/*
    Copyright (C) 2010 Paul Davis

    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 <exception>
#include <vector>
#include <cmath>
#include <fstream>
#include <map>

#include <boost/scoped_ptr.hpp>

#include <glibmm.h>
#include <gtkmm/messagedialog.h>

#include "pbd/error.h"
#include "pbd/xml++.h"

#include <gtkmm/stock.h>
#include <gtkmm/notebook.h>
#include <gtkmm2ext/utils.h>

#include "ardour/audio_backend.h"
#include "ardour/audioengine.h"
#include "ardour/rc_configuration.h"

#include "pbd/convert.h"
#include "pbd/error.h"

#include "engine_dialog.h"
#include "i18n.h"

using namespace std;
using namespace Gtk;
using namespace Gtkmm2ext;
using namespace PBD;
using namespace Glib;

EngineControl::EngineControl ()
	: input_latency_adjustment (0, 0, 99999, 1)
	, input_latency (input_latency_adjustment)
	, output_latency_adjustment (0, 0, 99999, 1)
	, output_latency (output_latency_adjustment)
	, input_channels_adjustment (0, 0, 256, 1)
	, input_channels (input_channels_adjustment)
	, output_channels_adjustment (0, 0, 256, 1)
	, output_channels (output_channels_adjustment)
	, ports_adjustment (128, 8, 1024, 1, 16)
	, ports_spinner (ports_adjustment)
	, realtime_button (_("Realtime"))
	, basic_packer (9, 3)
{
	using namespace Notebook_Helpers;
	Label* label;
	vector<string> strings;
	int row = 0;

	vector<const ARDOUR::AudioBackendInfo*> backends = ARDOUR::AudioEngine::instance()->available_backends();
	for (vector<const ARDOUR::AudioBackendInfo*>::const_iterator b = backends.begin(); b != backends.end(); ++b) {
		strings.push_back ((*b)->name);
	}

	set_popdown_strings (backend_combo, strings);
	backend_combo.set_active_text (strings.front());
	backend_combo.signal_changed().connect (sigc::mem_fun (*this, &EngineControl::backend_changed));
	backend_changed ();

	driver_combo.signal_changed().connect (sigc::mem_fun (*this, &EngineControl::driver_changed));

	basic_packer.set_spacings (6);
	basic_packer.set_border_width (12);
	basic_packer.set_homogeneous (true);

	row = 0;

	const AttachOptions xopt = AttachOptions (FILL|EXPAND);

	label = manage (left_aligned_label (_("Audio System:")));
	basic_packer.attach (*label, 0, 1, row, row + 1, xopt, (AttachOptions) 0);
	basic_packer.attach (backend_combo, 1, 2, row, row + 1, xopt, (AttachOptions) 0);
	row++;

	label = manage (left_aligned_label (_("Driver:")));
	basic_packer.attach (*label, 0, 1, row, row + 1, xopt, (AttachOptions) 0);
	basic_packer.attach (driver_combo, 1, 2, row, row + 1, xopt, (AttachOptions) 0);
	row++;

	label = manage (left_aligned_label (_("Device:")));
	basic_packer.attach (*label, 0, 1, row, row + 1, xopt, (AttachOptions) 0);
	basic_packer.attach (device_combo, 1, 2, row, row + 1, xopt, (AttachOptions) 0);
	row++;

	label = manage (left_aligned_label (_("Sample rate:")));
	basic_packer.attach (*label, 0, 1, row, row + 1, xopt, (AttachOptions) 0);
	basic_packer.attach (sample_rate_combo, 1, 2, row, row + 1, xopt, (AttachOptions) 0);
	row++;

	sr_connection = sample_rate_combo.signal_changed().connect (sigc::mem_fun (*this, &EngineControl::sample_rate_changed));

	label = manage (left_aligned_label (_("Buffer size:")));
	basic_packer.attach (*label, 0, 1, row, row + 1, xopt, (AttachOptions) 0);
	basic_packer.attach (buffer_size_combo, 1, 2, row, row + 1, xopt, (AttachOptions) 0);
	buffer_size_duration_label.set_alignment (0.0); /* left-align */
	basic_packer.attach (buffer_size_duration_label, 2, 3, row, row+1, xopt, (AttachOptions) 0);
	row++;

	bs_connection = buffer_size_combo.signal_changed().connect (sigc::mem_fun (*this, &EngineControl::buffer_size_changed));

