package net.floodlightcontroller.bgproute;

import java.net.UnknownHostException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.Map;

import net.floodlightcontroller.core.IFloodlightProviderService;
import net.floodlightcontroller.core.module.FloodlightModuleContext;
import net.floodlightcontroller.core.module.FloodlightModuleException;
import net.floodlightcontroller.core.module.IFloodlightModule;
import net.floodlightcontroller.core.module.IFloodlightService;
import net.floodlightcontroller.linkdiscovery.ILinkDiscovery;
import net.floodlightcontroller.linkdiscovery.ILinkDiscovery.LDUpdate;
import net.floodlightcontroller.restserver.IRestApiService;
import net.floodlightcontroller.topology.ITopologyListener;
import net.floodlightcontroller.topology.ITopologyService;
import net.sf.json.JSONArray;
import net.sf.json.JSONObject;
import net.sf.json.JSONSerializer;

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

public class BgpRoute implements IFloodlightModule, IBgpRouteService, ITopologyListener {
	
	protected static Logger log = LoggerFactory.getLogger(BgpRoute.class);

	protected IFloodlightProviderService floodlightProvider;
	protected IRestApiService restApi;
	protected ITopologyService topology;
	
	protected static Ptree ptree;
	protected String bgpdRestIp;
	protected String routerId;
	
	
	@Override
	public Collection<Class<? extends IFloodlightService>> getModuleServices() {
		Collection<Class<? extends IFloodlightService>> l 
			= new ArrayList<Class<? extends IFloodlightService>>();
		l.add(IBgpRouteService.class);
		return l;
	}

	@Override
	public Map<Class<? extends IFloodlightService>, IFloodlightService> getServiceImpls() {
		Map<Class<? extends IFloodlightService>, IFloodlightService> m 
			= new HashMap<Class<? extends IFloodlightService>, IFloodlightService>();
		m.put(IBgpRouteService.class, this);
		return m;
	}

	@Override
	public Collection<Class<? extends IFloodlightService>> getModuleDependencies() {
		Collection<Class<? extends IFloodlightService>> l 
			= new ArrayList<Class<? extends IFloodlightService>>();
		l.add(IFloodlightProviderService.class);
		l.add(ITopologyService.class);
		l.add(IBgpRouteService.class);
		return l;
	}
	
	@Override
	public void init(FloodlightModuleContext context)
			throws FloodlightModuleException {
	    
	    ptree = new Ptree(32);
		
		// Register floodlight provider and REST handler.
		floodlightProvider = context.getServiceImpl(IFloodlightProviderService.class);
		restApi = context.getServiceImpl(IRestApiService.class);
		topology = context.getServiceImpl(ITopologyService.class);
		
		//Read in config values
		bgpdRestIp = context.getConfigParams(this).get("BgpdRestIp");
		if (bgpdRestIp == null){
			log.error("BgpdRestIp property not found in config file");
			System.exit(1);
		}
		else {
			log.info("BgpdRestIp set to {}", bgpdRestIp);
		}
		
		routerId = context.getConfigParams(this).get("RouterId");
		if (routerId == null){
			log.error("RouterId property not found in config file");
			System.exit(1);
		}
		else {
			log.info("RouterId set to {}", routerId);
		}
		// Test.
		//test();
	}

	public Ptree getPtree() {
		return ptree;
	}
	
	public void clearPtree() {
		//ptree = null;
		ptree = new Ptree(32);	
	}
	
	public String getBGPdRestIp() {
		return bgpdRestIp;
	}
	
	public String getRouterId() {
		return routerId;
	}
	
	// Return nexthop address as byte array.
	public Rib lookupRib(byte[] dest) {
		if (ptree == null) {
		    log.debug("lookupRib: ptree null");
		    return null;
		}
		
		PtreeNode node = ptree.match(dest, 32);
		if (node == null) {
            log.debug("lookupRib: ptree node null");
			return null;
		}
		
		if (node.rib == null) {
            log.debug("lookupRib: ptree rib null");
			return null;
		}
		
		ptree.delReference(node);
		
		return node.rib;
	}
	
	//TODO looks like this should be a unit test
	@SuppressWarnings("unused")
    private void test() throws UnknownHostException {
		System.out.println("Here it is");
		Prefix p = new Prefix("128.0.0.0", 8);
		Prefix q = new Prefix("8.0.0.0", 8);
		Prefix r = new Prefix("10.0.0.0", 24);
		Prefix a = new Prefix("10.0.0.1", 32);
	
		ptree.acquire(p.getAddress(), p.masklen);
		ptree.acquire(q.getAddress(), q.masklen);
		ptree.acquire(r.getAddress(), r.masklen);
	
