/**************************************************************/
/*  treebnf: a tree oriented bnf library                      */
/*  Copyright (C) 2024  SysDeer Technologies, LLC             */
/*  Released under GPLv2 and GPLv3; see COPYING.TREEBNF.      */
/**************************************************************/

#ifndef TBNF_REGEX_SCANFNS_H
#define TBNF_REGEX_SCANFNS_H

#include <treebnf/treebnf.h>

/* in-brace scanners */
static inline int tbnf_regex_scan_brace_rbrace(const struct tbnf_scan_ctx * sctx)
{
	if (sctx->tok_scan_mark[0] == '}')
		return 1;

	return -1;
}

static inline int tbnf_regex_scan_brace_digit(const struct tbnf_scan_ctx * sctx)
{
	if (sctx->tok_scan_mark[0] >= '0')
		if (sctx->tok_scan_mark[0] <= '9')
			return 1;

	return -1;
}

static inline int tbnf_regex_scan_brace_comma(const struct tbnf_scan_ctx * sctx)
{
	if (sctx->tok_scan_mark[0] == ',')
		return 1;

	return -1;
}


/* in-bracket scanners */
static inline int tbnf_regex_scan_bracket_escaped_char(const struct tbnf_scan_ctx * sctx)
{
	if (sctx->tok_scan_mark[0] == '\\')
		if (&sctx->tok_scan_mark[1] < sctx->tok_scan_cap)
			if (sctx->tok_scan_mark[1])
				return 2;

	return -1;
}

static inline int tbnf_regex_scan_bracket_character_class(const struct tbnf_scan_ctx * sctx)
{
	const char * ch = 0;

	if (&sctx->tok_scan_mark[4] >= sctx->tok_scan_cap)
		return -1;

	if (sctx->tok_scan_mark[0] == '[')
		if (sctx->tok_scan_mark[1] == ':')
			ch = &sctx->tok_scan_mark[2];

	if (!ch)
		return -1;

	for (; (*ch >= 'a') && (*ch <= 'z') && (&ch[2] < sctx->tok_scan_cap); )
		ch++;

	if ((*ch++ == ':') && (*ch++ == ']'))
			return (ch - sctx->tok_scan_mark);

	return -1;
}

static inline int tbnf_regex_scan_bracket_collation_symbol(const struct tbnf_scan_ctx * sctx)
{
	if (&sctx->tok_scan_mark[4] >= sctx->tok_scan_cap)
		return -1;

	if (sctx->tok_scan_mark[0] == '[')
		if (sctx->tok_scan_mark[1] == '.')
			if (sctx->tok_scan_mark[3] == '.')
				if (sctx->tok_scan_mark[4] == ']')
					if (sctx->tok_scan_mark[2])
						return 5;

	return -1;
}

static inline int tbnf_regex_scan_bracket_equivalence_class(const struct tbnf_scan_ctx * sctx)
{
	const char * ch = 0;

	if (&sctx->tok_scan_mark[4] >= sctx->tok_scan_cap)
		return -1;

	if (sctx->tok_scan_mark[0] == '[')
		if (sctx->tok_scan_mark[1] == '=')
			ch = &sctx->tok_scan_mark[2];

	if (!ch)
		return -1;

	for (; (*ch >= 'a') && (*ch <= 'z') && (&ch[2] < sctx->tok_scan_cap); )
		ch++;

	if ((*ch++ == '=') && (*ch++ == ']'))
			return (ch - sctx->tok_scan_mark);

	return -1;
}

static inline int tbnf_regex_scan_bracket_rbracket(const struct tbnf_scan_ctx * sctx)
{
	if (sctx->tok_scan_mark[0] == ']')
		return 1;

	return -1;
}

static inline int tbnf_regex_scan_bracket_hyphen(const struct tbnf_scan_ctx * sctx)
{
	if (sctx->tok_scan_mark[0] == '-')
		return 1;

	return -1;
}

static inline int tbnf_regex_scan_bracket_error(const struct tbnf_scan_ctx * sctx)
{
	if (sctx->tok_scan_mark[0] == '[')
		return 1;

