map.end(); ++i) {
		/* XXX: dubious */
		string const uri = string_compose ("%1", _presets.size ());
		_presets.insert (make_pair (uri, Plugin::PresetRecord (uri, i->first, i->second)));
	}
}

bool
AUPlugin::has_editor () const
{
	// even if the plugin doesn't have its own editor, the AU API can be used
	// to create one that looks native.
	return true;
}

AUPluginInfo::AUPluginInfo (boost::shared_ptr<CAComponentDescription> d)
	: descriptor (d)
{
	type = ARDOUR::AudioUnit;
}

AUPluginInfo::~AUPluginInfo ()
{
	type = ARDOUR::AudioUnit;
}

PluginPtr
AUPluginInfo::load (Session& session)
{
	try {
		PluginPtr plugin;

		DEBUG_TRACE (DEBUG::AudioUnits, "load AU as a component\n");
		boost::shared_ptr<CAComponent> comp (new CAComponent(*descriptor));

		if (!comp->IsValid()) {
			error << ("AudioUnit: not a valid Component") << endmsg;
		} else {
			plugin.reset (new AUPlugin (session.engine(), session, comp));
		}

		AUPluginInfo *aup = new AUPluginInfo (*this);
		DEBUG_TRACE (DEBUG::AudioUnits, string_compose ("plugin info for %1 = %2\n", this, aup));
		plugin->set_info (PluginInfoPtr (aup));
		boost::dynamic_pointer_cast<AUPlugin> (plugin)->set_fixed_size_buffers (aup->creator == "Universal Audio");
		return plugin;
	}

	catch (failed_constructor &err) {
		DEBUG_TRACE (DEBUG::AudioUnits, "failed to load component/plugin\n");
		return PluginPtr ();
	}
}

Glib::ustring
AUPluginInfo::au_cache_path ()
{
	return Glib::build_filename (ARDOUR::user_config_directory(), "au_cache");
}

PluginInfoList*
AUPluginInfo::discover ()
{
	XMLTree tree;

	if (!Glib::file_test (au_cache_path(), Glib::FILE_TEST_EXISTS)) {
		ARDOUR::BootMessage (_("Discovering AudioUnit plugins (could take some time ...)"));
	}

	PluginInfoList* plugs = new PluginInfoList;

	discover_fx (*plugs);
	discover_music (*plugs);
	discover_generators (*plugs);
	discover_instruments (*plugs);

	DEBUG_TRACE (DEBUG::PluginManager, string_compose ("AU: discovered %1 plugins\n", plugs->size()));

	return plugs;
}

void
AUPluginInfo::discover_music (PluginInfoList& plugs)
{
	CAComponentDescription desc;
	desc.componentFlags = 0;
	desc.componentFlagsMask = 0;
	desc.componentSubType = 0;
	desc.componentManufacturer = 0;
	desc.componentType = kAudioUnitType_MusicEffect;

	discover_by_description (plugs, desc);
}

void
AUPluginInfo::discover_fx (PluginInfoList& plugs)
{
	CAComponentDescription desc;
	desc.componentFlags = 0;
	desc.componentFlagsMask = 0;
	desc.componentSubType = 0;
	desc.componentManufacturer = 0;
	desc.componentType = kAudioUnitType_Effect;

	discover_by_description (plugs, desc);
}

void
AUPluginInfo::discover_generators (PluginInfoList& plugs)
{
	CAComponentDescription desc;
	desc.componentFlags = 0;
	desc.componentFlagsMask = 0;
	desc.componentSubType = 0;
	desc.componentManufacturer = 0;
	desc.componentType = kAudioUnitType_Generator;

	discover_by_description (plugs, desc);
}

void
AUPluginInfo::discover_instruments (PluginInfoList& plugs)
{
	CAComponentDescription desc;
	desc.componentFlags = 0;
	desc.componentFlagsMask = 0;
	desc.componentSubType = 0;
	desc.componentManufacturer = 0;
	desc.componentType = kAudioUnitType_MusicDevice;

	discover_by_description (plugs, desc);
}

void
AUPluginInfo::discover_by_description (PluginInfoList& plugs, CAComponentDescription& desc)
{
	Component comp = 0;

	comp = FindNextComponent (NULL, &desc);

	while (comp != NULL) {
		CAComponentDescription temp;
		GetComponentInfo (comp, &temp, NULL, NULL, NULL);

		AUPluginInfoPtr info (new AUPluginInfo
				      (boost::shared_ptr<CAComponentDescription> (new CAComponentDescription(temp))));

		/* although apple designed the subtype field to be a "category" indicator,
		   its really turned into a plugin ID field for a given manufacturer. Hence
		   there are no categories for AudioUnits. However, to keep the plugins
		   showing up under "categories", we'll use the "type" as a high level
		   selector.

