#include <stddef.h>
#include <stdint.h>

#include "bin.h"
#include "bits.h"
#include "buf.h"
#include "def.h"
#include "std.h"

bool com_bin_read_i16(com_bin *b, int16_t *value) {
  int16_t buf;
  if (!b->interface.readn(b->ctx, (char *)&buf, 2))
    return false;
  if (COM_DEF_CPU_LITEND && (b->flags & COM_BIN_BIG_ENDIAN)) {
    *value = __builtin_bswap16(buf);
  } else
    *value = buf;
  return true;
}

/* Same thing, really. */
bool com_bin_read_u16(com_bin *b, uint16_t *value) {
  return (com_bin_read_i16(b, (int16_t *)value));
}

bool com_bin_read_bufb(com_bin *b, struct com_buf *buf, uint32_t bytes) {
  com_std_assert(buf->typesz == 1);

  if (!com_buf_make_room(buf, bytes))
    return false;
  bool s = b->interface.readn(b->ctx, (char *)&buf->data[buf->len], bytes);
  if (s)
    buf->len += bytes;
  return s;
}

bool com_bin_read_bufbi(com_bin *b, struct com_buf *buf, uint32_t *index,
                        uint32_t bytes) {
  com_std_assert(buf->typesz == 1);

  uint32_t const alignextra =
      com_bits_nalign(buf->len, COM_DEF_ALIGNMENT) - buf->len;

  if (!com_buf_make_room(buf, alignextra + sizeof(struct com_buf) + bytes))
    return false;

  buf->len += alignextra;
  struct com_buf *in = (struct com_buf *)&buf->data[buf->len];
  buf->len += sizeof(struct com_buf);
  bool s = b->interface.readn(b->ctx, (char *)&buf->data[buf->len], bytes);
  if (s) {
    buf->len += bytes;
    *in = (struct com_buf){.cap = bytes,
                           .len = bytes,
                           .typesz = 1,
                           .flags = (buf->flags & COM_BUF_STACK) | COM_BUF_SUB};
    *index = ((ptrdiff_t)in - (ptrdiff_t)buf->data) / sizeof(struct com_buf);
  }
  return s;
}

bool com_bin_skip(com_bin *b, uint32_t bytes) {
  return b->interface.skipn(b->ctx, bytes);
}