#ifndef CST_TEXTSEL_H
#define CST_TEXTSEL_H

#include <stddef.h>
#include <wchar.h>

/* UTF-8 / ANSI helpers shared by the TUI renderer and mouse selection, so both
 * agree on which character occupies each column. */
int cst_utf8_decode(const char *s, size_t avail, wchar_t *wc, size_t *eaten);
/* wcwidth(), with an East-Asian / ASCII heuristic on Windows. */
int cst_wcwidth(wchar_t wc);
/* Columns of wc; 1 for non-printing characters. */
int cst_utf8_width(wchar_t wc);
/* Length of the escape sequence at s (CSI or two-byte ESC), 0 if none. */
size_t cst_ansi_skip(const char *s, size_t n);

typedef struct {
  char *s; /* NUL-terminated once anything was appended */
  size_t n, cap;
} cst_selbuf_t;

void cst_selbuf_free(cst_selbuf_t *b);
int cst_selbuf_putc(cst_selbuf_t *b, char c);

/* Appends the text drawn in columns [c1, c2] of a row whose content `line`
 * (ANSI escapes allowed) starts at column `indent`; c2 < 0 means the end of
 * the row. A wide character is taken whole when either of its cells is in
 * range. With `trim`, trailing spaces of the appended part are dropped.
 * Returns 0, or -1 when out of memory. */
int cst_textsel_append(cst_selbuf_t *b, const char *line, int indent, int c1,
                       int c2, int trim);

/* Column span [*c1, *c2] of the word under column `col`; just that cell (or
 * both cells of a wide character) when it is not on a word character. */
void cst_textsel_word(const char *line, int indent, int col, int *c1, int *c2);

/* Widens [*c1, *c2] so that neither end splits a wide character; highlighting
 * half of one desynchronizes curses from the terminal. *c2 < 0 is left as is. */
void cst_textsel_snap(const char *line, int indent, int *c1, int *c2);

#endif