/*
 * Copyright (c) 2014 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.controller.cluster.datastore.node.utils.stream;

import static java.util.Objects.requireNonNull;

import com.google.common.collect.ImmutableMap;
import java.math.BigDecimal;
import java.math.BigInteger;
import java.util.Set;
import org.opendaylight.yangtools.yang.common.Empty;
import org.opendaylight.yangtools.yang.common.QName;
import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;

final class ValueTypes {
    // The String length threshold beyond which a String should be encoded as bytes
    static final int STRING_BYTES_LENGTH_THRESHOLD = Short.MAX_VALUE / 4;

    static final byte SHORT_TYPE = 1;
    static final byte BYTE_TYPE = 2;
    static final byte INT_TYPE = 3;
    static final byte LONG_TYPE = 4;
    static final byte BOOL_TYPE = 5;
    static final byte QNAME_TYPE = 6;
    static final byte BITS_TYPE = 7;
    static final byte YANG_IDENTIFIER_TYPE = 8;
    static final byte STRING_TYPE = 9;
    static final byte BIG_INTEGER_TYPE = 10;
    static final byte BIG_DECIMAL_TYPE = 11;
    static final byte BINARY_TYPE = 12;
    // Leaf nodes no longer allow null values. The "empty" type is now represented as
    // org.opendaylight.yangtools.yang.common.Empty. This is kept for backwards compatibility.
    @Deprecated
    static final byte NULL_TYPE = 13;
    static final byte STRING_BYTES_TYPE = 14;
    static final byte EMPTY_TYPE = 15;

    private static final ImmutableMap<Class<?>, Byte> TYPES = ImmutableMap.<Class<?>, Byte>builder()
            .put(String.class, STRING_TYPE)
            .put(Byte.class, BYTE_TYPE)
            .put(Integer.class, INT_TYPE)
            .put(Long.class, LONG_TYPE)
            .put(Boolean.class, BOOL_TYPE)
            .put(QName.class, QNAME_TYPE)
            .put(Short.class, SHORT_TYPE)
            .put(BigInteger.class, BIG_INTEGER_TYPE)
            .put(BigDecimal.class, BIG_DECIMAL_TYPE)
            .put(byte[].class, BINARY_TYPE)
            .put(Empty.class, EMPTY_TYPE)
            .build();

    private ValueTypes() {
        throw new UnsupportedOperationException("Utility class");
    }

    static byte getSerializableType(final Object node) {
        final Byte type = TYPES.get(requireNonNull(node).getClass());
        if (type != null) {
            if (type == STRING_TYPE && ((String) node).length() >= STRING_BYTES_LENGTH_THRESHOLD) {
                return STRING_BYTES_TYPE;
            }
            return type;
        }

        if (node instanceof Set) {
            return BITS_TYPE;
        }

        if (node instanceof YangInstanceIdentifier) {
            return YANG_IDENTIFIER_TYPE;
        }

        throw new IllegalArgumentException("Unknown value type " + node.getClass().getSimpleName());
    }
}