#ifndef muz_LEXER_HPP
#define muz_LEXER_HPP

#include "commons.hpp"
#include "Node.hpp"

namespace muz
{
  MUZ_ERROR(lexical_error);

  struct TokenInfo
  {
    size_t position;
    NodeType type;
    std::string value;
  };

  /**
   * Scan a text and gives corresponding tokens.
   * @see Node
   **/
  class Lexer
  {
  public:
    explicit Lexer();
    virtual ~Lexer();

    void scan(std::string const& source);
    std::vector<std::shared_ptr<Node>> all();
    std::shared_ptr<Node> next();

  private:
    std::string m_source;
    size_t m_cursor = 0;
    int m_line = 1;
    std::vector<char> m_seps;

    void skip_spaces();

    std::optional<TokenInfo> next_word();
    bool is_sep(size_t index) const;
    bool is_num(std::string const& word) const;
    bool is_ident(std::string const& word) const;
    bool is_dir_ident(std::string const& word) const;
  };
}

#endif