		   NOTE: no panners, format converters or i/o AU's for our purposes
		 */

		switch (info->descriptor->Type()) {
		case kAudioUnitType_Panner:
		case kAudioUnitType_OfflineEffect:
		case kAudioUnitType_FormatConverter:
			continue;

		case kAudioUnitType_Output:
			info->category = _("AudioUnit Outputs");
			break;
		case kAudioUnitType_MusicDevice:
			info->category = _("AudioUnit Instruments");
			break;
		case kAudioUnitType_MusicEffect:
			info->category = _("AudioUnit MusicEffects");
			break;
		case kAudioUnitType_Effect:
			info->category = _("AudioUnit Effects");
			break;
		case kAudioUnitType_Mixer:
			info->category = _("AudioUnit Mixers");
			break;
		case kAudioUnitType_Generator:
			info->category = _("AudioUnit Generators");
			break;
		default:
			info->category = _("AudioUnit (Unknown)");
			break;
		}

		AUPluginInfo::get_names (temp, info->name, info->creator);

		info->type = ARDOUR::AudioUnit;
		info->unique_id = stringify_descriptor (*info->descriptor);

		/* XXX not sure of the best way to handle plugin versioning yet
		 */

		CAComponent cacomp (*info->descriptor);

		if (cacomp.GetResourceVersion (info->version) != noErr) {
			info->version = 0;
		}

		if (cached_io_configuration (info->unique_id, info->version, cacomp, info->cache, info->name)) {

			/* here we have to map apple's wildcard system to a simple pair
			   of values. in ::can_do() we use the whole system, but here
			   we need a single pair of values. XXX probably means we should
			   remove any use of these values.

			   for now, if the plugin provides a wildcard, treat it as 1. we really
			   don't care much, because whether we can handle an i/o configuration
			   depends upon ::can_support_io_configuration(), not these counts.

			   they exist because other parts of ardour try to present i/o configuration
			   info to the user, which should perhaps be revisited.
			*/

			int32_t possible_in = info->cache.io_configs.front().first;
			int32_t possible_out = info->cache.io_configs.front().second;
			
			if (possible_in > 0) {
				info->n_inputs.set (DataType::AUDIO, possible_in);
			} else {
				info->n_inputs.set (DataType::AUDIO, 1);
			}

			if (possible_out > 0) {
				info->n_outputs.set (DataType::AUDIO, possible_out);
			} else {
				info->n_outputs.set (DataType::AUDIO, 1);
			}

			DEBUG_TRACE (DEBUG::AudioUnits, string_compose ("detected AU %1 with %2 i/o configurations - %3\n",
									info->name.c_str(), info->cache.io_configs.size(), info->unique_id));

			plugs.push_back (info);

		} else {
			error << string_compose (_("Cannot get I/O configuration info for AU %1"), info->name) << endmsg;
		}

		comp = FindNextComponent (comp, &desc);
	}
}

bool
AUPluginInfo::cached_io_configuration (const std::string& unique_id,
				       UInt32 version,
				       CAComponent& comp,
				       AUPluginCachedInfo& cinfo,
				       const std::string& name)
{
	std::string id;
	char buf[32];

	/* concatenate unique ID with version to provide a key for cached info lookup.
	   this ensures we don't get stale information, or should if plugin developers
	   follow Apple "guidelines".
	 */

	snprintf (buf, sizeof (buf), "%u", (uint32_t) version);
	id = unique_id;
	id += '/';
	id += buf;

	CachedInfoMap::iterator cim = cached_info.find (id);

	if (cim != cached_info.end()) {
		cinfo = cim->second;
		return true;
	}

	CAAudioUnit unit;
	AUChannelInfo* channel_info;
	UInt32 cnt;
	int ret;

	ARDOUR::BootMessage (string_compose (_("Checking AudioUnit: %1"), name));

	try {

		if (CAAudioUnit::Open (comp, unit) != noErr) {
			return false;
		}

	} catch (...) {

		warning << string_compose (_("Could not load AU plugin %1 - ignored"), name) << endmsg;
		return false;

