#ifndef SPX_UTILS_H
#define SPX_UTILS_H

#include <Library/UefiLib.h>
#include <Library/BaseLib.h>
#include <Library/UefiBootServicesTableLib.h>
#include <Library/BaseMemoryLib.h>
#include <Uefi.h>

#include "params.h"
#include "context.h"


/* To support MSVC use alloca() instead of VLAs. See #20. */
#ifdef _MSC_VER
/* MSVC defines _alloca in malloc.h */
# include <malloc.h>
/* Note: _malloca(), which is recommended over deprecated _alloca,
   requires that you call _freea(). So we stick with _alloca */
# define SPX_VLA(__t,__x,__s) __t *__x = (__t*)_alloca((__s)*sizeof(__t))
#else
# define SPX_VLA(__t,__x,__s) __t __x[__s]
#endif

/**
 * Converts the value of 'in' to 'outlen' bytes in big-endian byte order.
 */
#define ull_to_bytes SPX_NAMESPACE(ull_to_bytes)
VOID ull_to_bytes(UINT8 *out, UINT32 outlen,
                  UINT64 in);
#define u32_to_bytes SPX_NAMESPACE(u32_to_bytes)
VOID u32_to_bytes(UINT8 *out, UINT32 in);

/**
 * Converts the inlen bytes in 'in' from big-endian byte order to an integer.
 */
#define bytes_to_ull SPX_NAMESPACE(bytes_to_ull)
UINT64 bytes_to_ull(const UINT8 *in, UINT32 inlen);

/**
 * Computes a root node given a leaf and an auth path.
 * Expects address to be complete other than the tree_height and tree_index.
 */
#define compute_root SPX_NAMESPACE(compute_root)
VOID compute_root(UINT8 *root, const UINT8 *leaf,
                  UINT32 leaf_idx, UINT32 idx_offset,
                  const UINT8 *auth_path, UINT32 tree_height,
                  const spx_ctx *ctx, UINT32 addr[8]);

/**
 * For a given leaf index, computes the authentication path and the resulting
 * root node using Merkle's TreeHash algorithm.
 * Expects the layer and tree parts of the tree_addr to be set, as well as the
 * tree type (i.e. SPX_ADDR_TYPE_HASHTREE or SPX_ADDR_TYPE_FORSTREE).
 * Applies the offset idx_offset to indices before building addresses, so that
 * it is possible to continue counting indices across trees.
 */
#define treehash SPX_NAMESPACE(treehash)
VOID treehash(UINT8 *root, UINT8 *auth_path,
              const spx_ctx* ctx,
              UINT32 leaf_idx, UINT32 idx_offset, UINT32 tree_height,
              VOID (*gen_leaf)(
                 UINT8* /* leaf */,
                 const spx_ctx* ctx /* ctx */,
                 UINT32 /* addr_idx */, const UINT32[8] /* tree_addr */),
              UINT32 tree_addr[8]);


#endif
