/**
 * Copyright (c) 2015 Cisco Systems, Inc. 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.stmt.rfc6020;

import com.google.common.collect.ImmutableList;
import java.util.Collection;
import java.util.Objects;
import javax.annotation.Nonnull;
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.meta.StatementDefinition;
import org.opendaylight.yangtools.yang.model.api.meta.StatementSource;
import org.opendaylight.yangtools.yang.model.api.stmt.MandatoryStatement;

abstract class EmptyMandatoryStatement implements MandatoryStatement {
    static final MandatoryStatement FALSE = new EmptyMandatoryStatement() {
        @Nonnull
        @Override
        public Boolean getValue() {
            return Boolean.FALSE;
        }

        @Override
        EffectiveStatement<Boolean, MandatoryStatement> toEffective() {
            return EmptyMandatoryEffectiveStatement.FALSE;
        }
    };

    static final MandatoryStatement TRUE = new EmptyMandatoryStatement() {
        @Nonnull
        @Override
        public Boolean getValue() {
            return Boolean.TRUE;
        }

        @Override
        EffectiveStatement<Boolean, MandatoryStatement> toEffective() {
            return EmptyMandatoryEffectiveStatement.TRUE;
        }
    };

    private EmptyMandatoryStatement() {
        // Invisible on purpose
    }

    abstract EffectiveStatement<Boolean, MandatoryStatement> toEffective();

    @Nonnull
    @Override
    public final Collection<? extends DeclaredStatement<?>> declaredSubstatements() {
        return ImmutableList.of();
    }

    @Nonnull
    @Override
    public final StatementDefinition statementDefinition() {
        return YangStmtMapping.MANDATORY;
    }

    @Override
    public final String rawArgument() {
        return getValue().toString();
    }

    @Override
    public final Boolean argument() {
        return getValue();
    }

    @Nonnull
    @Override
    public final StatementSource getStatementSource() {
        return StatementSource.DECLARATION;
    }

    @Override
    public final int hashCode() {
        return Objects.hash(statementDefinition(), getStatementSource(), argument(),
            rawArgument(), declaredSubstatements(), getValue());
    }

    @Override
    public final boolean equals(final Object obj) {
        if (this == obj) {
            return true;
        }
        if (!(obj instanceof MandatoryStatement)) {
            return false;
        }

        final MandatoryStatement other = (MandatoryStatement) obj;

        return  argument().equals(other.argument()) &&
                rawArgument().equals(other.rawArgument()) &&
                getValue().equals(other.getValue()) &&
                statementDefinition().equals(other.statementDefinition()) &&
                getStatementSource().equals(other.getStatementSource()) &&
                declaredSubstatements().equals(other.declaredSubstatements());
    }
}