/*
 * @(#)CompositeType.java	3.32 06/05/03
 * 
 * Copyright 2006 Sun Microsystems, Inc. All rights reserved.
 * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */


package javax.management.openmbean;


// java import
//
import java.util.Set;
import java.util.TreeMap;
import java.util.Collections;
import java.util.Iterator;

// jmx import
//


/**
 * The <code>CompositeType</code> class is the <i>open type</i> class 
 * whose instances describe the types of {@link CompositeData <code>CompositeData</code>} values.
 *
 * @version     3.32  06/05/03
 * @author      Sun Microsystems, Inc.
 *
 * @since 1.5
 * @since.unbundled JMX 1.1
 */
public class CompositeType extends OpenType<CompositeData> {

    /* Serial version */
    static final long serialVersionUID = -5366242454346948798L;

    /**
     * @serial Sorted mapping of the item names to their descriptions
     */
    private TreeMap<String,String> nameToDescription;
    
    /**
     * @serial Sorted mapping of the item names to their open types
     */
    private TreeMap<String,OpenType<?>> nameToType;	

    /* As this instance is immutable, following three values need only
     * be calculated once.  */
    private transient Integer myHashCode = null;
    private transient String  myToString = null;
    private transient Set<String> myNamesSet = null;


    /* *** Constructor *** */

    /**
     * Constructs a <code>CompositeType</code> instance, checking for the validity of the given parameters.
     * The validity constraints are described below for each parameter. 
     * <p>
     * Note that the contents of the three array parameters 
     * <var>itemNames</var>, <var>itemDescriptions</var> and <var>itemTypes</var>
     * are internally copied so that any subsequent modification of these arrays by the caller of this constructor
     * has no impact on the constructed <code>CompositeType</code> instance.
     * <p>
     * The Java class name of composite data values this composite type represents 
     * (ie the class name returned by the {@link OpenType#getClassName() getClassName} method) 
     * is set to the string value returned by <code>CompositeData.class.getName()</code>.
     * <p>
     * @param  typeName  The name given to the composite type this instance represents; cannot be a null or empty string.
     * <br>&nbsp;
     * @param  description  The human readable description of the composite type this instance represents; 
     *			    cannot be a null or empty string.
     * <br>&nbsp;
     * @param  itemNames  The names of the items contained in the 
     *			  composite data values described by this <code>CompositeType</code> instance; 
     *			  cannot be null and should contain at least one element; no element can be a null or empty string.
     *                    Note that the order in which the item names are given is not important to differentiate a
     *			  <code>CompositeType</code> instance from another;
     *			  the item names are internally stored sorted in ascending alphanumeric order.
     * <br>&nbsp;
     * @param  itemDescriptions  The descriptions, in the same order as <var>itemNames</var>, of the items contained in the 
     *			         composite data values described by this <code>CompositeType</code> instance; 
     *				 should be of the same size as <var>itemNames</var>;
     *				 no element can be a null or empty string.
     * <br>&nbsp;
     * @param  itemTypes  The open type instances, in the same order as <var>itemNames</var>, describing the items contained  
     *			  in the composite data values described by this <code>CompositeType</code> instance; 
     *			  should be of the same size as <var>itemNames</var>;
     *			  no element can be null.
     * <br>&nbsp;
     * @throws IllegalArgumentException  If <var>typeName</var> or <var>description</var> is a null or empty string,
     *					 or <var>itemNames</var> or <var>itemDescriptions</var> or <var>itemTypes</var> is null,
     *					 or any element of <var>itemNames</var> or <var>itemDescriptions</var> 
     *					 is a null or empty string,
     *					 or any element of <var>itemTypes</var> is null,
     *					 or <var>itemNames</var> or <var>itemDescriptions</var> or <var>itemTypes</var> 
     *					 are not of the same size.
     * <br>&nbsp;
     * @throws OpenDataException  If <var>itemNames</var> contains duplicate item names
     *				  (case sensitive, but leading and trailing whitespaces removed).
     */
    public CompositeType(String        typeName,
			 String        description, 
			 String[]      itemNames,
			 String[]      itemDescriptions,
			 OpenType<?>[] itemTypes) throws OpenDataException {

	// Check and construct state defined by parent
	//
	super(CompositeData.class.getName(), typeName, description, false);

	// Check the 3 arrays are not null or empty (ie length==0) and that there is no null element or empty string in them
	//
	checkForNullElement(itemNames, "itemNames");
	checkForNullElement(itemDescriptions, "itemDescriptions");
	checkForNullElement(itemTypes, "itemTypes");
	checkForEmptyString(itemNames, "itemNames");
	checkForEmptyString(itemDescriptions, "itemDescriptions");

