#include <string.h>
#include "forth.h"
#include "fh_runtime.h"
#include "fh_mem.h"

/** Allocate a heap region, e.g. for a string. The address is stored to `addr` */
enum fh_error fh_heap_reserve(
    struct fh_thread_s *fh,
    size_t len,
    uint32_t *addr
)
{
  uint32_t p = WORDALIGNED(fh->heap_top); // FIXME this shouldn't be needed

  if (p + len > HEAP_SIZE) {
    return FH_ERR_HEAP_FULL;
  }

  *addr = p;

  fh->heap_top = WORDALIGNED(p + len);

  return FH_OK;
}

/** Write bytes to heap at a given location. The region must have been previously allocated! */
void fh_heap_write(struct fh_thread_s *fh, uint32_t addr, const void *src, uint32_t len)
{
  memcpy(&fh->heap[addr], src, len);
}

/** Allocate heap region and write bytes to it */
enum fh_error fh_heap_put(struct fh_thread_s *fh, const void *src, uint32_t len)
{
  enum fh_error rv;
  uint32_t addr;
  TRY(fh_heap_reserve(fh, len, &addr));
  fh_heap_write(fh, addr, src, len);
  return FH_OK;
}

/** Copy bytes from compile area to heap. The region must have been previously allocated! */
void fh_heap_copy_from_compile(struct fh_thread_s *fh, uint32_t addr, uint32_t srcaddr, uint32_t len)
{
  memcpy(&fh->heap[addr], &fh->compile[srcaddr], len);
}

/** Reserve space in the compile memory area */
enum fh_error fh_compile_reserve(
    struct fh_thread_s *fh,
    size_t len,
    uint32_t *addr
)
{
  uint32_t p = WORDALIGNED(fh->compile_top); // FIXME this shouldn't be needed

  if (p + len > COMPILED_BUFFER_SIZE) {
    return FH_ERR_HEAP_FULL;
  }

  *addr = p;

  fh->compile_top = WORDALIGNED(p + len);

  return FH_OK;
}

/** Write bytes to compile area at a given location. The region must have been previously allocated! */
void fh_compile_write(struct fh_thread_s *fh, uint32_t addr, const void *src, uint32_t len)
{
  memcpy(&fh->compile[addr], src, len);
}

/** Allocate compile region and write bytes to it */
enum fh_error fh_compile_put(struct fh_thread_s *fh, const void *src, uint32_t len)
{
  enum fh_error rv;
  uint32_t addr;
  TRY(fh_compile_reserve(fh, len, &addr));
  fh_compile_write(fh, addr, src, len);
  return FH_OK;
}