/*
 * 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.meta;

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

import com.google.common.collect.ImmutableList;
import com.google.common.collect.Iterables;
import org.opendaylight.yangtools.yang.model.api.YangStmtMapping;
import org.opendaylight.yangtools.yang.model.api.meta.DeclarationReference;
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.DeviationEffectiveStatement;
import org.opendaylight.yangtools.yang.model.api.stmt.DeviationStatement;
import org.opendaylight.yangtools.yang.model.api.stmt.SchemaNodeIdentifier.Absolute;
import org.opendaylight.yangtools.yang.model.api.stmt.SubmoduleStatement;
import org.opendaylight.yangtools.yang.model.ri.stmt.DeclaredStatementDecorators;
import org.opendaylight.yangtools.yang.model.ri.stmt.DeclaredStatements;
import org.opendaylight.yangtools.yang.model.ri.stmt.EffectiveStatements;
import org.opendaylight.yangtools.yang.parser.api.YangParserConfiguration;
import org.opendaylight.yangtools.yang.parser.rfc7950.stmt.ArgumentUtils;
import org.opendaylight.yangtools.yang.parser.spi.meta.AbstractStatementSupport;
import org.opendaylight.yangtools.yang.parser.spi.meta.BoundStmtCtx;
import org.opendaylight.yangtools.yang.parser.spi.meta.EffectiveStmtCtx.Current;
import org.opendaylight.yangtools.yang.parser.spi.meta.InferenceException;
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.SubstatementValidator;
import org.opendaylight.yangtools.yang.parser.spi.source.BelongsToPrefixToModuleCtx;
import org.opendaylight.yangtools.yang.parser.spi.source.ModuleCtxToModuleQName;

public final class DeviationStatementSupport
        extends AbstractStatementSupport<Absolute, DeviationStatement, DeviationEffectiveStatement> {
    private static final SubstatementValidator SUBSTATEMENT_VALIDATOR =
        SubstatementValidator.builder(YangStmtMapping.DEVIATION)
            .addOptional(YangStmtMapping.DESCRIPTION)
            .addAny(YangStmtMapping.DEVIATE)
            .addOptional(YangStmtMapping.REFERENCE)
            .build();

    public DeviationStatementSupport(final YangParserConfiguration config) {
        super(YangStmtMapping.DEVIATION, StatementPolicy.reject(), config, SUBSTATEMENT_VALIDATOR);
    }

    @Override
    public Absolute parseArgumentValue(final StmtContext<?, ?, ?> ctx, final String value) {
        return ArgumentUtils.parseAbsoluteSchemaNodeIdentifier(ctx, value);
    }

    @Override
    public void onFullDefinitionDeclared(final Mutable<Absolute, DeviationStatement, DeviationEffectiveStatement> ctx) {
        super.onFullDefinitionDeclared(ctx);

        StmtContext<?, ?, ?> root = ctx.getRoot();
        if (root.producesDeclared(SubmoduleStatement.class)) {
            // root is submodule, we need to find the module we belong to. We can rely on there being exactly one
            // belongs-to statement, enforced SubmoduleStatementSupport's validator.
            root = Iterables.getOnlyElement(
                root.getAllFromNamespace(BelongsToPrefixToModuleCtx.class).values());
        }

        final var currentModule = verifyNotNull(ctx.getFromNamespace(ModuleCtxToModuleQName.class, root),
            "Failed to find QName for %s", root);
        final var targetModule = Iterables.getLast(ctx.getArgument().getNodeIdentifiers()).getModule();
        if (currentModule.equals(targetModule)) {
            throw new InferenceException(ctx,
                    "Deviation must not target the same module as the one it is defined in: %s", currentModule);
        }
    }

    @Override
    protected DeviationStatement createDeclared(final BoundStmtCtx<Absolute> ctx,
            final ImmutableList<DeclaredStatement<?>> substatements) {
        return DeclaredStatements.createDeviation(ctx.getRawArgument(), ctx.getArgument(), substatements);
    }

    @Override
    protected DeviationStatement attachDeclarationReference(final DeviationStatement stmt,
            final DeclarationReference reference) {
        return DeclaredStatementDecorators.decorateDeviation(stmt, reference);
    }

    @Override
    protected DeviationEffectiveStatement createEffective(final Current<Absolute, DeviationStatement> stmt,
            final ImmutableList<? extends EffectiveStatement<?, ?>> substatements) {
        return EffectiveStatements.createDeviation(stmt.declared(), substatements);
    }
}