/*
 * demo_noise.h
 * Copyright (c) 2025 Christopher Herb
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#pragma once

#include <math.h>

namespace trnr {

struct demo_noise {
	double samplerate;
	int counter = 0;
	// initialize with sane defaults
	int noise_len_sec = 3;
	int pause_len_sec = 17;
	float noise_gain = 0.1f;
};

inline void demo_nose_init(demo_noise& d, double samplerate)
{
	d.samplerate = samplerate;
	d.counter = 0;
}

// overwrites the input buffer with noise in the specified time frame
inline void process_block(demo_noise& d, float** samples, int blocksize)
{
	int noise_len_samples = d.noise_len_sec * d.samplerate;
	int pause_len_samples = d.pause_len_sec * d.samplerate;
	int total_len_samples = noise_len_samples + pause_len_samples;

	for (int s = 0; s < blocksize; s++) {
		d.counter++;

		if (d.counter > total_len_samples) { d.counter = 0; }
		if (d.counter > pause_len_samples) {
			float r1 = static_cast<float>(rand()) / static_cast<float>(RAND_MAX);
			float r2 = static_cast<float>(rand()) / static_cast<float>(RAND_MAX);

			float noise = static_cast<float>(sqrt(-2.0 * log(r1)) * cos(2.0 * M_PI * r2));

			samples[0][s] = samples[1][s] = noise * d.noise_gain;
		}
	}
}
} // namespace trnr