#include "json_utils.h"
#include "node_internals.h"
#include "node_report.h"
#include "util-inl.h"

namespace node {
namespace report {

static constexpr auto null = JSONWriter::Null{};

// Utility function to format socket information.
static void ReportEndpoint(uv_handle_t* h,
                           struct sockaddr* addr,
                           const char* name,
                           JSONWriter* writer) {
  if (addr == nullptr) {
    writer->json_keyvalue(name, null);
    return;
  }

  uv_getnameinfo_t endpoint;
  char* host = nullptr;
  char hostbuf[INET6_ADDRSTRLEN];
  const int family = addr->sa_family;
  const int port = ntohs(family == AF_INET ?
                         reinterpret_cast<sockaddr_in*>(addr)->sin_port :
                         reinterpret_cast<sockaddr_in6*>(addr)->sin6_port);

  if (uv_getnameinfo(h->loop, &endpoint, nullptr, addr, NI_NUMERICSERV) == 0) {
    host = endpoint.host;
    DCHECK_EQ(port, std::stoi(endpoint.service));
  } else {
    const void* src = family == AF_INET ?
                      static_cast<void*>(
                        &(reinterpret_cast<sockaddr_in*>(addr)->sin_addr)) :
                      static_cast<void*>(
                        &(reinterpret_cast<sockaddr_in6*>(addr)->sin6_addr));
    if (uv_inet_ntop(family, src, hostbuf, sizeof(hostbuf)) == 0) {
      host = hostbuf;
    }
  }
  writer->json_objectstart(name);
  if (host != nullptr) {
    writer->json_keyvalue("host", host);
  }
  writer->json_keyvalue("port", port);
  writer->json_objectend();
}

// Utility function to format libuv socket information.
static void ReportEndpoints(uv_handle_t* h, JSONWriter* writer) {
  struct sockaddr_storage addr_storage;
  struct sockaddr* addr = reinterpret_cast<sockaddr*>(&addr_storage);
  uv_any_handle* handle = reinterpret_cast<uv_any_handle*>(h);
  int addr_size = sizeof(addr_storage);
  int rc = -1;

  switch (h->type) {
    case UV_UDP:
      rc = uv_udp_getsockname(&handle->udp, addr, &addr_size);
      break;
    case UV_TCP:
      rc = uv_tcp_getsockname(&handle->tcp, addr, &addr_size);
      break;
    default:
      break;
  }
  ReportEndpoint(h, rc == 0 ? addr : nullptr,  "localEndpoint", writer);

  switch (h->type) {
    case UV_UDP:
      rc = uv_udp_getpeername(&handle->udp, addr, &addr_size);
      break;
    case UV_TCP:
      rc = uv_tcp_getpeername(&handle->tcp, addr, &addr_size);
      break;
    default:
      break;
  }
  ReportEndpoint(h, rc == 0 ? addr : nullptr, "remoteEndpoint", writer);
}

// Utility function to format libuv pipe information.
static void ReportPipeEndpoints(uv_handle_t* h, JSONWriter* writer) {
  uv_any_handle* handle = reinterpret_cast<uv_any_handle*>(h);
  MallocedBuffer<char> buffer(0);
  size_t buffer_size = 0;
  int rc = -1;

  // First call to get required buffer size.
  rc = uv_pipe_getsockname(&handle->pipe, buffer.data, &buffer_size);
  if (rc == UV_ENOBUFS) {
    buffer = MallocedBuffer<char>(buffer_size);
    if (buffer.data != nullptr) {
      rc = uv_pipe_getsockname(&handle->pipe, buffer.data, &buffer_size);
    } else {
      buffer_size = 0;
    }
  }
  if (rc == 0 && buffer_size != 0 && buffer.data != nullptr) {
    writer->json_keyvalue("localEndpoint", buffer.data);
  } else {
    writer->json_keyvalue("localEndpoint", null);
  }

  // First call to get required buffer size.
  rc = uv_pipe_getpeername(&handle->pipe, buffer.data, &buffer_size);
  if (rc == UV_ENOBUFS) {
    buffer = MallocedBuffer<char>(buffer_size);
    if (buffer.data != nullptr) {
      rc = uv_pipe_getpeername(&handle->pipe, buffer.data, &buffer_size);
    }
  }
  if (rc == 0 && buffer_size != 0 && buffer.data != nullptr) {
    writer->json_keyvalue("remoteEndpoint", buffer.data);
  } else {
    writer->json_keyvalue("remoteEndpoint", null);
  }
}