	label = manage (left_aligned_label (_("Input Channels:")));
	basic_packer.attach (*label, 0, 1, row, row+1, xopt, (AttachOptions) 0);
	basic_packer.attach (input_channels, 1, 2, row, row+1, xopt, (AttachOptions) 0);
	++row;

	input_channels.signal_output().connect (sigc::bind (sigc::ptr_fun (&EngineControl::print_channel_count), &input_channels));

	label = manage (left_aligned_label (_("Output Channels:")));
	basic_packer.attach (*label, 0, 1, row, row+1, xopt, (AttachOptions) 0);
	basic_packer.attach (output_channels, 1, 2, row, row+1, xopt, (AttachOptions) 0);
	++row;

	output_channels.signal_output().connect (sigc::bind (sigc::ptr_fun (&EngineControl::print_channel_count), &output_channels));

	label = manage (left_aligned_label (_("Hardware input latency:")));
	basic_packer.attach (*label, 0, 1, row, row+1, xopt, (AttachOptions) 0);
	basic_packer.attach (input_latency, 1, 2, row, row+1, xopt, (AttachOptions) 0);
	label = manage (left_aligned_label (_("samples")));
	basic_packer.attach (*label, 2, 3, row, row+1, xopt, (AttachOptions) 0);
	++row;

	label = manage (left_aligned_label (_("Hardware output latency:")));
	basic_packer.attach (*label, 0, 1, row, row+1, xopt, (AttachOptions) 0);
	basic_packer.attach (output_latency, 1, 2, row, row+1, xopt, (AttachOptions) 0);
	label = manage (left_aligned_label (_("samples")));
	basic_packer.attach (*label, 2, 3, row, row+1, xopt, (AttachOptions) 0);
	++row;

	device_combo.signal_changed().connect (sigc::mem_fun (*this, &EngineControl::device_changed));

	basic_hbox.pack_start (basic_packer, false, false);

	midi_packer.set_border_width (12);

	notebook.pages().push_back (TabElem (basic_hbox, _("Audio")));
	notebook.pages().push_back (TabElem (midi_hbox, _("MIDI")));
	notebook.set_border_width (12);

	notebook.set_tab_pos (POS_RIGHT);
	notebook.show_all ();

	notebook.set_name ("SettingsNotebook");

	set_border_width (12);
	pack_start (notebook);

	/* Pick up any existing audio setup configuration, if appropriate */

	XMLNode* audio_setup = ARDOUR::Config->extra_xml ("AudioMIDISetup");
	
	if (audio_setup) {
		set_state (*audio_setup);
	}
}

EngineControl::~EngineControl ()
{

}

void
EngineControl::backend_changed ()
{
	string backend_name = backend_combo.get_active_text();
	boost::shared_ptr<ARDOUR::AudioBackend> backend;

	if (!(backend = ARDOUR::AudioEngine::instance()->set_backend (backend_name, "ardour", ""))) {
		/* eh? */
		return;
	}

	if (backend->requires_driver_selection()) {
		vector<string> drivers = backend->enumerate_drivers();
		driver_combo.set_sensitive (true);
		set_popdown_strings (driver_combo, drivers);
		driver_combo.set_active_text (drivers.front());
		driver_changed ();
	} else {
		driver_combo.set_sensitive (false);
		list_devices ();
	}
	
	maybe_set_state ();
}

bool
EngineControl::print_channel_count (Gtk::SpinButton* sb)
{
	uint32_t cnt = (uint32_t) sb->get_value();
	if (cnt == 0) {
		sb->set_text (_("all available channels"));
	} else {
		char buf[32];
		snprintf (buf, sizeof (buf), "%d", cnt);
		sb->set_text (buf);
	}
	return true;
}

void
EngineControl::list_devices ()
{
	boost::shared_ptr<ARDOUR::AudioBackend> backend = ARDOUR::AudioEngine::instance()->current_backend();
	assert (backend);

	/* now fill out devices, mark sample rates, buffer sizes insensitive */
	    
	vector<ARDOUR::AudioBackend::DeviceStatus> all_devices = backend->enumerate_devices ();
	
