#ifndef UIO_HH
#define UIO_HH

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

#include <cstddef>
#include <expected>
#include <string>

namespace u {

enum class ReaderInputFormat {
  UTF8,
  UTF16_BE,
  UTF16_LE,
  DETECT,
};

struct ReaderConfig {
  // If false (default), invalid data is replaced with U+FFFD
  bool strict{false};
  // Input format
  ReaderInputFormat input{ReaderInputFormat::DETECT};
  // If true (default), any BOM found at start of stream will be skipped
  bool skip_bom{true};
};

}  // namespace u8

namespace u8 {

class Reader : public io::Reader {
 public:
  using io::Reader::read;
  using io::Reader::repeat_read;

  [[nodiscard]] std::expected<size_t, io::ReadError> read(
      std::string& data, size_t max);

  [[nodiscard]] std::expected<size_t, io::ReadError> repeat_read(
      std::string& data, size_t max);
};

[[nodiscard]] std::unique_ptr<Reader> open(
    std::unique_ptr<io::Reader> reader, u::ReaderConfig config = {});

[[nodiscard]] std::expected<std::unique_ptr<Reader>, io::OpenError> open(
    const std::string& file_path, u::ReaderConfig config = {});
[[nodiscard]] std::expected<std::unique_ptr<Reader>, io::OpenError> openat(
    int dirfd, const std::string& file_path, u::ReaderConfig config = {});

}  // namespace u8

namespace u16 {

class Reader : public io::Reader {
 public:
  using io::Reader::read;
  using io::Reader::repeat_read;

  [[nodiscard]] std::expected<size_t, io::ReadError> read(
      std::u16string& data, size_t max);

  [[nodiscard]] std::expected<size_t, io::ReadError> repeat_read(
      std::u16string& data, size_t max);
};

[[nodiscard]] std::unique_ptr<Reader> open(
    std::unique_ptr<io::Reader> reader, u::ReaderConfig config = {});

[[nodiscard]] std::expected<std::unique_ptr<Reader>, io::OpenError> open(
    const std::string& file_path, u::ReaderConfig config = {});
[[nodiscard]] std::expected<std::unique_ptr<Reader>, io::OpenError> openat(
    int dirfd, const std::string& file_path, u::ReaderConfig config = {});

}  // namespace u16

#endif  // UIO_HH