package org.onlab.onos.of.controller.impl;

import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;

import org.apache.felix.scr.annotations.Activate;
import org.apache.felix.scr.annotations.Component;
import org.apache.felix.scr.annotations.Deactivate;
import org.apache.felix.scr.annotations.Service;
import org.onlab.onos.of.controller.DefaultPacketContext;
import org.onlab.onos.of.controller.Dpid;
import org.onlab.onos.of.controller.OpenFlowController;
import org.onlab.onos.of.controller.OpenFlowSwitch;
import org.onlab.onos.of.controller.OpenFlowSwitchListener;
import org.onlab.onos.of.controller.PacketListener;
import org.onlab.onos.of.controller.RoleState;
import org.onlab.onos.of.controller.driver.OpenFlowAgent;
import org.projectfloodlight.openflow.protocol.OFMessage;
import org.projectfloodlight.openflow.protocol.OFPacketIn;
import org.projectfloodlight.openflow.protocol.OFPortStatus;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

@Component(immediate = true)
@Service
public class OpenFlowControllerImpl implements OpenFlowController {

    private static final Logger log =
            LoggerFactory.getLogger(OpenFlowControllerImpl.class);

    protected ConcurrentHashMap<Dpid, OpenFlowSwitch> connectedSwitches =
            new ConcurrentHashMap<Dpid, OpenFlowSwitch>();
    protected ConcurrentHashMap<Dpid, OpenFlowSwitch> activeMasterSwitches =
            new ConcurrentHashMap<Dpid, OpenFlowSwitch>();
    protected ConcurrentHashMap<Dpid, OpenFlowSwitch> activeEqualSwitches =
            new ConcurrentHashMap<Dpid, OpenFlowSwitch>();

    protected OpenFlowSwitchAgent agent = new OpenFlowSwitchAgent();
    protected Set<OpenFlowSwitchListener> ofEventListener =
            new HashSet<>();

            protected List<PacketListener> ofPacketListener =
                    new ArrayList<>();

                    private final Controller ctrl = new Controller();

                    @Activate
                    public void activate() {
                        ctrl.start(agent);
                    }

                    @Deactivate
                    public void deactivate() {
                        ctrl.stop();
                    }

                    @Override
                    public Iterable<OpenFlowSwitch> getSwitches() {
                        return connectedSwitches.values();
                    }

                    @Override
                    public Iterable<OpenFlowSwitch> getMasterSwitches() {
                        return activeMasterSwitches.values();
                    }

                    @Override
                    public Iterable<OpenFlowSwitch> getEqualSwitches() {
                        return activeEqualSwitches.values();
                    }

                    @Override
                    public OpenFlowSwitch getSwitch(Dpid dpid) {
                        return connectedSwitches.get(dpid);
                    }

                    @Override
                    public OpenFlowSwitch getMasterSwitch(Dpid dpid) {
                        return activeMasterSwitches.get(dpid);
                    }

                    @Override
                    public OpenFlowSwitch getEqualSwitch(Dpid dpid) {
                        return activeEqualSwitches.get(dpid);
                    }

                    @Override
                    public void addListener(OpenFlowSwitchListener listener) {
                        if (!ofEventListener.contains(listener)) {
                            this.ofEventListener.add(listener);
                        }
                    }

                    @Override
                    public void removeListener(OpenFlowSwitchListener listener) {
                        this.ofEventListener.remove(listener);
                    }

                    @Override
                    public void addPacketListener(int priority, PacketListener listener) {
                        ofPacketListener.add(priority, listener);
                    }

                    @Override
                    public void removePacketListener(PacketListener listener) {
                        ofPacketListener.remove(listener);
                    }

                    @Override
                    public void write(Dpid dpid, OFMessage msg) {
                        this.getSwitch(dpid).sendMsg(msg);
                    }

                    @Override
                    public void processPacket(Dpid dpid, OFMessage msg) {
                        switch (msg.getType()) {
                        case PORT_STATUS:
                            for (OpenFlowSwitchListener l : ofEventListener) {
                                l.portChanged(dpid, (OFPortStatus) msg);
                            }
                            break;
                        case PACKET_IN:
                            for (PacketListener p : ofPacketListener) {
                                //TODO fix me!
                                p.handlePacket(DefaultPacketContext
                                        .packetContextFromPacketIn(this.getSwitch(dpid),
                                                (OFPacketIn) msg));
                            }
                            break;
                        default:
                            log.warn("Handling message type {} not yet implemented {}",
                                    msg.getType(), msg);
                        }
                    }

                    @Override
                    public void setRole(Dpid dpid, RoleState role) {
                        getSwitch(dpid).setRole(role);
                    }

