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

#include "compile.h"

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

#define BUFFER_START_CAPACITY 128

#define PREFIX ".*("
#define PREFIX_LEN 3
#define SUFFIX ").*"
#define SUFFIX_LEN 3

int main(int argc, char *argv[])
{
	if (argc != 2) {
		fprintf(stderr, "Usage: %s REGEX\n", argv[0]);
		return EXIT_FAILURE;
	}

	const int input_len = strlen(argv[1]);
	const int regex_len = input_len + 6;
	char *regex = malloc(regex_len);
	memcpy(regex, PREFIX, PREFIX_LEN);
	memcpy(regex + PREFIX_LEN, argv[1], input_len);
	memcpy(regex + PREFIX_LEN + input_len, SUFFIX, SUFFIX_LEN);

	fsa_t dfa;
	if (!compile(regex, regex_len, &dfa)) {
		fprintf(stderr, "Failed to parse regex\n");
		return EXIT_FAILURE;
	}

	int len = 0, capacity = BUFFER_START_CAPACITY;
	char *buffer = malloc(capacity);
	assert(NULL != buffer);

	int c;
	while ((c = getchar()) != EOF) {
		if (capacity < len + 1) {
			capacity *= 2;
			buffer = realloc(buffer, capacity);
			assert(NULL != buffer);
		}
		if ('\n' == c) {
			if (fsa_accepts(&dfa, buffer, len)) {
				buffer[len++] = '\n';
				fwrite(buffer, 1, len, stdout);
			}
			len = 0;
		} else {
			buffer[len++] = c;
		}
	}

	fsa_free(&dfa);
	free(buffer);
	return EXIT_SUCCESS;
}