#pragma once

#include <cstdint>

#include <string>

#include "envoy/api/os_sys_calls.h"

#include "source/common/filesystem/file_shared_impl.h"

namespace Envoy {

namespace Filesystem {

class FileImplPosix : public FileSharedImpl {

public:

  ~FileImplPosix() override;

protected:

  struct FlagsAndMode {

    int flags_ = 0;

    mode_t mode_ = 0;

  };

  Api::IoCallBoolResult open(FlagSet flag) override;

  Api::IoCallSizeResult write(absl::string_view buffer) override;

  Api::IoCallBoolResult close() override;

  Api::IoCallSizeResult pread(void* buf, uint64_t count, uint64_t offset) override;

  Api::IoCallSizeResult pwrite(const void* buf, uint64_t count, uint64_t offset) override;

  Api::IoCallResult<FileInfo> info() override;

  FlagsAndMode translateFlag(FlagSet in);

private:

  friend class FileSystemImplTest;

};

class TmpFileImplPosix : public FileImplPosix {

public:

  Api::IoCallBoolResult open(FlagSet flag) override;

  Api::IoCallBoolResult close() override;

  ~TmpFileImplPosix() override;

private:

  // Ideally opening a tmp file opens it with no name; this is a fallback option for

  // when the OS or filesystem doesn't support that. with_unlink is a test-only

  // parameter to allow us to also test-cover the path where unlinking an open file

  // doesn't work.

  Api::IoCallBoolResult openNamedTmpFile(FlagsAndMode flags_and_mode, bool with_unlink = true);

  // This is only set in the case where the file system does not support nameless tmp files.

  std::string tmp_file_path_;

  friend class FileSystemImplTest;

};

class InstanceImplPosix : public Instance {

public:

  // Filesystem::Instance

  FilePtr createFile(const FilePathAndType& file_info) override;

  bool fileExists(const std::string& path) override;

  bool directoryExists(const std::string& path) override;

  ssize_t fileSize(const std::string& path) override;

  absl::StatusOr<std::string> fileReadToEnd(const std::string& path) override;

  absl::StatusOr<PathSplitResult> splitPathFromFilename(absl::string_view path) override;

  bool illegalPath(const std::string& path) override;

  Api::IoCallResult<FileInfo> stat(absl::string_view path) override;

  Api::IoCallBoolResult createPath(absl::string_view path) override;

private:

  Api::SysCallStringResult canonicalPath(const std::string& path);

  friend class FileSystemImplTest;

};

using FileImpl = FileImplPosix;

using InstanceImpl = InstanceImplPosix;

} // namespace Filesystem

} // namespace Envoy