	/* NOTE: Ardour currently does not display the "available" field of the
	 * returned devices.
	 *
	 * Doing so would require a different GUI widget than the combo
	 * box/popdown that we currently use, since it has no way to list
	 * items that are not selectable. Something more like a popup menu,
	 * which could have unselectable items, would be appropriate.
	 */

	vector<string> available_devices;

	for (vector<ARDOUR::AudioBackend::DeviceStatus>::const_iterator i = all_devices.begin(); i != all_devices.end(); ++i) {
		available_devices.push_back (i->name);
	}

	set_popdown_strings (device_combo, available_devices);
	set_popdown_strings (input_device_combo, available_devices);
	set_popdown_strings (output_device_combo, available_devices);
	
	if (!available_devices.empty()) {
		device_combo.set_active_text (available_devices.front());
		input_device_combo.set_active_text (available_devices.front());
		output_device_combo.set_active_text (available_devices.front());
	}

	device_changed ();
}
	
void
EngineControl::driver_changed ()
{
	boost::shared_ptr<ARDOUR::AudioBackend> backend = ARDOUR::AudioEngine::instance()->current_backend();
	assert (backend);

	backend->set_driver (driver_combo.get_active_text());
	list_devices ();

	maybe_set_state ();
}

void
EngineControl::device_changed ()
{
	boost::shared_ptr<ARDOUR::AudioBackend> backend = ARDOUR::AudioEngine::instance()->current_backend();
	assert (backend);
	string device_name = device_combo.get_active_text ();
	vector<string> s;

	/* don't allow programmatic change to sample_rate_combo to cause a
	   recursive call to this method.
	*/
	   
	sr_connection.block ();

	/* sample rates */

	vector<float> sr = backend->available_sample_rates (device_name);
	for (vector<float>::const_iterator x = sr.begin(); x != sr.end(); ++x) {
		char buf[32];
		if (fmod (*x, 1000.0f)) {
			snprintf (buf, sizeof (buf), "%.1f kHz", (*x)/1000.0);
		} else {
			snprintf (buf, sizeof (buf), "%.0f kHz", (*x)/1000.0);
		}
		s.push_back (buf);
	}

	set_popdown_strings (sample_rate_combo, s);
	sample_rate_combo.set_active_text (s.front());

	sr_connection.unblock ();

	vector<uint32_t> bs = backend->available_buffer_sizes(device_name);
	s.clear ();
	for (vector<uint32_t>::const_iterator x = bs.begin(); x != bs.end(); ++x) {
		char buf[32];
		/* Translators: "samples" is always plural here, so no
		   need for plural+singular forms.
		*/
		snprintf (buf, sizeof (buf), _("%u samples"), *x);
		s.push_back (buf);
	}

	set_popdown_strings (buffer_size_combo, s);
	buffer_size_combo.set_active_text (s.front());
	show_buffer_duration ();

	maybe_set_state ();
}	

void 
EngineControl::sample_rate_changed ()
{
	/* reset the strings for buffer size to show the correct msec value
	   (reflecting the new sample rate).
	*/

	show_buffer_duration ();
	save_state ();

}

void 
EngineControl::buffer_size_changed ()
{
	show_buffer_duration ();
	save_state ();
}

void
EngineControl::show_buffer_duration ()
{

	/* buffer sizes  - convert from just samples to samples + msecs for
	 * the displayed string
	 */

	string bs_text = buffer_size_combo.get_active_text ();
	uint32_t samples = atoi (bs_text); /* will ignore trailing text */
	uint32_t rate = get_rate();

	/* Translators: "msecs" is ALWAYS plural here, so we do not
	   need singular form as well.
	*/
	/* Developers: note the hard-coding of a double buffered model
	   in the (2 * samples) computation of latency. we always start
	   the audiobackend in this configuration.
	*/
	char buf[32];
	snprintf (buf, sizeof (buf), _("(%.1f msecs)"), (2 * samples) / (rate/1000.0));
	buffer_size_duration_label.set_text (buf);
}

void
EngineControl::audio_mode_changed ()
{
	std::string str = audio_mode_combo.get_active_text();

	if (str == _("Playback/recording on 1 device")) {
		input_device_combo.set_sensitive (false);
		output_device_combo.set_sensitive (false);
	} else if (str == _("Playback/recording on 2 devices")) {
		input_device_combo.set_sensitive (true);
		output_device_combo.set_sensitive (true);
	} else if (str == _("Playback only")) {
		output_device_combo.set_sensitive (true);
		input_device_combo.set_sensitive (false);
	} else if (str == _("Recording only")) {
		input_device_combo.set_sensitive (true);
		output_device_combo.set_sensitive (false);
	}
}

EngineControl::State*
EngineControl::get_matching_state (const string& backend,
				   const string& driver,
				   const string& device)
{
	for (StateList::iterator i = states.begin(); i != states.end(); ++i) {
		if ((*i).backend == backend &&
		    (*i).driver == driver &&
		    (*i).device == device) {
			return &(*i);
		}
	}
	return 0;
}

