/*
 * Copyright (c) 2014-2017 Pavel Kalvoda <me@pavelkalvoda.com>
 *
 * libcbor is free software; you can redistribute it and/or modify
 * it under the terms of the MIT license. See LICENSE for details.
 */

#include "cbor.h"
#include <stdio.h>
#include <string.h>

void usage()
{
	printf("Usage: streaming_parser [input file]\n");
	exit(1);
}

/*
 * Illustrates how one might skim through a map (which is assumed to have
 * string keys and values only), looking for the value of a specific key
 *
 * Use the examples/data/map.cbor input to test this.
 */

const char * key = "a secret key";
bool key_found = false;

void find_string(void * _ctx, cbor_data buffer, size_t len)
{
	if (key_found) {
		printf("Found the value: %*s\n", (int) len, buffer);
		key_found = false;
	} else if (len == strlen(key)) {
		key_found = (memcmp(key, buffer, len) == 0);
	}
}

int main(int argc, char * argv[])
{
	if (argc != 2)
		usage();
	FILE * f = fopen(argv[1], "rb");
	if (f == NULL)
		usage();
	fseek(f, 0, SEEK_END);
	size_t length = (size_t)ftell(f);
	fseek(f, 0, SEEK_SET);
	unsigned char * buffer = malloc(length);
	fread(buffer, length, 1, f);

	struct cbor_callbacks callbacks = cbor_empty_callbacks;
	struct cbor_decoder_result decode_result;
	size_t bytes_read = 0;
	callbacks.string = find_string;
	while (bytes_read < length) {
		decode_result = cbor_stream_decode(buffer + bytes_read,
										   length - bytes_read,
										   &callbacks, NULL);
		bytes_read += decode_result.read;
	}

	free(buffer);
	fclose(f);
}

