/*----------------------------------------------------------------------------*/
/* Copyright (c) 2008-2018 FIRST. All Rights Reserved.                        */
/* Open Source Software - may be modified and shared by FRC teams. The code   */
/* must be accompanied by the FIRST BSD license file in the root directory of */
/* the project.                                                               */
/*----------------------------------------------------------------------------*/

#include "DriverStation.h"

#include <chrono>

#include <HAL/HAL.h>
#include <HAL/Power.h>
#include <HAL/cpp/Log.h>
#include <networktables/NetworkTable.h>
#include <networktables/NetworkTableEntry.h>
#include <networktables/NetworkTableInstance.h>
#include <wpi/SmallString.h>
#include <wpi/StringRef.h>

#include "AnalogInput.h"
#include "MotorSafetyHelper.h"
#include "Timer.h"
#include "Utility.h"
#include "WPIErrors.h"

namespace frc {
struct MatchInfoData {
  std::string eventName;
  std::string gameSpecificMessage;
  int matchNumber = 0;
  int replayNumber = 0;
  DriverStation::MatchType matchType = DriverStation::MatchType::kNone;
};

class MatchDataSender {
 public:
  std::shared_ptr<nt::NetworkTable> table;
  nt::NetworkTableEntry typeMetadata;
  nt::NetworkTableEntry gameSpecificMessage;
  nt::NetworkTableEntry eventName;
  nt::NetworkTableEntry matchNumber;
  nt::NetworkTableEntry replayNumber;
  nt::NetworkTableEntry matchType;
  nt::NetworkTableEntry alliance;
  nt::NetworkTableEntry station;
  nt::NetworkTableEntry controlWord;

  MatchDataSender() {
    table = nt::NetworkTableInstance::GetDefault().GetTable("FMSInfo");
    typeMetadata = table->GetEntry(".type");
    typeMetadata.ForceSetString("FMSInfo");
    gameSpecificMessage = table->GetEntry("GameSpecificMessage");
    gameSpecificMessage.ForceSetString("");
    eventName = table->GetEntry("EventName");
    eventName.ForceSetString("");
    matchNumber = table->GetEntry("MatchNumber");
    matchNumber.ForceSetDouble(0);
    replayNumber = table->GetEntry("ReplayNumber");
    replayNumber.ForceSetDouble(0);
    matchType = table->GetEntry("MatchType");
    matchType.ForceSetDouble(0);
    alliance = table->GetEntry("IsRedAlliance");
    alliance.ForceSetBoolean(true);
    station = table->GetEntry("StationNumber");
    station.ForceSetDouble(1);
    controlWord = table->GetEntry("FMSControlData");
    controlWord.ForceSetDouble(0);
  }
};
}  // namespace frc

using namespace frc;

static constexpr double kJoystickUnpluggedMessageInterval = 1.0;

DriverStation::~DriverStation() {
  m_isRunning = false;
  // Trigger a DS mutex release in case there is no driver station running.
  HAL_ReleaseDSMutex();
  m_dsThread.join();
}

/**
 * Return a pointer to the singleton DriverStation.
 *
 * @return Pointer to the DS instance
 */
DriverStation& DriverStation::GetInstance() {
  static DriverStation instance;
  return instance;
}

/**
 * Report an error to the DriverStation messages window.
 *
 * The error is also printed to the program console.
 */
void DriverStation::ReportError(const wpi::Twine& error) {
  wpi::SmallString<128> temp;
  HAL_SendError(1, 1, 0, error.toNullTerminatedStringRef(temp).data(), "", "",
                1);
}

/**
 * Report a warning to the DriverStation messages window.
 *
 * The warning is also printed to the program console.
 */
void DriverStation::ReportWarning(const wpi::Twine& error) {
  wpi::SmallString<128> temp;
  HAL_SendError(0, 1, 0, error.toNullTerminatedStringRef(temp).data(), "", "",
                1);
}

