/*******************************************************************************
 * Copyright (c) 2017 Politecnico di Torino and others.
 *
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Apache License, Version 2.0
 * which accompanies this distribution, and is available at
 * http://www.apache.org/licenses/LICENSE-2.0
 *******************************************************************************/
package it.polito.verigraph.grpc.server;

import java.io.IOException;
import java.util.HashMap;
import java.util.Map;
import java.util.logging.FileHandler;
import java.util.logging.Level;
import java.util.logging.Logger;
import java.util.logging.SimpleFormatter;
import io.grpc.Server;
import io.grpc.ServerBuilder;
import io.grpc.stub.StreamObserver;
import it.polito.verigraph.grpc.ConfigurationGrpc;
import it.polito.verigraph.grpc.GetRequest;
import it.polito.verigraph.grpc.GraphGrpc;
import it.polito.verigraph.grpc.NeighbourGrpc;
import it.polito.verigraph.grpc.NewGraph;
import it.polito.verigraph.grpc.NewNeighbour;
import it.polito.verigraph.grpc.NewNode;
import it.polito.verigraph.grpc.NodeGrpc;
import it.polito.verigraph.grpc.Policy;
import it.polito.verigraph.grpc.RequestID;
import it.polito.verigraph.grpc.Status;
import it.polito.verigraph.grpc.VerificationGrpc;
import it.polito.verigraph.grpc.VerigraphGrpc;
import it.polito.verigraph.exception.BadRequestException;
import it.polito.verigraph.exception.DataNotFoundException;
import it.polito.verigraph.exception.ForbiddenException;
import it.polito.verigraph.model.Configuration;
import it.polito.verigraph.model.Graph;
import it.polito.verigraph.model.Neighbour;
import it.polito.verigraph.model.Node;
import it.polito.verigraph.model.Verification;
import it.polito.verigraph.resources.beans.VerificationBean;
import it.polito.verigraph.service.GraphService;
import it.polito.verigraph.service.NeighbourService;
import it.polito.verigraph.service.NodeService;
import it.polito.verigraph.service.VerificationService;

public class Service {
    /** Port on which the server should run. */
    private static final Logger logger = Logger.getLogger(Service.class.getName());
    private static final int port = 50051;
    private static final String internalError = "Internal Server Error";
    private Server server;
    private GraphService graphService= new GraphService();
    private VerificationService verificationService = new VerificationService();
    private NodeService nodeService = new NodeService();
    private NeighbourService neighboursService = new NeighbourService();

    public Service(int port) {
        this(ServerBuilder.forPort(port), port);
    }

    /** Create a RouteGuide server using serverBuilder as a base and features as data. */
    public Service(ServerBuilder<?> serverBuilder, int port) {
        server = serverBuilder.addService(new VerigraphImpl())
                .build();
    }

    public void start() throws IOException {
        FileHandler fileTxt = new FileHandler("grpc_server_log.txt");
        SimpleFormatter formatterTxt = new SimpleFormatter();
        fileTxt.setFormatter(formatterTxt);
        logger.addHandler(fileTxt);
        server.start();
        logger.info("Server started, listening on "+ port);
        Runtime.getRuntime().addShutdownHook(new Thread() {
            @Override
            public void run() {
                logger.info("*** Shutting down gRPC server since JVM is shutting down");
                Service.this.stop();
                logger.info("*** Server shut down");
            }
        });
    }

    public void stop() {
        if (server != null) {
            server.shutdown();
        }
    }

    private void blockUntilShutdown() throws InterruptedException {
        if (server != null) {
            server.awaitTermination();
        }
    }

    /** Main function to launch server from cmd. */
    public static void main(String[] args) throws IOException, InterruptedException {
        try{
            Service server = new Service(port);
            server.start();
            server.blockUntilShutdown();
        }
        catch(Exception ex){
            logger.log(Level.WARNING, ex.getMessage());
        }
    }

    /**Here start method of my implementation*/
    private class VerigraphImpl extends VerigraphGrpc.VerigraphImplBase{

        /** Here start methods of GraphResource*/
        @Override
        public void getGraphs(GetRequest request, StreamObserver<GraphGrpc> responseObserver) {
            try{
                for(Graph item : graphService.getAllGraphs()) {
                    GraphGrpc gr = GrpcUtils.obtainGraph(item);
                    responseObserver.onNext(gr);
                }
            }catch(Exception ex){
                GraphGrpc nr = GraphGrpc.newBuilder().setErrorMessage(internalError).build();
                responseObserver.onNext(nr);
                logger.log(Level.WARNING, ex.getMessage());
            }
            responseObserver.onCompleted();
        }

