//
// MessagePack for Java
//
// Copyright (C) 2009 - 2013 FURUHASHI Sadayuki
//
//    Licensed 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.msgpack.template;

import java.io.IOException;
import java.util.HashMap;

import org.msgpack.MessageTypeException;
import org.msgpack.annotation.OrdinalEnum;
import org.msgpack.packer.Packer;
import org.msgpack.unpacker.Unpacker;

public class OrdinalEnumTemplate<T> extends AbstractTemplate<T> {
    protected T[] entries;
    protected HashMap<T, Integer> reverse;
    protected boolean strict;

    public OrdinalEnumTemplate(Class<T> targetClass) {
        entries = targetClass.getEnumConstants();
        reverse = new HashMap<T, Integer>();
        for (int i = 0; i < entries.length; i++) {
            reverse.put(entries[i], i);
        }
		strict = !targetClass.isAnnotationPresent(OrdinalEnum.class)
				|| targetClass.getAnnotation(OrdinalEnum.class).strict();
    }

    @Override
    public void write(Packer pk, T target, boolean required) throws IOException {
        if (target == null) {
            if (required) {
                throw new MessageTypeException("Attempted to write null");
            }
            pk.writeNil();
            return;
        }
        Integer ordinal = reverse.get(target);
        if (ordinal == null) {
            throw new MessageTypeException(
                    new IllegalArgumentException("ordinal: " + ordinal));
        }
        pk.write((int) ordinal);
    }

    @Override
    public T read(Unpacker pac, T to, boolean required) throws IOException,
            MessageTypeException {
        if (!required && pac.trySkipNil()) {
            return null;
        }

        int ordinal = pac.readInt();

		if (ordinal < entries.length) {
			return entries[ordinal];
		}

		if (!strict) {
			return null;
		}

		throw new MessageTypeException(new IllegalArgumentException("ordinal: "
				+ ordinal));

    }
}