/**
 * Report an error to the DriverStation messages window.
 *
 * The error is also printed to the program console.
 */
void DriverStation::ReportError(bool isError, int32_t code,
                                const wpi::Twine& error,
                                const wpi::Twine& location,
                                const wpi::Twine& stack) {
  wpi::SmallString<128> errorTemp;
  wpi::SmallString<128> locationTemp;
  wpi::SmallString<128> stackTemp;
  HAL_SendError(isError, code, 0,
                error.toNullTerminatedStringRef(errorTemp).data(),
                location.toNullTerminatedStringRef(locationTemp).data(),
                stack.toNullTerminatedStringRef(stackTemp).data(), 1);
}

/**
 * The state of one joystick button. Button indexes begin at 1.
 *
 * @param stick  The joystick to read.
 * @param button The button index, beginning at 1.
 * @return The state of the joystick button.
 */
bool DriverStation::GetStickButton(int stick, int button) {
  if (stick < 0 || stick >= kJoystickPorts) {
    wpi_setWPIError(BadJoystickIndex);
    return false;
  }
  if (button <= 0) {
    ReportJoystickUnpluggedError(
        "ERROR: Button indexes begin at 1 in WPILib for C++ and Java");
    return false;
  }

  std::unique_lock<wpi::mutex> lock(m_cacheDataMutex);
  if (button > m_joystickButtons[stick].count) {
    // Unlock early so error printing isn't locked.
    lock.unlock();
    ReportJoystickUnpluggedWarning(
        "Joystick Button missing, check if all controllers are plugged in");
    return false;
  }

  return m_joystickButtons[stick].buttons & 1 << (button - 1);
}

/**
 * Whether one joystick button was pressed since the last check. Button indexes
 * begin at 1.
 *
 * @param stick  The joystick to read.
 * @param button The button index, beginning at 1.
 * @return Whether the joystick button was pressed since the last check.
 */
bool DriverStation::GetStickButtonPressed(int stick, int button) {
  if (stick < 0 || stick >= kJoystickPorts) {
    wpi_setWPIError(BadJoystickIndex);
    return false;
  }
  if (button <= 0) {
    ReportJoystickUnpluggedError(
        "ERROR: Button indexes begin at 1 in WPILib for C++ and Java");
    return false;
  }

  std::unique_lock<wpi::mutex> lock(m_cacheDataMutex);
  if (button > m_joystickButtons[stick].count) {
    // Unlock early so error printing isn't locked.
    lock.unlock();
    ReportJoystickUnpluggedWarning(
        "Joystick Button missing, check if all controllers are plugged in");
    return false;
  }

  // If button was pressed, clear flag and return true
  if (m_joystickButtonsPressed[stick] & 1 << (button - 1)) {
    m_joystickButtonsPressed[stick] &= ~(1 << (button - 1));
    return true;
  } else {
    return false;
  }
}

/**
 * Whether one joystick button was released since the last check. Button indexes
 * begin at 1.
 *
 * @param stick  The joystick to read.
 * @param button The button index, beginning at 1.
 * @return Whether the joystick button was released since the last check.
 */
bool DriverStation::GetStickButtonReleased(int stick, int button) {
  if (stick < 0 || stick >= kJoystickPorts) {
    wpi_setWPIError(BadJoystickIndex);
    return false;
  }
  if (button == 0) {
    ReportJoystickUnpluggedError(
        "ERROR: Button indexes begin at 1 in WPILib for C++ and Java");
    return false;
  }

  std::unique_lock<wpi::mutex> lock(m_cacheDataMutex);
  if (button > m_joystickButtons[stick].count) {
    // Unlock early so error printing isn't locked.
    lock.unlock();
    ReportJoystickUnpluggedWarning(
        "Joystick Button missing, check if all controllers are plugged in");
    return false;
  }

  // If button was released, clear flag and return true
  if (m_joystickButtonsReleased[stick] & 1 << (button - 1)) {
    m_joystickButtonsReleased[stick] &= ~(1 << (button - 1));
    return true;
  } else {
    return false;
  }
}

