/* An actor that computes a specified math function of the input.

 Copyright (c) 1998-2014 The Regents of the University of California.
 All rights reserved.
 Permission is hereby granted, without written agreement and without
 license or royalty fees, to use, copy, modify, and distribute this
 software and its documentation for any purpose, provided that the above
 copyright notice and the following two paragraphs appear in all copies
 of this software.

 IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY
 FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
 ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF
 THE UNIVERSITY OF CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF
 SUCH DAMAGE.

 THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY WARRANTIES,
 INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE
 PROVIDED HEREUNDER IS ON AN "AS IS" BASIS, AND THE UNIVERSITY OF
 CALIFORNIA HAS NO OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES,
 ENHANCEMENTS, OR MODIFICATIONS.

 PT_COPYRIGHT_VERSION_2
 COPYRIGHTENDKEY

 */
package ptolemy.actor.lib;

import ptolemy.actor.TypedAtomicActor;
import ptolemy.actor.TypedIOPort;
import ptolemy.data.DoubleToken;
import ptolemy.data.ScalarToken;
import ptolemy.data.Token;
import ptolemy.data.expr.StringParameter;
import ptolemy.data.type.BaseType;
import ptolemy.kernel.CompositeEntity;
import ptolemy.kernel.util.Attribute;
import ptolemy.kernel.util.IllegalActionException;
import ptolemy.kernel.util.InternalErrorException;
import ptolemy.kernel.util.NameDuplicationException;
import ptolemy.kernel.util.Workspace;

// NOTE: If you update the list of functions, then you will want
// to update the list in actor/lib/math.xml.
///////////////////////////////////////////////////////////////////
//// MathFunction

/**
 Produce an output token on each firing with a value that is
 equal to the specified math function of the input.
 The input and output types are DoubleToken.  The functions
 are a subset of those in the java.lang.Math class.  They are:
 <ul>
 <li> <b>exp</b>: The exponential function.
 This is the default function for this actor
 If the argument is NaN, then the result is NaN.
 <li> <b>log</b>: The natural logarithm function.
 If the argument is NaN, then the result is NaN.
 <li> <b>modulo</b>: The modulo after division.
 If the second operand is zero, then the result is NaN.
 <li> <b>sign</b>: If the argument is greater than 0, return 1.0, if
 it is less than 0, return -1.0, otherwise return 0.0.
 <li> <b>square</b>: The square function
 If the argument is NaN, then the result is NaN.
 <li> <b>sqrt</b>: The square root function.
 If the argument is NaN, then the result is NaN.
 </ul>
 <p>

 NOTES:
 <p>1. Some functions like exp, log, square, and sqrt act on a single
 operand only.  Other functions like modulo act on two operands.
 The actor acquires a second input when the function is changed to
 modulo, and loses the input when the function is changed back.
 <p>2. There is an alternative to using the MathFunction.modulo() method
 If you want to use the IEEE remainder standard, use the Remainder actor.

 @author C. Fong
 @version $Id$
 @since Ptolemy II 1.0
 @Pt.ProposedRating Yellow (chf)
 @Pt.AcceptedRating Yellow (janneck)
 @see AbsoluteValue
 @see Remainder
 @see Scale
 @see TrigFunction
 @deprecated This breaks the class mechanism.  Generally, it is
 awkward to have the ports of an actor depend on parameter values.
 Use UnaryMathFunction instead.
 */
@Deprecated
public class MathFunction extends TypedAtomicActor {
    /** Construct an actor with the given container and name.
     *  @param container The container.
     *  @param name The name of this actor.
     *  @exception IllegalActionException If the actor cannot be contained
     *   by the proposed container.
     *  @exception NameDuplicationException If the container already has an
     *   actor with this name.
     */
    public MathFunction(CompositeEntity container, String name)
            throws NameDuplicationException, IllegalActionException {
        super(container, name);

        // Parameters
        function = new StringParameter(this, "function");
        function.setExpression("exp");
        function.addChoice("exp");
        function.addChoice("log");
        function.addChoice("modulo");
        function.addChoice("sign");
        function.addChoice("square");
        function.addChoice("sqrt");
        _function = _EXP;