// Utility function to format libuv path information.
static void ReportPath(uv_handle_t* h, JSONWriter* writer) {
  MallocedBuffer<char> buffer(0);
  int rc = -1;
  size_t size = 0;
  uv_any_handle* handle = reinterpret_cast<uv_any_handle*>(h);
  bool wrote_filename = false;
  // First call to get required buffer size.
  switch (h->type) {
    case UV_FS_EVENT:
      rc = uv_fs_event_getpath(&(handle->fs_event), buffer.data, &size);
      break;
    case UV_FS_POLL:
      rc = uv_fs_poll_getpath(&(handle->fs_poll), buffer.data, &size);
      break;
    default:
      break;
  }
  if (rc == UV_ENOBUFS) {
    buffer = MallocedBuffer<char>(size + 1);
    switch (h->type) {
      case UV_FS_EVENT:
        rc = uv_fs_event_getpath(&(handle->fs_event), buffer.data, &size);
        break;
      case UV_FS_POLL:
        rc = uv_fs_poll_getpath(&(handle->fs_poll), buffer.data, &size);
        break;
      default:
        break;
    }
    if (rc == 0) {
      // buffer is not null terminated.
      buffer.data[size] = '\0';
      writer->json_keyvalue("filename", buffer.data);
      wrote_filename = true;
    }
  }
  if (!wrote_filename) writer->json_keyvalue("filename", null);
}

// Utility function to walk libuv handles.
void WalkHandle(uv_handle_t* h, void* arg) {
  const char* type = uv_handle_type_name(h->type);
  JSONWriter* writer = static_cast<JSONWriter*>(arg);
  uv_any_handle* handle = reinterpret_cast<uv_any_handle*>(h);

  writer->json_start();
  writer->json_keyvalue("type", type);
  writer->json_keyvalue("is_active", static_cast<bool>(uv_is_active(h)));
  writer->json_keyvalue("is_referenced", static_cast<bool>(uv_has_ref(h)));
  writer->json_keyvalue("address",
                        ValueToHexString(reinterpret_cast<uint64_t>(h)));

  switch (h->type) {
    case UV_FS_EVENT:
    case UV_FS_POLL:
      ReportPath(h, writer);
      break;
    case UV_PROCESS:
      writer->json_keyvalue("pid", handle->process.pid);
      break;
    case UV_TCP:
    case UV_UDP:
      ReportEndpoints(h, writer);
      break;
    case UV_NAMED_PIPE:
      ReportPipeEndpoints(h, writer);
      break;
    case UV_TIMER: {
      uint64_t due = handle->timer.timeout;
      uint64_t now = uv_now(handle->timer.loop);
      writer->json_keyvalue("repeat", uv_timer_get_repeat(&handle->timer));
      writer->json_keyvalue("firesInMsFromNow",
                            static_cast<int64_t>(due - now));
      writer->json_keyvalue("expired", now >= due);
      break;
    }
    case UV_TTY: {
      int height, width, rc;
      rc = uv_tty_get_winsize(&(handle->tty), &width, &height);
      if (rc == 0) {
        writer->json_keyvalue("width", width);
        writer->json_keyvalue("height", height);
      }
      break;
    }
    case UV_SIGNAL:
      // SIGWINCH is used by libuv so always appears.
      // See http://docs.libuv.org/en/v1.x/signal.html
      writer->json_keyvalue("signum", handle->signal.signum);
      writer->json_keyvalue("signal", signo_string(handle->signal.signum));
      break;
    default:
      break;
  }

  if (h->type == UV_TCP || h->type == UV_UDP
#ifndef _WIN32
      || h->type == UV_NAMED_PIPE
#endif
  ) {
    // These *must* be 0 or libuv will set the buffer sizes to the non-zero
    // values they contain.
    int send_size = 0;
    int recv_size = 0;
    uv_send_buffer_size(h, &send_size);
    uv_recv_buffer_size(h, &recv_size);
    writer->json_keyvalue("sendBufferSize", send_size);
    writer->json_keyvalue("recvBufferSize", recv_size);
  }

#ifndef _WIN32
  if (h->type == UV_TCP || h->type == UV_NAMED_PIPE || h->type == UV_TTY ||
      h->type == UV_UDP || h->type == UV_POLL) {
    uv_os_fd_t fd_v;
    int rc = uv_fileno(h, &fd_v);

    if (rc == 0) {
      writer->json_keyvalue("fd", static_cast<int>(fd_v));
      switch (fd_v) {
        case STDIN_FILENO:
          writer->json_keyvalue("stdio", "stdin");
          break;
        case STDOUT_FILENO:
          writer->json_keyvalue("stdio", "stdout");
          break;
        case STDERR_FILENO:
          writer->json_keyvalue("stdio", "stderr");
          break;
        default:
          break;
      }
    }
  }
#endif

  if (h->type == UV_TCP || h->type == UV_NAMED_PIPE || h->type == UV_TTY) {
    writer->json_keyvalue("writeQueueSize", handle->stream.write_queue_size);
    writer->json_keyvalue("readable",
                          static_cast<bool>(uv_is_readable(&handle->stream)));
    writer->json_keyvalue("writable",
                          static_cast<bool>(uv_is_writable(&handle->stream)));
  }

  writer->json_end();
}

}  // namespace report
}  // namespace node