/**
 * Get the value of the axis on a joystick.
 *
 * This depends on the mapping of the joystick connected to the specified port.
 *
 * @param stick The joystick to read.
 * @param axis  The analog axis value to read from the joystick.
 * @return The value of the axis on the joystick.
 */
double DriverStation::GetStickAxis(int stick, int axis) {
  if (stick < 0 || stick >= kJoystickPorts) {
    wpi_setWPIError(BadJoystickIndex);
    return 0.0;
  }
  if (axis >= HAL_kMaxJoystickAxes) {
    wpi_setWPIError(BadJoystickAxis);
    return 0.0;
  }

  std::unique_lock<wpi::mutex> lock(m_cacheDataMutex);
  if (axis >= m_joystickAxes[stick].count) {
    // Unlock early so error printing isn't locked.
    lock.unlock();
    ReportJoystickUnpluggedWarning(
        "Joystick Axis missing, check if all controllers are plugged in");
    return 0.0;
  }

  return m_joystickAxes[stick].axes[axis];
}

/**
 * Get the state of a POV on the joystick.
 *
 * @return the angle of the POV in degrees, or -1 if the POV is not pressed.
 */
int DriverStation::GetStickPOV(int stick, int pov) {
  if (stick < 0 || stick >= kJoystickPorts) {
    wpi_setWPIError(BadJoystickIndex);
    return -1;
  }
  if (pov >= HAL_kMaxJoystickPOVs) {
    wpi_setWPIError(BadJoystickAxis);
    return -1;
  }

  std::unique_lock<wpi::mutex> lock(m_cacheDataMutex);
  if (pov >= m_joystickPOVs[stick].count) {
    // Unlock early so error printing isn't locked.
    lock.unlock();
    ReportJoystickUnpluggedWarning(
        "Joystick POV missing, check if all controllers are plugged in");
    return -1;
  }

  return m_joystickPOVs[stick].povs[pov];
}

/**
 * The state of the buttons on the joystick.
 *
 * @param stick The joystick to read.
 * @return The state of the buttons on the joystick.
 */
int DriverStation::GetStickButtons(int stick) const {
  if (stick < 0 || stick >= kJoystickPorts) {
    wpi_setWPIError(BadJoystickIndex);
    return 0;
  }

  std::lock_guard<wpi::mutex> lock(m_cacheDataMutex);
  return m_joystickButtons[stick].buttons;
}

/**
 * Returns the number of axes on a given joystick port.
 *
 * @param stick The joystick port number
 * @return The number of axes on the indicated joystick
 */
int DriverStation::GetStickAxisCount(int stick) const {
  if (stick < 0 || stick >= kJoystickPorts) {
    wpi_setWPIError(BadJoystickIndex);
    return 0;
  }

  std::lock_guard<wpi::mutex> lock(m_cacheDataMutex);
  return m_joystickAxes[stick].count;
}

/**
 * Returns the number of POVs on a given joystick port.
 *
 * @param stick The joystick port number
 * @return The number of POVs on the indicated joystick
 */
int DriverStation::GetStickPOVCount(int stick) const {
  if (stick < 0 || stick >= kJoystickPorts) {
    wpi_setWPIError(BadJoystickIndex);
    return 0;
  }

  std::lock_guard<wpi::mutex> lock(m_cacheDataMutex);
  return m_joystickPOVs[stick].count;
}

/**
 * Returns the number of buttons on a given joystick port.
 *
 * @param stick The joystick port number
 * @return The number of buttons on the indicated joystick
 */
int DriverStation::GetStickButtonCount(int stick) const {
  if (stick < 0 || stick >= kJoystickPorts) {
    wpi_setWPIError(BadJoystickIndex);
    return 0;
  }

  std::lock_guard<wpi::mutex> lock(m_cacheDataMutex);
  return m_joystickButtons[stick].count;
}