EngineControl::State*
EngineControl::get_current_state ()
{
	boost::shared_ptr<ARDOUR::AudioBackend> backend = ARDOUR::AudioEngine::instance()->current_backend();

	if (backend) {
		return get_matching_state (backend_combo.get_active_text(),
					    (backend->requires_driver_selection() ? (std::string) driver_combo.get_active_text() : string()),
					    device_combo.get_active_text());
	}


	return get_matching_state (backend_combo.get_active_text(),
				   string(),
				   device_combo.get_active_text());
}

void
EngineControl::save_state ()
{
	bool existing = true;
	State* state = get_current_state ();

	if (!state) {
		existing = false;
		state = new State;
	}
	
	state->backend = backend_combo.get_active_text ();
	state->driver = driver_combo.get_active_text ();
	state->device = device_combo.get_active_text ();
	state->buffer_size = buffer_size_combo.get_active_text ();
	state->sample_rate = sample_rate_combo.get_active_text ();
	state->input_latency = (uint32_t) input_latency.get_value();
	state->output_latency = (uint32_t) output_latency.get_value();
	state->input_channels = (uint32_t) input_channels.get_value();
	state->output_channels = (uint32_t) output_channels.get_value();

	if (!existing) {
		states.push_back (*state);
	}
}

void
EngineControl::maybe_set_state ()
{
	State* state = get_current_state ();

	if (state) {
		sr_connection.block ();
		bs_connection.block ();
		sample_rate_combo.set_active_text (state->sample_rate);
		buffer_size_combo.set_active_text (state->buffer_size);
		input_latency.set_value (state->input_latency);
		output_latency.set_value (state->output_latency);
		bs_connection.unblock ();
		sr_connection.unblock ();
	}
}
	
XMLNode&
EngineControl::get_state ()
{
	XMLNode* root = new XMLNode ("AudioMIDISetup");
	std::string path;

	if (!states.empty()) {
		XMLNode* state_nodes = new XMLNode ("EngineStates");
		
		for (StateList::const_iterator i = states.begin(); i != states.end(); ++i) {
			
			XMLNode* node = new XMLNode ("State");
			
			node->add_property ("backend", (*i).backend);
			node->add_property ("driver", (*i).driver);
			node->add_property ("device", (*i).device);
			node->add_property ("sample-rate", (*i).sample_rate);
			node->add_property ("buffer-size", (*i).buffer_size);
			node->add_property ("input-latency", (*i).input_latency);
			node->add_property ("output-latency", (*i).output_latency);
			node->add_property ("input-channels", (*i).input_channels);
			node->add_property ("output-channels", (*i).output_channels);
			node->add_property ("active", (*i).active ? "yes" : "no");
			
			state_nodes->add_child_nocopy (*node);
		}
		
		root->add_child_nocopy (*state_nodes);
	}

	return *root;
}

void
EngineControl::set_state (const XMLNode& root)
{
	XMLNodeList          clist, cclist;
	XMLNodeConstIterator citer, cciter;
	XMLNode* child;
	XMLNode* grandchild;
	XMLProperty* prop = NULL;

	if (root.name() != "AudioMIDISetup") {
		return;
	}

	clist = root.children();

	states.clear ();

	for (citer = clist.begin(); citer != clist.end(); ++citer) {

		child = *citer;
		
		if (child->name() != "EngineStates") {
			continue;
		}

		cclist = child->children();

		for (cciter = cclist.begin(); cciter != cclist.end(); ++cciter) {
			State state;
			
			grandchild = *cciter;

			if (grandchild->name() != "State") {
				continue;
			}
			
			if ((prop = grandchild->property ("backend")) == 0) {
				continue;
			}
			state.backend = prop->value ();
			
			if ((prop = grandchild->property ("driver")) == 0) {
				continue;
			}
			state.driver = prop->value ();
			
			if ((prop = grandchild->property ("device")) == 0) {
				continue;
			}
			state.device = prop->value ();
			
			if ((prop = grandchild->property ("sample-rate")) == 0) {
				continue;
			}
			state.sample_rate = prop->value ();
			
			if ((prop = grandchild->property ("buffer-size")) == 0) {
				continue;
			}
			state.buffer_size = prop->value ();
			
			if ((prop = grandchild->property ("input-latency")) == 0) {
				continue;
			}
			state.input_latency = atoi (prop->value ());
			
			if ((prop = grandchild->property ("output-latency")) == 0) {
				continue;
			}
			state.output_latency = atoi (prop->value ());
			
