/**
 * *  Copyright (C) 2011 Citrix Systems, Inc.  All rights reserved
*
 *
 * This software is licensed under the GNU General Public License v3 or later.
 *
 * It is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or any later version.
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

package com.cloud.network.element;

import java.net.URI;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;

import javax.ejb.Local;

import org.apache.log4j.Logger;

import com.cloud.agent.AgentManager;
import com.cloud.api.ApiConstants;
import com.cloud.api.commands.AddNetscalerLoadBalancerCmd;
import com.cloud.api.commands.ConfigureNetscalerLoadBalancerCmd;
import com.cloud.api.commands.DeleteNetscalerLoadBalancerCmd;
import com.cloud.api.commands.ListNetscalerLoadBalancerNetworksCmd;
import com.cloud.api.commands.ListNetscalerLoadBalancersCmd;
import com.cloud.api.response.NetscalerLoadBalancerResponse;
import com.cloud.configuration.ConfigurationManager;
import com.cloud.dc.dao.DataCenterDao;
import com.cloud.deploy.DeployDestination;
import com.cloud.exception.ConcurrentOperationException;
import com.cloud.exception.InsufficientCapacityException;
import com.cloud.exception.InsufficientNetworkCapacityException;
import com.cloud.exception.InvalidParameterValueException;
import com.cloud.exception.ResourceUnavailableException;
import com.cloud.host.Host;
import com.cloud.host.HostVO;
import com.cloud.host.dao.HostDao;
import com.cloud.host.dao.HostDetailsDao;
import com.cloud.network.ExternalLoadBalancerDeviceManager;
import com.cloud.network.ExternalLoadBalancerDeviceManagerImpl;
import com.cloud.network.ExternalLoadBalancerDeviceVO;
import com.cloud.network.ExternalLoadBalancerDeviceVO.LBDeviceState;
import com.cloud.network.ExternalNetworkDeviceManager.NetworkDevice;
import com.cloud.network.Network;
import com.cloud.network.Network.Capability;
import com.cloud.network.Network.Provider;
import com.cloud.network.Network.Service;
import com.cloud.network.NetworkExternalLoadBalancerVO;
import com.cloud.network.NetworkManager;
import com.cloud.network.NetworkVO;
import com.cloud.network.Networks.TrafficType;
import com.cloud.network.PhysicalNetworkServiceProvider;
import com.cloud.network.PhysicalNetworkVO;
import com.cloud.network.PublicIpAddress;
import com.cloud.network.dao.ExternalLoadBalancerDeviceDao;
import com.cloud.network.dao.NetworkDao;
import com.cloud.network.dao.NetworkExternalLoadBalancerDao;
import com.cloud.network.dao.NetworkServiceMapDao;
import com.cloud.network.dao.PhysicalNetworkDao;
import com.cloud.network.lb.LoadBalancingRule;
import com.cloud.network.resource.NetscalerResource;
import com.cloud.network.rules.LbStickinessMethod;
import com.cloud.network.rules.LbStickinessMethod.StickinessMethodType;
import com.cloud.offering.NetworkOffering;
import com.cloud.resource.ServerResource;
import com.cloud.utils.component.Inject;
import com.cloud.utils.db.DB;
import com.cloud.utils.db.Transaction;
import com.cloud.utils.exception.CloudRuntimeException;
import com.cloud.utils.net.UrlUtil;
import com.cloud.vm.NicProfile;
import com.cloud.vm.ReservationContext;
import com.cloud.vm.VirtualMachine;
import com.cloud.vm.VirtualMachineProfile;
import com.google.gson.Gson;

@Local(value=NetworkElement.class)
public class NetscalerExternalLoadBalancerElement extends ExternalLoadBalancerDeviceManagerImpl implements LoadBalancingServiceProvider, NetscalerLoadBalancerElementService, ExternalLoadBalancerDeviceManager, IpDeployer {

    private static final Logger s_logger = Logger.getLogger(NetscalerExternalLoadBalancerElement.class);