/**
 * Returns a boolean indicating if the controller is an xbox controller.
 *
 * @param stick The joystick port number
 * @return A boolean that is true if the controller is an xbox controller.
 */
bool DriverStation::GetJoystickIsXbox(int stick) const {
  if (stick < 0 || stick >= kJoystickPorts) {
    wpi_setWPIError(BadJoystickIndex);
    return false;
  }

  std::lock_guard<wpi::mutex> lock(m_cacheDataMutex);
  return static_cast<bool>(m_joystickDescriptor[stick].isXbox);
}

/**
 * Returns the type of joystick at a given port.
 *
 * @param stick The joystick port number
 * @return The HID type of joystick at the given port
 */
int DriverStation::GetJoystickType(int stick) const {
  if (stick < 0 || stick >= kJoystickPorts) {
    wpi_setWPIError(BadJoystickIndex);
    return -1;
  }

  std::lock_guard<wpi::mutex> lock(m_cacheDataMutex);
  return static_cast<int>(m_joystickDescriptor[stick].type);
}

/**
 * Returns the name of the joystick at the given port.
 *
 * @param stick The joystick port number
 * @return The name of the joystick at the given port
 */
std::string DriverStation::GetJoystickName(int stick) const {
  if (stick < 0 || stick >= kJoystickPorts) {
    wpi_setWPIError(BadJoystickIndex);
  }

  std::lock_guard<wpi::mutex> lock(m_cacheDataMutex);
  return m_joystickDescriptor[stick].name;
}

/**
 * Returns the types of Axes on a given joystick port.
 *
 * @param stick The joystick port number and the target axis
 * @return What type of axis the axis is reporting to be
 */
int DriverStation::GetJoystickAxisType(int stick, int axis) const {
  if (stick < 0 || stick >= kJoystickPorts) {
    wpi_setWPIError(BadJoystickIndex);
    return -1;
  }

  std::lock_guard<wpi::mutex> lock(m_cacheDataMutex);
  return m_joystickDescriptor[stick].axisTypes[axis];
}

/**
 * Check if the DS has enabled the robot.
 *
 * @return True if the robot is enabled and the DS is connected
 */
bool DriverStation::IsEnabled() const {
  HAL_ControlWord controlWord;
  UpdateControlWord(false, controlWord);
  return controlWord.enabled && controlWord.dsAttached;
}

/**
 * Check if the robot is disabled.
 *
 * @return True if the robot is explicitly disabled or the DS is not connected
 */
bool DriverStation::IsDisabled() const {
  HAL_ControlWord controlWord;
  UpdateControlWord(false, controlWord);
  return !(controlWord.enabled && controlWord.dsAttached);
}

/**
 * Check if the DS is commanding autonomous mode.
 *
 * @return True if the robot is being commanded to be in autonomous mode
 */
bool DriverStation::IsAutonomous() const {
  HAL_ControlWord controlWord;
  UpdateControlWord(false, controlWord);
  return controlWord.autonomous;
}

/**
 * Check if the DS is commanding teleop mode.
 *
 * @return True if the robot is being commanded to be in teleop mode
 */
bool DriverStation::IsOperatorControl() const {
  HAL_ControlWord controlWord;
  UpdateControlWord(false, controlWord);
  return !(controlWord.autonomous || controlWord.test);
}

/**
 * Check if the DS is commanding test mode.
 *
 * @return True if the robot is being commanded to be in test mode
 */
bool DriverStation::IsTest() const {
  HAL_ControlWord controlWord;
  UpdateControlWord(false, controlWord);
  return controlWord.test;
}

/**
 * Check if the DS is attached.
 *
 * @return True if the DS is connected to the robot
 */
bool DriverStation::IsDSAttached() const {
  HAL_ControlWord controlWord;
  UpdateControlWord(false, controlWord);
  return controlWord.dsAttached;
}

/**
 * Has a new control packet from the driver station arrived since the last time
 * this function was called?
 *
 * Warning: If you call this function from more than one place at the same time,
 * you will not get the intended behavior.
 *
 * @return True if the control data has been updated since the last call.
 */
bool DriverStation::IsNewControlData() const { return HAL_IsNewControlData(); }