	// Check the sizes of the 3 arrays are the same
	//
	if ( (itemNames.length != itemDescriptions.length) || (itemNames.length != itemTypes.length) ) {
	    throw new IllegalArgumentException("Array arguments itemNames[], itemDescriptions[] and itemTypes[] "+
					       "should be of same length (got "+ itemNames.length +", "+ 
					       itemDescriptions.length +" and "+ itemTypes.length +").");
	}
	
	// Initialize internal "names to descriptions" and "names to types" sorted maps,
	// and, by doing so, check there are no duplicate item names
	//
	nameToDescription = new TreeMap<String,String>();
	nameToType        = new TreeMap<String,OpenType<?>>();
	String key;
	for (int i=0; i<itemNames.length; i++) {
	    key = itemNames[i].trim();
	    if (nameToDescription.containsKey(key)) {
		throw new OpenDataException("Argument's element itemNames["+ i +"]=\""+ itemNames[i] +
					    "\" duplicates a previous item names.");
	    }	
	    nameToDescription.put(key, itemDescriptions[i].trim());
	    nameToType.put(key, itemTypes[i]);
	}
    }

    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.");
	    }
	}
    }

    private static void checkForEmptyString(String[] arg, String argName) {
	for (int i=0; i<arg.length; i++) {
	    if (arg[i].trim().equals("")) {
		throw new IllegalArgumentException("Argument's element "+ argName +"["+ i +"] cannot be an empty string.");
	    }
	}
    }

    /* *** Composite type specific information methods *** */

    /**
     * Returns <code>true</code> if this <code>CompositeType</code> instance defines an item
     * whose name is <var>itemName</var>.
     *
     * @param itemName the name of the item.
     *
     * @return true if an item of this name is present.
     */
    public boolean containsKey(String itemName) {

	if (itemName == null) {
	    return false;
	}
	return nameToDescription.containsKey(itemName);
    }

    /**
     * Returns the description of the item whose name is <var>itemName</var>, 
     * or <code>null</code> if this <code>CompositeType</code> instance does not define any item
     * whose name is <var>itemName</var>.
     *
     * @param itemName the name of the item.
     *
     * @return the description.
     */
    public String getDescription(String itemName) {

	if (itemName == null) {
	    return null;
	}
	return (String) nameToDescription.get(itemName);
    }

    /**
     * Returns the <i>open type</i> of the item whose name is <var>itemName</var>, 
     * or <code>null</code> if this <code>CompositeType</code> instance does not define any item
     * whose name is <var>itemName</var>.
     *
     * @param itemName the name of the time.
     *
     * @return the type.
     */
    public OpenType<?> getType(String itemName) {

	if (itemName == null) {
	    return null;
	}
	return (OpenType<?>) nameToType.get(itemName);
    }

    /**
     * Returns an unmodifiable Set view of all the item names defined by this <code>CompositeType</code> instance.
     * The set's iterator will return the item names in ascending order. 
     *
     * @return a {@link Set} of {@link String}.
     */
    public Set<String> keySet() {

	// Initializes myNamesSet on first call
	if (myNamesSet == null) {
	    myNamesSet = Collections.unmodifiableSet(nameToDescription.keySet());
	}

	return myNamesSet; // always return the same value
    }


    /**
     * Tests whether <var>obj</var> is a value which could be
     * described by this <code>CompositeType</code> instance.
     *
     * <p>If <var>obj</var> is null or is not an instance of
     * <code>javax.management.openmbean.CompositeData</code>,
     * <code>isValue</code> returns <code>false</code>.</p>
     *
     * <p>If <var>obj</var> is an instance of
     * <code>javax.management.openmbean.CompositeData</code>, then let
     * {@code ct} be its {@code CompositeType} as returned by {@link
     * CompositeData#getCompositeType()}.  The result is true if
     * {@code this} is <em>assignable from</em> {@code ct}.  This
     * means that:</p>
     *
     * <ul>
     * <li>{@link #getTypeName() this.getTypeName()} equals
     * {@code ct.getTypeName()}, and
     * <li>there are no item names present in {@code this} that are
     * not also present in {@code ct}, and
     * <li>for every item in {@code this}, its type is assignable from
     * the type of the corresponding item in {@code ct}.
     * </ul>
     *
     * <p>A {@code TabularType} is assignable from another {@code
     * TabularType} if they have the same {@linkplain
     * TabularType#getTypeName() typeName} and {@linkplain
     * TabularType#getIndexNames() index name list}, and the
     * {@linkplain TabularType#getRowType() row type} of the first is
     * assignable from the row type of the second.
     *
     * <p>An {@code ArrayType} is assignable from another {@code
     * ArrayType} if they have the same {@linkplain
     * ArrayType#getDimension() dimension}; and both are {@linkplain
     * ArrayType#isPrimitiveArray() primitive arrays} or neither is;
     * and the {@linkplain ArrayType#getElementOpenType() element
     * type} of the first is assignable from the element type of the
     * second.
     *
     * <p>In every other case, an {@code OpenType} is assignable from
     * another {@code OpenType} only if they are equal.</p>
     *
     * <p>These rules mean that extra items can be added to a {@code
     * CompositeData} without making it invalid for a {@code CompositeType}
     * that does not have those items.</p>
     *
     * @param  obj  the value whose open type is to be tested for compatibility
     * with this <code>CompositeType</code> instance.
     *
     * @return <code>true</code> if <var>obj</var> is a value for this
     * composite type, <code>false</code> otherwise.
     */
    public boolean isValue(Object obj) {