    @Inject NetworkManager _networkManager;
    @Inject ConfigurationManager _configMgr;
    @Inject NetworkServiceMapDao _ntwkSrvcDao;
    @Inject AgentManager _agentMgr;
    @Inject NetworkManager _networkMgr;
    @Inject HostDao _hostDao;
    @Inject DataCenterDao _dcDao;
    @Inject ExternalLoadBalancerDeviceDao _lbDeviceDao;
    @Inject NetworkExternalLoadBalancerDao _networkLBDao;
    @Inject PhysicalNetworkDao _physicalNetworkDao;
    @Inject NetworkDao _networkDao;
    @Inject HostDetailsDao _detailsDao;

    private boolean canHandle(Network config) {
        if (config.getGuestType() != Network.GuestType.Isolated || config.getTrafficType() != TrafficType.Guest) {
            s_logger.trace("Not handling network with Type  " + config.getGuestType() + " and traffic type " + config.getTrafficType());
            return false;
        }
        
        return  (_networkManager.isProviderForNetwork(getProvider(), config.getId()) && 
                _ntwkSrvcDao.canProviderSupportServiceInNetwork(config.getId(), Service.Lb, Network.Provider.Netscaler));
    }

    @Override
    public boolean implement(Network guestConfig, NetworkOffering offering, DeployDestination dest, ReservationContext context) throws ResourceUnavailableException, ConcurrentOperationException, InsufficientNetworkCapacityException {
        
        if (!canHandle(guestConfig)) {
            return false;
        }

        try {
            return manageGuestNetworkWithExternalLoadBalancer(true, guestConfig);
        } catch (InsufficientCapacityException capacityException) {
            // TODO: handle out of capacity exception gracefully in case of multple providers available
            return false;
        }        
    }

    @Override
    public boolean prepare(Network config, NicProfile nic, VirtualMachineProfile<? extends VirtualMachine> vm, DeployDestination dest, ReservationContext context) throws ConcurrentOperationException, InsufficientNetworkCapacityException, ResourceUnavailableException {
        return true;
    }

    @Override
    public boolean release(Network config, NicProfile nic, VirtualMachineProfile<? extends VirtualMachine> vm, ReservationContext context) {	
        return true;
    }

    @Override
    public boolean shutdown(Network guestConfig, ReservationContext context, boolean cleanup) throws ResourceUnavailableException, ConcurrentOperationException {
        if (!canHandle(guestConfig)) {
            return false;
        }

        try {
            return manageGuestNetworkWithExternalLoadBalancer(false, guestConfig);
        } catch (InsufficientCapacityException capacityException) {
            // TODO: handle out of capacity exception gracefully in case of multple providers available
            return false;
        }
    }

    @Override
    public boolean destroy(Network config) {
        return true;
    }

    @Override
    public boolean applyLBRules(Network config, List<LoadBalancingRule> rules) throws ResourceUnavailableException {
        if (!canHandle(config)) {
            return false;
        }
    	
    	return applyLoadBalancerRules(config, rules);
    }

    @Override
    public Map<Service, Map<Capability, String>> getCapabilities() {
    	 Map<Service, Map<Capability, String>> capabilities = new HashMap<Service, Map<Capability, String>>();
    	 
    	 // Set capabilities for LB service
         Map<Capability, String> lbCapabilities = new HashMap<Capability, String>();
         
         // Specifies that the RoundRobin and Leastconn algorithms are supported for load balancing rules
         lbCapabilities.put(Capability.SupportedLBAlgorithms, "roundrobin,leastconn");

         // specifies that Netscaler network element can provided both shared and isolation modes
         lbCapabilities.put(Capability.SupportedLBIsolation, "dedicated, shared");

         // Specifies that load balancing rules can be made for either TCP or UDP traffic
         lbCapabilities.put(Capability.SupportedProtocols, "tcp,udp");
         
         // Specifies that this element can measure network usage on a per public IP basis
         lbCapabilities.put(Capability.TrafficStatistics, "per public ip");

         // Specifies that load balancing rules can only be made with public IPs that aren't source NAT IPs
         lbCapabilities.put(Capability.LoadBalancingSupportedIps, "additional");
 
         LbStickinessMethod method;
         List <LbStickinessMethod> methodList = new ArrayList<LbStickinessMethod>();
         method = new LbStickinessMethod(StickinessMethodType.LBCookieBased,"This is cookie based sticky method, can be used only for http");
         methodList.add(method);
         method.addParam("holdtime", false, "time period in minutes for which persistence is in effect.",false);

         method = new LbStickinessMethod(StickinessMethodType.AppCookieBased,"This is app session based sticky method, can be used only for http");
         methodList.add(method);
         method.addParam("name", true,  "cookie name passed in http header by apllication to the client",false);

         method = new LbStickinessMethod(StickinessMethodType.SourceBased,"This is source based sticky method, can be used for any type of protocol.");
         methodList.add(method);
         method.addParam("holdtime", false, "time period for which persistence is in effect.",false);

