/*
 * 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.onlab.onos.net.flow.instructions;

import static com.google.common.base.MoreObjects.toStringHelper;
import static com.google.common.base.Preconditions.checkNotNull;

import java.util.Objects;

import org.onlab.onos.net.PortNumber;
import org.onlab.onos.net.flow.instructions.L2ModificationInstruction.L2SubType;
import org.onlab.onos.net.flow.instructions.L2ModificationInstruction.ModEtherInstruction;
import org.onlab.onos.net.flow.instructions.L3ModificationInstruction.L3SubType;
import org.onlab.onos.net.flow.instructions.L3ModificationInstruction.ModIPInstruction;
import org.onlab.packet.IpPrefix;
import org.onlab.packet.MacAddress;
import org.onlab.packet.VlanId;

/**
 * Factory class for creating various traffic treatment instructions.
 */
public final class Instructions {


    // Ban construction
    private Instructions() {}

    /**
     * Creates an output instruction using the specified port number. This can
     * include logical ports such as CONTROLLER, FLOOD, etc.
     *
     * @param number port number
     * @return output instruction
     */
    public static OutputInstruction createOutput(final PortNumber number) {
        checkNotNull(number, "PortNumber cannot be null");
        return new OutputInstruction(number);
    }

    /**
     * Creates a drop instruction.
     * @return drop instruction
     */
    public static DropInstruction createDrop() {
        return new DropInstruction();
    }

    /**
     * Creates a l2 src modification.
     * @param addr the mac address to modify to.
     * @return a l2 modification
     */
    public static L2ModificationInstruction modL2Src(MacAddress addr) {
        checkNotNull(addr, "Src l2 address cannot be null");
        return new ModEtherInstruction(L2SubType.ETH_SRC, addr);
    }

    /**
     * Creates a L2 dst modification.
     * @param addr the mac address to modify to.
     * @return a L2 modification
     */
    public static L2ModificationInstruction modL2Dst(MacAddress addr) {
        checkNotNull(addr, "Dst l2 address cannot be null");
        return new L2ModificationInstruction.ModEtherInstruction(L2SubType.ETH_DST, addr);
    }

    /**
     * Creates a Vlan id modification.
     * @param vlanId the vlan id to modify to.
     * @return a L2 modification
     */
    public static L2ModificationInstruction modVlanId(VlanId vlanId) {
        checkNotNull(vlanId, "VLAN id cannot be null");
        return new L2ModificationInstruction.ModVlanIdInstruction(vlanId);
    }

    /**
     * Creates a Vlan pcp modification.
     * @param vlanPcp the pcp to modify to.
     * @return a L2 modification
     */
    public static L2ModificationInstruction modVlanPcp(Byte vlanPcp) {
        checkNotNull(vlanPcp, "VLAN Pcp cannot be null");
        return new L2ModificationInstruction.ModVlanPcpInstruction(vlanPcp);
    }

    /**
     * Creates a L3 src modification.
     * @param addr the ip address to modify to.
     * @return a L3 modification
     */
    public static L3ModificationInstruction modL3Src(IpPrefix addr) {
        checkNotNull(addr, "Src l3 address cannot be null");
        return new ModIPInstruction(L3SubType.IP_SRC, addr);
    }

    /**
     * Creates a L3 dst modification.
     * @param addr the ip address to modify to.
     * @return a L3 modification
     */
    public static L3ModificationInstruction modL3Dst(IpPrefix addr) {
        checkNotNull(addr, "Dst l3 address cannot be null");
        return new ModIPInstruction(L3SubType.IP_DST, addr);
    }


    /*
     *  Output instructions
     */

    public static final class DropInstruction implements Instruction {
        @Override
        public Type type() {
            return Type.DROP;
        }

        @Override
        public String toString() {
            return toStringHelper(type()).toString();

        }

        @Override
        public int hashCode() {
            return Objects.hash(type());
        }

        @Override
        public boolean equals(Object obj) {
            if (this == obj) {
                return true;
            }
            if (obj instanceof DropInstruction) {
                DropInstruction that = (DropInstruction) obj;
                return Objects.equals(type(), that.type());

            }
            return false;
        }
    }


    public static final class OutputInstruction implements Instruction {
        private final PortNumber port;

        private OutputInstruction(PortNumber port) {
            this.port = port;
        }

        public PortNumber port() {
            return port;
        }

        @Override
        public Type type() {
            return Type.OUTPUT;
        }
        @Override
        public String toString() {
            return toStringHelper(type().toString())
                    .add("port", port).toString();
        }

        @Override
        public int hashCode() {
            return Objects.hash(port, type());
        }

        @Override
        public boolean equals(Object obj) {
            if (this == obj) {
                return true;
            }
            if (obj instanceof OutputInstruction) {
                OutputInstruction that = (OutputInstruction) obj;
                        Objects.equals(port, that.port);

            }
            return false;
        }
    }

}