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/*
 *  Copyright 2024 Budapest University of Technology and Economics
 *
 *  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 hu.bme.mit.theta.xta.analysis.lazy;

import static hu.bme.mit.theta.core.type.booltype.SmartBoolExprs.Not;

import java.util.Collection;

import hu.bme.mit.theta.analysis.State;
import hu.bme.mit.theta.analysis.algorithm.arg.ArgEdge;
import hu.bme.mit.theta.analysis.algorithm.arg.ArgNode;
import hu.bme.mit.theta.analysis.expl.ExplState;
import hu.bme.mit.theta.core.model.Valuation;
import hu.bme.mit.theta.core.type.Expr;
import hu.bme.mit.theta.core.type.booltype.BoolLitExpr;
import hu.bme.mit.theta.core.type.booltype.BoolType;
import hu.bme.mit.theta.core.utils.ExprUtils;
import hu.bme.mit.theta.xta.XtaSystem;
import hu.bme.mit.theta.xta.analysis.XtaAction;
import hu.bme.mit.theta.xta.analysis.expl.XtaExplUtils;
import hu.bme.mit.theta.xta.analysis.expl.itp.ItpExplState;
import hu.bme.mit.theta.xta.analysis.lazy.LazyXtaStatistics.Builder;

final class BwItpExplStrategy extends ItpExplStrategy {

    public BwItpExplStrategy(final XtaSystem system, final Lens lens) {
        super(system, lens);
    }

    @Override
    protected Valuation blockExpl(final ArgNode node, final Expr expr,
                                  final Collection> uncoveredNodes, final Builder stats) {
        assert !node.getState().isBottom();

        final ExplState abstractExpl = getLens().get(node.getState()).getAbstrState();

        final Expr simplifiedExpr = ExprUtils.simplify(expr, abstractExpl);
        if (simplifiedExpr instanceof BoolLitExpr) {
            assert !((BoolLitExpr) simplifiedExpr).getValue();
            return abstractExpl;
        }

        stats.refineExpl();

        final ExplState concreteExpl = getLens().get(node.getState()).getConcrState();
        final Valuation valI = XtaExplUtils.interpolate(concreteExpl, expr);

        strengthen(node, valI);
        maintainCoverage(node, valI, uncoveredNodes);

        if (node.getParent().isPresent()) {
            final ArgEdge inEdge = node.getInEdge().get();
            final XtaAction action = inEdge.getAction();
            final Expr newB = XtaExplUtils.pre(Not(valI.toExpr()), action);
            blockExpl(node.getParent().get(), newB, uncoveredNodes, stats);
        }

        return valI;
    }

}