         Gson gson = new Gson();
         String stickyMethodList = gson.toJson(methodList);
         lbCapabilities.put(Capability.SupportedStickinessMethods,stickyMethodList);
         
         capabilities.put(Service.Lb, lbCapabilities);
         
         return capabilities;
    }

    @Override
    public ExternalLoadBalancerDeviceVO addNetscalerLoadBalancer(AddNetscalerLoadBalancerCmd cmd) {
        String deviceName = cmd.getDeviceType();

        if (!isNetscalerDevice(deviceName)) {
            throw new InvalidParameterValueException("Invalid Netscaler device type");
        }

        URI uri;
        try {
            uri = new URI(cmd.getUrl());
        } catch (Exception e) {
            String msg = "Error parsing the url parameter specified in addNetscalerLoadBalancer command due to " + e.getMessage();
            s_logger.debug(msg);
            throw new InvalidParameterValueException(msg);
        }
        Map<String, String> configParams = new HashMap<String, String>();
        UrlUtil.parseQueryParameters(uri.getQuery(), false, configParams);
        boolean dedicatedUse = (configParams.get(ApiConstants.LOAD_BALANCER_DEVICE_DEDICATED) != null) ? Boolean.parseBoolean(configParams.get(ApiConstants.LOAD_BALANCER_DEVICE_DEDICATED)) : false;

        if (dedicatedUse && !deviceName.equals(NetworkDevice.NetscalerVPXLoadBalancer.getName())) {
            String msg = "Only Netscaler VPX load balancers can be specified for dedicated use";
            s_logger.debug(msg);
            throw new InvalidParameterValueException(msg);
        }

        ExternalLoadBalancerDeviceVO lbDeviceVO = addExternalLoadBalancer(cmd.getPhysicalNetworkId(), cmd.getUrl(), cmd.getUsername(), cmd.getPassword(), deviceName, (ServerResource) new NetscalerResource());
        return lbDeviceVO;
    }

    @Override
    public boolean deleteNetscalerLoadBalancer(DeleteNetscalerLoadBalancerCmd cmd) {
        Long lbDeviceId = cmd.getLoadBalancerDeviceId();

        ExternalLoadBalancerDeviceVO lbDeviceVo = _lbDeviceDao.findById(lbDeviceId);
        if ((lbDeviceVo == null) || !isNetscalerDevice(lbDeviceVo.getDeviceName())) {
            throw new InvalidParameterValueException("No netscaler device found with ID: " + lbDeviceId);
        }

        return deleteExternalLoadBalancer(lbDeviceVo.getHostId());
    }

    @Override
    public ExternalLoadBalancerDeviceVO configureNetscalerLoadBalancer(ConfigureNetscalerLoadBalancerCmd cmd) {
        Long lbDeviceId = cmd.getLoadBalancerDeviceId();
        Boolean dedicatedUse = cmd.getLoadBalancerDedicated();
        Boolean inline = cmd.getLoadBalancerInline();
        Long capacity = cmd.getLoadBalancerCapacity();

        try {
            return configureNetscalerLoadBalancer(lbDeviceId, capacity, inline, dedicatedUse);
        } catch (Exception e) {
            throw new CloudRuntimeException("failed to configure netscaler device due to " + e.getMessage());
        }
    }

    @DB
    private ExternalLoadBalancerDeviceVO configureNetscalerLoadBalancer(long lbDeviceId, Long capacity, Boolean inline, Boolean dedicatedUse) {
        ExternalLoadBalancerDeviceVO lbDeviceVo = _lbDeviceDao.findById(lbDeviceId);
        Map<String, String> lbDetails = _detailsDao.findDetails(lbDeviceVo.getHostId());

        if ((lbDeviceVo == null) || !isNetscalerDevice(lbDeviceVo.getDeviceName())) {
            throw new InvalidParameterValueException("No netscaler device found with ID: " + lbDeviceId);
        }

