// Copyright 2007 Google Inc. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS-IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//

//

#ifndef S2_UTIL_GTL_BTREE_CONTAINER_H_
#define S2_UTIL_GTL_BTREE_CONTAINER_H_

#include <algorithm>
#include <initializer_list>
#include <utility>

#include "s2/third_party/absl/base/internal/throw_delegate.h"
#include "s2/util/gtl/btree.h"  // IWYU pragma: export

namespace gtl {
namespace internal_btree {

// A common base class for btree_set, btree_map, btree_multiset, and
// btree_multimap.
template <typename Tree>
class btree_container {
 public:
  using key_type = typename Tree::key_type;
  using value_type = typename Tree::value_type;
  using size_type = typename Tree::size_type;
  using difference_type = typename Tree::difference_type;
  using key_compare = typename Tree::key_compare;
  using value_compare = typename Tree::value_compare;
  using allocator_type = typename Tree::allocator_type;
  using reference = typename Tree::reference;
  using const_reference = typename Tree::const_reference;
  using pointer = typename Tree::pointer;
  using const_pointer = typename Tree::const_pointer;
  using iterator = typename Tree::iterator;
  using const_iterator = typename Tree::const_iterator;
  using reverse_iterator = typename Tree::reverse_iterator;
  using const_reverse_iterator = typename Tree::const_reverse_iterator;

  // Constructors/assignments.
  btree_container() : tree_(key_compare(), allocator_type()) {}
  explicit btree_container(const key_compare &comp,
                           const allocator_type &alloc = allocator_type())
      : tree_(comp, alloc) {}
  btree_container(const btree_container &x) = default;
  btree_container(btree_container &&x) noexcept = default;
  btree_container &operator=(const btree_container &x) = default;
  btree_container &operator=(btree_container &&x) noexcept(
      std::is_nothrow_move_assignable<Tree>::value) = default;

  // Iterator routines.
  iterator begin() { return tree_.begin(); }
  const_iterator begin() const { return tree_.begin(); }
  const_iterator cbegin() const { return tree_.begin(); }
  iterator end() { return tree_.end(); }
  const_iterator end() const { return tree_.end(); }
  const_iterator cend() const { return tree_.end(); }
  reverse_iterator rbegin() { return tree_.rbegin(); }
  const_reverse_iterator rbegin() const { return tree_.rbegin(); }
  const_reverse_iterator crbegin() const { return tree_.rbegin(); }
  reverse_iterator rend() { return tree_.rend(); }
  const_reverse_iterator rend() const { return tree_.rend(); }
  const_reverse_iterator crend() const { return tree_.rend(); }

  // Lookup routines.
  template <typename K>
  iterator lower_bound(const K &key) {
    return tree_.lower_bound(key);
  }
  template <typename K>
  const_iterator lower_bound(const K &key) const {
    return tree_.lower_bound(key);
  }
  template <typename K>
  iterator upper_bound(const K &key) {
    return tree_.upper_bound(key);
  }
  template <typename K>
  const_iterator upper_bound(const K &key) const {
    return tree_.upper_bound(key);
  }
  template <typename K>
  std::pair<iterator, iterator> equal_range(const K &key) {
    return tree_.equal_range(key);
  }
  template <typename K>
  std::pair<const_iterator, const_iterator> equal_range(const K &key) const {
    return tree_.equal_range(key);
  }

  // Utility routines.
  void clear() { tree_.clear(); }
  void swap(btree_container &x) { tree_.swap(x.tree_); }
  void verify() const { tree_.verify(); }

  // Size routines.
  size_type size() const { return tree_.size(); }
  size_type max_size() const { return tree_.max_size(); }
  bool empty() const { return tree_.empty(); }
  size_type height() const { return tree_.height(); }
  size_type internal_nodes() const { return tree_.internal_nodes(); }
  size_type leaf_nodes() const { return tree_.leaf_nodes(); }
  size_type nodes() const { return tree_.nodes(); }
  size_type bytes_used() const { return tree_.bytes_used(); }
  static double average_bytes_per_value() {
    return Tree::average_bytes_per_value();
  }
  double fullness() const { return tree_.fullness(); }
  double overhead() const { return tree_.overhead(); }

  friend bool operator==(const btree_container &x, const btree_container &y) {
    if (x.size() != y.size()) return false;
    return std::equal(x.begin(), x.end(), y.begin());
  }

  friend bool operator!=(const btree_container &x, const btree_container &y) {
    return !(x == y);
  }

  friend bool operator<(const btree_container &x, const btree_container &y) {
    return std::lexicographical_compare(x.begin(), x.end(), y.begin(), y.end());
  }

  friend bool operator>(const btree_container &x, const btree_container &y) {
    return y < x;
  }

  friend bool operator<=(const btree_container &x, const btree_container &y) {
    return !(y < x);
  }

  friend bool operator>=(const btree_container &x, const btree_container &y) {
    return !(x < y);
  }