		System.out.println("Traverse start");
		for (PtreeNode node = ptree.begin(); node != null; node = ptree.next(node)) {
			Prefix p_result = new Prefix(node.key, node.keyBits);
		}
	
		PtreeNode n = ptree.match(a.getAddress(), a.masklen);
		if (n != null) {
			System.out.println("Matched prefix for 10.0.0.1:");
			Prefix x = new Prefix(n.key, n.keyBits);
			ptree.delReference(n);
		}
		
		n = ptree.lookup(p.getAddress(), p.masklen);
		if (n != null) {
			ptree.delReference(n);
			ptree.delReference(n);
		}
		System.out.println("Traverse start");
		for (PtreeNode node = ptree.begin(); node != null; node = ptree.next(node)) {
			Prefix p_result = new Prefix(node.key, node.keyBits);
		}
		
		n = ptree.lookup(q.getAddress(), q.masklen);
		if (n != null) {
			ptree.delReference(n);
			ptree.delReference(n);
		}
		System.out.println("Traverse start");
		for (PtreeNode node = ptree.begin(); node != null; node = ptree.next(node)) {
			Prefix p_result = new Prefix(node.key, node.keyBits);
		}
		
		n = ptree.lookup(r.getAddress(), r.masklen);
		if (n != null) {
			ptree.delReference(n);
			ptree.delReference(n);
		}
		System.out.println("Traverse start");
		for (PtreeNode node = ptree.begin(); node != null; node = ptree.next(node)) {
			Prefix p_result = new Prefix(node.key, node.keyBits);
		}

	}
	
	private void retrieveRib(){
		String url = "http://" + bgpdRestIp + "/wm/bgp/" + routerId;
		String response = RestClient.get(url);
		
		if (response.equals("")){
			return;
		}
		
		response = response.replaceAll("\"", "'");
		JSONObject jsonObj = (JSONObject) JSONSerializer.toJSON(response);  
		JSONArray rib_json_array = jsonObj.getJSONArray("rib");
		String router_id = jsonObj.getString("router-id");

		int size = rib_json_array.size();

		log.info("Retrived RIB of {} entries from BGPd", size);
		
		for (int j = 0; j < size; j++) {
			JSONObject second_json_object = rib_json_array.getJSONObject(j);
			String prefix = second_json_object.getString("prefix");
			String nexthop = second_json_object.getString("nexthop");

			//insert each rib entry into the local rib;
			String[] substring = prefix.split("/");
			String prefix1 = substring[0];
			String mask1 = substring[1];

			Prefix p;
			try {
				p = new Prefix(prefix1, Integer.valueOf(mask1));
			} catch (NumberFormatException e) {
				log.warn("Wrong mask format in RIB JSON: {}", mask1);
				continue;
			} catch (UnknownHostException e1) {
				log.warn("Wrong prefix format in RIB JSON: {}", prefix1);
				continue;
			}
			
			PtreeNode node = ptree.acquire(p.getAddress(), p.masklen);
			Rib rib = new Rib(router_id, nexthop, p.masklen);
			
			if (node.rib != null) {
				node.rib = null;
				ptree.delReference(node);
			}
			
			node.rib = rib;
		} 
	}
	
	@Override
	public void startUp(FloodlightModuleContext context) {
		restApi.addRestletRoutable(new BgpRouteWebRoutable());
		topology.addListener(this);
		
		//Retrieve the RIB from BGPd during startup
		retrieveRib();
	}

	@Override
	public void topologyChanged() {
		boolean change = false;
		String changelog = "";
		
		for (LDUpdate ldu : topology.getLastLinkUpdates()) {
			if (ldu.getOperation().equals(ILinkDiscovery.UpdateOperation.PORT_DOWN)) {
				change = true;
				changelog = changelog + " down ";
			} else if (ldu.getOperation().equals(ILinkDiscovery.UpdateOperation.PORT_UP)) {
				change = true;
				changelog = changelog + " up ";
			}
		}
		log.info ("received topo change" + changelog);

		if (change) {
			//RestClient.get ("http://localhost:5000/topo_change");
		}
	}
}