/**
 * Copyright (c) FIRST 2008-2012. 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.
 *
 * Copyright (c) 2011-2012, 2015-2016 Luke Shumaker
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     * Neither the name of the FIRST nor the
 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY FIRST AND CONTRIBUTORS``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY NONINFRINGEMENT AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL FIRST OR CONTRIBUTORS BE LIABLE FOR
 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * @author Luke Shumaker <lukeshu@sbcglobal.net>
 */
package org.usfirst.frc.team4272.robotlib;

import edu.wpi.first.wpilibj.PIDOutput;
import edu.wpi.first.wpilibj.PIDSource;
import edu.wpi.first.wpilibj.SpeedController;
//import edu.wpi.first.wpilibj.PIDController;

/**
 * An enhanced variant of {@link edu.wpi.first.wpilibj.PIDController wpilibj PIDController}
 * (implements a PID Control Loop).
 *
 * It is enhanced from
 * {@link edu.wpi.first.wpilibj.PIDController wpilibj PIDController}
 * in that it that also:
 *
 * <ul>
 *  <li> implements SpeedController (and therefore PIDOutput)
 *  <li> has auto-enable/disable functionality to avoid "locking" the
 *       motor when the setpoint is 0.
 *
 * @author Luke Shumaker <lukeshu@sbcglobal.net>
 */
public class PIDController extends edu.wpi.first.wpilibj.PIDController implements SpeedController {
	private boolean NaNDisabled = false;
	private boolean inverted = false;
	public final PIDSource source;
	public final PIDOutput output;

	/**
	 * Allocate a PID object with the given constants for P, I, D, and F
	 *$
	 * @param Kp the proportional coefficient
	 * @param Ki the integral coefficient
	 * @param Kd the derivative coefficient
	 * @param Kf the feed forward term
	 * @param source The PIDSource object that is used to get values
	 * @param output The PIDOutput object that is set to the output percentage
	 * @param period the loop time for doing calculations. This particularly
	 *        effects calculations of the integral and differential terms. The
	 *        default is 50ms.
	 */
	public PIDController(double Kp, double Ki, double Kd, double Kf,
	                     PIDSource source, PIDOutput output,
	                     double period) {
		super(Kp, Ki, Kd, Kf, source, output, period);
		this.source = source;
		this.output = output;
	}

	/* Convenience constructors *******************************************/
	/* `Kf`, and `period` are optional */

	/**
	 * Convenience constructor with {@code Kf} defaulting to
	 * {@code 0.0}.
	 */
	public PIDController(double Kp, double Ki, double Kd,
	                     PIDSource source, PIDOutput output,
	                     double period) {
		this(Kp, Ki, Kd, 0.0, source, output, period);
	}

	/**
	 * Convenience constructor with {@code period} defaulting to
	 * {@link #kDefaultPeriod}.
	 */
	public PIDController(double Kp, double Ki, double Kd, double Kf,
	                     PIDSource source, PIDOutput output) {
		this(Kp, Ki, Kd, Kf, source, output, kDefaultPeriod);
	}

	/**
	 * Convenience constructor with {@code Kf} defaulting to
	 * {@code 0.0}, and {@code period} defaulting to
	 * {@link #kDefaultPeriod}.
	 */
	public PIDController(double Kp, double Ki, double Kd,
	                     PIDSource source, PIDOutput output) {
		this(Kp, Ki, Kd, 0.0, source, output, kDefaultPeriod);
	}

	/* Override to auto-disable if setpoint is NaN, and invert ************/

	/**
	 * {@inheritDoc}
	 */
	@Override
	public synchronized void setSetpoint(double setpoint) {
		if (Double.isNaN(setpoint)) {
			NaNDisabled = true;
			super.disable();
		} else {
			if (NaNDisabled && !isEnabled()) {
				enable();
			}
			super.setSetpoint((inverted ? -1 : 1) * setpoint);
		}
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	public synchronized void enable() {
		NaNDisabled = false;
		super.enable();
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	public synchronized void disable() {
		NaNDisabled = false;
		super.disable();
	}

	/* Implement PIDOutput (a parent of SpeedController) *******************/

	/**
	 * {@inheritDoc}
	 */
	@Override
	public void pidWrite(double output) {
		setSetpoint(output);
	}

	/* Implement SpeedController *******************************************/

	/**
	 * {@inheritDoc}
	 */
	@Override
	public void set(double output) {
		setSetpoint(output);
	}

	/**
	 * Don't use this; it is leaking up from
	 * {@link edu.wpi.first.wpilibj.CANJaguar CANJaguar} through
	 * {@link edu.wpi.first.wpilibj.SpeedController SpeedController}
	 *
	 * @param output
	 * @param syncGroup
	 *
	 * @deprecated Don't use this, it is leaking up from
	 *   {@link edu.wpi.first.wpilibj.CANJaguar CANJaguar}
	 */
	@Override
	public void set(double output, byte syncGroup) {
		set(output);
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	public void setInverted(boolean isInverted) {
		inverted = isInverted;
	}

	/**
	 * {@inheritDoc}
	 */
	@Override
	public boolean getInverted() {
		return inverted;
	}
}