/*

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package javax.management.openmbean;

// java import

//

import java.util.ArrayList;

import java.util.Collections;

import java.util.Iterator;

import java.util.List;

// jmx import

//

/**

 * The <code>TabularType</code> class is the <i> open type</i> class

 * whose instances describe the types of {@link TabularData TabularData} values.

 *

 * @since 1.5

 */

public class TabularType extends OpenType<TabularData> {

    /* Serial version */

    static final long serialVersionUID = 6554071860220659261L;

    /**

     * @serial The composite type of rows

     */

    private CompositeType  rowType;

    /**

     * @serial The items used to index each row element, kept in the order the user gave

     *         This is an unmodifiable {@link ArrayList}

     */

    private List<String> indexNames;

    private transient Integer myHashCode = null; // As this instance is immutable, these two values

    private transient String  myToString = null; // need only be calculated once.

    /* *** Constructor *** */

    /**

     * Constructs a <code>TabularType</code> instance, checking for the validity of the given parameters.

     * The validity constraints are described below for each parameter.

     * <p>

     * The Java class name of tabular data values this tabular type represents

     * (ie the class name returned by the {@link OpenType#getClassName() getClassName} method)

     * is set to the string value returned by <code>TabularData.class.getName()</code>.

     *

     * @param  typeName  The name given to the tabular type this instance represents; cannot be a null or empty string.

     * <br>&nbsp;

     * @param  description  The human readable description of the tabular type this instance represents;

     *                      cannot be a null or empty string.

     * <br>&nbsp;

     * @param  rowType  The type of the row elements of tabular data values described by this tabular type instance;

     *                  cannot be null.

     * <br>&nbsp;

     * @param  indexNames  The names of the items the values of which are used to uniquely index each row element in the

     *                     tabular data values described by this tabular type instance;

     *                     cannot be null or empty. Each element should be an item name defined in <var>rowType</var>

     *                     (no null or empty string allowed).

     *                     It is important to note that the <b>order</b> of the item names in <var>indexNames</var>

     *                     is used by the methods {@link TabularData#get(java.lang.Object[]) get} and

     *                     {@link TabularData#remove(java.lang.Object[]) remove} of class

     *                     <code>TabularData</code> to match their array of values parameter to items.

     * <br>&nbsp;

     * @throws IllegalArgumentException  if <var>rowType</var> is null,

     *                                   or <var>indexNames</var> is a null or empty array,

     *                                   or an element in <var>indexNames</var> is a null or empty string,

     *                                   or <var>typeName</var> or <var>description</var> is a null or empty string.

     * <br>&nbsp;

     * @throws OpenDataException  if an element's value of <var>indexNames</var>

     *                            is not an item name defined in <var>rowType</var>.

     */

    public TabularType(String         typeName,

                       String         description,

                       CompositeType  rowType,

                       String[]       indexNames) throws OpenDataException {

        // Check and initialize state defined by parent.

        //

        super(TabularData.class.getName(), typeName, description, false);

        // Check rowType is not null

        //

        if (rowType == null) {

            throw new IllegalArgumentException("Argument rowType cannot be null.");

        }

        // Check indexNames is neither null nor empty and does not contain any null element or empty string

        //

        checkForNullElement(indexNames, "indexNames");

        checkForEmptyString(indexNames, "indexNames");

        // Check all indexNames values are valid item names for rowType

        //

        for (int i=0; i<indexNames.length; i++) {

            if ( ! rowType.containsKey(indexNames[i]) ) {

                throw new OpenDataException("Argument's element value indexNames["+ i +"]=\""+ indexNames[i] +

                                            "\" is not a valid item name for rowType.");

            }

        }

        // initialize rowType

        //

        this.rowType    = rowType;

        // initialize indexNames (copy content so that subsequent

        // modifs to the array referenced by the indexNames parameter

        // have no impact)

        //

        List<String> tmpList = new ArrayList<String>(indexNames.length + 1);

        for (int i=0; i<indexNames.length; i++) {

            tmpList.add(indexNames[i]);

        }

        this.indexNames = Collections.unmodifiableList(tmpList);

    }

    /**

     * Checks that Object[] arg is neither null nor empty (ie length==0)

     * and that it does not contain any null element.

     */

    private static void checkForNullElement(Object[] arg, String argName) {

        if ( (arg == null) || (arg.length == 0) ) {

            throw new IllegalArgumentException("Argument "+ argName +"[] cannot be null or empty.");

        }

        for (int i=0; i<arg.length; i++) {

            if (arg[i] == null) {

                throw new IllegalArgumentException("Argument's element "+ argName +"["+ i +"] cannot be null.");

            }

        }

    }

    /**

     * Checks that String[] does not contain any empty (or blank characters only) string.

     */

    private static void checkForEmptyString(String[] arg, String argName) {

        for (int i=0; i<arg.length; i++) {

            if (arg[i].trim().isEmpty()) {

                throw new IllegalArgumentException("Argument's element "+ argName +"["+ i +"] cannot be an empty string.");

            }

        }

    }

    /* *** Tabular type specific information methods *** */

    /**

     * Returns the type of the row elements of tabular data values

     * described by this <code>TabularType</code> instance.

     *

     * @return the type of each row.

     */

    public CompositeType getRowType() {

        return rowType;

    }

    /**

     * <p>Returns, in the same order as was given to this instance's

     * constructor, an unmodifiable List of the names of the items the

     * values of which are used to uniquely index each row element of

     * tabular data values described by this <code>TabularType</code>

     * instance.</p>

     *

     * @return a List of String representing the names of the index

     * items.

