/*----------------------------------------------------------------------------*/
/* Copyright (c) 2019-2020 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 <functional>
#include <initializer_list>
#include <utility>

#include <wpi/ArrayRef.h>

#include "Trigger.h"

namespace frc2 {
class Command;
/**
 * A class used to bind command scheduling to button presses.  Can be composed
 * with other buttons with the operators in Trigger.
 *
 * @see Trigger
 */
class Button : public Trigger {
 public:
  /**
   * Create a new button that is pressed when the given condition is true.
   *
   * @param isActive Whether the button is pressed.
   */
  explicit Button(std::function<bool()> isPressed);

  /**
   * Create a new button that is pressed active (default constructor) - activity
   *  can be further determined by subclass code.
   */
  Button() = default;

  /**
   * Binds a command to start when the button is pressed.  Takes a
   * raw pointer, and so is non-owning; users are responsible for the lifespan
   * of the command.
   *
   * @param command The command to bind.
   * @param interruptible Whether the command should be interruptible.
   * @return The trigger, for chained calls.
   */
  Button WhenPressed(Command* command, bool interruptible = true);

  /**
   * Binds a command to start when the button is pressed.  Transfers
   * command ownership to the button scheduler, so the user does not have to
   * worry about lifespan - rvalue refs will be *moved*, lvalue refs will be
   * *copied.*
   *
   * @param command The command to bind.
   * @param interruptible Whether the command should be interruptible.
   * @return The trigger, for chained calls.
   */
  template <class T, typename = std::enable_if_t<std::is_base_of_v<
                         Command, std::remove_reference_t<T>>>>
  Button WhenPressed(T&& command, bool interruptible = true) {
    WhenActive(std::forward<T>(command), interruptible);
    return *this;
  }

  /**
   * Binds a runnable to execute when the button is pressed.
   *
   * @param toRun the runnable to execute.
   * @param requirements the required subsystems.
   */
  Button WhenPressed(std::function<void()> toRun,
                     std::initializer_list<Subsystem*> requirements);

  /**
   * Binds a runnable to execute when the button is pressed.
   *
   * @param toRun the runnable to execute.
   * @param requirements the required subsystems.
   */
  Button WhenPressed(std::function<void()> toRun,
                     wpi::ArrayRef<Subsystem*> requirements = {});

  /**
   * Binds a command to be started repeatedly while the button is pressed, and
   * cancelled when it is released.  Takes a raw pointer, and so is non-owning;
   * users are responsible for the lifespan of the command.
   *
   * @param command The command to bind.
   * @param interruptible Whether the command should be interruptible.
   * @return The button, for chained calls.
   */
  Button WhileHeld(Command* command, bool interruptible = true);

  /**
   * Binds a command to be started repeatedly while the button is pressed, and
   * cancelled when it is released.  Transfers command ownership to the button
   * scheduler, so the user does not have to worry about lifespan - rvalue refs
   * will be *moved*, lvalue refs will be *copied.*
   *
   * @param command The command to bind.
   * @param interruptible Whether the command should be interruptible.
   * @return The button, for chained calls.
   */
  template <class T, typename = std::enable_if_t<std::is_base_of_v<
                         Command, std::remove_reference_t<T>>>>
  Button WhileHeld(T&& command, bool interruptible = true) {
    WhileActiveContinous(std::forward<T>(command), interruptible);
    return *this;
  }

  /**
   * Binds a runnable to execute repeatedly while the button is pressed.
   *
   * @param toRun the runnable to execute.
   * @param requirements the required subsystems.
   */
  Button WhileHeld(std::function<void()> toRun,
                   std::initializer_list<Subsystem*> requirements);

  /**
   * Binds a runnable to execute repeatedly while the button is pressed.
   *
   * @param toRun the runnable to execute.
   * @param requirements the required subsystems.
   */
  Button WhileHeld(std::function<void()> toRun,
                   wpi::ArrayRef<Subsystem*> requirements = {});