/**
 * Is the driver station attached to a Field Management System?
 *
 * @return True if the robot is competing on a field being controlled by a Field
 *         Management System
 */
bool DriverStation::IsFMSAttached() const {
  HAL_ControlWord controlWord;
  UpdateControlWord(false, controlWord);
  return controlWord.fmsAttached;
}

/**
 * Check if the FPGA outputs are enabled.
 *
 * The outputs may be disabled if the robot is disabled or e-stopped, the
 * watchdog has expired, or if the roboRIO browns out.
 *
 * @return True if the FPGA outputs are enabled.
 * @deprecated Use RobotController static class method
 */
bool DriverStation::IsSysActive() const {
  int32_t status = 0;
  bool retVal = HAL_GetSystemActive(&status);
  wpi_setErrorWithContext(status, HAL_GetErrorMessage(status));
  return retVal;
}

/**
 * Check if the system is browned out.
 *
 * @return True if the system is browned out
 * @deprecated Use RobotController static class method
 */
bool DriverStation::IsBrownedOut() const {
  int32_t status = 0;
  bool retVal = HAL_GetBrownedOut(&status);
  wpi_setErrorWithContext(status, HAL_GetErrorMessage(status));
  return retVal;
}

std::string DriverStation::GetGameSpecificMessage() const {
  std::lock_guard<wpi::mutex> lock(m_cacheDataMutex);
  return m_matchInfo->gameSpecificMessage;
}

std::string DriverStation::GetEventName() const {
  std::lock_guard<wpi::mutex> lock(m_cacheDataMutex);
  return m_matchInfo->eventName;
}

DriverStation::MatchType DriverStation::GetMatchType() const {
  std::lock_guard<wpi::mutex> lock(m_cacheDataMutex);
  return m_matchInfo->matchType;
}

int DriverStation::GetMatchNumber() const {
  std::lock_guard<wpi::mutex> lock(m_cacheDataMutex);
  return m_matchInfo->matchNumber;
}

int DriverStation::GetReplayNumber() const {
  std::lock_guard<wpi::mutex> lock(m_cacheDataMutex);
  return m_matchInfo->replayNumber;
}

/**
 * Return the alliance that the driver station says it is on.
 *
 * This could return kRed or kBlue.
 *
 * @return The Alliance enum (kRed, kBlue or kInvalid)
 */
DriverStation::Alliance DriverStation::GetAlliance() const {
  int32_t status = 0;
  auto allianceStationID = HAL_GetAllianceStation(&status);
  switch (allianceStationID) {
    case HAL_AllianceStationID_kRed1:
    case HAL_AllianceStationID_kRed2:
    case HAL_AllianceStationID_kRed3:
      return kRed;
    case HAL_AllianceStationID_kBlue1:
    case HAL_AllianceStationID_kBlue2:
    case HAL_AllianceStationID_kBlue3:
      return kBlue;
    default:
      return kInvalid;
  }
}

/**
 * Return the driver station location on the field.
 *
 * This could return 1, 2, or 3.
 *
 * @return The location of the driver station (1-3, 0 for invalid)
 */
int DriverStation::GetLocation() const {
  int32_t status = 0;
  auto allianceStationID = HAL_GetAllianceStation(&status);
  switch (allianceStationID) {
    case HAL_AllianceStationID_kRed1:
    case HAL_AllianceStationID_kBlue1:
      return 1;
    case HAL_AllianceStationID_kRed2:
    case HAL_AllianceStationID_kBlue2:
      return 2;
    case HAL_AllianceStationID_kRed3:
    case HAL_AllianceStationID_kBlue3:
      return 3;
    default:
      return 0;
  }
}

/**
 * Wait until a new packet comes from the driver station.
 *
 * This blocks on a semaphore, so the waiting is efficient.
 *
 * This is a good way to delay processing until there is new driver station data
 * to act on.
 */
void DriverStation::WaitForData() { WaitForData(0); }