     *

     */

    public List<String> getIndexNames() {

        return indexNames;

    }

    /**

     * Tests whether <var>obj</var> is a value which could be

     * described by this <code>TabularType</code> instance.

     *

     * <p>If <var>obj</var> is null or is not an instance of

     * <code>javax.management.openmbean.TabularData</code>,

     * <code>isValue</code> returns <code>false</code>.</p>

     *

     * <p>If <var>obj</var> is an instance of

     * <code>javax.management.openmbean.TabularData</code>, say {@code

     * td}, the result is true if this {@code TabularType} is

     * <em>assignable from</em> {@link TabularData#getTabularType()

     * td.getTabularType()}, as defined in {@link

     * CompositeType#isValue CompositeType.isValue}.</p>

     *

     * @param obj the value whose open type is to be tested for

     * compatibility with this <code>TabularType</code> instance.

     *

     * @return <code>true</code> if <var>obj</var> is a value for this

     * tabular type, <code>false</code> otherwise.

     */

    public boolean isValue(Object obj) {

        // if obj is null or not a TabularData, return false

        //

        if (!(obj instanceof TabularData))

            return false;

        // if obj is not a TabularData, return false

        //

        TabularData value = (TabularData) obj;

        TabularType valueType = value.getTabularType();

        return isAssignableFrom(valueType);

    }

    @Override

    boolean isAssignableFrom(OpenType<?> ot) {

        if (!(ot instanceof TabularType))

            return false;

        TabularType tt = (TabularType) ot;

        if (!getTypeName().equals(tt.getTypeName()) ||

                !getIndexNames().equals(tt.getIndexNames()))

            return false;

        return getRowType().isAssignableFrom(tt.getRowType());

    }

    /* *** Methods overriden from class Object *** */

    /**

     * Compares the specified <code>obj</code> parameter with this <code>TabularType</code> instance for equality.

     * <p>

     * Two <code>TabularType</code> instances are equal if and only if all of the following statements are true:

     * <ul>

     * <li>their type names are equal</li>

     * <li>their row types are equal</li>

     * <li>they use the same index names, in the same order</li>

     * </ul>

     * <br>&nbsp;

     * @param  obj  the object to be compared for equality with this <code>TabularType</code> instance;

     *              if <var>obj</var> is <code>null</code>, <code>equals</code> returns <code>false</code>.

     *

     * @return  <code>true</code> if the specified object is equal to this <code>TabularType</code> instance.

     */

    public boolean equals(Object obj) {

        // if obj is null, return false

        //

        if (obj == null) {

            return false;

        }

        // if obj is not a TabularType, return false

        //

        TabularType other;

        try {

            other = (TabularType) obj;

        } catch (ClassCastException e) {

            return false;

        }

        // Now, really test for equality between this TabularType instance and the other:

        //

        // their names should be equal

        if ( ! this.getTypeName().equals(other.getTypeName()) ) {

            return false;

        }

        // their row types should be equal

        if ( ! this.rowType.equals(other.rowType) ) {

            return false;

        }

        // their index names should be equal and in the same order (ensured by List.equals())

        if ( ! this.indexNames.equals(other.indexNames) ) {

            return false;

        }

        // All tests for equality were successfull

        //

        return true;

    }

    /**

     * Returns the hash code value for this <code>TabularType</code> instance.

     * <p>

     * The hash code of a <code>TabularType</code> instance is the sum of the hash codes

     * of all elements of information used in <code>equals</code> comparisons

     * (ie: name, row type, index names).

     * This ensures that <code> t1.equals(t2) </code> implies that <code> t1.hashCode()==t2.hashCode() </code>

     * for any two <code>TabularType</code> instances <code>t1</code> and <code>t2</code>,

     * as required by the general contract of the method

     * {@link Object#hashCode() Object.hashCode()}.

     * <p>

     * As <code>TabularType</code> instances are immutable, the hash code for this instance is calculated once,

     * on the first call to <code>hashCode</code>, and then the same value is returned for subsequent calls.

     *

     * @return  the hash code value for this <code>TabularType</code> instance

     */

    public int hashCode() {

        // Calculate the hash code value if it has not yet been done (ie 1st call to hashCode())

        //

        if (myHashCode == null) {

            int value = 0;

            value += this.getTypeName().hashCode();

            value += this.rowType.hashCode();

            for (String index : indexNames)

                value += index.hashCode();

            myHashCode = Integer.valueOf(value);

        }

        // return always the same hash code for this instance (immutable)

        //

        return myHashCode.intValue();

    }

    /**

     * Returns a string representation of this <code>TabularType</code> instance.

     * <p>

     * The string representation consists of the name of this class (ie <code>javax.management.openmbean.TabularType</code>),

     * the type name for this instance, the row type string representation of this instance,

     * and the index names of this instance.

     * <p>

     * As <code>TabularType</code> instances are immutable, the string representation for this instance is calculated once,

     * on the first call to <code>toString</code>, and then the same value is returned for subsequent calls.

     *

     * @return  a string representation of this <code>TabularType</code> instance

     */

    public String toString() {

        // Calculate the string representation if it has not yet been done (ie 1st call to toString())

        //

        if (myToString == null) {

            final StringBuilder result = new StringBuilder()

                .append(this.getClass().getName())

                .append("(name=")

                .append(getTypeName())

                .append(",rowType=")

                .append(rowType.toString())

                .append(",indexNames=(");

            String sep = "";

            for (String index : indexNames) {

                result.append(sep).append(index);

                sep = ",";

            }

            result.append("))");

            myToString = result.toString();

        }

        // return always the same string representation for this instance (immutable)

        //

        return myToString;

    }

}