  /**
   * Binds a command to be started when the button is pressed, and cancelled
   * when it is released.  Takes a raw pointer, and so is non-owning; users are
   * responsible for the lifespan of the command.
   *
   * @param command The command to bind.
   * @param interruptible Whether the command should be interruptible.
   * @return The button, for chained calls.
   */
  Button WhenHeld(Command* command, bool interruptible = true);

  /**
   * Binds a command to be started when the button is pressed, and cancelled
   * when it is released.  Transfers command ownership to the button scheduler,
   * so the user does not have to worry about lifespan - rvalue refs will be
   * *moved*, lvalue refs will be *copied.*
   *
   * @param command The command to bind.
   * @param interruptible Whether the command should be interruptible.
   * @return The button, for chained calls.
   */
  template <class T, typename = std::enable_if_t<std::is_base_of_v<
                         Command, std::remove_reference_t<T>>>>
  Button WhenHeld(T&& command, bool interruptible = true) {
    WhileActiveOnce(std::forward<T>(command), interruptible);
    return *this;
  }

  /**
   * Binds a command to start when the button is released.  Takes a
   * raw pointer, and so is non-owning; users are responsible for the lifespan
   * of the command.
   *
   * @param command The command to bind.
   * @param interruptible Whether the command should be interruptible.
   * @return The button, for chained calls.
   */
  Button WhenReleased(Command* command, bool interruptible = true);

  /**
   * Binds a command to start when the button is pressed.  Transfers
   * command ownership to the button scheduler, so the user does not have to
   * worry about lifespan - rvalue refs will be *moved*, lvalue refs will be
   * *copied.*
   *
   * @param command The command to bind.
   * @param interruptible Whether the command should be interruptible.
   * @return The button, for chained calls.
   */
  template <class T, typename = std::enable_if_t<std::is_base_of_v<
                         Command, std::remove_reference_t<T>>>>
  Button WhenReleased(T&& command, bool interruptible = true) {
    WhenInactive(std::forward<T>(command), interruptible);
    return *this;
  }

  /**
   * Binds a runnable to execute when the button is released.
   *
   * @param toRun the runnable to execute.
   * @param requirements the required subsystems.
   */
  Button WhenReleased(std::function<void()> toRun,
                      std::initializer_list<Subsystem*> requirements);

  /**
   * Binds a runnable to execute when the button is released.
   *
   * @param toRun the runnable to execute.
   * @param requirements the required subsystems.
   */
  Button WhenReleased(std::function<void()> toRun,
                      wpi::ArrayRef<Subsystem*> requirements = {});

  /**
   * Binds a command to start when the button is pressed, and be cancelled when
   * it is pressed again.  Takes a raw pointer, and so is non-owning; users are
   * responsible for the lifespan of the command.
   *
   * @param command The command to bind.
   * @param interruptible Whether the command should be interruptible.
   * @return The button, for chained calls.
   */
  Button ToggleWhenPressed(Command* command, bool interruptible = true);

  /**
   * Binds a command to start when the button is pressed, and be cancelled when
   * it is pessed again.  Transfers command ownership to the button scheduler,
   * so the user does not have to worry about lifespan - rvalue refs will be
   * *moved*, lvalue refs will be *copied.*
   *
   * @param command The command to bind.
   * @param interruptible Whether the command should be interruptible.
   * @return The button, for chained calls.
   */
  template <class T, typename = std::enable_if_t<std::is_base_of_v<
                         Command, std::remove_reference_t<T>>>>
  Button ToggleWhenPressed(T&& command, bool interruptible = true) {
    ToggleWhenActive(std::forward<T>(command), interruptible);
    return *this;
  }

  /**
   * Binds a command to be cancelled when the button is pressed.  Takes a
   * raw pointer, and so is non-owning; users are responsible for the lifespan
   *  and scheduling of the command.
   *
   * @param command The command to bind.
   * @return The button, for chained calls.
   */
  Button CancelWhenPressed(Command* command);
};
}  // namespace frc2
