/*
Wotonomy: OpenStep design patterns for pure Java applications.
Copyright (C) 2001 Michael Powers

This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.

This library 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
Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public
License along with this library; if not, see http://www.gnu.org
*/

package net.wotonomy.control;

import net.wotonomy.foundation.NSKeyValueCoding;
import net.wotonomy.foundation.NSMutableDictionary;
import net.wotonomy.foundation.NSSelector;
import net.wotonomy.foundation.internal.WotonomyException;

/**
 * EOKeyValueQualifier performs a property-based comparison against a specified
 * value. The comparison is specified in the form of a NSSelector. The selector
 * is expected to take two arguments, the property value on an object and the
 * comparison value, and return a Boolean indicating whether the object is
 * qualified. EOQualifier defines selectors that may be used in creating
 * EOKeyValueQualifiers.
 *
 * @author michael@mpowers.net
 * @author yjcheung@intersectsoft.com
 * @author $Author: cgruber $
 * @version $Revision: 894 $
 */
public class EOKeyValueQualifier extends EOQualifier implements EOKeyValueArchiving, EOQualifierEvaluation {
	private String key;
	private NSSelector selector;
	private Object value;

	/**
	 * Constructor specifying a property key, a selector, and a value for
	 * comparison. The selector may be one of the constant selectors defined on
	 * EOQualifier.
	 */
	public EOKeyValueQualifier(String aKey, NSSelector aSelector, Object aValue) {
		key = aKey;
		selector = aSelector;
		value = aValue;
	}

	/**
	 * Returns the key for this qualifier.
	 */
	public String key() {
		return key;
	}

	/**
	 * Returns the selector for this qualifier.
	 */
	public NSSelector selector() {
		return selector;
	}

	/**
	 * Returns the value for this qualifier.
	 */
	public Object value() {
		return value;
	}

	/**
	 * Evaluates this qualifier for the specified object, and returns whether the
	 * object is qualified. selector() is invoked on the value for key() on the
	 * specified object, with value() as the parameter.
	 */
	public boolean evaluateWithObject(Object anObject) {
		try {
			Object value;
			if (anObject instanceof EOKeyValueCoding) {
				value = ((EOKeyValueCoding) anObject).valueForKey(key());
			} else {
				value = EOKeyValueCodingSupport.valueForKey(anObject, key());
			}
			return ((Boolean) selector.invoke(value(), value)).booleanValue();
		} catch (Exception exc) {
			throw new WotonomyException(exc);
		}
	}

	/**
	 * Returns a string representation of this qualifier.
	 */
	public String toString() {
		return "( " + key + " " + selector + " " + value + " )";
	}

	public void encodeWithKeyValueArchiver(EOKeyValueArchiver arch) {
		arch.encodeObject("EOKeyValueQualifier", "class");
		arch.encodeObject(key, "key");
		NSMutableDictionary d = new NSMutableDictionary(2);
		if (value instanceof String)
			d.setObjectForKey("NSString", "class");
		else if (value instanceof java.math.BigDecimal)
			d.setObjectForKey("NSDecimalNumber", "class");
		else if (value instanceof Number)
			d.setObjectForKey("NSNumber", "class");
		else if (value instanceof NSKeyValueCoding.Null)
			d.setObjectForKey("EONull", "class");
		if (value != null && !(value instanceof NSKeyValueCoding.Null))
			d.setObjectForKey(value.toString(), "value");
		arch.encodeObject(d, "value");
		String selname = null;
		if (selector.equals(EOQualifier.QualifierOperatorCaseInsensitiveLike))
			selname = "caseInsensitiveLike:";
		else if (selector.equals(EOQualifier.QualifierOperatorContains))
			selname = "contains:";
		else if (selector.equals(EOQualifier.QualifierOperatorEqual))
			selname = "isEqualTo:";
		else if (selector.equals(EOQualifier.QualifierOperatorGreaterThan))
			selname = "greaterThan:";
		else if (selector.equals(EOQualifier.QualifierOperatorGreaterThanOrEqualTo))
			selname = "greaterThanOrEqualTo:";
		else if (selector.equals(EOQualifier.QualifierOperatorLessThan))
			selname = "lessThan:";
		else if (selector.equals(EOQualifier.QualifierOperatorLessThanOrEqualTo))
			selname = "lessThanOrEqualTo:";
		else if (selector.equals(EOQualifier.QualifierOperatorLike))
			selname = "like:";
		else if (selector.equals(EOQualifier.QualifierOperatorNotEqual))
			selname = "isNotEqualTo:";
		else
			selname = selector.name() + ":";
		arch.encodeObject(selname, "selectorName");
	}