  // The allocator used by the btree.
  allocator_type get_allocator() const { return tree_.get_allocator(); }

  // The key comparator used by the btree.
  key_compare key_comp() const { return tree_.key_comp(); }
  value_compare value_comp() const { return tree_.value_comp(); }

  // Support absl::Hash.
  template <typename State>
  friend State AbslHashValue(State h, const btree_container &b) {
    for (const auto &v : b) {
      h = State::combine(std::move(h), v);
    }
    return State::combine(std::move(h), b.size());
  }

  // Exposed only for tests.
  static bool testonly_uses_linear_node_search() {
    return Tree::testonly_uses_linear_node_search();
  }

 protected:
  Tree tree_;
};

// A common base class for btree_set and btree_map.
template <typename Tree>
class btree_set_container : public btree_container<Tree> {
  using super_type = btree_container<Tree>;
  using mutable_value_type = typename Tree::mutable_value_type;
  using params_type = typename Tree::params_type;
  friend class BtreeNodePeer;

 public:
  using value_type = typename Tree::value_type;
  using size_type = typename Tree::size_type;
  using key_compare = typename Tree::key_compare;
  using allocator_type = typename Tree::allocator_type;
  using iterator = typename Tree::iterator;
  using const_iterator = typename Tree::const_iterator;

  // Inherit constructors.
  using super_type::super_type;
  btree_set_container() {}

  // Range constructor.
  template <class InputIterator>
  btree_set_container(InputIterator b, InputIterator e,
                      const key_compare &comp = key_compare(),
                      const allocator_type &alloc = allocator_type())
      : super_type(comp, alloc) {
    insert(b, e);
  }

  // Initializer list constructor.
  btree_set_container(std::initializer_list<value_type> init,
                      const key_compare &comp = key_compare(),
                      const allocator_type &alloc = allocator_type())
      : btree_set_container(init.begin(), init.end(), comp, alloc) {}

  // Lookup routines.
  template <typename K>
  iterator find(const K &key) {
    return this->tree_.find_unique(key);
  }
  template <typename K>
  const_iterator find(const K &key) const {
    return this->tree_.find_unique(key);
  }
  template <typename K>
  size_type count(const K &key) const {
    return this->tree_.count_unique(key);
  }

  // Insertion routines.
  std::pair<iterator, bool> insert(const value_type &x) {
    return this->tree_.insert_unique(params_type::key(x), x);
  }
  std::pair<iterator, bool> insert(value_type &&x) {
    return this->tree_.insert_unique(params_type::key(x), std::move(x));
  }
  template <typename... Args>
  std::pair<iterator, bool> emplace(Args &&... args) {
    mutable_value_type v(std::forward<Args>(args)...);
    return this->tree_.insert_unique(params_type::key(v), std::move(v));
  }
  iterator insert(iterator position, const value_type &x) {
    return this->tree_.insert_hint_unique(position, params_type::key(x), x);
  }
  iterator insert(iterator position, value_type &&x) {
    return this->tree_.insert_hint_unique(position, params_type::key(x),
                                          std::move(x));
  }
  template <typename... Args>
  iterator emplace_hint(iterator position, Args &&... args) {
    mutable_value_type v(std::forward<Args>(args)...);
    return this->tree_.insert_hint_unique(position, params_type::key(v),
                                          std::move(v));
  }
  template <typename InputIterator>
  void insert(InputIterator b, InputIterator e) {
    this->tree_.insert_iterator_unique(b, e);
  }
  void insert(std::initializer_list<value_type> init) {
    this->tree_.insert_iterator_unique(init.begin(), init.end());
  }

  // Deletion routines.
  template <typename K>
  int erase(const K &key) {
    return this->tree_.erase_unique(key);
  }
  // Erase the specified iterator from the btree. The iterator must be valid
  // (i.e. not equal to end()).  Return an iterator pointing to the node after
  // the one that was erased (or end() if none exists).
  iterator erase(const iterator &iter) { return this->tree_.erase(iter); }
  void erase(const iterator &first, const iterator &last) {
    this->tree_.erase(first, last);
  }
};

