/*
 * A standalone AM/FM Radio QML plugin (for RTL2832U and Maxim hardware)
 * Copyright © 2015-2016 Manuel Bachmann <manuel.bachmann@iot.bzh>
 * Copyright © 2016 Scott Murray <scott.murray@konsulko.com>
 *
 * 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, see <http://www.gnu.org/licenses/>.
 */

#include <iostream>
#include "radio_output.h"
#include "rtl_fm.h"

RadioOutputAlsa::RadioOutputAlsa() : RadioOutputImplementation(),
				     dev(NULL),
				     hw_params(NULL)
{
	unsigned int rate = 24000;

	if (snd_pcm_open(&dev, "default", SND_PCM_STREAM_PLAYBACK, 0) < 0) {
		std::cerr << "Could not open primary ALSA device" << std::endl;
		works = false;
		return;
	}

	snd_pcm_hw_params_malloc(&hw_params);
	snd_pcm_hw_params_any(dev, hw_params);

	snd_pcm_hw_params_set_access (dev, hw_params, SND_PCM_ACCESS_RW_INTERLEAVED);
	snd_pcm_hw_params_set_format (dev, hw_params, SND_PCM_FORMAT_S16_LE);
	snd_pcm_hw_params_set_rate_near (dev, hw_params, &rate, 0);
	snd_pcm_hw_params_set_channels (dev, hw_params, 2);

	if (snd_pcm_hw_params (dev, hw_params) < 0) {
		std::cerr << "Could not set hardware parameters" << std::endl;
		works = false;
	} else {
		works = true;
	}
	snd_pcm_hw_params_free (hw_params);

	snd_pcm_prepare (dev);
}

RadioOutputAlsa::~RadioOutputAlsa()
{
	snd_pcm_close (dev);
}

bool RadioOutputAlsa::play(void *buf, int len)
{
	int16_t *cbuf = (int16_t *)buf;
	int frames = len / 2;
	int res;

	if ((res = snd_pcm_writei(dev, cbuf, frames)) != frames) {
		snd_pcm_recover(dev, res, 0);
		snd_pcm_prepare(dev);
	}
	//snd_pcm_drain(dev);

	return true;
}


RadioOutputPulse::RadioOutputPulse() : RadioOutputImplementation(),
				       pa(NULL),
				       pa_spec(NULL)
{
	int error;

	pa_spec = (pa_sample_spec*) malloc(sizeof(pa_sample_spec));
	pa_spec->format = PA_SAMPLE_S16LE;
	pa_spec->rate = 24000;
	pa_spec->channels = 2;

	if (!(pa = pa_simple_new(NULL, "qtmultimedia-rtlfm-radio-plugin", PA_STREAM_PLAYBACK, NULL,
	                         "radio-output", pa_spec, NULL, NULL, &error))) {
		std::cerr << "Error connecting to PulseAudio : " << pa_strerror(error) << std::endl;
		works = false;
	} else {
		std::cerr << "RadioOutputPulse::RadioOutputPulse: Connected to PulseAudio" << std::endl;
		works = true;
	}

	extra = 0;
	output_buf = new unsigned char[RTL_FM_MAXIMUM_BUF_LENGTH];

	free(pa_spec);	
}

RadioOutputPulse::~RadioOutputPulse()
{
	pa_simple_free(pa);
	delete [] output_buf;
}

bool RadioOutputPulse::play(void *buf, int len)
{
	int error;
	size_t n = len * 2;
	void *p;

	if (!buf) {
		std::cerr << "Error buf == null!" << std::endl;
		return false;
	}

	// Handle the rtl_fm code giving us an odd number of samples, which
	// PA does not like.  This extra buffer copying approach is not
	// particularly efficient, but works for now.  It looks feasible to
	// hack in something in the demod and output thread routines in
	// rtl_fm.c to handle it there if more performance is required.
	p = output_buf;
	if(extra) {
		memcpy(output_buf, extra_buf, sizeof(int16_t));
		if((extra + len) % 2) {
			// We end up with len + 1 samples, n remains the same, store the extra
			memcpy(output_buf + sizeof(int16_t), buf, n - 2);
			memcpy(extra_buf, ((unsigned char*) buf) + n - 2, sizeof(int16_t));
		} else {
			// We end up with an extra sample
			memcpy(output_buf + sizeof(int16_t), buf, n);
			n += 2;
			extra = 0;
		}
	} else if(len % 2) {
		// We have an extra sample, store it, and decrease n
		n -= 2;
		memcpy(output_buf + sizeof(int16_t), buf, n);
		memcpy(extra_buf, ((unsigned char*) buf) + n, sizeof(int16_t));
		extra = 1;
	} else {
		p = buf;
	}

	if (pa_simple_write(pa, p, n, &error) < 0)
		std::cerr << "Error writing " << n << " bytes to PulseAudio : " << pa_strerror(error) << std::endl;
	//pa_simple_drain(pa, &error);

	return true;
}