redfish_authorization/redfish_entity_trie_node.h

#ifndef THIRD_PARTY_MILOTIC_EXTERNAL_CC_AUTHZ_REDFISH_ENTITY_TRIE_NODE_H_
#define THIRD_PARTY_MILOTIC_EXTERNAL_CC_AUTHZ_REDFISH_ENTITY_TRIE_NODE_H_

#include <cstddef>
#include <limits>
#include <memory>
#include <string>
#include <string_view>

#include "absl/container/flat_hash_map.h"
#include "absl/strings/string_view.h"
#include "authorizer_enums.h"

namespace milotic::authz::internal {

class RedfishEntityTrieNode {
 public:
  // Have to create a default constructor for the root
  RedfishEntityTrieNode() = default;

  // For purposes of inserting a uri, we will need to return a modifiable
  // RedfishEntityTrieNode pointer. This method encapsulates this as it will
  // either get a modifiable pointer to a child that exists or create a child
  // that doesn't exist and return its pointer to be modified when inserting
  // uris into the Trie.
  RedfishEntityTrieNode* GetOrDefaultChild(std::string_view path);

  // For purposes of getting an entity type from the uri, we can have a separate
  // Get method that is marked const to prevent the Trie from being modified
  // when only querying it.
  RedfishEntityTrieNode* GetChild(std::string_view path) const;

  ecclesia::ResourceEntity GetEntityTag() const;
  void SetEntityTag(ecclesia::ResourceEntity tag);
  std::size_t GetNodeIndexInPatternArray() const;
  void SetNodeIndexInPatternArray(std::size_t index);

 private:
  static bool IsWildcard(absl::string_view path);
  absl::flat_hash_map<std::string, std::unique_ptr<RedfishEntityTrieNode>>
      children_;
  ecclesia::ResourceEntity entity_tag_ = ecclesia::ResourceEntity::kUndefined;
  std::size_t node_index_in_pattern_array_ =
      std::numeric_limits<std::size_t>::max();
  // Hold at most one child for collection.
  // Read more about resource collections on page 28 below
  // https://www.dmtf.org/sites/default/files/standards/documents/DSP2046_2020.3_1.pdf
  RedfishEntityTrieNode* collection_child_ = nullptr;
};

}  // namespace milotic::authz::internal

#endif  // THIRD_PARTY_MILOTIC_EXTERNAL_CC_AUTHZ_REDFISH_ENTITY_TRIE_NODE_H_