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 *   Licensed to the Apache Software Foundation (ASF) under one
 *  or more contributor license agreements.  See the NOTICE file
 *  distributed with this work for additional information
 *  regarding copyright ownership.  The ASF licenses this file
 *  to you under the Apache License, Version 2.0 (the
 *  "License"); you may not use this file except in compliance
 *  with the License.  You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing,
 *  software distributed under the License is distributed on an
 *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 *  KIND, either express or implied.  See the License for the
 *  specific language governing permissions and limitations
 *  under the License.
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package org.apache.cayenne.dba.openbase;

import java.io.IOException;

import org.apache.cayenne.CayenneRuntimeException;
import org.apache.cayenne.access.translator.select.QualifierTranslator;
import org.apache.cayenne.access.translator.select.QueryAssembler;
import org.apache.cayenne.exp.Expression;
import org.apache.cayenne.exp.parser.ASTExtract;
import org.apache.cayenne.exp.parser.PatternMatchNode;
import org.apache.cayenne.map.DbAttribute;

/**
 * Translates query qualifier to SQL. Used as a helper class by query
 * translators.
 * 
 * @since 1.1
 */
public class OpenBaseQualifierTranslator extends QualifierTranslator {

	public OpenBaseQualifierTranslator(QueryAssembler queryAssembler) {
		super(queryAssembler);
	}

	@Override
	public void startNode(Expression node, Expression parentNode) {

		if (node.getOperandCount() == 2) {
			// binary nodes are the only ones that currently require this
			detectObjectMatch(node);

			if (parenthesisNeeded(node, parentNode)) {
				out.append('(');
			}

			// super implementation has special handling
			// of LIKE_IGNORE_CASE and NOT_LIKE_IGNORE_CASE
			// OpenBase is case-insensitive by default
			// ...

		} else {
			super.startNode(node, parentNode);
		}
	}

	@Override
	public void endNode(Expression node, Expression parentNode) {
		if (node.getOperandCount() == 2) {

			try {
				// check if we need to use objectMatchTranslator to finish
				// building the
				// expression
				if (matchingObject) {
					appendObjectMatch();
				}

				if (PatternMatchNode.class.isAssignableFrom(node.getClass())) {
					appendLikeEscapeCharacter((PatternMatchNode) node);
				}

				if (parenthesisNeeded(node, parentNode)) {
					out.append(')');
				}

				// super implementation has special handling
				// of LIKE_IGNORE_CASE and NOT_LIKE_IGNORE_CASE
				// OpenBase is case-insensitive by default
				// ...
			} catch (IOException ioex) {
				throw new CayenneRuntimeException("Error appending content", ioex);
			}
		} else {
			super.endNode(node, parentNode);
		}
	}

	@Override
	protected void appendLiteralDirect(Object val, DbAttribute attr, Expression parentExpression) throws IOException {

		// Special handling of string matching is needed:
		// Case-sensitive LIKE must be converted to [x][Y][z] format
		if (val instanceof String
				&& (parentExpression.getType() == Expression.LIKE || parentExpression.getType() == Expression.NOT_LIKE)) {

			val = caseSensitiveLikePattern((String) val);
		}

		super.appendLiteralDirect(val, attr, parentExpression);
	}

	private String caseSensitiveLikePattern(String pattern) {
		int len = pattern.length();
		StringBuilder buffer = new StringBuilder(len * 3);

		for (int i = 0; i < len; i++) {
			char c = pattern.charAt(i);
			if (c == '%' || c == '?') {
				buffer.append(c);
			} else {
				buffer.append("[").append(c).append("]");
			}
		}

		return buffer.toString();
	}

	@Override
	public void finishedChild(Expression node, int childIndex, boolean hasMoreChildren) {
		if (!hasMoreChildren) {
			return;
		}

		// super implementation has special handling
		// of LIKE_IGNORE_CASE and NOT_LIKE_IGNORE_CASE
		// OpenBase is case-insensitive by default
		// ...

		try {
			switch (node.getType()) {

			case Expression.LIKE_IGNORE_CASE:
				finishedChildNodeAppendExpression(node, " LIKE ");
				break;
			case Expression.NOT_LIKE_IGNORE_CASE:
				finishedChildNodeAppendExpression(node, " NOT LIKE ");
				break;
			default:
				super.finishedChild(node, childIndex, hasMoreChildren);
			}
		} catch (IOException ioex) {
			throw new CayenneRuntimeException("Error appending content", ioex);
		}
	}

	private void finishedChildNodeAppendExpression(Expression node, String operation) throws IOException {
		Appendable out = matchingObject ? new StringBuilder() : this.out;
		out.append(operation);
		if (matchingObject) {
			objectMatchTranslator.setOperation(out.toString());
			objectMatchTranslator.setExpression(node);
		}
	}

	@Override
	protected void appendExtractFunction(ASTExtract functionExpression) {
		switch (functionExpression.getPart()) {
			case DAY_OF_WEEK:
			case DAY_OF_MONTH:
			case DAY_OF_YEAR:
				// openbase variants are without '_'
				out.append(functionExpression.getPart().name().replace("_", ""));
				break;
			default:
				appendFunction(functionExpression);
		}
	}
}