	return -1;
}



/* bracket state entry scanners */
static inline int tbnf_regex_scan_lbracket_circumflex_rbracket(const struct tbnf_scan_ctx * sctx)
{
	if (sctx->tok_scan_mark[0] == '[')
		if (&sctx->tok_scan_mark[2] < sctx->tok_scan_cap)
			if (sctx->tok_scan_mark[1] == '^')
				if (sctx->tok_scan_mark[2] == ']')
					return 3;

	return -1;
}

static inline int tbnf_regex_scan_lbracket_circumflex(const struct tbnf_scan_ctx * sctx)
{
	if (sctx->tok_scan_mark[0] == '[')
		if (&sctx->tok_scan_mark[1] < sctx->tok_scan_cap)
			if (sctx->tok_scan_mark[1] == '^')
				return 2;

	return -1;
}

static inline int tbnf_regex_scan_lbracket_rbracket(const struct tbnf_scan_ctx * sctx)
{
	if (sctx->tok_scan_mark[0] == '[')
		if (&sctx->tok_scan_mark[1] < sctx->tok_scan_cap)
			if (sctx->tok_scan_mark[1] == ']')
				return 2;

	return -1;
}

static inline int tbnf_regex_scan_lbracket(const struct tbnf_scan_ctx * sctx)
{
	if (sctx->tok_scan_mark[0] == '[')
		return 1;

	return -1;
}


/* common scanners */
static inline int tbnf_regex_scan_escaped_char(const struct tbnf_scan_ctx * sctx)
{
	if (sctx->tok_scan_mark[0] == '\\')
		if (&sctx->tok_scan_mark[1] < sctx->tok_scan_cap)
			if (sctx->tok_scan_mark[1])
				return 2;

	return -1;
}

static inline int tbnf_regex_scan_circumflex_asterisk(const struct tbnf_scan_ctx * sctx)
{
	if (sctx->tok_scan_mark[0] == '^')
		if (&sctx->tok_scan_mark[1] < sctx->tok_scan_cap)
			if (sctx->tok_scan_mark[1] == '*')
				return 2;

	return -1;
}

static inline int tbnf_regex_scan_circumflex(const struct tbnf_scan_ctx * sctx)
{
	if (sctx->tok_scan_mark[0] == '^')
		return 1;

	return -1;
}

static inline int tbnf_regex_scan_lbrace(const struct tbnf_scan_ctx * sctx)
{
	if (sctx->tok_scan_mark[0] == '{')
		return 1;

	return -1;
}

static inline int tbnf_regex_scan_lparen(const struct tbnf_scan_ctx * sctx)
{
	if (sctx->tok_scan_mark[0] == '(')
		return 1;

	return -1;
}

static inline int tbnf_regex_scan_rparen(const struct tbnf_scan_ctx * sctx)
{
	if (sctx->tok_scan_mark[0] == ')')
		return 1;

	return -1;
}

static inline int tbnf_regex_scan_asterisk(const struct tbnf_scan_ctx * sctx)
{
	if (sctx->tok_scan_mark[0] == '*')
		return 1;

	return -1;
}

static inline int tbnf_regex_scan_period(const struct tbnf_scan_ctx * sctx)
{
	if (sctx->tok_scan_mark[0] == '.')
		return 1;

	return -1;
}

static inline int tbnf_regex_scan_dollar(const struct tbnf_scan_ctx * sctx)
{
	if (sctx->tok_scan_mark[0] == '$')
		return 1;

	return -1;
}

static inline int tbnf_regex_scan_vline(const struct tbnf_scan_ctx * sctx)
{
	if (sctx->tok_scan_mark[0] == '|')
		return 1;

	return -1;
}

static inline int tbnf_regex_scan_qmark(const struct tbnf_scan_ctx * sctx)
{
	if (sctx->tok_scan_mark[0] == '?')
		return 1;

	return -1;
}

static inline int tbnf_regex_scan_plus(const struct tbnf_scan_ctx * sctx)
{
	if (sctx->tok_scan_mark[0] == '+')
		return 1;

	return -1;
}

static inline int tbnf_regex_scan_char(const struct tbnf_scan_ctx * sctx)
{
	if (sctx->tok_scan_mark[0])
		return 1;

	return -1;
}

#endif