/* A new type of token

 Copyright (c) 1997-2014 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.data.type.test;

import ptolemy.data.BooleanToken;
import ptolemy.data.Token;
import ptolemy.data.type.Type;
import ptolemy.kernel.util.IllegalActionException;

///////////////////////////////////////////////////////////////////
//// TestToken

/**

 This is a new type of token.  It is used to test the TypeLattice to
 ensure that unspecified token types are allowed, and simply made incomparable
 to everything else.

 @author Steve Neuendorffer
 @version $Id: TestToken.java 69607 2014-07-30 17:07:26Z cxh $
 @since Ptolemy II 2.0
 @Pt.ProposedRating Red (neuendor)
 @Pt.AcceptedRating Red (neuendor)

 */
public class TestToken extends Token {
    /** Construct a token to be used for testing that encapsulates an object.
     *  @param object The object to be encapsulated
     */
    public TestToken(Object object) {
        super();
        _object = object;
    }

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

    /** Return the object contained by this token.
     *  @return The object.
     */
    public Object getObject() {
        return _object;
    }

    /** Return the type of this token.
     *  @return {@link #TYPE}, the type of this token.
     */
    @Override
    public Type getType() {
        return TYPE;
    }

    /** Test for equality of the values of this Token and the argument Token.
     *  It should be overridden in derived classes to provide type specific
     *  actions for equality testing.
     *  @param token The token with which to test equality.
     *  @exception IllegalActionException If this method is not
     *   supported by the derived class.
     *  @return A BooleanToken which contains the result of the test.
     */
    @Override
    public BooleanToken isEqualTo(Token token) throws IllegalActionException {
        if (token instanceof TestToken) {
            return new BooleanToken(this == token);
        } else {
            throw new IllegalActionException(
                    "Equality test not supported between "
                            + this.getClass().getName() + " and "
                            + token.getClass().getName() + ".");
        }
    }

    /** Return the value of this token as a string that can be parsed
     *  by the expression language to recover a token with the same value.
     *  This method should be overridden by derived classes.
     *  In this base class, return the String "present" to indicate
     *  that an event is present.
     *  @return The String "present".
     */
    @Override
    public String toString() {
        return "TestToken(" + _object + ")";
    }

    /** The class of this token.
     */
    public static class TestType implements Type, Cloneable {
        ///////////////////////////////////////////////////////////////////
        ////                         public methods                    ////

        /** Return a new type which represents the type that results from
         *  adding a token of this type and a token of the given argument
         *  type.
         *  @param rightArgumentType The type to add to this type.
         *  @return A new type, or BaseType.GENERAL, if the operation does
         *  not make sense for the given types.
         */
        @Override
        public Type add(Type rightArgumentType) {
            return this;
        }

        /** Return this, that is, return the reference to this object.
         *  @return A TestType
         *  @exception CloneNotSupportedException Not thrown in this baseclass
         *  unless thrown by a parent class.
         */
        @Override
        public Object clone() throws CloneNotSupportedException {
            super.clone();
            return this;
        }

        /** Convert the specified token to a token having the type
         *  represented by this object.
         *  @param token A token.
         *  @return A token.
         *  @exception IllegalActionException If lossless conversion cannot
         *   be done.
         */
        @Override
        public Token convert(Token token) throws IllegalActionException {
            if (token instanceof TestToken) {
                return token;
            } else {
                throw new IllegalActionException("Attempt to convert token "
                        + token + " into a test token, which is not possible.");
            }
        }

        /** Return a new type which represents the type that results from
         *  dividing a token of this type and a token of the given
         *  argument type.
         *  @param rightArgumentType The type to add to this type.
         *  @return A new type, or BaseType.GENERAL, if the operation does
         *  not make sense for the given types.
         */
        @Override
        public Type divide(Type rightArgumentType) {
            return this;
        }

        /** Return the class for tokens that this basetype represents.
         *  @return The class.
         */
        @Override
        public Class getTokenClass() {
            return TestToken.class;
        }

        /** Return true if this type does not correspond to a single token
         *  class.  This occurs if the type is not instantiable, or it
         *  represents either an abstract base class or an interface.
         *  @return Always return false, this token is instantiable.
         */
        @Override
        public boolean isAbstract() {
            return false;
        }

        /** Test if the argument type is compatible with this type.
         *  The method returns true if this type is UNKNOWN, since any type
         *  is a substitution instance of it. If this type is not UNKNOWN,
         *  this method returns true if the argument type is less than or
         *  equal to this type in the type lattice, and false otherwise.
         *  @param type An instance of Type.
         *  @return True if the argument type is compatible with this type.
         */
        @Override
        public boolean isCompatible(Type type) {
            return type == this;
        }

        /** Test if this Type is UNKNOWN.
         *  @return True if this Type is not UNKNOWN; false otherwise.
         */
        @Override
        public boolean isConstant() {
            return true;
        }

        /** Return this type's node index in the (constant) type lattice.
         * @return this type's node index in the (constant) type lattice.
         */
        @Override
        public int getTypeHash() {
            return Type.HASH_INVALID;
        }

        /** Determine if this type corresponds to an instantiable token
         *  classes. A BaseType is instantiable if it does not correspond
         *  to an abstract token class, or an interface, or UNKNOWN.
         *  @return True if this type is instantiable.
         */
        @Override
        public boolean isInstantiable() {
            return true;
        }

        /** Return true if the argument is a
         *  substitution instance of this type.
         *  @param type A Type.
         *  @return True if this type is UNKNOWN; false otherwise.
         */
        @Override
        public boolean isSubstitutionInstance(Type type) {
            return this == type;
        }

        /** Return a new type which represents the type that results from
         *  moduloing a token of this type and a token of the given
         *  argument type.
         *  @param rightArgumentType The type to add to this type.
         *  @return A new type, or BaseType.GENERAL, if the operation does
         *  not make sense for the given types.
         */
        @Override
        public Type modulo(Type rightArgumentType) {
            return this;
        }

        /** Return a new type which represents the type that results from
         *  multiplying a token of this type and a token of the given
         *  argument type.
         *  @param rightArgumentType The type to add to this type.
         *  @return A new type, or BaseType.GENERAL, if the operation does
         *  not make sense for the given types.
         */
        @Override
        public Type multiply(Type rightArgumentType) {
            return this;
        }

        /** Return the type of the multiplicative identity for elements of
         *  this type.
         *  @return A new type, or BaseType.GENERAL, if the operation does
         *  not make sense for the given types.
         */
        @Override
        public Type one() {
            return this;
        }

        /** Return a new type which represents the type that results from
         *  subtracting a token of this type and a token of the given
         *  argument type.
         *  @param rightArgumentType The type to add to this type.
         *  @return A new type, or BaseType.GENERAL, if the operation does
         *  not make sense for the given types.
         */
        @Override
        public Type subtract(Type rightArgumentType) {
            return this;
        }

        /** Return the string representation of this type.
         *  @return A String.
         */
        @Override
        public String toString() {
            return "test";
        }

        /** Return the type of the additive identity for elements of
         *  this type.
         *  @return A new type, or BaseType.GENERAL, if the operation does
         *  not make sense for the given types.
         */
        @Override
        public Type zero() {
            return this;
        }
    }

    /** The type of this token. */
    public static final Type TYPE = new TestType();

    ///////////////////////////////////////////////////////////////////
    ////                         private variables                 ////
    private Object _object;
}