	// if obj is null or not CompositeData, return false
	//
	if (!(obj instanceof CompositeData)) {
	    return false;
	}

	// if obj is not a CompositeData, return false
	//
	CompositeData value = (CompositeData) obj;

	// test value's CompositeType is assignable to this CompositeType instance
	//
	CompositeType valueType = value.getCompositeType();
        return this.isAssignableFrom(valueType);
    }
    
    /**
     * Tests whether values of the given type can be assigned to this
     * open type.  The result is true if the given type is also a
     * CompositeType with the same name ({@link #getTypeName()}), and
     * every item in this type is also present in the given type with
     * the same name and assignable type.  There can be additional
     * items in the given type, which are ignored.
     *
     * @param ot the type to be tested.
     *
     * @return true if {@code ot} is assignable to this open type.
     */
@Override
    boolean isAssignableFrom(OpenType ot) {
        if (!(ot instanceof CompositeType))
            return false;
        CompositeType ct = (CompositeType) ot;
        if (!ct.getTypeName().equals(getTypeName()))
            return false;
        for (String key : keySet()) {
            OpenType<?> otItemType = ct.getType(key);
            OpenType<?> thisItemType = getType(key);
            if (otItemType == null ||
                    !thisItemType.isAssignableFrom(otItemType))
                return false;
        }
        return true;
    }


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

    /**
     * Compares the specified <code>obj</code> parameter with this <code>CompositeType</code> instance for equality. 
     * <p>
     * Two <code>CompositeType</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 items' names and types are equal</li>
     * </ul>
     * <br>&nbsp;
     * @param  obj  the object to be compared for equality with this <code>CompositeType</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>CompositeType</code> instance.
     */
    public boolean equals(Object obj) {

	// if obj is null, return false
	//
	if (obj == null) {
	    return false;
	}

	// if obj is not a CompositeType, return false
	//
	CompositeType other;
	try {
	    other = (CompositeType) obj;
	} catch (ClassCastException e) {
	    return false;
	}

	// Now, really test for equality between this CompositeType instance and the other
	//
	
	// their names should be equal
	if ( ! this.getTypeName().equals(other.getTypeName()) ) {
	    return false;
	}

	// their items names and types should be equal
	if ( ! this.nameToType.equals(other.nameToType) ) {
	    return false;
	}

	// All tests for equality were successfull
	//
	return true;
    }

    /**
     * Returns the hash code value for this <code>CompositeType</code> instance. 
     * <p>
     * The hash code of a <code>CompositeType</code> instance is the sum of the hash codes
     * of all elements of information used in <code>equals</code> comparisons 
     * (ie: name, items names, items types). 
     * This ensures that <code> t1.equals(t2) </code> implies that <code> t1.hashCode()==t2.hashCode() </code> 
     * for any two <code>CompositeType</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>CompositeType</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>CompositeType</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();
	    String key;
	    for (Iterator k = nameToDescription.keySet().iterator(); k.hasNext();  ) {
		key = (String) k.next();
		value += key.hashCode();
		value += this.nameToType.get(key).hashCode();
	    }
	    myHashCode = new Integer(value);
	}
	
	// return always the same hash code for this instance (immutable)
	//
	return myHashCode.intValue();
    }

    /**
     * Returns a string representation of this <code>CompositeType</code> instance. 
     * <p>
     * The string representation consists of 
     * the name of this class (ie <code>javax.management.openmbean.CompositeType</code>), the type name for this instance, 
     * and the list of the items names and types string representation of this instance.
     * <p>
     * As <code>CompositeType</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>CompositeType</code> instance
     */
    public String toString() {

	// Calculate the string representation if it has not yet been done (ie 1st call to toString())
	//
	if (myToString == null) {
	    StringBuffer result = new StringBuffer();
	    result.append(this.getClass().getName());
	    result.append("(name=");
	    result.append(getTypeName());
	    result.append(",items=(");
	    int i=0; 
	    Iterator k=nameToType.keySet().iterator();
	    String key;
	    while (k.hasNext()) {
		key = (String) k.next();
		if (i > 0) result.append(",");
		result.append("(itemName=");
		result.append(key);
		result.append(",itemType=");
		result.append(nameToType.get(key).toString() +")");
		i++;
	    }
	    result.append("))");
	    myToString = result.toString();
	}

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

}