        // Ports
        // secondOperand port is not allocated in the constructor
        // instead it will allocated dynamically during run-time
        firstOperand = new TypedIOPort(this, "firstOperand");
        firstOperand.setInput(true);
        output = new TypedIOPort(this, "output");
        output.setOutput(true);
        firstOperand.setTypeEquals(BaseType.DOUBLE);
        output.setTypeEquals(BaseType.DOUBLE);

        _attachText("_iconDescription",
                "<svg>\n" + "<rect x=\"-30\" y=\"-15\" "
                        + "width=\"60\" height=\"30\" "
                        + "style=\"fill:white\"/>\n" + "</svg>\n");
    }

    ///////////////////////////////////////////////////////////////////
    ////                     ports and parameters                  ////

    /** The function to compute.  This is a string-valued attribute
     *  that defaults to "exp".
     */
    public StringParameter function;

    /** The port for the first operand.
     *  The port has type BaseType.DOUBLE
     */
    public TypedIOPort firstOperand = null;

    /** The port for the second operand, if it is needed.
     *  The port has type BaseType.DOUBLE
     */
    public TypedIOPort secondOperand = null;

    /** Output port.
     *  The port has type BaseType.DOUBLE
     */
    public TypedIOPort output = null;

    ///////////////////////////////////////////////////////////////////
    ////                         public methods                    ////

    /** Override the base class to determine which function is being
     *  specified.
     *  @param attribute The attribute that changed.
     *  @exception IllegalActionException If the function is not recognized.
     */
    @Override
    public void attributeChanged(Attribute attribute)
            throws IllegalActionException {
        try {
            if (attribute == function) {
                String functionName = function.stringValue();

                if (functionName.equals("exp")) {
                    _function = _EXP;

                    if (secondOperand != null) {
                        secondOperand.setContainer(null);
                    }
                } else if (functionName.equals("log")) {
                    _function = _LOG;

                    if (secondOperand != null) {
                        secondOperand.setContainer(null);
                    }
                } else if (functionName.equals("modulo")) {
                    _function = _MODULO;
                    _createSecondPort();
                } else if (functionName.equals("sign")) {
                    _function = _SIGN;

                    if (secondOperand != null) {
                        secondOperand.setContainer(null);
                    }
                } else if (functionName.equals("square")) {
                    _function = _SQUARE;

                    if (secondOperand != null) {
                        secondOperand.setContainer(null);
                    }
                } else if (functionName.equals("sqrt")) {
                    _function = _SQRT;

                    if (secondOperand != null) {
                        secondOperand.setContainer(null);
                    }
                } else {
                    throw new IllegalActionException(this,
                            "Unrecognized math function: " + functionName);
                }
            } else {
                super.attributeChanged(attribute);
            }
        } catch (NameDuplicationException nameDuplication) {
            throw new InternalErrorException(this, nameDuplication,
                    "Unexpected name duplication");
        }
    }

    /** Clone the actor into the specified workspace.
     *  @param workspace The workspace for the new object.
     *  @return A new actor.
     *  @exception CloneNotSupportedException If a derived class contains
     *   an attribute that cannot be cloned.
     */
    @Override
    public Object clone(Workspace workspace) throws CloneNotSupportedException {
        MathFunction newObject = (MathFunction) super.clone(workspace);

        newObject._resultArray = new DoubleToken[_resultArray.length];
        System.arraycopy(_resultArray, 0, newObject._resultArray, 0,
                _resultArray.length);
        return newObject;
    }

    /** Consume at most one input token from each input channel, and
     *  compute the specified math function of the input.
     *  If there is no input, then produce no output.
     *  @exception IllegalActionException If there is no director.
     */
    @Override
    public void fire() throws IllegalActionException {
        super.fire();
        if (firstOperand.hasToken(0)) {
            double input1 = ((DoubleToken) firstOperand.get(0)).doubleValue();
            double input2 = 1.0;

            if (_function == _MODULO) {
                if (secondOperand.hasToken(0)) {
                    input2 = ((DoubleToken) secondOperand.get(0)).doubleValue();
                }
            }

