/* Spa
 *
 * Copyright © 2018 Wim Taymans
 *
 * 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 (including the next
 * paragraph) 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.
 */

#include <math.h>
#include <errno.h>

#include <spa/param/audio/format.h>

#include "resample-peaks-impl.h"

static void resample_peaks_process_c(struct resample *r,
			const void * SPA_RESTRICT src[], uint32_t *in_len,
			void * SPA_RESTRICT dst[], uint32_t *out_len)
{
	struct peaks_data *pd = r->data;
	uint32_t c, i, o, end, chunk, o_count, i_count;

	if (SPA_UNLIKELY(r->channels == 0))
		return;

	for (c = 0; c < r->channels; c++) {
		const float *s = src[c];
		float *d = dst[c], m = pd->max_f[c];

		o_count = pd->o_count;
		i_count = pd->i_count;
		o = i = 0;

		while (i < *in_len && o < *out_len) {
			end = ((uint64_t) (o_count + 1) * r->i_rate) / r->o_rate;
			end = end > i_count ? end - i_count : 0;
			chunk = SPA_MIN(end, *in_len);

			for (; i < chunk; i++)
				m = SPA_MAX(fabsf(s[i]), m);

			if (i == end) {
				d[o++] = m;
				m = 0.0f;
				o_count++;
			}
		}
		pd->max_f[c] = m;
	}

	*out_len = o;
	*in_len = i;
	pd->o_count = o_count;
	pd->i_count = i_count + i;

	while (pd->i_count >= r->i_rate) {
		pd->i_count -= r->i_rate;
		pd->o_count -= r->o_rate;
	}
}

struct resample_info {
	uint32_t format;
	uint32_t cpu_flags;
	void (*process) (struct resample *r,
			const void * SPA_RESTRICT src[], uint32_t *in_len,
			void * SPA_RESTRICT dst[], uint32_t *out_len);
};

static struct resample_info resample_table[] =
{
#if defined (HAVE_SSE)
	{ SPA_AUDIO_FORMAT_F32, SPA_CPU_FLAG_SSE, resample_peaks_process_sse, },
#endif
	{ SPA_AUDIO_FORMAT_F32, 0, resample_peaks_process_c, },
};

#define MATCH_CPU_FLAGS(a,b)	((a) == 0 || ((a) & (b)) == a)
static const struct resample_info *find_resample_info(uint32_t format, uint32_t cpu_flags)
{
	size_t i;
	for (i = 0; i < SPA_N_ELEMENTS(resample_table); i++) {
		if (resample_table[i].format == format &&
		    MATCH_CPU_FLAGS(resample_table[i].cpu_flags, cpu_flags)) {
			return &resample_table[i];
		}
	}
	return NULL;
}

static void impl_peaks_free(struct resample *r)
{
	free(r->data);
	r->data = NULL;
}

static void impl_peaks_update_rate(struct resample *r, double rate)
{
}

static uint32_t impl_peaks_delay (struct resample *r)
{
	return 0;
}

static uint32_t impl_peaks_in_len(struct resample *r, uint32_t out_len)
{
	return out_len;
}

static void impl_peaks_reset (struct resample *r)
{
	struct peaks_data *d = r->data;
	d->i_count = d->o_count = 0;
}

int resample_peaks_init(struct resample *r)
{
	struct peaks_data *d;
	const struct resample_info *info;

	r->free = impl_peaks_free;
	r->update_rate = impl_peaks_update_rate;

	if ((info = find_resample_info(SPA_AUDIO_FORMAT_F32, r->cpu_flags)) == NULL)
		return -ENOTSUP;

	r->process = info->process;
	r->reset = impl_peaks_reset;
	r->delay = impl_peaks_delay;
	r->in_len = impl_peaks_in_len;

	d = r->data = calloc(1, sizeof(struct peaks_data) + sizeof(float) * r->channels);
	if (r->data == NULL)
		return -errno;

	spa_log_debug(r->log, "peaks %p: in:%d out:%d features:%08x:%08x", r,
			r->i_rate, r->o_rate, r->cpu_flags, info->cpu_flags);

	r->cpu_flags = info->cpu_flags;
	d->i_count = d->o_count = 0;
	return 0;
}
