#include "library/common/network/utility.h"

#include "source/common/api/os_sys_calls_impl.h"
#include "source/common/network/address_impl.h"

namespace Envoy {
namespace Network {
namespace Android {
namespace Utility {

#if defined(INCLUDE_ANDROID_IFADDRS)
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wold-style-cast"
namespace {
#include "third_party/android/ifaddrs-android.h"
}
#pragma clang diagnostic pop
#endif

/**
 */
void setAlternateGetifaddrs() {
#if defined(INCLUDE_ANDROID_IFADDRS)
  auto& os_syscalls = Api::OsSysCallsSingleton::get();
  if (!os_syscalls.supportsGetifaddrs()) {
    Api::AlternateGetifaddrs android_getifaddrs =
        [](Api::InterfaceAddressVector& interfaces) -> Api::SysCallIntResult {
      struct ifaddrs* ifaddr;
      struct ifaddrs* ifa;

      const int rc = getifaddrs(&ifaddr);
      if (rc == -1) {
        return {rc, errno};
      }

      for (ifa = ifaddr; ifa != nullptr; ifa = ifa->ifa_next) {
        if (ifa->ifa_addr == nullptr) {
          continue;
        }

        if (ifa->ifa_addr->sa_family == AF_INET || ifa->ifa_addr->sa_family == AF_INET6) {
          const sockaddr_storage* ss = reinterpret_cast<sockaddr_storage*>(ifa->ifa_addr);
          size_t ss_len =
              ifa->ifa_addr->sa_family == AF_INET ? sizeof(sockaddr_in) : sizeof(sockaddr_in6);
          StatusOr<Address::InstanceConstSharedPtr> address =
              Address::addressFromSockAddr(*ss, ss_len, ifa->ifa_addr->sa_family == AF_INET6);
          if (address.ok()) {
            interfaces.emplace_back(ifa->ifa_name, ifa->ifa_flags, *address);
          }
        }
      }

      if (ifaddr) {
        freeifaddrs(ifaddr);
      }

      return {rc, 0};
    };

    os_syscalls.setAlternateGetifaddrs(android_getifaddrs);
  } else {
    // FIXME: assert that this function is not called more than once?
  }
#endif
}

} // namespace Utility
} // namespace Android
} // namespace Network
} // namespace Envoy