/*----------------------------------------------------------------------------*/
/* 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.                                                               */
/*----------------------------------------------------------------------------*/

#pragma once

#include <memory>

#include <hal/Types.h>

#include "frc/AnalogTriggerOutput.h"
#include "frc/ErrorBase.h"
#include "frc/smartdashboard/SendableBase.h"

namespace frc {

class AnalogInput;

class AnalogTrigger : public ErrorBase, public SendableBase {
  friend class AnalogTriggerOutput;

 public:
  /**
   * Constructor for an analog trigger given a channel number.
   *
   * @param channel The channel number on the roboRIO to represent. 0-3 are
   *                on-board 4-7 are on the MXP port.
   */
  explicit AnalogTrigger(int channel);

  /**
   * Construct an analog trigger given an analog input.
   *
   * This should be used in the case of sharing an analog channel between the
   * trigger and an analog input object.
   *
   * @param channel The pointer to the existing AnalogInput object
   */
  explicit AnalogTrigger(AnalogInput* channel);

  ~AnalogTrigger() override;

  /**
   * Set the upper and lower limits of the analog trigger.
   *
   * The limits are given as floating point voltage values.
   *
   * @param lower The lower limit of the trigger in Volts.
   * @param upper The upper limit of the trigger in Volts.
   */
  void SetLimitsVoltage(double lower, double upper);

  /**
   * Set the upper and lower limits of the analog trigger.
   *
   * The limits are given in ADC codes.  If oversampling is used, the units must
   * be scaled appropriately.
   *
   * @param lower The lower limit of the trigger in ADC codes (12-bit values).
   * @param upper The upper limit of the trigger in ADC codes (12-bit values).
   */
  void SetLimitsRaw(int lower, int upper);

  /**
   * Configure the analog trigger to use the averaged vs. raw values.
   *
   * If the value is true, then the averaged value is selected for the analog
   * trigger, otherwise the immediate value is used.
   *
   * @param useAveragedValue If true, use the Averaged value, otherwise use the
   *                         instantaneous reading
   */
  void SetAveraged(bool useAveragedValue);

  /**
   * Configure the analog trigger to use a filtered value.
   *
   * The analog trigger will operate with a 3 point average rejection filter.
   * This is designed to help with 360 degree pot applications for the period
   * where the pot crosses through zero.
   *
   * @param useFilteredValue If true, use the 3 point rejection filter,
   *                         otherwise use the unfiltered value
   */
  void SetFiltered(bool useFilteredValue);

  /**
   * Return the index of the analog trigger.
   *
   * This is the FPGA index of this analog trigger instance.
   *
   * @return The index of the analog trigger.
   */
  int GetIndex() const;

  /**
   * Return the InWindow output of the analog trigger.
   *
   * True if the analog input is between the upper and lower limits.
   *
   * @return True if the analog input is between the upper and lower limits.
   */
  bool GetInWindow();

  /**
   * Return the TriggerState output of the analog trigger.
   *
   * True if above upper limit.
   * False if below lower limit.
   * If in Hysteresis, maintain previous state.
   *
   * @return True if above upper limit. False if below lower limit. If in
   *         Hysteresis, maintain previous state.
   */
  bool GetTriggerState();

  /**
   * Creates an AnalogTriggerOutput object.
   *
   * Gets an output object that can be used for routing. Caller is responsible
   * for deleting the AnalogTriggerOutput object.
   *
   * @param type An enum of the type of output object to create.
   * @return A pointer to a new AnalogTriggerOutput object.
   */
  std::shared_ptr<AnalogTriggerOutput> CreateOutput(
      AnalogTriggerType type) const;

  void InitSendable(SendableBuilder& builder) override;

 private:
  int m_index;
  HAL_AnalogTriggerHandle m_trigger;
  AnalogInput* m_analogInput = nullptr;
  bool m_ownsAnalog = false;
};

}  // namespace frc