/**
 * Wait until a new packet comes from the driver station, or wait for a timeout.
 *
 * If the timeout is less then or equal to 0, wait indefinitely.
 *
 * Timeout is in milliseconds
 *
 * This blocks on a semaphore, so the waiting is efficient.
 *
 * This is a good way to delay processing until there is new driver station data
 * to act on.
 *
 * @param timeout Timeout time in seconds
 *
 * @return true if new data, otherwise false
 */
bool DriverStation::WaitForData(double timeout) {
  auto timeoutTime =
      std::chrono::steady_clock::now() + std::chrono::duration<double>(timeout);

  std::unique_lock<wpi::mutex> lock(m_waitForDataMutex);
  int currentCount = m_waitForDataCounter;
  while (m_waitForDataCounter == currentCount) {
    if (timeout > 0) {
      auto timedOut = m_waitForDataCond.wait_until(lock, timeoutTime);
      if (timedOut == std::cv_status::timeout) {
        return false;
      }
    } else {
      m_waitForDataCond.wait(lock);
    }
  }
  return true;
}

/**
 * Return the approximate match time.
 *
 * The FMS does not send an official match time to the robots, but does send an
 * approximate match time.  The value will count down the time remaining in the
 * current period (auto or teleop).
 *
 * Warning: This is not an official time (so it cannot be used to dispute ref
 * calls or guarantee that a function will trigger before the match ends).
 *
 * The Practice Match function of the DS approximates the behaviour seen on the
 * field.
 *
 * @return Time remaining in current match period (auto or teleop)
 */
double DriverStation::GetMatchTime() const {
  int32_t status;
  return HAL_GetMatchTime(&status);
}

/**
 * Read the battery voltage.
 *
 * @return The battery voltage in Volts.
 */
double DriverStation::GetBatteryVoltage() const {
  int32_t status = 0;
  double voltage = HAL_GetVinVoltage(&status);
  wpi_setErrorWithContext(status, "getVinVoltage");

  return voltage;
}

void DriverStation::SendMatchData() {
  int32_t status = 0;
  HAL_AllianceStationID alliance = HAL_GetAllianceStation(&status);
  bool isRedAlliance = false;
  int stationNumber = 1;
  switch (alliance) {
    case HAL_AllianceStationID::HAL_AllianceStationID_kBlue1:
      isRedAlliance = false;
      stationNumber = 1;
      break;
    case HAL_AllianceStationID::HAL_AllianceStationID_kBlue2:
      isRedAlliance = false;
      stationNumber = 2;
      break;
    case HAL_AllianceStationID::HAL_AllianceStationID_kBlue3:
      isRedAlliance = false;
      stationNumber = 3;
      break;
    case HAL_AllianceStationID::HAL_AllianceStationID_kRed1:
      isRedAlliance = true;
      stationNumber = 1;
      break;
    case HAL_AllianceStationID::HAL_AllianceStationID_kRed2:
      isRedAlliance = true;
      stationNumber = 2;
      break;
    default:
      isRedAlliance = true;
      stationNumber = 3;
      break;
  }

  MatchInfoData tmpDataStore;
  {
    std::lock_guard<wpi::mutex> lock(m_cacheDataMutex);
    tmpDataStore = *m_matchInfo;
  }

  m_matchDataSender->alliance.SetBoolean(isRedAlliance);
  m_matchDataSender->station.SetDouble(stationNumber);
  m_matchDataSender->eventName.SetString(tmpDataStore.eventName);
  m_matchDataSender->gameSpecificMessage.SetString(
      tmpDataStore.gameSpecificMessage);
  m_matchDataSender->matchNumber.SetDouble(tmpDataStore.matchNumber);
  m_matchDataSender->replayNumber.SetDouble(tmpDataStore.replayNumber);
  m_matchDataSender->matchType.SetDouble(
      static_cast<int>(tmpDataStore.matchType));

