package net.onrc.onos.datastore.topology;

import java.nio.ByteBuffer;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
import java.util.TreeSet;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.esotericsoftware.kryo.Kryo;

import edu.stanford.ramcloud.JRamCloud;
import net.onrc.onos.datastore.RCObject;
import net.onrc.onos.datastore.RCTable;
import net.onrc.onos.datastore.topology.RCLink.STATUS;
import net.onrc.onos.datastore.utils.ByteArrayComparator;
import net.onrc.onos.datastore.utils.ByteArrayUtil;

public class RCDevice extends RCObject {
    @SuppressWarnings("unused")
    private static final Logger log = LoggerFactory.getLogger(RCDevice.class);

    private static final ThreadLocal<Kryo> deviceKryo = new ThreadLocal<Kryo>() {
	@Override
	protected Kryo initialValue() {
	    Kryo kryo = new Kryo();
	    kryo.setRegistrationRequired(true);
	    kryo.setReferences(false);
	    kryo.register(byte[].class);
	    kryo.register(byte[][].class);
	    kryo.register(HashMap.class);
	    // TODO check if we should explicitly specify EnumSerializer
	    kryo.register(STATUS.class);
	    return kryo;
	}
    };

    public static final String GLOBAL_DEVICE_TABLE_NAME = "G:Device";

    // FIXME these should be Enum or some number, not String
    private static final String PROP_MAC = "mac";
    private static final String PROP_PORT_IDS = "port-ids";

    private final byte[] mac;
    private TreeSet<byte[]> portIds;
    transient private boolean isPortIdsModified;

    // Assuming mac is unique cluster-wide
    public static byte[] getDeviceID(final byte[] mac) {
	return ByteBuffer.allocate(2 + mac.length).putChar('D').put(mac)
	        .array();
    }

    public static StringBuilder keysToSB(Collection<byte[]> keys) {
	StringBuilder sb = new StringBuilder();
	sb.append("[");
	boolean hasWritten = false;
	for (byte[] key : keys) {
	    if (hasWritten) {
		sb.append(", ");
	    }
	    sb.append(keyToString(key));
	    hasWritten = true;
	}
	sb.append("]");
	return sb;
    }

    public static String keyToString(byte[] key) {
	// For debug log
	byte[] mac = getMacFromKey(key);
	return "D" + ByteArrayUtil.toHexStringBuffer(mac, ":");
    }

    public static byte[] getMacFromKey(byte[] key) {
	ByteBuffer keyBuf = ByteBuffer.wrap(key);
	if (keyBuf.getChar() != 'D') {
	    throw new IllegalArgumentException("Invalid Device key");
	}
	byte[] mac = new byte[keyBuf.remaining()];
	keyBuf.get(mac);
	return mac;
    }

    public RCDevice(byte[] mac) {
	super(RCTable.getTable(GLOBAL_DEVICE_TABLE_NAME), getDeviceID(mac));

	this.mac = mac;
	this.portIds = new TreeSet<>(ByteArrayComparator.BYTEARRAY_COMPARATOR);
	this.isPortIdsModified = true;
    }

    /**
     * Get an instance from Key.
     *
     * @note You need to call `read()` to get the DB content.
     * @param key
     * @return
     */
    public static <D extends RCObject> D createFromKey(byte[] key) {
	@SuppressWarnings("unchecked")
	D d = (D) new RCDevice(getMacFromKey(key));
	return d;
    }

    public static Iterable<RCDevice> getAllDevices() {
	return new DeviceEnumerator();
    }

    public static class DeviceEnumerator implements Iterable<RCDevice> {

	@Override
	public Iterator<RCDevice> iterator() {
	    return new DeviceIterator();
	}
    }

    public static class DeviceIterator extends ObjectIterator<RCDevice> {

	public DeviceIterator() {
	    super(RCTable.getTable(GLOBAL_DEVICE_TABLE_NAME));
	}

	@Override
	public RCDevice next() {
	    JRamCloud.Object o = enumerator.next();
	    RCDevice e = RCDevice.createFromKey(o.key);
	    e.setValueAndDeserialize(o.value, o.version);
	    return e;
	}
    }

    public byte[] getMac() {
	// TODO may need to clone() to be sure this object will be immutable.
	return mac;
    }

    public byte[] getId() {
	return getKey();
    }

    public void addPortId(byte[] portId) {
	// TODO: Should we copy portId, or reference is OK.
	isPortIdsModified |= portIds.add(portId);
    }

    public void removePortId(byte[] portId) {
	isPortIdsModified |= portIds.remove(portId);
    }

    public void emptyPortIds() {
	portIds.clear();
	this.isPortIdsModified = true;
    }

    public void addAllToPortIds(Collection<byte[]> portIds) {
	// TODO: Should we copy portId, or reference is OK.
	isPortIdsModified |= this.portIds.addAll(portIds);
    }

    /**
     *
     * @return Unmodifiable Set view of all the PortIds;
     */
    public Set<byte[]> getAllPortIds() {
	return Collections.unmodifiableSet(portIds);
    }

    @Override
    public void serializeAndSetValue() {
	Map<Object, Object> map = getObjectMap();

	map.put(PROP_MAC, mac);
	if (isPortIdsModified) {
	    byte[] portIdArray[] = new byte[portIds.size()][];
	    map.put(PROP_PORT_IDS, portIds.toArray(portIdArray));
	    isPortIdsModified = false;
	}

	serializeAndSetValue(deviceKryo.get(), map);
    }

    @Override
    public Map<Object, Object> deserializeObjectFromValue() {
	Map<Object, Object> map = deserializeObjectFromValue(deviceKryo.get());

	if (this.portIds == null) {
	    this.portIds = new TreeSet<>(
		    ByteArrayComparator.BYTEARRAY_COMPARATOR);
	}
	byte[] portIdArray[] = (byte[][]) map.get(PROP_PORT_IDS);
	if (portIdArray != null) {
	    this.portIds.clear();
	    this.portIds.addAll(Arrays.asList(portIdArray));
	    isPortIdsModified = false;
	} else {
	    // trigger write on next serialize
	    isPortIdsModified = true;
	}

	return map;
    }

    @Override
    public String toString() {
	// TODO OUTPUT ALL?
	return "[RCDevice " + ByteArrayUtil.toHexStringBuffer(mac, ":") + "]";
    }

    public static void main(String[] args) {
	// TODO Auto-generated method stub

    }

}