/*
Wotonomy: OpenStep design patterns for pure Java applications.
Copyright (C) 2000 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.access;

import net.wotonomy.control.EOAndQualifier;
import net.wotonomy.control.EOKeyComparisonQualifier;
import net.wotonomy.control.EOKeyValueQualifier;
import net.wotonomy.control.EONotQualifier;
import net.wotonomy.control.EOOrQualifier;
import net.wotonomy.control.EOQualifier;
import net.wotonomy.foundation.NSArray;
import net.wotonomy.foundation.NSMutableDictionary;

/**
* @author ezamudio@nasoft.com
* @author $Author: cgruber $
* @version $Revision: 894 $
*/

public interface EOQualifierSQLGeneration {

	public EOQualifier qualifierMigratedFromEntityRelationshipPath( 
				EOEntity entity, String path);

	public EOQualifier schemaBasedQualifierWithRootEntity(EOEntity entity);

	public String sqlStringForSQLExpression(EOSQLExpression expression);

	public abstract class Support {

		private static NSMutableDictionary _classes = new NSMutableDictionary();

		static {
			setSupportForClass(new KeyValueQualifierSupport(), EOKeyValueQualifier.class);
			setSupportForClass(new KeyComparisonQualifierSupport(), EOKeyComparisonQualifier.class);
			setSupportForClass(new AndQualifierSupport(), EOAndQualifier.class);
			setSupportForClass(new OrQualifierSupport(), EOOrQualifier.class);
			setSupportForClass(new NotQualifierSupport(), EONotQualifier.class);
		}

		public Support() {
			super();
		}

		public static void setSupportForClass(Support sup, Class aClass) {
			_classes.setObjectForKey(sup, aClass.getName());
		}
		public static Support supportForClass(Class aClass) {
			return (Support)_classes.objectForKey(aClass.getName());
		}

		public abstract String sqlStringForSQLExpression(EOQualifier q, EOSQLExpression exp);

		public abstract EOQualifier schemaBasedQualifierWithRootEntity(EOQualifier q, EOEntity e);

		public abstract EOQualifier qualifierMigratedFromEntityRelationshipPath(EOQualifier q, EOEntity e, String path);

	}

	public class KeyValueQualifierSupport extends Support {

		public KeyValueQualifierSupport() {
			super();
		}

		public String sqlStringForSQLExpression(EOQualifier qualifier, EOSQLExpression exp) {
			EOKeyValueQualifier q = (EOKeyValueQualifier)qualifier;
			String sql1 = exp.sqlStringForAttributeNamed(q.key());
			String sql2 = exp.sqlStringForSelector(q.selector(), q.value());
			String sql3 = exp.sqlStringForValue(q.value(), q.key());
			if (q.selector() == EOQualifier.QualifierOperatorCaseInsensitiveLike)
				return exp.sqlStringForCaseInsensitiveLike(sql1, sql3);
			else if (q.selector() == EOQualifier.QualifierOperatorLike)
				sql3 = exp.sqlPatternFromShellPattern(sql3);
			return  sql1 + sql2 + sql3;
		}

		public EOQualifier schemaBasedQualifierWithRootEntity(EOQualifier q, EOEntity e) {
			return q;
		}

		public EOQualifier qualifierMigratedFromEntityRelationshipPath(EOQualifier q, EOEntity e, String path) {
			return q;
		}

	}

	public class KeyComparisonQualifierSupport extends Support {

		public KeyComparisonQualifierSupport() {
			super();
		}

		public String sqlStringForSQLExpression(EOQualifier qualifier, EOSQLExpression exp) {
			EOKeyComparisonQualifier q = (EOKeyComparisonQualifier)qualifier;
			return exp.sqlStringForAttributeNamed(q.leftKey()) +
				exp.sqlStringForSelector(q.selector(), null) +
				exp.sqlStringForAttributeNamed(q.rightKey());
		}

		public EOQualifier schemaBasedQualifierWithRootEntity(EOQualifier q, EOEntity e) {
			return q;
		}

		public EOQualifier qualifierMigratedFromEntityRelationshipPath(EOQualifier q, EOEntity e, String path) {
			return q;
		}

