/*
 *  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
 *
 *    https://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.grails.datastore.gorm.timestamp;

import java.util.Date;

import org.codehaus.groovy.runtime.DefaultGroovyMethods;

import org.springframework.util.ClassUtils;

/**
 * Default implementation of TimestampProvider
 *
 * supports creating timestamps for any class that supports a constructor that accepts a Long or long value.
 *
 * "currentTimeMillis" can be overrided in subclasses (useful for testing purposes)
 *
 */
public class DefaultTimestampProvider implements TimestampProvider {

    protected long currentTimeMillis() {
        return System.currentTimeMillis();
    }

    @Override
    public boolean supportsCreating(Class<?> dateTimeClass) {
        return true;
    }

    @SuppressWarnings("unchecked")
    @Override
    public <T> T createTimestamp(final Class<T> dateTimeClass) {
        long timestampMillis = currentTimeMillis();
        if (dateTimeClass == String.class) {
            return (T) String.valueOf(timestampMillis);
        } else {
            Class<?> actualDateTimeClass;
            if (dateTimeClass == Object.class) {
                actualDateTimeClass = Date.class;
            } else {
                actualDateTimeClass = ClassUtils.resolvePrimitiveIfNecessary(dateTimeClass);
            }
            try {
                return (T) DefaultGroovyMethods.newInstance(actualDateTimeClass, new Object[] { timestampMillis });
            } catch (Exception e) {
                return (T) DefaultGroovyMethods.invokeMethod(actualDateTimeClass, "now", null);
            }
        }
    }
}