  HAL_ControlWord ctlWord;
  {
    // Valid, as in other places we guarentee ctlWord >= int32
    std::lock_guard<wpi::mutex> lock(m_controlWordMutex);
    ctlWord = m_controlWordCache;
  }
  int32_t wordInt = 0;
  std::memcpy(&wordInt, &ctlWord, sizeof(wordInt));
  m_matchDataSender->controlWord.SetDouble(wordInt);
}

/**
 * Copy data from the DS task for the user.
 *
 * If no new data exists, it will just be returned, otherwise
 * the data will be copied from the DS polling loop.
 */
void DriverStation::GetData() {
  // Get the status of all of the joysticks, and save to the cache
  for (uint8_t stick = 0; stick < kJoystickPorts; stick++) {
    HAL_GetJoystickAxes(stick, &m_joystickAxesCache[stick]);
    HAL_GetJoystickPOVs(stick, &m_joystickPOVsCache[stick]);
    HAL_GetJoystickButtons(stick, &m_joystickButtonsCache[stick]);
    HAL_GetJoystickDescriptor(stick, &m_joystickDescriptorCache[stick]);
  }
  // Grab match specific data
  HAL_MatchInfo matchInfo;
  auto status = HAL_GetMatchInfo(&matchInfo);
  if (status == 0) {
    m_matchInfoCache->eventName = matchInfo.eventName;
    m_matchInfoCache->matchNumber = matchInfo.matchNumber;
    m_matchInfoCache->replayNumber = matchInfo.replayNumber;
    m_matchInfoCache->matchType =
        static_cast<DriverStation::MatchType>(matchInfo.matchType);
    m_matchInfoCache->gameSpecificMessage = matchInfo.gameSpecificMessage;
  }
  HAL_FreeMatchInfo(&matchInfo);

  // Force a control word update, to make sure the data is the newest.
  HAL_ControlWord controlWord;
  UpdateControlWord(true, controlWord);

  {
    // Obtain a write lock on the data, swap the cached data into the
    // main data arrays
    std::lock_guard<wpi::mutex> lock(m_cacheDataMutex);

    for (int32_t i = 0; i < kJoystickPorts; i++) {
      // If buttons weren't pressed and are now, set flags in m_buttonsPressed
      m_joystickButtonsPressed[i] |=
          ~m_joystickButtons[i].buttons & m_joystickButtonsCache[i].buttons;

      // If buttons were pressed and aren't now, set flags in m_buttonsReleased
      m_joystickButtonsReleased[i] |=
          m_joystickButtons[i].buttons & ~m_joystickButtonsCache[i].buttons;
    }

    m_joystickAxes.swap(m_joystickAxesCache);
    m_joystickPOVs.swap(m_joystickPOVsCache);
    m_joystickButtons.swap(m_joystickButtonsCache);
    m_joystickDescriptor.swap(m_joystickDescriptorCache);
    m_matchInfo.swap(m_matchInfoCache);
  }

  {
    std::lock_guard<wpi::mutex> waitLock(m_waitForDataMutex);
    // Nofify all threads
    m_waitForDataCounter++;
    m_waitForDataCond.notify_all();
  }

  SendMatchData();
}

/**
 * DriverStation constructor.
 *
 * This is only called once the first time GetInstance() is called
 */
DriverStation::DriverStation() {
  HAL_Initialize(500, 0);
  m_waitForDataCounter = 0;
  m_joystickAxes = std::make_unique<HAL_JoystickAxes[]>(kJoystickPorts);
  m_joystickPOVs = std::make_unique<HAL_JoystickPOVs[]>(kJoystickPorts);
  m_joystickButtons = std::make_unique<HAL_JoystickButtons[]>(kJoystickPorts);
  m_joystickDescriptor =
      std::make_unique<HAL_JoystickDescriptor[]>(kJoystickPorts);
  m_matchInfo = std::make_unique<MatchInfoData>();
  m_joystickAxesCache = std::make_unique<HAL_JoystickAxes[]>(kJoystickPorts);
  m_joystickPOVsCache = std::make_unique<HAL_JoystickPOVs[]>(kJoystickPorts);
  m_joystickButtonsCache =
      std::make_unique<HAL_JoystickButtons[]>(kJoystickPorts);
  m_joystickDescriptorCache =
      std::make_unique<HAL_JoystickDescriptor[]>(kJoystickPorts);
  m_matchInfoCache = std::make_unique<MatchInfoData>();

  m_matchDataSender = std::make_unique<MatchDataSender>();

