#include <stdint.h>
#include <stdio.h>
#include <zstd.h>

#include "zstdseek.h"
#include "vendor/zstdseek/zstd_seekable.h"

/**
 * Returns zero if decompression fails, non-zero otherwise.
 */
size_t
zstdseek_decompress(
	uint8_t *dest, size_t expected_len, uint8_t *compressed,
	size_t compressed_len
)
{
	ZSTD_seekable *zs;
	size_t result;

	result = 0;
	zs = ZSTD_seekable_create();
	if (zs == NULL) {
		fprintf(stderr, "ZSTD_seekable_create() failed");
		goto out;
	}

	result = ZSTD_seekable_initBuff(zs, compressed, compressed_len);
	if (ZSTD_isError(result)) {
		fprintf(stderr, "ZSTD_seekable_init() error: %s\n",
			ZSTD_getErrorName(result));
		result = 0;
		goto outfreezs;
	}

	result = ZSTD_seekable_decompress(zs, dest, expected_len, 0);
	if (ZSTD_isError(result)) {
		fprintf(stderr, "ZSTD_seekable_decompress() error: %s\n",
			ZSTD_getErrorName(result));
		result = 0;
		goto outfreezs;
	}
	if (result != expected_len) {
		fprintf(stderr, "decoded %lu bytes, wanted %lu\n", result,
			expected_len);
		result = 0;
	}
outfreezs:
	ZSTD_seekable_free(zs);
out:
	return result;
}