#include <stdio.h>

#include "libcinputstream.h"
#include "assert.h"
#include "native_types.h"

void native_jvm_internal_libcinputstream_open_1(struct vm * vm, uint32_t * args)
{
  struct arrayref * arrayref = (struct arrayref *)args[0];
  assert(arrayref != nullptr);
  assert(arrayref->length > 0);
  assert(arrayref->u8[arrayref->length - 1] == 0);
  FILE * file = fopen((const char *)arrayref->u8, "rb");
  assert(file != nullptr);

  operand_stack_push_u32(vm->current_frame, (uint32_t)file);
}

void native_jvm_internal_libcinputstream_close_1(struct vm * vm, uint32_t * args)
{
  FILE * file = (FILE *)args[0];
  assert(file != nullptr);
  int ret = fclose(file);
  assert(ret == 0);
}

void native_jvm_internal_libcinputstream_read_1(struct vm * vm, uint32_t * args)
{
  FILE * file = (FILE *)args[0];
  assert(file != nullptr);

  uint8_t buf[1];
  int32_t size = fread(buf, 1, 1, file);
  if (size == 0)
    operand_stack_push_u32(vm->current_frame, (uint32_t)-1);
  else
    operand_stack_push_u32(vm->current_frame, (uint32_t)buf[0]);
}