/*
 * Copyright (c) Camden Dixie O'Brien
 * SPDX-License-Identifier: AGPL-3.0-only
 */

#include "construct.h"

#include <assert.h>
#include <stdlib.h>

static void construct_literal(char literal, fsa_t *out)
{
	fsa_init(out);
	const int id = fsa_add_state(out);
	fsa_add_rule(out, id, out->initial, literal);
	out->initial = id;
}

static void construct_term(const regex_term_t *term, fsa_t *out)
{
	switch (term->type) {
	case REGEX_TERM_EMPTY:
		fsa_init(out);
		break;
	case REGEX_TERM_LITERAL:
		construct_literal(term->literal, out);
		break;
	case REGEX_TERM_SUBEXPR:
		return;

	case REGEX_TERM_WILDCARD:
	case REGEX_TERM_CLASS:
		assert(false);
	}
}

static void construct_sequence(const regex_sequence_t *seq, fsa_t *out)
{
	construct_term(&seq->contents[0], out);
}

void construct(const regex_t *regex, fsa_t *out)
{
	construct_sequence(&regex->contents[0], out);
}