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Provides seamlessly integrated Java access to graph databases (Neo4J) at different levels of abstraction.
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/************************************************************************
 * Copyright (c) 2014 IoT-Solutions e.U.
 * 
 * Licensed 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.
 ************************************************************************/

package iot.jcypher.query.factories.clause;

import iot.jcypher.query.api.APIObject;
import iot.jcypher.query.api.APIObjectAccess;
import iot.jcypher.query.api.collection.IPredicateFunction;
import iot.jcypher.query.api.pattern.IElement;
import iot.jcypher.query.api.predicate.BooleanOperation;
import iot.jcypher.query.api.predicate.Concat;
import iot.jcypher.query.api.predicate.Concatenator;
import iot.jcypher.query.api.predicate.IBeforePredicate;
import iot.jcypher.query.ast.ASTNode;
import iot.jcypher.query.ast.ClauseType;
import iot.jcypher.query.factories.xpression.P;
import iot.jcypher.query.values.IHas;
import iot.jcypher.query.values.ValueElement;

/**
 * JCYPHER CLAUSE
 */
public class WHERE {

	/**
	 * JCYPHER
	 * takes an expression like 'n.property("age")', yielding a property,
	 * or 'x.length()', calculating some value
	 * e.g. WHERE.valueOf(n.property("age"))...
	 * 

	 */
	public static BooleanOperation valueOf(ValueElement val) {
		BooleanOperation ret = P.valueOf(val);
		ASTNode an = APIObjectAccess.getAstNode(ret);
		an.setClauseType(ClauseType.WHERE);
		return ret;
	}
	
	/**
	 * JCYPHER
	 * tests for existence of node labels or node/relation properties,
	 * accepts expressions like 'n.property("age")',
	 * or 'n.label("Swedish")'
	 * e.g. WHERE.has(n.property("age"))
	 * 

	 */
	public static Concatenator has(IHas val) {
		Concatenator ret = P.has(val);
		ASTNode an = APIObjectAccess.getAstNode(ret);
		an.setClauseType(ClauseType.WHERE);
		return ret;
	}
	
	/**
	 * JCYPHER
	 * negate a boolean
	 * e.g. WHERE.NOT().has(n.property("age"))
	 * 

	 */
	public static IBeforePredicate NOT() {
		IBeforePredicate ret = P.NOT();
		ASTNode an = APIObjectAccess.getAstNode((APIObject) ret);
		an.setClauseType(ClauseType.WHERE);
		return ret;
	}
	
	/**
	 * JCYPHER
	 * open a bracket; allows to nest expressions, must have a matching BR_CLOSE()
	 * e.g. WHERE... ...BR_OPEN()
	 * 
.valueOf(charlie.property("lastName")).EQUALS("Sheen")
.BR_CLOSE()
	 * 

	 */
	public static Concat BR_OPEN() {
		Concat ret = P.BR_OPEN();
		ASTNode an = APIObjectAccess.getAstNode(ret);
		an.setClauseType(ClauseType.WHERE);
		return ret;
	}
	
	/**
	 * JCYPHER
	 * matches a pattern expression against the graph. If the result is empty, returns false, else returns true
	 * Use Factory Class X to create Expressions
	 * e.g. ...existsPattern(X.node(n)...)
	 * 

	 */
	public static Concatenator existsPattern(IElement X) {
		Concatenator ret = P.existsPattern(X);
		ASTNode an = APIObjectAccess.getAstNode(ret);
		an.setClauseType(ClauseType.WHERE);
		return ret;
	}
	
	/**
	 * JCYPHER
	 * iterates over a collection allowing to test each element of the collection against a predicate expression
	 * Use Factory Class I to create Expressions
	 * e.g. ...holdsTrue(I.forAll(n)...)
	 * 

	 */
	public static Concatenator holdsTrue(IPredicateFunction I) {
		Concatenator ret = P.holdsTrue(I);
		ASTNode an = APIObjectAccess.getAstNode(ret);
		an.setClauseType(ClauseType.WHERE);
		return ret;
	}
}