/**
 *    Copyright 2011, Big Switch Networks, Inc.
 *    Originally created by David Erickson, Stanford University
 *
 *    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 net.onrc.onos.core.packet;

import java.nio.ByteBuffer;
import java.util.Arrays;
import java.util.HashMap;
import java.util.Map;

import net.floodlightcontroller.util.MACAddress;

import org.projectfloodlight.openflow.util.HexString;

// CHECKSTYLE IGNORE WriteTag FOR NEXT 2 LINES
/**
 * @author David Erickson (daviderickson@cs.stanford.edu)
 */
public class Ethernet extends BasePacket {
    private static final String HEXES = "0123456789ABCDEF";
    public static final short TYPE_ARP = 0x0806;
    public static final short TYPE_RARP = (short) 0x8035;
    public static final short TYPE_IPV4 = 0x0800;
    public static final short TYPE_LLDP = (short) 0x88cc;
    public static final short TYPE_BSN = (short) 0x8942;
    public static final short VLAN_UNTAGGED = (short) 0xffff;
    public static final short DATALAYER_ADDRESS_LENGTH = 6; // bytes
    public static final Map<Short, Class<? extends IPacket>> ETHER_TYPE_CLASS_MAP;

    static {
        ETHER_TYPE_CLASS_MAP = new HashMap<Short, Class<? extends IPacket>>();
        ETHER_TYPE_CLASS_MAP.put(TYPE_ARP, ARP.class);
        ETHER_TYPE_CLASS_MAP.put(TYPE_RARP, ARP.class);
        ETHER_TYPE_CLASS_MAP.put(TYPE_IPV4, IPv4.class);
        ETHER_TYPE_CLASS_MAP.put(TYPE_LLDP, LLDP.class);
    }

    protected MACAddress destinationMACAddress;
    protected MACAddress sourceMACAddress;
    protected byte priorityCode;
    protected short vlanID;
    protected short etherType;
    protected boolean pad = false;

    /**
     * By default, set Ethernet to untagged.
     */
    public Ethernet() {
        super();
        this.vlanID = VLAN_UNTAGGED;
    }

    /**
     * @return the destination MAC as a byte array
     */
    public byte[] getDestinationMACAddress() {
        return destinationMACAddress.toBytes();
    }

    /**
     * @return the destination MAC
     */
    public MACAddress getDestinationMAC() {
        return destinationMACAddress;
    }

    /**
     * @param destinationMACAddress the destination MAC to set
     */
    public Ethernet setDestinationMACAddress(byte[] destinationMACAddress) {
        this.destinationMACAddress = MACAddress.valueOf(destinationMACAddress);
        return this;
    }

    /**
     * @param destinationMACAddress the destination MAC to set
     */
    public Ethernet setDestinationMACAddress(String destinationMACAddress) {
        this.destinationMACAddress = MACAddress.valueOf(destinationMACAddress);
        return this;
    }

    /**
     * @return the source MACAddress as a byte array
     */
    public byte[] getSourceMACAddress() {
        return sourceMACAddress.toBytes();
    }

    /**
     * @return the source MACAddress
     */
    public MACAddress getSourceMAC() {
        return sourceMACAddress;
    }

    /**
     * @param sourceMACAddress the source MAC to set
     */
    public Ethernet setSourceMACAddress(byte[] sourceMACAddress) {
        this.sourceMACAddress = MACAddress.valueOf(sourceMACAddress);
        return this;
    }

    /**
     * @param sourceMACAddress the source MAC to set
     */
    public Ethernet setSourceMACAddress(String sourceMACAddress) {
        this.sourceMACAddress = MACAddress.valueOf(sourceMACAddress);
        return this;
    }

    /**
     * @return the priorityCode
     */
    public byte getPriorityCode() {
        return priorityCode;
    }

    /**
     * @param priorityCode the priorityCode to set
     */
    public Ethernet setPriorityCode(byte priorityCode) {
        this.priorityCode = priorityCode;
        return this;
    }

    /**
     * @return the vlanID
     */
    public short getVlanID() {
        return vlanID;
    }

    /**
     * @param vlanID the vlanID to set
     */
    public Ethernet setVlanID(short vlanID) {
        this.vlanID = vlanID;
        return this;
    }

    /**
     * @return the etherType
     */
    public short getEtherType() {
        return etherType;
    }

    /**
     * @param etherType the etherType to set
     */
    public Ethernet setEtherType(short etherType) {
        this.etherType = etherType;
        return this;
    }

    /**
     * @return True if the Ethernet frame is broadcast, false otherwise
     */
    public boolean isBroadcast() {
        assert (destinationMACAddress.length() == 6);
        return destinationMACAddress.isBroadcast();
    }

    /**
     * @return True is the Ethernet frame is multicast, False otherwise
     */
    public boolean isMulticast() {
        return destinationMACAddress.isMulticast();
    }

