/* ************************************************************************ *
 *    lib11sht.h, v1.0                                                      *
 *    Fuzzy comparison library: public API                                  *
 *                                                                          *
 *    Copyright (C) 2025 by Ruben Carlo Benante <rcb@beco.cc>               *
 *    GNU GPL version 2 or later.                                           *
 * ************************************************************************ */

#ifndef LIB11SHT_H
#define LIB11SHT_H

#include <stddef.h>  /* size_t */

#define LEVN_SBUFF 256  /* recommended size for s1/s2 buffers */

/* Compare similarity between two strings (after asciify + trim + lowercase).
 * Symmetric in shape with fequal(a, b, delta).
 * Returns:
 *      0  if equal or similar above the lratio threshold
 *     -1  if a < b alphabetically (after normalization)
 *     +1  if a > b alphabetically (after normalization)
 * On error: sets errno = EINVAL and returns 0; comparison result is undefined.
 * Caller must reset errno = 0 before the call to detect errors.
 *
 * Parameters:
 *   a, b   input strings (NUL-terminated, may contain UTF-8 accented Latin chars)
 *   shold  Levenshtein similarity threshold 0.0..1.0; matches above this count as equal
 */
int sequal(char *a, char *b, float shold);

/* Full variant of sequal: same comparison but also returns diagnostics.
 * Used by callers that need the computed ratio or the normalized strings
 * (e.g. cmp11sht CLI's -o / -n flags).
 *
 * Extra parameters:
 *   ratio    out: Levenshtein similarity 0.0..1.0 (1.0 on exact-after-normalize)
 *   s1, s2   out: caller-provided buffers filled with the normalized inputs
 *   s1_size  size of s1 in bytes (writes capped at s1_size-1 + final NUL)
 *   s2_size  size of s2 in bytes (writes capped at s2_size-1 + final NUL)
 */
int sequal_full(char *a, char *b, float shold, float *ratio,
                char *s1, size_t s1_size,
                char *s2, size_t s2_size);

/* Compare two floats within ±delta.
 * Returns:
 *      0  if |a - b| <= delta
 *     -1  if a < b - delta
 *     +1  if a > b + delta
 */
int fequal(float a, float b, float delta);

/* String trim: removes leading + trailing whitespace (including UTF-8
 * NBSP bytes 0xC2 / 0xA0) AND collapses internal runs of whitespace
 * to a single space. Modifies s in place. Caller's buffer must already
 * be NUL-terminated. */
void trim(char *s);

#endif /* LIB11SHT_H */