/*
    Copyright (C) 2004-2007 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 <algorithm>
#include <cmath>

#include "pbd/error.h"

#include "ardour/types.h"
#include "ardour/stretch.h"
#include "ardour/audiofilesource.h"
#include "ardour/session.h"
#include "ardour/audioregion.h"

#include "pbd/i18n.h"

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

STStretch::STStretch (Session& s, TimeFXRequest& req)
	: Filter (s)
	, tsr (req)
{
	float percentage;

	/* the soundtouch code wants a *tempo* change percentage, which is
	   of opposite sign to the length change.
	*/

	percentage = -tsr.time_fraction;

	st.setSampleRate (s.sample_rate());
	st.setChannels (1);
	st.setTempoChange (percentage);
	st.setPitchSemiTones (0);
	st.setRateChange (0);

	st.setSetting(SETTING_USE_QUICKSEEK, tsr.quick_seek);
	st.setSetting(SETTING_USE_AA_FILTER, tsr.antialias);

}

STStretch::~STStretch ()
{
}

int
STStretch::run (boost::shared_ptr<Region> a_region, Progress* progress)
{
	SourceList nsrcs;
	samplecnt_t total_samples;
	samplecnt_t done;
	int ret = -1;
	const samplecnt_t bufsize = 16384;
	gain_t *gain_buffer = 0;
	Sample *buffer = 0;
	char suffix[32];
	string new_name;
	string::size_type at;

	progress->set_progress (0);
	tsr.done = false;

	boost::shared_ptr<AudioRegion> region = boost::dynamic_pointer_cast<AudioRegion>(a_region);

	total_samples = region->length() * region->n_channels();
	done = 0;

	/* the name doesn't need to be super-precise, but allow for 2 fractional
	   digits just to disambiguate close but not identical stretches.
	*/

	snprintf (suffix, sizeof (suffix), "@%d", (int) floor (tsr.time_fraction * 100.0f));

	/* create new sources */

	if (make_new_sources (region, nsrcs, suffix)) {
		goto out;
	}

	gain_buffer = new gain_t[bufsize];
	buffer = new Sample[bufsize];

	// soundtouch throws runtime_error on error

	try {
		for (uint32_t i = 0; i < nsrcs.size(); ++i) {

			boost::shared_ptr<AudioSource> asrc
				= boost::dynamic_pointer_cast<AudioSource>(nsrcs[i]);

			samplepos_t pos = 0;
			samplecnt_t this_read = 0;

			st.clear();

			while (!tsr.cancel && pos < region->length()) {
				samplecnt_t this_time;

				this_time = min (bufsize, region->length() - pos);

				/* read from the master (original) sources for the region,
				   not the ones currently in use, in case it's already been
				   subject to timefx.
				*/

				if ((this_read = region->master_read_at (buffer, buffer, gain_buffer, pos + region->position(), this_time)) != this_time) {
					error << string_compose (_("tempoize: error reading data from %1"), asrc->name()) << endmsg;
					goto out;
				}

				pos += this_read;
				done += this_read;

				progress->set_progress ((float) done / total_samples);

				st.putSamples (buffer, this_read);

				while ((this_read = st.receiveSamples (buffer, bufsize)) > 0 && !tsr.cancel) {
					if (asrc->write (buffer, this_read) != this_read) {
						error << string_compose (_("error writing tempo-adjusted data to %1"), asrc->name()) << endmsg;
						goto out;
					}
				}
			}

			if (!tsr.cancel) {
				st.flush ();
			}

			while (!tsr.cancel && (this_read = st.receiveSamples (buffer, bufsize)) > 0) {
				if (asrc->write (buffer, this_read) != this_read) {
					error << string_compose (_("error writing tempo-adjusted data to %1"), asrc->name()) << endmsg;
					goto out;
				}
			}
		}

	} catch (runtime_error& err) {
		error << _("timefx code failure. please notify ardour-developers.") << endmsg;
		error << err.what() << endmsg;
		goto out;
	}

	new_name = region->name();
	at = new_name.find ('@');

	// remove any existing stretch indicator

	if (at != string::npos && at > 2) {
		new_name = new_name.substr (0, at - 1);
	}

	new_name += suffix;

	ret = finish (region, nsrcs, new_name);

	/* now reset ancestral data for each new region */

	for (vector<boost::shared_ptr<Region> >::iterator x = results.begin(); x != results.end(); ++x) {
		samplepos_t astart = (*x)->ancestral_start();
		samplepos_t alength = (*x)->ancestral_length();
		samplepos_t start;
		samplecnt_t length;

		// note: tsr.fraction is a percentage of original length. 100 = no change,
		// 50 is half as long, 200 is twice as long, etc.

		float stretch = (*x)->stretch() * (tsr.time_fraction/100.0);

		start = (samplepos_t) floor (astart + ((astart - (*x)->start()) / stretch));
		length = (samplecnt_t) floor (alength / stretch);

		(*x)->set_ancestral_data (start, length, stretch, (*x)->shift());
	}

  out:

	delete [] gain_buffer;
	delete [] buffer;

	if (ret || tsr.cancel) {
		for (SourceList::iterator si = nsrcs.begin(); si != nsrcs.end(); ++si) {
			(*si)->mark_for_remove ();
		}
	}

	return ret;
}