    /**
     * Pad this packet to 60 bytes minimum, filling with zeros?
     *
     * @return the pad
     */
    public boolean isPad() {
        return pad;
    }

    /**
     * Pad this packet to 60 bytes minimum, filling with zeros?
     *
     * @param pad the pad to set
     */
    public Ethernet setPad(boolean pad) {
        this.pad = pad;
        return this;
    }

    @Override
    public byte[] serialize() {
        byte[] payloadData = null;
        if (payload != null) {
            payload.setParent(this);
            payloadData = payload.serialize();
        }
        int length = 14 + ((vlanID == VLAN_UNTAGGED) ? 0 : 4) +
                ((payloadData == null) ? 0 : payloadData.length);
        if (pad && length < 60) {
            length = 60;
        }
        byte[] data = new byte[length];
        ByteBuffer bb = ByteBuffer.wrap(data);
        bb.put(destinationMACAddress.toBytes());
        bb.put(sourceMACAddress.toBytes());
        if (vlanID != VLAN_UNTAGGED) {
            bb.putShort((short) 0x8100);
            bb.putShort((short) ((priorityCode << 13) | (vlanID & 0x0fff)));
        }
        bb.putShort(etherType);
        if (payloadData != null) {
            bb.put(payloadData);
        }
        if (pad) {
            Arrays.fill(data, bb.position(), data.length, (byte) 0x0);
        }
        return data;
    }

    @Override
    public IPacket deserialize(byte[] data, int offset, int length) {
        if (length <= 0) {
            return null;
        }
        ByteBuffer bb = ByteBuffer.wrap(data, offset, length);
        if (this.destinationMACAddress == null) {
            this.destinationMACAddress = MACAddress.valueOf(new byte[6]);
        }
        byte[] dstAddr = new byte[MACAddress.MAC_ADDRESS_LENGTH];
        bb.get(dstAddr);
        this.destinationMACAddress = MACAddress.valueOf(dstAddr);

        if (this.sourceMACAddress == null) {
            this.sourceMACAddress = MACAddress.valueOf(new byte[6]);
        }
        byte[] srcAddr = new byte[MACAddress.MAC_ADDRESS_LENGTH];
        bb.get(srcAddr);
        this.sourceMACAddress = MACAddress.valueOf(srcAddr);

        short etherType = bb.getShort();
        if (etherType == (short) 0x8100) {
            short tci = bb.getShort();
            this.priorityCode = (byte) ((tci >> 13) & 0x07);
            this.vlanID = (short) (tci & 0x0fff);
            etherType = bb.getShort();
        } else {
            this.vlanID = VLAN_UNTAGGED;
        }
        this.etherType = etherType;

        IPacket payload;
        if (Ethernet.ETHER_TYPE_CLASS_MAP.containsKey(this.etherType)) {
            Class<? extends IPacket> clazz = Ethernet.ETHER_TYPE_CLASS_MAP.get(this.etherType);
            try {
                payload = clazz.newInstance();
            } catch (Exception e) {
                throw new RuntimeException("Error parsing payload for Ethernet packet", e);
            }
        } else {
            payload = new Data();
        }
        this.payload = payload.deserialize(data, bb.position(), bb.limit() - bb.position());
        this.payload.setParent(this);
        return this;
    }

    /**
     * Checks to see if a string is a valid MAC address.
     *
     * @param macAddress MAC address to be checked
     * @return True if macAddress is a valid MAC, False otherwise
     */
    public static boolean isMACAddress(String macAddress) {
        String[] macBytes = macAddress.split(":");
        if (macBytes.length != 6) {
            return false;
        }
        for (int i = 0; i < 6; ++i) {
            if (HEXES.indexOf(macBytes[i].toUpperCase().charAt(0)) == -1 ||
                    HEXES.indexOf(macBytes[i].toUpperCase().charAt(1)) == -1) {
                return false;
            }
        }
        return true;
    }

    /**
     * Accepts a MAC address of the form 00:aa:11:bb:22:cc, case does not
     * matter, and returns a corresponding byte[].
     *
     * @param macAddress The MAC address to convert into a bye array
     * @return The macAddress as a byte array
     */
    public static byte[] toMACAddress(String macAddress) {
        return MACAddress.valueOf(macAddress).toBytes();
    }


    /**
     * Accepts a MAC address and returns the corresponding long, where the
     * MAC bytes are set on the lower order bytes of the long.
     *
     * @param macAddress MAC address to be converted to long value
     * @return a long containing the mac address bytes
     */
    public static long toLong(byte[] macAddress) {
        return MACAddress.valueOf(macAddress).toLong();
    }

    /**
     * Convert a long MAC address to a byte array.
     *
     * @param macAddress MAC address to be converted to a byte array
     * @return the bytes of the mac address
     */
    public static byte[] toByteArray(long macAddress) {
        return MACAddress.valueOf(macAddress).toBytes();
    }

