/*
 * Copyright (c) 2017 Pantheon Technologies, s.r.o. and others.  All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v1.0 which accompanies this distribution,
 * and is available at http://www.eclipse.org/legal/epl-v10.html
 */
package org.opendaylight.yangtools.yang.parser.rfc7950.stmt.if_feature;

import static com.google.common.base.Verify.verifyNotNull;

import com.google.common.collect.ImmutableList;
import java.util.Collection;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
import org.opendaylight.yangtools.yang.common.QName;
import org.opendaylight.yangtools.yang.common.YangVersion;
import org.opendaylight.yangtools.yang.model.api.YangStmtMapping;
import org.opendaylight.yangtools.yang.model.api.meta.DeclaredStatement;
import org.opendaylight.yangtools.yang.model.api.meta.EffectiveStatement;
import org.opendaylight.yangtools.yang.model.api.stmt.IfFeatureEffectiveStatement;
import org.opendaylight.yangtools.yang.model.api.stmt.IfFeatureExpr;
import org.opendaylight.yangtools.yang.model.api.stmt.IfFeatureStatement;
import org.opendaylight.yangtools.yang.parser.rfc7950.stmt.BaseStatementSupport;
import org.opendaylight.yangtools.yang.parser.spi.FeatureNamespace;
import org.opendaylight.yangtools.yang.parser.spi.meta.InferenceException;
import org.opendaylight.yangtools.yang.parser.spi.meta.ModelActionBuilder;
import org.opendaylight.yangtools.yang.parser.spi.meta.ModelActionBuilder.InferenceAction;
import org.opendaylight.yangtools.yang.parser.spi.meta.ModelActionBuilder.InferenceContext;
import org.opendaylight.yangtools.yang.parser.spi.meta.ModelActionBuilder.Prerequisite;
import org.opendaylight.yangtools.yang.parser.spi.meta.ModelProcessingPhase;
import org.opendaylight.yangtools.yang.parser.spi.meta.StmtContext;
import org.opendaylight.yangtools.yang.parser.spi.meta.StmtContext.Mutable;
import org.opendaylight.yangtools.yang.parser.spi.meta.StmtContextUtils;
import org.opendaylight.yangtools.yang.parser.spi.meta.SubstatementValidator;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public final class IfFeatureStatementSupport
        extends BaseStatementSupport<IfFeatureExpr, IfFeatureStatement, IfFeatureEffectiveStatement> {
    private static final Logger LOG = LoggerFactory.getLogger(IfFeatureStatementSupport.class);
    private static final SubstatementValidator SUBSTATEMENT_VALIDATOR = SubstatementValidator.builder(
        YangStmtMapping.IF_FEATURE)
        .build();
    private static final IfFeatureStatementSupport INSTANCE = new IfFeatureStatementSupport();

    private IfFeatureStatementSupport() {
        super(YangStmtMapping.IF_FEATURE, CopyPolicy.CONTEXT_INDEPENDENT);
    }

    public static IfFeatureStatementSupport getInstance() {
        return INSTANCE;
    }

    @Override
    public IfFeatureExpr parseArgumentValue(final StmtContext<?, ?, ?> ctx, final String value) {
        if (YangVersion.VERSION_1_1.equals(ctx.getRootVersion())) {
            return IfFeaturePredicateVisitor.parseIfFeatureExpression(ctx, value);
        }
        return IfFeatureExpr.isPresent(StmtContextUtils.parseNodeIdentifier(ctx, value));
    }

    @Override
    public void onFullDefinitionDeclared(
            final Mutable<IfFeatureExpr, IfFeatureStatement, IfFeatureEffectiveStatement> stmt) {
        super.onFullDefinitionDeclared(stmt);

        final ModelActionBuilder verifyFeatures = stmt.newInferenceAction(ModelProcessingPhase.EFFECTIVE_MODEL);
        final Map<Prerequisite<?>, QName> backRef = new HashMap<>();
        for (QName feature : stmt.coerceStatementArgument().getReferencedFeatures()) {
            backRef.put(verifyFeatures.requiresCtx(stmt, FeatureNamespace.class, feature,
                ModelProcessingPhase.EFFECTIVE_MODEL), feature);
        }

        verifyFeatures.apply(new InferenceAction() {
            @Override
            public void apply(final InferenceContext ctx) {
                LOG.debug("Resolved all feature references in {}", backRef.values());
            }

            @Override
            public void prerequisiteFailed(final Collection<? extends Prerequisite<?>> failed) {
                final Set<QName> unresolvedFeatures = new HashSet<>();
                for (Prerequisite<?> prereq : failed) {
                    unresolvedFeatures.add(verifyNotNull(backRef.get(prereq)));
                }

                throw new InferenceException(stmt.getStatementSourceReference(),
                    "Failed to resolve feature references %s in \"%s\"", unresolvedFeatures,
                    stmt.rawStatementArgument());
            }
        });
    }

    @Override
    protected SubstatementValidator getSubstatementValidator() {
        return SUBSTATEMENT_VALIDATOR;
    }

    @Override
    protected IfFeatureStatement createDeclared(final StmtContext<IfFeatureExpr, IfFeatureStatement, ?> ctx,
            final ImmutableList<? extends DeclaredStatement<?>> substatements) {
        return new RegularIfFeatureStatement(ctx.coerceRawStatementArgument(), ctx.coerceStatementArgument(),
            substatements);
    }

    @Override
    protected IfFeatureStatement createEmptyDeclared(final StmtContext<IfFeatureExpr, IfFeatureStatement, ?> ctx) {
        return new EmptyIfFeatureStatement(ctx.coerceRawStatementArgument(), ctx.coerceStatementArgument());
    }

    @Override
    protected IfFeatureEffectiveStatement createEffective(
            final StmtContext<IfFeatureExpr, IfFeatureStatement, IfFeatureEffectiveStatement> ctx,
            final IfFeatureStatement declared, final ImmutableList<? extends EffectiveStatement<?, ?>> substatements) {
        return new RegularIfFeatureEffectiveStatement(declared, substatements);
    }

    @Override
    protected IfFeatureEffectiveStatement createEmptyEffective(
            final StmtContext<IfFeatureExpr, IfFeatureStatement, IfFeatureEffectiveStatement> ctx,
            final IfFeatureStatement declared) {
        return new EmptyIfFeatureEffectiveStatement(declared);
    }
}