	}

	public class NotQualifierSupport extends Support {

		public NotQualifierSupport() {
			super();
		}

		public String sqlStringForSQLExpression(EOQualifier qualifier, EOSQLExpression exp) {
			EONotQualifier q = (EONotQualifier)qualifier;
			return "NOT (" + EOQualifierSQLGeneration.Support.supportForClass(q.qualifier().getClass()).sqlStringForSQLExpression(q.qualifier(), exp) + ")";
		}

		public EOQualifier schemaBasedQualifierWithRootEntity(EOQualifier qualifier, EOEntity e) {
			EONotQualifier q = (EONotQualifier)qualifier;
			return new EONotQualifier(EOQualifierSQLGeneration.Support.supportForClass(q.qualifier().getClass()).schemaBasedQualifierWithRootEntity(q.qualifier(), e));
		}

		public EOQualifier qualifierMigratedFromEntityRelationshipPath(EOQualifier qualifier, EOEntity e, String path) {
			EONotQualifier q = (EONotQualifier)qualifier;
			return new EONotQualifier(EOQualifierSQLGeneration.Support.supportForClass(q.qualifier().getClass()).qualifierMigratedFromEntityRelationshipPath(q.qualifier(), e, path));
		}

	}

	public class AndQualifierSupport extends Support {

		public AndQualifierSupport() {
			super();
		}

		public String sqlStringForSQLExpression(EOQualifier qualifier, EOSQLExpression exp) {
			EOAndQualifier q = (EOAndQualifier)qualifier;
			NSArray qus = q.qualifiers();
			StringBuffer buf = new StringBuffer();
			for (int i = 0; i < qus.count(); i++) {
				EOQualifier sub = (EOQualifier)qus.objectAtIndex(i);
				EOQualifierSQLGeneration.Support sup = EOQualifierSQLGeneration.Support.supportForClass(sub.getClass());
				if (sup == null)
					throw new IllegalStateException("Cannot find support class for " + sub.getClass().getName());
				buf.append(sup.sqlStringForSQLExpression(sub, exp));
				if (i < qus.count()-1)
					buf.append(" AND ");
			}
			if (qus.count() > 1) {
				buf.insert(0, '(');
				buf.append(')');
			}
			return buf.toString();
		}

		public EOQualifier schemaBasedQualifierWithRootEntity(EOQualifier q, EOEntity e) {
			return q;
		}

		public EOQualifier qualifierMigratedFromEntityRelationshipPath(EOQualifier q, EOEntity e, String path) {
			return q;
		}

	}

	public class OrQualifierSupport extends Support {

		public OrQualifierSupport() {
			super();
		}

		public String sqlStringForSQLExpression(EOQualifier qualifier, EOSQLExpression exp) {
			EOOrQualifier q = (EOOrQualifier)qualifier;
			NSArray qus = q.qualifiers();
			StringBuffer buf = new StringBuffer();
			for (int i = 0; i < qus.count(); i++) {
				EOQualifier sub = (EOQualifier)qus.objectAtIndex(i);
				EOQualifierSQLGeneration.Support sup = EOQualifierSQLGeneration.Support.supportForClass(sub.getClass());
				if (sup == null)
					throw new IllegalStateException("Cannot find support class for " + sub.getClass().getName());
				buf.append(sup.sqlStringForSQLExpression(sub, exp));
				if (i < qus.count()-1)
					buf.append(" OR ");
			}
			if (qus.count() > 1) {
				buf.insert(0, '(');
				buf.append(')');
			}
			return buf.toString();
		}

		public EOQualifier schemaBasedQualifierWithRootEntity(EOQualifier q, EOEntity e) {
			return q;
		}

		public EOQualifier qualifierMigratedFromEntityRelationshipPath(EOQualifier q, EOEntity e, String path) {
			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 1.3  2003/08/14 02:13:10  chochos
 * KeyValueQualifierSupport generates proper SQL
 *
 * Revision 1.2  2003/08/14 01:05:51  chochos
 * added abstract Support inner class, with incomplete implementations for the main qualifiers (not, and, or, key-value, key-comparison)
 *
 * Revision 1.1  2003/08/12 01:45:49  chochos
 * interface to be implemented by qualifiers (or support classes) to indicate they can generate SQL
 *
 */