            output.send(0, new DoubleToken(_doFunction(input1, input2)));
        }
    }

    /** Invoke a specified number of iterations of this actor. Each
     *  iteration computes the math function specified by the
     *  <i>function</i> parameter on a single token. An invocation
     *  of this method therefore applies the function to <i>count</i>
     *  successive input tokens.
     *  <p>
     *  This method should be called instead of the usual prefire(),
     *  fire(), postfire() methods when this actor is used in a
     *  domain that supports vectorized actors.  This leads to more
     *  efficient execution.
     *  @param count The number of iterations to perform.
     *  @return COMPLETED if the actor was successfully iterated the
     *   specified number of times. Otherwise, return NOT_READY, and do
     *   not consume any input tokens.
     *  @exception IllegalActionException Not thrown in this base class
     */
    @Override
    public int iterate(int count) throws IllegalActionException {
        // Check whether we need to reallocate the output token array.
        Token[] inArray1;
        Token[] inArray2;

        if (count > _resultArray.length) {
            _resultArray = new DoubleToken[count];
        }

        if (firstOperand.hasToken(0, count)) {
            if (_function == _MODULO) {
                if (secondOperand.hasToken(0, count)) {
                    inArray1 = firstOperand.get(0, count);
                    inArray2 = secondOperand.get(0, count);

                    for (int i = 0; i < count; i++) {
                        double input1 = ((DoubleToken) inArray1[i])
                                .doubleValue();
                        double input2 = ((DoubleToken) inArray2[i])
                                .doubleValue();
                        _resultArray[i] = new DoubleToken(
                                _doFunction(input1, input2));
                    }

                    output.send(0, _resultArray, count);
                    return COMPLETED;
                } else {
                    return NOT_READY;
                }
            } else {
                inArray1 = firstOperand.get(0, count);

                for (int i = 0; i < count; i++) {
                    // Input could be an Integer, see test/auto/Differential.xml
                    double input1 = ((ScalarToken) inArray1[i]).doubleValue();
                    _resultArray[i] = new DoubleToken(_doFunction(input1, 0));
                }

                output.send(0, _resultArray, count);
                return COMPLETED;
            }
        } else {
            return NOT_READY;
        }

        // Note: constants COMPLETED and NOT_READY are defined in
        // ptolemy.actor.Executable
    }

    ///////////////////////////////////////////////////////////////////
    ////                         private methods                   ////

    /** Create the second port needed by modulo function
     */
    private void _createSecondPort()
            throws NameDuplicationException, IllegalActionException {
        // Go looking for the port in case somebody else created the port
        // already.  For example, this might
        // happen in shallow code generation.
        secondOperand = (TypedIOPort) getPort("secondOperand");

        if (secondOperand == null) {
            secondOperand = new TypedIOPort(this, "secondOperand", true, false);
        } else if (secondOperand.getContainer() == null) {
            secondOperand.setContainer(this);
        }

        secondOperand.setTypeEquals(BaseType.DOUBLE);
    }

    /** Calculate the function on the given argument.
     *  @param input1 The first input value.
     *  @param input2 The second input value.
     *  @return The result of applying the function.
     */
    private double _doFunction(double input1, double input2) {
        double result;

        switch (_function) {
        case _EXP:
            result = Math.exp(input1);
            break;

        case _LOG:
            result = Math.log(input1);
            break;

        case _MODULO:
            result = input1 % input2;
            break;

        case _SIGN:

            if (input1 > 0) {
                result = 1.0;
            } else if (input1 < 0) {
                result = -1.0;
            } else {
                result = 0.0;
            }

            break;

        case _SQUARE:
            result = input1 * input1;
            break;

        case _SQRT:
            result = Math.sqrt(input1);
            break;

        default:
            throw new InternalErrorException(
                    "Invalid value for _function private variable. "
                            + "MathFunction actor (" + getFullName() + ")"
                            + " on function type " + _function);
        }

        return result;
    }

    ///////////////////////////////////////////////////////////////////
    ////                         private variables                 ////
    private DoubleToken[] _resultArray = new DoubleToken[0];

    // An indicator for the function to compute.
    private int _function;

    // Constants used for more efficient execution.
    private static final int _EXP = 0;

    private static final int _LOG = 1;

    private static final int _MODULO = 2;

    private static final int _SIGN = 3;

    private static final int _SQUARE = 4;

    private static final int _SQRT = 5;
}