  // All joysticks should default to having zero axes, povs and buttons, so
  // uninitialized memory doesn't get sent to speed controllers.
  for (unsigned int i = 0; i < kJoystickPorts; i++) {
    m_joystickAxes[i].count = 0;
    m_joystickPOVs[i].count = 0;
    m_joystickButtons[i].count = 0;
    m_joystickDescriptor[i].isXbox = 0;
    m_joystickDescriptor[i].type = -1;
    m_joystickDescriptor[i].name[0] = '\0';

    m_joystickAxesCache[i].count = 0;
    m_joystickPOVsCache[i].count = 0;
    m_joystickButtonsCache[i].count = 0;
    m_joystickDescriptorCache[i].isXbox = 0;
    m_joystickDescriptorCache[i].type = -1;
    m_joystickDescriptorCache[i].name[0] = '\0';

    m_joystickButtonsPressed[i] = 0;
    m_joystickButtonsReleased[i] = 0;
  }

  m_dsThread = std::thread(&DriverStation::Run, this);
}

/**
 * Reports errors related to unplugged joysticks
 * Throttles the errors so that they don't overwhelm the DS
 */
void DriverStation::ReportJoystickUnpluggedError(const wpi::Twine& message) {
  double currentTime = Timer::GetFPGATimestamp();
  if (currentTime > m_nextMessageTime) {
    ReportError(message);
    m_nextMessageTime = currentTime + kJoystickUnpluggedMessageInterval;
  }
}

/**
 * Reports errors related to unplugged joysticks.
 *
 * Throttles the errors so that they don't overwhelm the DS.
 */
void DriverStation::ReportJoystickUnpluggedWarning(const wpi::Twine& message) {
  double currentTime = Timer::GetFPGATimestamp();
  if (currentTime > m_nextMessageTime) {
    ReportWarning(message);
    m_nextMessageTime = currentTime + kJoystickUnpluggedMessageInterval;
  }
}

void DriverStation::Run() {
  m_isRunning = true;
  int safetyCounter = 0;
  while (m_isRunning) {
    HAL_WaitForDSData();
    GetData();

    if (IsDisabled()) safetyCounter = 0;

    if (++safetyCounter >= 4) {
      MotorSafetyHelper::CheckMotors();
      safetyCounter = 0;
    }
    if (m_userInDisabled) HAL_ObserveUserProgramDisabled();
    if (m_userInAutonomous) HAL_ObserveUserProgramAutonomous();
    if (m_userInTeleop) HAL_ObserveUserProgramTeleop();
    if (m_userInTest) HAL_ObserveUserProgramTest();
  }
}

/**
 * Gets ControlWord data from the cache. If 50ms has passed, or the force
 * parameter is set, the cached data is updated. Otherwise the data is just
 * copied from the cache.
 *
 * @param force True to force an update to the cache, otherwise update if 50ms
 *              have passed.
 * @param controlWord Structure to put the return control word data into.
 */
void DriverStation::UpdateControlWord(bool force,
                                      HAL_ControlWord& controlWord) const {
  auto now = std::chrono::steady_clock::now();
  std::lock_guard<wpi::mutex> lock(m_controlWordMutex);
  // Update every 50 ms or on force.
  if ((now - m_lastControlWordUpdate > std::chrono::milliseconds(50)) ||
      force) {
    HAL_GetControlWord(&m_controlWordCache);
    m_lastControlWordUpdate = now;
  }
  controlWord = m_controlWordCache;
}