	}

	DEBUG_TRACE (DEBUG::AudioUnits, "get AU channel info\n");
	if ((ret = unit.GetChannelInfo (&channel_info, cnt)) < 0) {
		return false;
	}

	if (ret > 0) {

		/* no explicit info available, so default to 1in/1out */

		/* XXX this is wrong. we should be indicating wildcard values */

		cinfo.io_configs.push_back (pair<int,int> (-1, -1));

	} else {

		/* store each configuration */

		for (uint32_t n = 0; n < cnt; ++n) {
			cinfo.io_configs.push_back (pair<int,int> (channel_info[n].inChannels,
								   channel_info[n].outChannels));
		}

		free (channel_info);
	}

	add_cached_info (id, cinfo);
	save_cached_info ();

	return true;
}

void
AUPluginInfo::add_cached_info (const std::string& id, AUPluginCachedInfo& cinfo)
{
	cached_info[id] = cinfo;
}

#define AU_CACHE_VERSION "2.0"

void
AUPluginInfo::save_cached_info ()
{
	XMLNode* node;

	node = new XMLNode (X_("AudioUnitPluginCache"));
	node->add_property( "version", AU_CACHE_VERSION );

	for (map<string,AUPluginCachedInfo>::iterator i = cached_info.begin(); i != cached_info.end(); ++i) {
		XMLNode* parent = new XMLNode (X_("plugin"));
		parent->add_property ("id", i->first);
		node->add_child_nocopy (*parent);

		for (vector<pair<int, int> >::iterator j = i->second.io_configs.begin(); j != i->second.io_configs.end(); ++j) {

			XMLNode* child = new XMLNode (X_("io"));
			char buf[32];

			snprintf (buf, sizeof (buf), "%d", j->first);
			child->add_property (X_("in"), buf);
			snprintf (buf, sizeof (buf), "%d", j->second);
			child->add_property (X_("out"), buf);
			parent->add_child_nocopy (*child);
		}

	}

	Glib::ustring path = au_cache_path ();
	XMLTree tree;

	tree.set_root (node);

	if (!tree.write (path)) {
		error << string_compose (_("could not save AU cache to %1"), path) << endmsg;
		unlink (path.c_str());
	}
}

int
AUPluginInfo::load_cached_info ()
{
	Glib::ustring path = au_cache_path ();
	XMLTree tree;

	if (!Glib::file_test (path, Glib::FILE_TEST_EXISTS)) {
		return 0;
	}

	if ( !tree.read (path) ) {
		error << "au_cache is not a valid XML file.  AU plugins will be re-scanned" << endmsg;
		return -1;
	}

	const XMLNode* root (tree.root());

	if (root->name() != X_("AudioUnitPluginCache")) {
		return -1;
	}

	//initial version has incorrectly stored i/o info, and/or garbage chars.
	const XMLProperty* version = root->property(X_("version"));
	if (! ((version != NULL) && (version->value() == X_(AU_CACHE_VERSION)))) {
		error << "au_cache is not correct version.  AU plugins will be re-scanned" << endmsg;
		return -1;
	}

	cached_info.clear ();

	const XMLNodeList children = root->children();

	for (XMLNodeConstIterator iter = children.begin(); iter != children.end(); ++iter) {

		const XMLNode* child = *iter;

		if (child->name() == X_("plugin")) {

			const XMLNode* gchild;
			const XMLNodeList gchildren = child->children();
			const XMLProperty* prop = child->property (X_("id"));

			if (!prop) {
				continue;
			}

			string id = prop->value();
			string fixed;
			string version;

			string::size_type slash = id.find_last_of ('/');

			if (slash == string::npos) {
				continue;
			}

			version = id.substr (slash);
			id = id.substr (0, slash);
			fixed = AUPlugin::maybe_fix_broken_au_id (id);

			if (fixed.empty()) {
				error << string_compose (_("Your AudioUnit configuration cache contains an AU plugin whose ID cannot be understood - ignored (%1)"), id) << endmsg;
				continue;
			}

			id = fixed;
			id += version;

			AUPluginCachedInfo cinfo;

			for (XMLNodeConstIterator giter = gchildren.begin(); giter != gchildren.end(); giter++) {

				gchild = *giter;

				if (gchild->name() == X_("io")) {

					int in;
					int out;
					const XMLProperty* iprop;
					const XMLProperty* oprop;

					if (((iprop = gchild->property (X_("in"))) != 0) &&
					    ((oprop = gchild->property (X_("out"))) != 0)) {
						in = atoi (iprop->value());
						out = atoi (oprop->value());

						cinfo.io_configs.push_back (pair<int,int> (in, out));
					}
				}
			}

			if (cinfo.io_configs.size()) {
				add_cached_info (id, cinfo);
			}
		}
	}

	return 0;
}

void
AUPluginInfo::get_names (CAComponentDescription& comp_desc, std::string& name, std::string& maker)
{
	CFStringRef itemName = NULL;

