#ifndef LINE_HH
#define LINE_HH

#include "io.hh"  // IWYU pragma: export

#include <cstddef>
#include <expected>
#include <memory>
#include <optional>
#include <string_view>

namespace line {

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

  // Returned view is only valid until next call to read.
  [[nodiscard]]
  virtual std::expected<std::string_view, io::ReadError> read() = 0;
  // Starts at zero. Returns next line.
  // So, before first read it is zero, after first read it is one.
  [[nodiscard]] virtual uint64_t number() const = 0;

 protected:
  Reader() = default;

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

[[nodiscard]] std::unique_ptr<Reader> open(std::unique_ptr<io::Reader> reader,
                                           size_t max_len = 8192);

}  // namespace line

#endif  // LINE_HH