/**
 * Copyright (c) Facebook, Inc. and its affiliates.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 */

// -*- c++ -*-

#include <faiss/IndexBinary.h>
#include <faiss/impl/FaissAssert.h>

#include <cstring>

namespace faiss {

IndexBinary::~IndexBinary() {}

void IndexBinary::train(idx_t, const uint8_t *) {
  // Does nothing by default.
}

void IndexBinary::range_search(idx_t, const uint8_t *, int,
                               RangeSearchResult *) const {
  FAISS_THROW_MSG("range search not implemented");
}

void IndexBinary::assign(idx_t n, const uint8_t *x, idx_t *labels, idx_t k) {
  int *distances = new int[n * k];
  ScopeDeleter<int> del(distances);
  search(n, x, k, distances, labels);
}

void IndexBinary::add_with_ids(idx_t, const uint8_t *, const idx_t *) {
  FAISS_THROW_MSG("add_with_ids not implemented for this type of index");
}

size_t IndexBinary::remove_ids(const IDSelector&) {
  FAISS_THROW_MSG("remove_ids not implemented for this type of index");
  return 0;
}

void IndexBinary::reconstruct(idx_t, uint8_t *) const {
  FAISS_THROW_MSG("reconstruct not implemented for this type of index");
}

void IndexBinary::reconstruct_n(idx_t i0, idx_t ni, uint8_t *recons) const {
  for (idx_t i = 0; i < ni; i++) {
    reconstruct(i0 + i, recons + i * d);
  }
}

void IndexBinary::search_and_reconstruct(idx_t n, const uint8_t *x, idx_t k,
                                         int32_t *distances, idx_t *labels,
                                         uint8_t *recons) const {
  search(n, x, k, distances, labels);
  for (idx_t i = 0; i < n; ++i) {
    for (idx_t j = 0; j < k; ++j) {
      idx_t ij = i * k + j;
      idx_t key = labels[ij];
      uint8_t *reconstructed = recons + ij * d;
      if (key < 0) {
        // Fill with NaNs
        memset(reconstructed, -1, sizeof(*reconstructed) * d);
      } else {
        reconstruct(key, reconstructed);
      }
    }
  }
}

void IndexBinary::display() const {
  printf("Index: %s  -> %ld elements\n", typeid (*this).name(), ntotal);
}


}  // namespace faiss