        String deviceName = lbDeviceVo.getDeviceName();
        if (dedicatedUse != null || capacity != null || inline != null) {
            if (NetworkDevice.NetscalerSDXLoadBalancer.getName().equalsIgnoreCase(deviceName) ||
                    NetworkDevice.NetscalerMPXLoadBalancer.getName().equalsIgnoreCase(deviceName)) {
                if (dedicatedUse != null && dedicatedUse == true) {
                    throw new InvalidParameterValueException("Netscaler MPX and SDX device should be shared and can not be dedicated to a single account.");
                }
            }

            // check if any networks are using this netscaler device
            List<NetworkExternalLoadBalancerVO> networks = _networkLBDao.listByLoadBalancerDeviceId(lbDeviceId);
            if ((networks != null) && !networks.isEmpty()) {
                if (capacity != null && capacity < networks.size()) {
                    throw new CloudRuntimeException("There are more number of networks already using this netscaler device than configured capacity");
                }

                if (dedicatedUse !=null && dedicatedUse == true) {
                    throw new CloudRuntimeException("There are networks already using this netscaler device to make device dedicated");
                }

                if (inline != null) {
                    boolean _setInline = Boolean.parseBoolean((String) lbDetails.get("inline"));
                    if (inline != _setInline) {
                        throw new CloudRuntimeException("There are networks already using this netscaler device to change the device inline or side-by-side configuration");
                    }
                }
            }
        }

        if (!NetworkDevice.NetscalerSDXLoadBalancer.getName().equalsIgnoreCase(deviceName)) {
            if (capacity != null) {
                lbDeviceVo.setCapacity(capacity);
            }
        } else {
            // FIXME how to interpret configured capacity of the SDX device
        }

        if(dedicatedUse != null) {
            lbDeviceVo.setIsDedicatedDevice(dedicatedUse);
        }

        if (inline != null && inline == true) {
            lbDeviceVo.setIsInlineMode(true);
            lbDetails.put("inline", "true");
        } else {
            lbDeviceVo.setIsInlineMode(false);
            lbDetails.put("inline", "false");
        }

        Transaction txn = Transaction.currentTxn();
        txn.start();

        _lbDeviceDao.update(lbDeviceId, lbDeviceVo);

        // FIXME get the row lock to avoid race condition
        _detailsDao.persist(lbDeviceVo.getHostId(), lbDetails);
        HostVO host = _hostDao.findById(lbDeviceVo.getHostId());
        txn.commit();

        _agentMgr.reconnect(host.getId());
        return lbDeviceVo;
    }

    @Override
    public String getPropertiesFile() {
        return "netscalerloadbalancer_commands.properties";
    }

    @Override
    public List<? extends Network> listNetworks(ListNetscalerLoadBalancerNetworksCmd cmd) {
        Long lbDeviceId = cmd.getLoadBalancerDeviceId();
        List<NetworkVO> networks = new ArrayList<NetworkVO>();

        ExternalLoadBalancerDeviceVO lbDeviceVo = _lbDeviceDao.findById(lbDeviceId);
        if (lbDeviceVo == null || !isNetscalerDevice(lbDeviceVo.getDeviceName())) {
            throw new InvalidParameterValueException("Could not find Netscaler load balancer device with ID " + lbDeviceId);
        }

        List<NetworkExternalLoadBalancerVO> networkLbMaps = _networkLBDao.listByLoadBalancerDeviceId(lbDeviceId);
        if (networkLbMaps != null && !networkLbMaps.isEmpty()) {
            for (NetworkExternalLoadBalancerVO networkLbMap : networkLbMaps) {
                NetworkVO network = _networkDao.findById(networkLbMap.getNetworkId());
                networks.add(network);
            }
        }

        return networks;
    }

    @Override
    public List<ExternalLoadBalancerDeviceVO> listNetscalerLoadBalancers(ListNetscalerLoadBalancersCmd cmd) {
        Long physcialNetworkId = cmd.getPhysicalNetworkId();
        Long lbDeviceId = cmd.getLoadBalancerDeviceId();
        PhysicalNetworkVO pNetwork = null;
        List<ExternalLoadBalancerDeviceVO> lbDevices = new ArrayList<ExternalLoadBalancerDeviceVO> ();

        if (physcialNetworkId == null && lbDeviceId == null) {
            throw new InvalidParameterValueException("Either physical network Id or load balancer device Id must be specified");
        }