// Base class for btree_map.
template <typename Tree>
class btree_map_container : public btree_set_container<Tree> {
  using super_type = btree_set_container<Tree>;

 public:
  using key_type = typename Tree::key_type;
  using mapped_type = typename Tree::mapped_type;
  using value_type = typename Tree::value_type;
  using key_compare = typename Tree::key_compare;
  using allocator_type = typename Tree::allocator_type;

  // Inherit constructors.
  using super_type::super_type;
  btree_map_container() {}

  // Insertion routines.
  mapped_type &operator[](const key_type &key) {
    return this->tree_
        .insert_unique(key, std::piecewise_construct,
                       std::forward_as_tuple(key), std::forward_as_tuple())
        .first->second;
  }
  mapped_type &operator[](key_type &&key) {
    return this->tree_
        .insert_unique(key, std::piecewise_construct,
                       std::forward_as_tuple(std::move(key)),
                       std::forward_as_tuple())
        .first->second;
  }

  mapped_type &at(const key_type &key) {
    auto it = this->find(key);
    if (it == this->end())
      absl::base_internal::ThrowStdOutOfRange("btree_map::at");
    return it->second;
  }
  const mapped_type &at(const key_type &key) const {
    auto it = this->find(key);
    if (it == this->end())
      absl::base_internal::ThrowStdOutOfRange("btree_map::at");
    return it->second;
  }
};

// A common base class for btree_multiset and btree_multimap.
template <typename Tree>
class btree_multiset_container : public btree_container<Tree> {
  using super_type = btree_container<Tree>;

 public:
  using key_type = typename Tree::key_type;
  using value_type = typename Tree::value_type;
  using mapped_type = typename Tree::mapped_type;
  using size_type = typename Tree::size_type;
  using key_compare = typename Tree::key_compare;
  using allocator_type = typename Tree::allocator_type;
  using iterator = typename Tree::iterator;
  using const_iterator = typename Tree::const_iterator;

  // Inherit constructors.
  using super_type::super_type;
  btree_multiset_container() {}

  // Range constructor.
  template <class InputIterator>
  btree_multiset_container(InputIterator b, InputIterator e,
                           const key_compare &comp = key_compare(),
                           const allocator_type &alloc = allocator_type())
      : super_type(comp, alloc) {
    insert(b, e);
  }

  // Initializer list constructor.
  btree_multiset_container(std::initializer_list<value_type> init,
                           const key_compare &comp = key_compare(),
                           const allocator_type &alloc = allocator_type())
      : btree_multiset_container(init.begin(), init.end(), comp, alloc) {}

  // Lookup routines.
  template <typename K>
  iterator find(const K &key) {
    return this->tree_.find_multi(key);
  }
  template <typename K>
  const_iterator find(const K &key) const {
    return this->tree_.find_multi(key);
  }
  template <typename K>
  size_type count(const K &key) const {
    return this->tree_.count_multi(key);
  }

  // Insertion routines.
  iterator insert(const value_type &x) { return this->tree_.insert_multi(x); }
  iterator insert(value_type &&x) {
    return this->tree_.insert_multi(std::move(x));
  }
  iterator insert(iterator position, const value_type &x) {
    return this->tree_.insert_hint_multi(position, x);
  }
  iterator insert(iterator position, value_type &&x) {
    return this->tree_.insert_hint_multi(position, std::move(x));
  }
  template <typename InputIterator>
  void insert(InputIterator b, InputIterator e) {
    this->tree_.insert_iterator_multi(b, e);
  }
  void insert(std::initializer_list<value_type> init) {
    this->tree_.insert_iterator_multi(init.begin(), init.end());
  }

  // Deletion routines.
  template <typename K>
  int erase(const K &key) {
    return this->tree_.erase_multi(key);
  }
  // Erase the specified iterator from the btree. The iterator must be valid
  // (i.e. not equal to end()).  Return an iterator pointing to the node after
  // the one that was erased (or end() if none exists).
  iterator erase(const iterator &iter) { return this->tree_.erase(iter); }
  void erase(const iterator &first, const iterator &last) {
    this->tree_.erase(first, last);
  }
};

// A base class for btree_multimap.
template <typename Tree>
class btree_multimap_container : public btree_multiset_container<Tree> {
  using super_type = btree_multiset_container<Tree>;

 public:
  using mapped_type = typename Tree::mapped_type;

  // Inherit constructors.
  using super_type::super_type;
  btree_multimap_container() {}
};

}  // namespace internal_btree
}  // namespace gtl

#endif  // S2_UTIL_GTL_BTREE_CONTAINER_H_
