////////////////////////////////////////////////////////////////////////////////
// Copyright 2018 Google LLC.
//
// This software is licensed under the terms defined in the Widevine Master
// License Agreement. For a copy of this agreement, please contact
// widevine-licensing@google.com.
////////////////////////////////////////////////////////////////////////////////

// Example client for demonstrating network calls to public/simulcrypt_server.

#include <errno.h>
#include <netdb.h>
#include <netinet/in.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <unistd.h>

#include "gflags/gflags.h"
#include "glog/logging.h"

DEFINE_string(server, "", "Server host name");
DEFINE_int32(port, 0, "Server port number");

constexpr uint32_t kBufferSize = 256;

int main(int argc, char **argv) {
  gflags::ParseCommandLineFlags(&argc, &argv, true);
  CHECK(!FLAGS_server.empty()) << "need --server";
  CHECK(FLAGS_port != 0) << "need --port";

  struct hostent server;
  {
    int buflen = 1024;
    char buf[1024];
    struct hostent *result;
    int h_errnop;
    gethostbyname_r(/* __name= */ FLAGS_server.c_str(),
                    /* __result_buf= */ &server, /* __buf= */ buf,
                    /* __buflen= */ buflen,
                    /* __result= */ &result, /* __h_errnop= */ &h_errnop);
  }

  struct sockaddr_in server_addr;
  bzero(reinterpret_cast<char *>(&server_addr), sizeof(server_addr));
  server_addr.sin_family = AF_INET;
  // TODO(user): Consider using inet_pton() to populate server_addr.sin_addr.
  bcopy(server.h_addr, reinterpret_cast<char *>(&server_addr.sin_addr.s_addr),
        server.h_length);
  server_addr.sin_port = htons(FLAGS_port);

  int socket_fd = socket(AF_INET, SOCK_STREAM, /* protocol= */ 0);
  CHECK(socket_fd >= 0) << "failed to opening socket";
  CHECK(connect(socket_fd, (struct sockaddr *)&server_addr,
                sizeof(server_addr)) >= 0)
      << "failed to connect to socket";

  printf("Please enter the message: ");
  char buffer[kBufferSize];
  bzero(buffer, kBufferSize);
  fgets(buffer, kBufferSize - 1, stdin);
  int total_bytes_written = 0;
  while (total_bytes_written != strlen(buffer)) {
    int num_bytes_written = write(socket_fd, buffer, strlen(buffer));
    if (num_bytes_written < 0) {
      LOG(FATAL) << "ERROR writing to socket: " << strerror(errno);
    }
    total_bytes_written += num_bytes_written;
  }
  bzero(buffer, kBufferSize);
  if (read(socket_fd, buffer, kBufferSize - 1) < 0) {
    LOG(FATAL) << "ERROR reading from socket: " << strerror(errno);
  }
  printf("Read from buffer: %s\n", buffer);

  close(socket_fd);
  return 0;
}