	// Marc Poirier-style item name
	CAComponent auComponent (comp_desc);
	if (auComponent.IsValid()) {
		CAComponentDescription dummydesc;
		Handle nameHandle = NewHandle(sizeof(void*));
		if (nameHandle != NULL) {
			OSErr err = GetComponentInfo(auComponent.Comp(), &dummydesc, nameHandle, NULL, NULL);
			if (err == noErr) {
				ConstStr255Param nameString = (ConstStr255Param) (*nameHandle);
				if (nameString != NULL) {
					itemName = CFStringCreateWithPascalString(kCFAllocatorDefault, nameString, CFStringGetSystemEncoding());
				}
			}
			DisposeHandle(nameHandle);
		}
	}

	// if Marc-style fails, do the original way
	if (itemName == NULL) {
		CFStringRef compTypeString = UTCreateStringForOSType(comp_desc.componentType);
		CFStringRef compSubTypeString = UTCreateStringForOSType(comp_desc.componentSubType);
		CFStringRef compManufacturerString = UTCreateStringForOSType(comp_desc.componentManufacturer);

		itemName = CFStringCreateWithFormat(kCFAllocatorDefault, NULL, CFSTR("%@ - %@ - %@"),
			compTypeString, compManufacturerString, compSubTypeString);

		if (compTypeString != NULL)
			CFRelease(compTypeString);
		if (compSubTypeString != NULL)
			CFRelease(compSubTypeString);
		if (compManufacturerString != NULL)
			CFRelease(compManufacturerString);
	}

	string str = CFStringRefToStdString(itemName);
	string::size_type colon = str.find (':');

	if (colon) {
		name = str.substr (colon+1);
		maker = str.substr (0, colon);
		strip_whitespace_edges (maker);
		strip_whitespace_edges (name);
	} else {
		name = str;
		maker = "unknown";
		strip_whitespace_edges (name);
	}
}

std::string
AUPluginInfo::stringify_descriptor (const CAComponentDescription& desc)
{
	stringstream s;

	/* note: OSType is a compiler-implemenation-defined value,
	   historically a 32 bit integer created with a multi-character
	   constant such as 'abcd'. It is, fundamentally, an abomination.
	*/

	s << desc.Type();
	s << '-';
	s << desc.SubType();
	s << '-';
	s << desc.Manu();

	return s.str();
}

bool
AUPluginInfo::needs_midi_input ()
{
	return is_effect_with_midi_input () || is_instrument ();
}

bool
AUPluginInfo::is_effect () const
{
	return is_effect_without_midi_input() || is_effect_with_midi_input();
}

bool
AUPluginInfo::is_effect_without_midi_input () const
{
	return descriptor->IsAUFX();
}

bool
AUPluginInfo::is_effect_with_midi_input () const
{
	return descriptor->IsAUFM();
}

bool
AUPluginInfo::is_instrument () const
{
	return descriptor->IsMusicDevice();
}

void
AUPlugin::set_info (PluginInfoPtr info)
{
	Plugin::set_info (info);
	
	AUPluginInfoPtr pinfo = boost::dynamic_pointer_cast<AUPluginInfo>(get_info());
	_has_midi_input = pinfo->needs_midi_input ();
	_has_midi_output = false;
}

int
AUPlugin::create_parameter_listener (AUEventListenerProc cb, void* arg, float interval_secs)
{
#ifdef WITH_CARBON
	CFRunLoopRef run_loop = (CFRunLoopRef) GetCFRunLoopFromEventLoop(GetCurrentEventLoop()); 
#else
	CFRunLoopRef run_loop = CFRunLoopGetCurrent();
#endif
	CFStringRef  loop_mode = kCFRunLoopDefaultMode;

	if (AUEventListenerCreate (cb, arg, run_loop, loop_mode, interval_secs, interval_secs, &_parameter_listener) != noErr) {
		return -1;
	}

