#ifndef roza_LEXER_HPP
#define roza_LEXER_HPP

#include "commons.hpp"
#include "Node.hpp"
#include "SrcLoc.hpp"
#include "StatusLog.hpp"

namespace roza
{
  struct ScanInfo {
    std::shared_ptr<Node> node = nullptr;
    size_t cursor = 0;
  };

  using scanner = std::function<ScanInfo(void)>;

  class Lexer
  {
  public:
    explicit Lexer(StatusLog& log, SrcLoc loc);
    virtual ~Lexer();

    SrcLoc loc() const { return m_loc; }
    size_t size() const { return m_nodes.size(); }

    bool is_at_end() const;
    void scan(std::string const& source);
    void skip_blanks();
    std::shared_ptr<Node> get_or_nullptr(size_t index) const;

  private:
    StatusLog& m_log;
    SrcLoc m_loc;

    std::string m_source;
    size_t m_cursor = 0;
    std::vector<std::shared_ptr<Node>> m_nodes;
    std::vector<scanner> m_scanners;

    bool is_sep(size_t index) const;

    ScanInfo scan_int() const;
    ScanInfo scan_text(std::string const& text,
                       NodeType type,
                       bool value=false) const;

    ScanInfo scan_keyword(std::string const& keyword,
                          NodeType type,
                          bool value=false) const;

    ScanInfo scan_ident() const;
  };
}

#endif