	public static Object decodeWithKeyValueUnarchiver(EOKeyValueUnarchiver arch) {
		String k = (String) arch.decodeObjectForKey("key");
		Object v = arch.decodeObjectForKey("value");
		NSSelector sel = null;
		String sname = (String) arch.decodeObjectForKey("selectorName");
		if (sname.equals("isEqualTo:"))
			sel = EOQualifier.QualifierOperatorEqual;
		else if (sname.equals("isNotEqualTo:"))
			sel = EOQualifier.QualifierOperatorNotEqual;
		else if (sname.equals("caseInsensitiveLike:"))
			sel = EOQualifier.QualifierOperatorCaseInsensitiveLike;
		else if (sname.equals("contains:"))
			sel = EOQualifier.QualifierOperatorContains;
		else if (sname.equals("greaterThan:"))
			sel = EOQualifier.QualifierOperatorGreaterThan;
		else if (sname.equals("greaterThanOrEqualTo:"))
			sel = EOQualifier.QualifierOperatorGreaterThanOrEqualTo;
		else if (sname.equals("lessThan:"))
			sel = EOQualifier.QualifierOperatorLessThan;
		else if (sname.equals("lessThanOrEqualTo:"))
			sel = EOQualifier.QualifierOperatorLessThanOrEqualTo;
		else if (sname.equals("like:"))
			sel = EOQualifier.QualifierOperatorLike;
		EOKeyValueQualifier q = new EOKeyValueQualifier(k, sel, v);
		return q;
	}

}

/*
 * $Log$ Revision 1.2 2006/02/16 16:47:14 cgruber Move some classes in to
 * "internal" packages and re-work imports, etc.
 *
 * Also use UnsupportedOperationExceptions where appropriate, instead of
 * WotonomyExceptions.
 *
 * Revision 1.1 2006/02/16 13:19:57 cgruber Check in all sources in
 * eclipse-friendly maven-enabled packages.
 *
 * Revision 1.10 2003/08/12 01:43:04 chochos formally implement
 * EOQualifierEvaluation
 *
 * Revision 1.9 2003/08/11 19:39:30 chochos special conditions for
 * NSKeyValueCoding.NullValue -> EONull
 *
 * Revision 1.8 2003/08/09 01:22:51 chochos qualifiers implement
 * EOKeyValueArchiving
 *
 * Revision 1.7 2003/08/06 23:07:52 chochos general code cleanup (mostly,
 * removing unused imports)
 *
 * Revision 1.6 2001/10/31 15:26:06 mpowers Fixed typo.
 *
 * Revision 1.5 2001/10/31 15:25:14 mpowers Cleanup of qualifiers.
 *
 * Revision 1.4 2001/10/30 22:57:28 mpowers EOQualifier framework is now
 * working.
 *
 * Revision 1.3 2001/09/13 15:25:56 mpowers Started implementation of the
 * EOQualifier framework.
 *
 * Revision 1.2 2001/03/29 03:29:49 mpowers Now using KeyValueCoding and Support
 * instead of Introspector.
 *
 * Revision 1.1 2001/02/27 03:33:04 mpowers Initial draft of the key-value
 * qualifier.
 *
 *
 */