			if ((prop = grandchild->property ("input-channels")) == 0) {
				continue;
			}
			state.input_channels = atoi (prop->value ());
			
			if ((prop = grandchild->property ("output-channels")) == 0) {
				continue;
			}
			state.output_channels = atoi (prop->value ());

			if ((prop = grandchild->property ("active")) == 0) {
				continue;
			}
			state.active = string_is_affirmative (prop->value ());
			
			states.push_back (state);
		}
	}

	/* now see if there was an active state and switch the setup to it */
	
	for (StateList::const_iterator i = states.begin(); i != states.end(); ++i) {
		if ((*i).active) {
			sr_connection.block ();
			bs_connection.block ();
			backend_combo.set_active_text ((*i).backend);
			driver_combo.set_active_text ((*i).driver);
			device_combo.set_active_text ((*i).device);
			sample_rate_combo.set_active_text ((*i).sample_rate);
			buffer_size_combo.set_active_text ((*i).buffer_size);
			input_latency.set_value ((*i).input_latency);
			output_latency.set_value ((*i).output_latency);
			sr_connection.unblock ();
			bs_connection.unblock ();
			break;
		}
	}
}

int
EngineControl::setup_engine (bool start)
{
	boost::shared_ptr<ARDOUR::AudioBackend> backend = ARDOUR::AudioEngine::instance()->current_backend();
	assert (backend);

	/* grab the parameters from the GUI and apply them */

	try {
		if (backend->requires_driver_selection()) {
			if (backend->set_driver (get_driver())) {
				return -1;
			}
		}

		if (backend->set_device_name (get_device_name())) {
			return -1;
		}

		if (backend->set_sample_rate (get_rate())) {
			error << string_compose (_("Cannot set sample rate to %1"), get_rate()) << endmsg;
			return -1;
		}
		if (backend->set_buffer_size (get_buffer_size())) {
			error << string_compose (_("Cannot set buffer size to %1"), get_buffer_size()) << endmsg;
			return -1;
		}
		if (backend->set_input_channels (get_input_channels())) {
			error << string_compose (_("Cannot set input channels to %1"), get_input_channels()) << endmsg;
			return -1;
		}
		if (backend->set_output_channels (get_output_channels())) {
			error << string_compose (_("Cannot set output channels to %1"), get_output_channels()) << endmsg;
			return -1;
		}
		if (backend->set_systemic_input_latency (get_input_latency())) {
			error << string_compose (_("Cannot set input latency to %1"), get_input_latency()) << endmsg;
			return -1;
		}
		if (backend->set_systemic_output_latency (get_output_latency())) {
			error << string_compose (_("Cannot set output latency to %1"), get_output_latency()) << endmsg;
			return -1;
		}

		/* get a pointer to the current state object, creating one if
		 * necessary
		 */

		State* state = get_current_state ();

		if (!state) {
			save_state ();
			state = get_current_state ();
			assert (state);
		}

		/* all off */

		for (StateList::iterator i = states.begin(); i != states.end(); ++i) {
			(*i).active = false;
		}

		/* mark this one active (to be used next time the dialog is
		 * shown)
		 */

		state->active = true;
		
		if (start) {
			return ARDOUR::AudioEngine::instance()->start();
		}

		return 0;

	} catch (...) {
		cerr << "exception thrown...\n";
		return -1;
	}
}

uint32_t
EngineControl::get_rate () const
{
	double r = atof (sample_rate_combo.get_active_text ());
	/* the string may have been translated with an abbreviation for
	 * thousands, so use a crude heuristic to fix this.
	 */
	if (r < 1000.0) {
		r *= 1000.0;
	}
	return lrint (r);
}

uint32_t
EngineControl::get_buffer_size () const
{
	string txt = buffer_size_combo.get_active_text ();
	uint32_t samples;

	if (sscanf (txt.c_str(), "%d", &samples) != 1) {
		throw exception ();
	}

	return samples;
}

uint32_t
EngineControl::get_input_channels() const
{
	return (uint32_t) input_channels_adjustment.get_value();
}

uint32_t
EngineControl::get_output_channels() const
{
	return (uint32_t) output_channels_adjustment.get_value();
}

uint32_t
EngineControl::get_input_latency() const
{
	return (uint32_t) input_latency_adjustment.get_value();
}

uint32_t
EngineControl::get_output_latency() const
{
	return (uint32_t) output_latency_adjustment.get_value();
}

string
EngineControl::get_driver () const
{
	return driver_combo.get_active_text ();
}

string
EngineControl::get_device_name () const
{
	return device_combo.get_active_text ();
}