                    /**
                     * Implementation of an OpenFlow Agent which is responsible for
                     * keeping track of connected switches and the state in which
                     * they are.
                     */
                    public class OpenFlowSwitchAgent implements OpenFlowAgent {

                        private final Logger log = LoggerFactory.getLogger(OpenFlowSwitchAgent.class);
                        private final Lock switchLock = new ReentrantLock();

                        @Override
                        public boolean addConnectedSwitch(Dpid dpid, OpenFlowSwitch sw) {
                            if (connectedSwitches.get(dpid) != null) {
                                log.error("Trying to add connectedSwitch but found a previous "
                                        + "value for dpid: {}", dpid);
                                return false;
                            } else {
                                log.error("Added switch {}", dpid);
                                connectedSwitches.put(dpid, sw);
                                for (OpenFlowSwitchListener l : ofEventListener) {
                                    l.switchAdded(dpid);
                                }
                                return true;
                            }
                        }

                        @Override
                        public boolean validActivation(Dpid dpid) {
                            if (connectedSwitches.get(dpid) == null) {
                                log.error("Trying to activate switch but is not in "
                                        + "connected switches: dpid {}. Aborting ..",
                                        dpid);
                                return false;
                            }
                            if (activeMasterSwitches.get(dpid) != null ||
                                    activeEqualSwitches.get(dpid) != null) {
                                log.error("Trying to activate switch but it is already "
                                        + "activated: dpid {}. Found in activeMaster: {} "
                                        + "Found in activeEqual: {}. Aborting ..", new Object[]{
                                                dpid,
                                                (activeMasterSwitches.get(dpid) == null) ? 'N' : 'Y',
                                                        (activeEqualSwitches.get(dpid) == null) ? 'N' : 'Y'});
                                return false;
                            }
                            return true;
                        }


                        @Override
                        public boolean addActivatedMasterSwitch(Dpid dpid, OpenFlowSwitch sw) {
                            switchLock.lock();
                            try {
                                if (!validActivation(dpid)) {
                                    return false;
                                }
                                activeMasterSwitches.put(dpid, sw);
                                return true;
                            } finally {
                                switchLock.unlock();
                            }
                        }

                        @Override
                        public boolean addActivatedEqualSwitch(Dpid dpid, OpenFlowSwitch sw) {
                            switchLock.lock();
                            try {
                                if (!validActivation(dpid)) {
                                    return false;
                                }
                                activeEqualSwitches.put(dpid, sw);
                                log.info("Added Activated EQUAL Switch {}", dpid);
                                return true;
                            } finally {
                                switchLock.unlock();
                            }
                        }

                        @Override
                        public void transitionToMasterSwitch(Dpid dpid) {
                            switchLock.lock();
                            try {
                                if (activeMasterSwitches.containsKey(dpid)) {
                                    return;
                                }
                                OpenFlowSwitch sw = activeEqualSwitches.remove(dpid);
                                if (sw == null) {
                                    sw = getSwitch(dpid);
                                    if (sw == null) {
                                        log.error("Transition to master called on sw {}, but switch "
                                                + "was not found in controller-cache", dpid);
                                        return;
                                    }
                                }
                                log.info("Transitioned switch {} to MASTER", dpid);
                                activeMasterSwitches.put(dpid, sw);
                            } finally {
                                switchLock.unlock();
                            }
                        }


                        @Override
                        public void transitionToEqualSwitch(Dpid dpid) {
                            switchLock.lock();
                            try {
                                if (activeEqualSwitches.containsKey(dpid)) {
                                    return;
                                }
                                OpenFlowSwitch sw = activeMasterSwitches.remove(dpid);
                                if (sw == null) {
                                    log.error("Transition to equal called on sw {}, but switch "
                                            + "was not found in controller-cache", dpid);
                                    return;
                                }
                                log.info("Transitioned switch {} to EQUAL", dpid);
                                activeEqualSwitches.put(dpid, sw);
                            } finally {
                                switchLock.unlock();
                            }

                        }

                        @Override
                        public void removeConnectedSwitch(Dpid dpid) {
                            connectedSwitches.remove(dpid);
                            OpenFlowSwitch sw = activeMasterSwitches.remove(dpid);
                            if (sw == null) {
                                sw = activeEqualSwitches.remove(dpid);
                            }
                            for (OpenFlowSwitchListener l : ofEventListener) {
                                l.switchRemoved(dpid);
                            }
                        }

                        @Override
                        public void processMessage(Dpid dpid, OFMessage m) {
                            processPacket(dpid, m);
                        }
                    }


}