#ifndef PREFIX_TREE_HH
#define PREFIX_TREE_HH

#include <memory>
#include <optional>
#include <string>
#include <string_view>

namespace prefix_tree {

class Builder {
 public:
  virtual ~Builder() = default;

  virtual void add(std::string_view str) = 0;
  [[nodiscard]]
  virtual std::optional<std::string> build() const = 0;

 protected:
  Builder() = default;

  Builder(Builder const&) = delete;
  Builder& operator=(Builder const&) = delete;
};

[[nodiscard]]
std::unique_ptr<Builder> builder();

// Returns the length of the prefix of str that exists in tree.
// Returns nullopt if prefix of str doesn't match any string in tree.
[[nodiscard]]
std::optional<size_t> lookup(std::string_view tree, std::string_view str);

}  // namespace prefix_tree

#endif  // PREFIX_TREE_HH