// Copyright (c) 2023, Google Inc.
// SPDX-License-Identifier: ISC

#ifndef OPENSSL_HEADER_CRYPTO_TEST_FILE_UTIL_H
#define OPENSSL_HEADER_CRYPTO_TEST_FILE_UTIL_H

#include <stdio.h>

#include <memory>
#include <string>
#include <utility>

#include <openssl/span.h>

#if defined(OPENSSL_WINDOWS)
#include <io.h>
#else
#include <unistd.h>
#endif


struct FileDeleter {
  void operator()(FILE *f) const {
    if (f != nullptr) {
      fclose(f);
    }
  }
};

using ScopedFILE = std::unique_ptr<FILE, FileDeleter>;

class ScopedFD {
 public:
  ScopedFD() = default;
  explicit ScopedFD(int fd) : fd_(fd) {}
  ~ScopedFD() { reset(); }

  ScopedFD(ScopedFD &&other) noexcept { *this = std::move(other); }
  ScopedFD &operator=(ScopedFD&& other) {
    reset(other.release());
    return *this;
  }

  ScopedFD(const ScopedFD &other) = delete;
  ScopedFD &operator=(ScopedFD& other) = delete;

  bool is_valid() const { return fd_ >= 0; }
  int get() const { return fd_; }

  int release() {
    int old_fd = fd_;
    fd_ = -1;
    return old_fd;
  }
  void reset(int fd = -1) {
    if (is_valid()) {
#if defined(OPENSSL_WINDOWS)
      _close(fd_);
#else
      close(fd_);
#endif
    }
    fd_ = fd;
  }

 private:
  int fd_ = -1;
};

// SkipTempFileTests returns true and prints a warning if tests involving
// temporary files should be skipped because of platform issues.
bool SkipTempFileTests();

// TemporaryFile manages a temporary file for testing.
class TemporaryFile {
 public:
  TemporaryFile() = default;
  ~TemporaryFile();

  TemporaryFile(TemporaryFile&& other) noexcept { *this = std::move(other); }
  TemporaryFile& operator=(TemporaryFile&&other) {
    // Ensure |path_| is empty so it doesn't try to delete the File.
    auto old_other_path = other.path_;
    other.path_ = {};
    path_ = old_other_path;
    return *this;
  }

  TemporaryFile(const TemporaryFile&) = delete;
  TemporaryFile& operator=(const TemporaryFile&) = delete;

  // Init initializes the temporary file with the specified content. It returns
  // true on success and false on error. On error, callers should call
  // |IgnoreTempFileErrors| to determine whether to ignore the error.
  bool Init(bssl::Span<const uint8_t> content = {});
  bool Init(const std::string &content) {
    return Init(bssl::MakeConstSpan(
        reinterpret_cast<const uint8_t *>(content.data()), content.size()));
  }

  // Open opens the file as a |FILE| with the specified mode.
  ScopedFILE Open(const char *mode) const;

  // Open opens the file as a file descriptor with the specified flags.
  ScopedFD OpenFD(int flags) const;

  // path returns the path to the temporary file.
  const std::string &path() const { return path_; }

 private:
  std::string path_;
};

#endif  // OPENSSL_HEADER_CRYPTO_TEST_FILE_UTIL_H