/*
 * Copyright 2016 Red Hat, Inc. and/or its affiliates.
 *
 * 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 org.kie.dmn.feel.lang.ast;

import org.antlr.v4.runtime.ParserRuleContext;
import org.kie.dmn.api.feel.runtime.events.FEELEvent.Severity;
import org.kie.dmn.feel.lang.EvaluationContext;
import org.kie.dmn.feel.util.Msg;

public class IfExpressionNode
        extends BaseNode {

    private BaseNode condition;
    private BaseNode thenExpression;
    private BaseNode elseExpression;

    public IfExpressionNode(ParserRuleContext ctx, BaseNode condition, BaseNode thenExpression, BaseNode elseExpression) {
        super( ctx );
        this.condition = condition;
        this.thenExpression = thenExpression;
        this.elseExpression = elseExpression;
    }

    public BaseNode getCondition() {
        return condition;
    }

    public void setCondition(BaseNode condition) {
        this.condition = condition;
    }

    public BaseNode getThenExpression() {
        return thenExpression;
    }

    public void setThenExpression(BaseNode thenExpression) {
        this.thenExpression = thenExpression;
    }

    public BaseNode getElseExpression() {
        return elseExpression;
    }

    public void setElseExpression(BaseNode elseExpression) {
        this.elseExpression = elseExpression;
    }

    @Override
    public Object evaluate(EvaluationContext ctx) {
        Object cond = this.condition.evaluate( ctx );
        if ( cond instanceof Boolean ) {
            if ( ((Boolean) cond) ) {
                return this.thenExpression.evaluate( ctx );
            } else {
                return this.elseExpression.evaluate( ctx );
            }
        }
        ctx.notifyEvt( astEvent(Severity.ERROR, Msg.createMessage(Msg.CONDITION_WAS_NOT_A_BOOLEAN)) );
        return null;
    }
}