tlbmc/http/http_client.h

#ifndef THIRD_PARTY_MILOTIC_EXTERNAL_CC_TLBMC_HTTP_HTTP_CLIENT_H_
#define THIRD_PARTY_MILOTIC_EXTERNAL_CC_TLBMC_HTTP_HTTP_CLIENT_H_

#include <atomic>
#include <chrono>  // NOLINT: BMC code base can use chrono
#include <cstddef>
#include <memory>
#include <string>
#include <string_view>

#include "absl/functional/any_invocable.h"
#include "absl/status/status.h"
#include "boost/asio.hpp"  //NOLINT: boost::asio is commonly used in BMC
#include "boost/asio/error.hpp"  // NOLINT
#include "boost/asio/random_access_file.hpp"  // NOLINT: boost::asio is commonly used in BMC
#include "boost/asio/ssl.hpp"  // NOLINT: boost::asio is commonly used in BMC
#include "boost/beast/core.hpp"  // NOLINT: boost::beast is commonly used in BMC
#include "boost/beast/http.hpp"  // NOLINT: boost::beast is commonly used in BMC
#include "boost/beast/http/buffer_body.hpp"  // NOLINT: boost::beast is commonly used in BMC
#include "boost/beast/ssl.hpp"  // NOLINT: boost::beast is commonly used in BMC
#include "boost/beast/version.hpp"  // NOLINT: boost::beast is commonly used in BMC
#include "boost/filesystem.hpp"  // NOLINT: boost::filesystem is commonly used in BMC
#include "boost/filesystem/operations.hpp"  // NOLINT
#include "boost/system/detail/error_code.hpp"  // NOLINT: boost::asio is commonly used in BMC
#include "tlbmc/http/http_client_interface.h"

namespace milotic_tlbmc {

// A simple HTTP/HTTPS client for TLBMC. Only allows one active job at a time.
class HttpClient : public HttpClientInterface,
                   public std::enable_shared_from_this<HttpClient> {
 public:
  struct Options {
    std::string ca_cert_path;
    bool verify_hostname = true;
    bool verify_purpose = true;
    std::chrono::seconds resolve_timeout = std::chrono::seconds(10);
    std::chrono::seconds connect_timeout = std::chrono::seconds(10);
    std::chrono::seconds handshake_timeout = std::chrono::seconds(10);
    std::chrono::seconds read_write_timeout = std::chrono::seconds(10);
  };

  HttpClient(boost::asio::io_context& io_context, const Options& options);
  ~HttpClient() override = default;

  bool IsActive() override;
  void SendRequest(
      std::string_view host, std::string_view port, std::string_view target,
      bool use_tls,
      absl::AnyInvocable<
          void(boost::beast::error_code,
               boost::beast::http::response<boost::beast::http::string_body>)>
          callback) override;

  // Downloads the file from the given host, port, target, use_tls to the
  // destination_path. If progress_callback is provided, it will be called
  // with the number of bytes downloaded and the total content length.
  // If callback is provided, it will be called with the error code and the
  // response.
  // TODO(nanzhou): today this does a big read and small writes. This can be
  // optimized to read and write in chunks.
  void DownloadFile(
      std::string_view host, std::string_view port, std::string_view target,
      bool use_tls, std::string_view destination_path,
      absl::AnyInvocable<
          void(boost::beast::error_code,
               boost::beast::http::response<boost::beast::http::empty_body>)>
          callback,
      absl::AnyInvocable<void(std::size_t bytes_downloaded,
                              std::size_t bytes_written,
                              std::size_t content_length)>
          progress_callback) override;

  void OnResolve(boost::beast::error_code ec,
                 boost::asio::ip::tcp::resolver::results_type results) override;
  void OnConnect(boost::beast::error_code ec,
                 boost::asio::ip::tcp::resolver::results_type::endpoint_type
                     endpoint) override;
  void OnHandshake(boost::beast::error_code ec);
  void OnWrite(boost::beast::error_code ec,
               std::size_t bytes_transferred) override;
  void OnRead(boost::beast::error_code ec,
              std::size_t bytes_transferred) override;

  static std::unique_ptr<HttpClient> CreateWithOption(
      boost::asio::io_context& io_context, const Options& options) {
    return std::make_unique<HttpClient>(io_context, options);
  }

  static std::unique_ptr<HttpClient> Create(
      boost::asio::io_context& io_context) {
    return std::make_unique<HttpClient>(io_context, Options());
  }

 protected:
  void InitStream();
  boost::asio::strand<boost::asio::io_context::executor_type> executor_;
  // Networking objects
  boost::asio::ip::tcp::resolver resolver_;
  boost::asio::ssl::context ssl_ctx_;
  std::unique_ptr<boost::beast::ssl_stream<boost::beast::tcp_stream>> stream_;
  boost::beast::flat_buffer buffer_;

  std::string host_;
  std::string port_;
  bool use_tls_ = false;

  std::atomic<bool> is_active_ = false;
  bool connection_established_ = false;
  std::shared_ptr<ScanJob> job_;

  boost::system::error_code ca_load_ec_;
  Options options_;
};
}  // namespace milotic_tlbmc

#endif  // THIRD_PARTY_MILOTIC_EXTERNAL_CC_TLBMC_HTTP_HTTP_CLIENT_H_