/* SPDX-License-Identifier: GPL-2.0 OR MIT */
/*
 * Affine maps from master TSF to each radio TSF: t_radio ≈ α·t_master + β.
 * One master among N radios → (N−1) fitted maps + identity for the master.
 */

#ifndef TSF_AFFINE_H
#define TSF_AFFINE_H

#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>

#define TSF_AFFINE_MAX_RADIOS 32

struct tsf_affine_map {
	double alpha;
	double beta;
	uint64_t anchor_master;
	uint64_t anchor_radio;
	int have_anchor;
	/* Window of (dm, dr) with dm = master - anchor_master, dr = radio - anchor_radio */
	int64_t *dm;
	int64_t *dr;
	size_t win_cap;
	size_t win_count;
	size_t win_pos; /* next write index */
};

struct tsf_affine_pool {
	unsigned int n_radios;
	unsigned int master_idx;
	struct tsf_affine_map maps[TSF_AFFINE_MAX_RADIOS];
};

int tsf_affine_pool_init(struct tsf_affine_pool *p, unsigned int n_radios,
			  unsigned int master_idx, size_t window_cap);

void tsf_affine_pool_fini(struct tsf_affine_pool *p);

/* Push one simultaneous pair (same physical instant). Ignored for master_idx. */
void tsf_affine_pool_sample(struct tsf_affine_pool *p, unsigned int radio_idx,
			    uint64_t master_tsf, uint64_t radio_tsf);

/*
 * Given master TSF, fill out_radio[i] for all i.
 * Master index: out_radio[master_idx] == master_tsf exactly.
 */
void tsf_affine_pool_master_to_all(const struct tsf_affine_pool *p,
				   uint64_t master_tsf,
				   uint64_t out_radio[TSF_AFFINE_MAX_RADIOS]);

/* Single radio; returns false if radio_idx invalid or map not yet usable. */
bool tsf_affine_pool_master_to_radio(const struct tsf_affine_pool *p,
				     unsigned int radio_idx, uint64_t master_tsf,
				     uint64_t *out_radio_tsf);

bool tsf_affine_map_ready(const struct tsf_affine_map *m);

#endif