	_parameter_listener_arg = arg;

	return 0;
}

int
AUPlugin::listen_to_parameter (uint32_t param_id)
{
	AudioUnitEvent      event;

	if (!_parameter_listener || param_id >= descriptors.size()) {
		return -2;
	}

	event.mEventType = kAudioUnitEvent_ParameterValueChange;
	event.mArgument.mParameter.mAudioUnit = unit->AU();
	event.mArgument.mParameter.mParameterID = descriptors[param_id].id;
	event.mArgument.mParameter.mScope = descriptors[param_id].scope;
	event.mArgument.mParameter.mElement = descriptors[param_id].element;

	if (AUEventListenerAddEventType (_parameter_listener, _parameter_listener_arg, &event) != noErr) {
		return -1;
	} 

	event.mEventType = kAudioUnitEvent_BeginParameterChangeGesture;
	event.mArgument.mParameter.mAudioUnit = unit->AU();
	event.mArgument.mParameter.mParameterID = descriptors[param_id].id;
	event.mArgument.mParameter.mScope = descriptors[param_id].scope;
	event.mArgument.mParameter.mElement = descriptors[param_id].element;

	if (AUEventListenerAddEventType (_parameter_listener, _parameter_listener_arg, &event) != noErr) {
		return -1;
	} 

	event.mEventType = kAudioUnitEvent_EndParameterChangeGesture;
	event.mArgument.mParameter.mAudioUnit = unit->AU();
	event.mArgument.mParameter.mParameterID = descriptors[param_id].id;
	event.mArgument.mParameter.mScope = descriptors[param_id].scope;
	event.mArgument.mParameter.mElement = descriptors[param_id].element;

	if (AUEventListenerAddEventType (_parameter_listener, _parameter_listener_arg, &event) != noErr) {
		return -1;
	} 

	return 0;
}

int
AUPlugin::end_listen_to_parameter (uint32_t param_id)
{
	AudioUnitEvent      event;

	if (!_parameter_listener || param_id >= descriptors.size()) {
		return -2;
	}

	event.mEventType = kAudioUnitEvent_ParameterValueChange;
	event.mArgument.mParameter.mAudioUnit = unit->AU();
	event.mArgument.mParameter.mParameterID = descriptors[param_id].id;
	event.mArgument.mParameter.mScope = descriptors[param_id].scope;
	event.mArgument.mParameter.mElement = descriptors[param_id].element;

	if (AUEventListenerRemoveEventType (_parameter_listener, _parameter_listener_arg, &event) != noErr) {
		return -1;
	} 

	event.mEventType = kAudioUnitEvent_BeginParameterChangeGesture;
	event.mArgument.mParameter.mAudioUnit = unit->AU();
	event.mArgument.mParameter.mParameterID = descriptors[param_id].id;
	event.mArgument.mParameter.mScope = descriptors[param_id].scope;
	event.mArgument.mParameter.mElement = descriptors[param_id].element;

	if (AUEventListenerRemoveEventType (_parameter_listener, _parameter_listener_arg, &event) != noErr) {
		return -1;
	} 

	event.mEventType = kAudioUnitEvent_EndParameterChangeGesture;
	event.mArgument.mParameter.mAudioUnit = unit->AU();
	event.mArgument.mParameter.mParameterID = descriptors[param_id].id;
	event.mArgument.mParameter.mScope = descriptors[param_id].scope;
	event.mArgument.mParameter.mElement = descriptors[param_id].element;

	if (AUEventListenerRemoveEventType (_parameter_listener, _parameter_listener_arg, &event) != noErr) {
		return -1;
	} 

	return 0;
}

void
AUPlugin::_parameter_change_listener (void* arg, void* src, const AudioUnitEvent* event, UInt64 host_time, Float32 new_value)
{
	((AUPlugin*) arg)->parameter_change_listener (arg, src, event, host_time, new_value);
}

void
AUPlugin::parameter_change_listener (void* /*arg*/, void* /*src*/, const AudioUnitEvent* event, UInt64 /*host_time*/, Float32 new_value)
{
        ParameterMap::iterator i;

        if ((i = parameter_map.find (event->mArgument.mParameter.mParameterID)) == parameter_map.end()) {
                return;
        }
        
        switch (event->mEventType) {
        case kAudioUnitEvent_BeginParameterChangeGesture:
                StartTouch (i->second);
                break;
        case kAudioUnitEvent_EndParameterChangeGesture:
                EndTouch (i->second);
                break;
        case kAudioUnitEvent_ParameterValueChange:
                ParameterChanged (i->second, new_value);
                break;
        default:
                break;
        }
}