/**
 * 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.activemq.transport.amqp;

import java.nio.ByteBuffer;
import java.util.AbstractMap;
import java.util.Map;

import org.apache.activemq.command.ActiveMQDestination;
import org.apache.qpid.proton.amqp.Binary;
import org.apache.qpid.proton.amqp.DescribedType;
import org.apache.qpid.proton.amqp.Symbol;
import org.apache.qpid.proton.amqp.UnsignedLong;
import org.apache.qpid.proton.amqp.transaction.Coordinator;
import org.fusesource.hawtbuf.Buffer;

/**
 * Set of useful methods and definitions used in the AMQP protocol handling
 */
public class AmqpSupport {

    // Identification values used to locating JMS selector types.
    public static final UnsignedLong JMS_SELECTOR_CODE = UnsignedLong.valueOf(0x0000468C00000004L);
    public static final Symbol JMS_SELECTOR_NAME = Symbol.valueOf("apache.org:selector-filter:string");
    public static final Object[] JMS_SELECTOR_FILTER_IDS = new Object[] { JMS_SELECTOR_CODE, JMS_SELECTOR_NAME };
    public static final UnsignedLong NO_LOCAL_CODE = UnsignedLong.valueOf(0x0000468C00000003L);
    public static final Symbol NO_LOCAL_NAME = Symbol.valueOf("apache.org:selector-filter:string");
    public static final Object[] NO_LOCAL_FILTER_IDS = new Object[] { NO_LOCAL_CODE, NO_LOCAL_NAME };

    // Capabilities used to identify destination type in some requests.
    public static final Symbol TEMP_QUEUE_CAPABILITY = Symbol.valueOf("temporary-queue");
    public static final Symbol TEMP_TOPIC_CAPABILITY = Symbol.valueOf("temporary-topic");

    // Symbols used to announce connection information to remote peer.
    public static final Symbol INVALID_FIELD = Symbol.valueOf("invalid-field");
    public static final Symbol CONTAINER_ID = Symbol.valueOf("container-id");

    // Symbols used to announce connection information to remote peer.
    public static final Symbol ANONYMOUS_RELAY = Symbol.valueOf("ANONYMOUS-RELAY");
    public static final Symbol QUEUE_PREFIX = Symbol.valueOf("queue-prefix");
    public static final Symbol TOPIC_PREFIX = Symbol.valueOf("topic-prefix");
    public static final Symbol CONNECTION_OPEN_FAILED = Symbol.valueOf("amqp:connection-establishment-failed");

    // Symbols used in configuration of newly opened links.
    public static final Symbol COPY = Symbol.getSymbol("copy");

    // Lifetime policy symbols
    public static final Symbol LIFETIME_POLICY = Symbol.valueOf("lifetime-policy");

    /**
     * Search for a given Symbol in a given array of Symbol object.
     *
     * @param symbols
     *        the set of Symbols to search.
     * @param key
     *        the value to try and find in the Symbol array.
     *
     * @return true if the key is found in the given Symbol array.
     */
    public static boolean contains(Symbol[] symbols, Symbol key) {
        if (symbols == null || symbols.length == 0) {
            return false;
        }

        for (Symbol symbol : symbols) {
            if (symbol.equals(key)) {
                return true;
            }
        }

        return false;
    }

    /**
     * Search for a particular filter using a set of known indentification values
     * in the Map of filters.
     *
     * @param filters
     *        The filters map that should be searched.
     * @param filterIds
     *        The aliases for the target filter to be located.
     *
     * @return the filter if found in the mapping or null if not found.
     */
    public static Map.Entry<Symbol, DescribedType> findFilter(Map<Symbol, Object> filters, Object[] filterIds) {

        if (filterIds == null || filterIds.length == 0) {
            throw new IllegalArgumentException("Invalid Filter Ids array passed: " + filterIds);
        }

        if (filters == null || filters.isEmpty()) {
            return null;
        }

        for (Map.Entry<Symbol, Object> filter : filters.entrySet()) {
            if (filter.getValue() instanceof DescribedType) {
                DescribedType describedType = ((DescribedType) filter.getValue());
                Object descriptor = describedType.getDescriptor();

                for (Object filterId : filterIds) {
                    if (descriptor.equals(filterId)) {
                        return new AbstractMap.SimpleImmutableEntry<Symbol, DescribedType>(filter.getKey(), describedType);
                    }
                }
            }
        }

        return null;
    }

    /**
     * Conversion from Java ByteBuffer to a HawtBuf buffer.
     *
     * @param data
     *        the ByteBuffer instance to convert.
     *
     * @return a new HawtBuf buffer converted from the given ByteBuffer.
     */
    public static Buffer toBuffer(ByteBuffer data) {
        if (data == null) {
            return null;
        }

        Buffer rc;

        if (data.isDirect()) {
            rc = new Buffer(data.remaining());
            data.get(rc.data);
        } else {
            rc = new Buffer(data);
            data.position(data.position() + data.remaining());
        }

        return rc;
    }

    /**
     * Given a long value, convert it to a byte array for marshalling.
     *
     * @param value
     *        the value to convert.
     *
     * @return a new byte array that holds the big endian value of the long.
     */
    public static byte[] toBytes(long value) {
        Buffer buffer = new Buffer(8);
        buffer.bigEndianEditor().writeLong(value);
        return buffer.data;
    }

    /**
     * Converts a Binary value to a long assuming that the contained value is
     * stored in Big Endian encoding.
     *
     * @param value
     *        the Binary object whose payload is converted to a long.
     *
     * @return a long value constructed from the bytes of the Binary instance.
     */
    public static long toLong(Binary value) {
        Buffer buffer = new Buffer(value.getArray(), value.getArrayOffset(), value.getLength());
        return buffer.bigEndianEditor().readLong();
    }

    /**
     * Given an AMQP endpoint, deduce the appropriate ActiveMQDestination type and create
     * a new instance.  By default if the endpoint address does not carry the standard prefix
     * value then we default to a Queue type destination.  If the endpoint is null or is an
     * AMQP Coordinator type endpoint this method returns null to indicate no destination
     * can be mapped.
     *
     * @param endpoint
     *        the AMQP endpoint to construct an ActiveMQDestination from.
     *
     * @return a new ActiveMQDestination that best matches the address of the given endpoint
     *
     * @throws AmqpProtocolException if an error occurs while deducing the destination type.
     */
    public static ActiveMQDestination createDestination(Object endpoint) throws AmqpProtocolException {
        if (endpoint == null) {
            return null;
        } else if (endpoint instanceof Coordinator) {
            return null;
        } else if (endpoint instanceof org.apache.qpid.proton.amqp.messaging.Terminus) {
            org.apache.qpid.proton.amqp.messaging.Terminus terminus = (org.apache.qpid.proton.amqp.messaging.Terminus) endpoint;
            if (terminus.getAddress() == null || terminus.getAddress().length() == 0) {
                if (terminus instanceof org.apache.qpid.proton.amqp.messaging.Source) {
                    throw new AmqpProtocolException("amqp:invalid-field", "source address not set");
                } else {
                    throw new AmqpProtocolException("amqp:invalid-field", "target address not set");
                }
            }

            return ActiveMQDestination.createDestination(terminus.getAddress(), ActiveMQDestination.QUEUE_TYPE);
        } else {
            throw new RuntimeException("Unexpected terminus type: " + endpoint);
        }
    }
}