    /* (non-Javadoc)
     * @see java.lang.Object#hashCode()
     */
    @Override
    public int hashCode() {
        final int prime = 7867;
        int result = super.hashCode();
        result = prime * result + destinationMACAddress.hashCode();
        result = prime * result + etherType;
        result = prime * result + vlanID;
        result = prime * result + priorityCode;
        result = prime * result + (pad ? 1231 : 1237);
        result = prime * result + sourceMACAddress.hashCode();
        return result;
    }

    /* (non-Javadoc)
     * @see java.lang.Object#equals(java.lang.Object)
     */
    @Override
    public boolean equals(Object obj) {
        if (this == obj) {
            return true;
        }
        if (!super.equals(obj)) {
            return false;
        }
        if (!(obj instanceof Ethernet)) {
            return false;
        }
        Ethernet other = (Ethernet) obj;
        if (!destinationMACAddress.equals(other.destinationMACAddress)) {
            return false;
        }
        if (priorityCode != other.priorityCode) {
            return false;
        }
        if (vlanID != other.vlanID) {
            return false;
        }
        if (etherType != other.etherType) {
            return false;
        }
        if (pad != other.pad) {
            return false;
        }
        if (!sourceMACAddress.equals(other.sourceMACAddress)) {
            return false;
        }
        return true;
    }

    /* (non-Javadoc)
     * @see java.lang.Object#toString(java.lang.Object)
     */
    @Override
    public String toString() {

        StringBuffer sb = new StringBuffer("\n");

        IPacket pkt = this.getPayload();

        if (pkt instanceof ARP) {
            sb.append("arp");
        } else if (pkt instanceof LLDP) {
            sb.append("lldp");
        } else if (pkt instanceof ICMP) {
            sb.append("icmp");
        } else if (pkt instanceof IPv4) {
            sb.append("ip");
        } else if (pkt instanceof DHCP) {
            sb.append("dhcp");
        } else {
            sb.append(this.getEtherType());
        }

        sb.append("\ndl_vlan: ");
        if (this.getVlanID() == Ethernet.VLAN_UNTAGGED) {
            sb.append("untagged");
        } else {
            sb.append(this.getVlanID());
        }
        sb.append("\ndl_vlan_pcp: ");
        sb.append(this.getPriorityCode());
        sb.append("\ndl_src: ");
        sb.append(HexString.toHexString(this.getSourceMACAddress()));
        sb.append("\ndl_dst: ");
        sb.append(HexString.toHexString(this.getDestinationMACAddress()));


        if (pkt instanceof ARP) {
            ARP p = (ARP) pkt;
            sb.append("\nnw_src: ");
            sb.append(IPv4.fromIPv4Address(IPv4.toIPv4Address(p.getSenderProtocolAddress())));
            sb.append("\nnw_dst: ");
            sb.append(IPv4.fromIPv4Address(IPv4.toIPv4Address(p.getTargetProtocolAddress())));
        } else if (pkt instanceof LLDP) {
            sb.append("lldp packet");
        } else if (pkt instanceof ICMP) {
            ICMP icmp = (ICMP) pkt;
            sb.append("\nicmp_type: ");
            sb.append(icmp.getIcmpType());
            sb.append("\nicmp_code: ");
            sb.append(icmp.getIcmpCode());
        } else if (pkt instanceof IPv4) {
            IPv4 p = (IPv4) pkt;
            sb.append("\nnw_src: ");
            sb.append(IPv4.fromIPv4Address(p.getSourceAddress()));
            sb.append("\nnw_dst: ");
            sb.append(IPv4.fromIPv4Address(p.getDestinationAddress()));
            sb.append("\nnw_tos: ");
            sb.append(p.getDiffServ());
            sb.append("\nnw_proto: ");
            sb.append(p.getProtocol());

            IPacket payload = pkt.getPayload();
            if (payload instanceof TCP) {
                sb.append("\ntp_src: ");
                sb.append(((TCP) payload).getSourcePort());
                sb.append("\ntp_dst: ");
                sb.append(((TCP) payload).getDestinationPort());

            } else if (payload instanceof UDP) {
                sb.append("\ntp_src: ");
                sb.append(((UDP) payload).getSourcePort());
                sb.append("\ntp_dst: ");
                sb.append(((UDP) payload).getDestinationPort());
            } else if (payload instanceof ICMP) {
                ICMP icmp = (ICMP) payload;
                sb.append("\nicmp_type: ");
                sb.append(icmp.getIcmpType());
                sb.append("\nicmp_code: ");
                sb.append(icmp.getIcmpCode());
            } else {
                sb.append("\nunknown IPv4 packet");
            }

        } else if (pkt instanceof DHCP) {
            sb.append("\ndhcp packet");
        } else if (pkt instanceof Data) {
            sb.append("\ndata packet");
        } else if (pkt instanceof LLC) {
            sb.append("\nllc packet");
        } else {
            sb.append("\nunknown packet");
        }

        return sb.toString();
    }
}