        if (lbDeviceId != null) {
            ExternalLoadBalancerDeviceVO lbDeviceVo = _lbDeviceDao.findById(lbDeviceId);
            if (lbDeviceVo == null || !isNetscalerDevice(lbDeviceVo.getDeviceName())) {
                throw new InvalidParameterValueException("Could not find Netscaler load balancer device with ID: " + lbDeviceId);
            }
            lbDevices.add(lbDeviceVo);
            return lbDevices;
        }

        if (physcialNetworkId != null) {
            pNetwork = _physicalNetworkDao.findById(physcialNetworkId);
            if (pNetwork == null) {
                throw new InvalidParameterValueException("Could not find phyical network with ID: " + physcialNetworkId);
            }
            lbDevices = _lbDeviceDao.listByPhysicalNetworkAndProvider(physcialNetworkId, Provider.Netscaler.getName());
            return lbDevices;
        }

        return null;
    }

    @Override
    public NetscalerLoadBalancerResponse createNetscalerLoadBalancerResponse(ExternalLoadBalancerDeviceVO lbDeviceVO) {
        NetscalerLoadBalancerResponse response = new NetscalerLoadBalancerResponse();
        Host lbHost = _hostDao.findById(lbDeviceVO.getHostId());
        Map<String, String> lbDetails = _detailsDao.findDetails(lbDeviceVO.getHostId());

        response.setId(lbDeviceVO.getId());
        response.setIpAddress(lbHost.getPrivateIpAddress());
        response.setPhysicalNetworkId(lbDeviceVO.getPhysicalNetworkId());
        response.setPublicInterface(lbDetails.get("publicInterface"));
        response.setPrivateInterface(lbDetails.get("privateInterface"));
        response.setDeviceName(lbDeviceVO.getDeviceName());
        response.setDeviceCapacity(lbDeviceVO.getCapacity());
        response.setInlineMode(lbDeviceVO.getIsInLineMode());
        response.setDedicatedLoadBalancer(lbDeviceVO.getIsDedicatedDevice());
        response.setProvider(lbDeviceVO.getProviderName());
        response.setDeviceState(lbDeviceVO.getState().name());
        response.setObjectName("netscalerloadbalancer");
        return response;
    }

    @Override
    public Provider getProvider() {
        return Provider.Netscaler;
    }

    @Override
    public boolean isReady(PhysicalNetworkServiceProvider provider) {
        List<ExternalLoadBalancerDeviceVO> lbDevices = _lbDeviceDao.listByPhysicalNetworkAndProvider(provider.getPhysicalNetworkId(), Provider.Netscaler.getName());

        // true if at-least one Netscaler device is added in to physical network and is in configured (in enabled state) state
        if (lbDevices != null && !lbDevices.isEmpty()) {
            for (ExternalLoadBalancerDeviceVO lbDevice : lbDevices) {
                if (lbDevice.getState() == LBDeviceState.Enabled) {
                    return true;
                }
            }
        }
        return false;
    }

    @Override
    public boolean shutdownProviderInstances(PhysicalNetworkServiceProvider provider, ReservationContext context) throws ConcurrentOperationException,
            ResourceUnavailableException {
        // TODO reset the configuration on all of the netscaler devices in this physical network 
        return true;
    }

    @Override
    public boolean canEnableIndividualServices() {
        return false;
    }

    private boolean isNetscalerDevice(String deviceName) {
        if ((deviceName == null) || ((!deviceName.equalsIgnoreCase(NetworkDevice.NetscalerMPXLoadBalancer.getName())) && 
                (!deviceName.equalsIgnoreCase(NetworkDevice.NetscalerSDXLoadBalancer.getName())) &&
                (!deviceName.equalsIgnoreCase(NetworkDevice.NetscalerVPXLoadBalancer.getName())))) {
            return false;
        } else {
            return true;
        }
    }
    
    @Override
    public boolean verifyServicesCombination(List<String> services) {
        return true;
    }

    @Override
    public boolean applyIps(Network network, List<? extends PublicIpAddress> ipAddress, Set<Service> service) throws ResourceUnavailableException {
		// return true, as IP will be associated as part of LB rule configuration
        return false;
    }

    @Override
    public IpDeployer getIpDeployer(Network network) {
        return this;
    }
}