/*
 *  Licensed to the Apache Software Foundation (ASF) under one
 *  or more contributor license agreements.  See the NOTICE file
 *  distributed with this work for additional information
 *  regarding copyright ownership.  The ASF licenses this file
 *  to you 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 org.apache.causeway.persistence.jdo.datanucleus.valuetypes;

import java.util.UUID;

import javax.annotation.Priority;
import javax.jdo.identity.ObjectIdentity;

import org.springframework.stereotype.Component;

import org.apache.causeway.applib.annotation.PriorityPrecedence;
import org.apache.causeway.applib.util.schema.CommonDtoUtils;
import org.apache.causeway.applib.value.semantics.ValueDecomposition;
import org.apache.causeway.applib.value.semantics.ValueSemanticsBasedOnIdStringifier;
import org.apache.causeway.commons.internal.factory._InstanceUtil;
import org.apache.causeway.schema.common.v2.ValueType;

import lombok.Builder;
import lombok.NonNull;
import lombok.val;

/**
 * Implementation for application-defined primary keys.
 *
 * <p>
 *     For the most part this relies on the JDO spec (5.4.3), but with special case handling if the primary key is
 *     of type int, long or UUID: rather than encode the fully qualified classname, instead uses a simpler prefix.
 * </p>
 */
@Component
@Priority(PriorityPrecedence.LATE)
@Builder
public class JdoObjectIdentityValueSemantics
extends ValueSemanticsBasedOnIdStringifier<ObjectIdentity> {

    private static final String PREFIX_UUID = "u_";
    private static final String PREFIX_LONG = "l_";
    private static final String PREFIX_INT = "i_";

    public JdoObjectIdentityValueSemantics() {
        super(ObjectIdentity.class);
    }

    // -- COMPOSER

    @Override
    public ValueDecomposition decompose(final ObjectIdentity value) {
        return CommonDtoUtils.typedTupleBuilder(value)
                .addFundamentalType(ValueType.STRING, "targetClassName", ObjectIdentity::getTargetClassName)
                .addFundamentalType(ValueType.STRING, "key", this::enstring)
                .buildAsDecomposition();
    }

    @Override
    public ObjectIdentity compose(final ValueDecomposition decomposition) {
        val elementMap = CommonDtoUtils.typedTupleAsMap(decomposition.rightIfAny());
        final String targetClassName = (String)elementMap.get("targetClassName");
        final String key = (String)elementMap.get("key");
        return destring(_InstanceUtil.loadClass(targetClassName), key);
    }

    // -- ID STRINGIFIER

    @Override
    public String enstring(final @NonNull ObjectIdentity value) {
        Object keyAsObject = value.getKeyAsObject();
        if (keyAsObject instanceof Long) {
            return PREFIX_LONG + keyAsObject;
        }
        if (keyAsObject instanceof Integer) {
            return PREFIX_INT + keyAsObject;
        }
        if (keyAsObject instanceof UUID) {
            return PREFIX_UUID + keyAsObject;
        }
        // fall through to JDO spec (5.4.3)
        return keyAsObject.toString();
    }

    @Override
    public ObjectIdentity destring(
            final @NonNull Class<?> targetEntityClass,
            final @NonNull String stringified) {
        if (stringified.startsWith(PREFIX_LONG)) {
            return new ObjectIdentity(targetEntityClass, Long.parseLong(stringified.substring(PREFIX_LONG.length())));
        }
        if (stringified.startsWith(PREFIX_INT)) {
            return new ObjectIdentity(targetEntityClass, Integer.parseInt(stringified.substring(PREFIX_INT.length())));
        }
        if (stringified.startsWith(PREFIX_UUID)) {
            return new ObjectIdentity(targetEntityClass, UUID.fromString(stringified.substring(PREFIX_UUID.length())));
        }
        // fall through to JDO spec (5.4.3)
        return new ObjectIdentity(targetEntityClass, stringified);
    }
}