        @Override
        public void createGraph(GraphGrpc request, StreamObserver<NewGraph> responseObserver) {
            NewGraph.Builder response = NewGraph.newBuilder();
            try{
                Graph graph = GrpcUtils.deriveGraph(request);
                Graph newGraph = graphService.addGraph(graph);
                response.setSuccess(true).setGraph(GrpcUtils.obtainGraph(newGraph));
            }catch(BadRequestException ex){
                response.setSuccess(false).setErrorMessage(ex.getMessage());
                logger.log(Level.WARNING, ex.getClass().toString());
                logger.log(Level.WARNING, ex.getMessage());

            }
            catch(Exception ex){
                response.setSuccess(false).setErrorMessage(internalError);
                logger.log(Level.WARNING, ex.getClass().toString());
                logger.log(Level.WARNING, ex.getMessage());
            }
            responseObserver.onNext(response.build());
            responseObserver.onCompleted();
        }

        @Override
        public void deleteGraph(RequestID request, StreamObserver<Status> responseObserver) {

            Status.Builder response = Status.newBuilder();
            try{
                graphService.removeGraph(request.getIdGraph());
                response.setSuccess(true);
            }catch(ForbiddenException ex){
                response.setSuccess(false).setErrorMessage(ex.getMessage());
                logger.log(Level.WARNING, ex.getMessage());
            }catch(Exception ex){
                response.setSuccess(false).setErrorMessage(internalError);
                logger.log(Level.WARNING, ex.getMessage());
            }
            responseObserver.onNext(response.build());
            responseObserver.onCompleted();
        }

        @Override
        public void getGraph(RequestID request, StreamObserver<GraphGrpc> responseObserver) {
            try{
                Graph graph = graphService.getGraph(request.getIdGraph());
                GraphGrpc gr = GrpcUtils.obtainGraph(graph);
                responseObserver.onNext(gr);
            }catch(ForbiddenException | DataNotFoundException ex){
                GraphGrpc grError = GraphGrpc.newBuilder().setErrorMessage(ex.getMessage()).build();
                responseObserver.onNext(grError);
                logger.log(Level.WARNING, ex.getMessage());
            }catch(Exception ex){
                GraphGrpc grError = GraphGrpc.newBuilder().setErrorMessage(internalError).build();
                responseObserver.onNext(grError);
                logger.log(Level.WARNING, ex.getMessage());
            }
            responseObserver.onCompleted();
        }

        @Override
        public void updateGraph(GraphGrpc request, StreamObserver<NewGraph> responseObserver) {
            NewGraph.Builder response = NewGraph.newBuilder();
            try{
                Graph graph = GrpcUtils.deriveGraph(request);
                graph.setId(request.getId());
                Graph newGraph = graphService.updateGraph(graph);
                response.setSuccess(true).setGraph(GrpcUtils.obtainGraph(newGraph));
            }catch(ForbiddenException | DataNotFoundException | BadRequestException ex){
                response.setSuccess(false).setErrorMessage(ex.getMessage());
                logger.log(Level.WARNING, ex.getMessage());
            }catch(Exception ex){
                response.setSuccess(false).setErrorMessage(internalError);
                logger.log(Level.WARNING, ex.getMessage());
            }
            responseObserver.onNext(response.build());
            responseObserver.onCompleted();
        }

        @Override
        public void verifyPolicy(Policy request, StreamObserver<VerificationGrpc> responseObserver) {

            VerificationGrpc.Builder verification;
            try{
                //Convert request
                VerificationBean verify = new VerificationBean();
                verify.setDestination(request.getDestination());
                verify.setSource(request.getSource());
                verify.setType(request.getType().toString());
                verify.setMiddlebox(request.getMiddlebox());

                //Convert Response
                Verification ver = verificationService.verify(request.getIdGraph(), verify);
                verification = VerificationGrpc.newBuilder(GrpcUtils.obtainVerification(ver))
                        .setSuccessOfOperation(true);
            }catch(ForbiddenException | DataNotFoundException | BadRequestException ex){
                verification = VerificationGrpc.newBuilder().setSuccessOfOperation(false)
                        .setErrorMessage(ex.getMessage());
                logger.log(Level.WARNING, ex.getMessage());
            }catch(Exception ex){
                verification = VerificationGrpc.newBuilder().setSuccessOfOperation(false)
                        .setErrorMessage(internalError);
                logger.log(Level.WARNING, ex.getMessage());
            }
            responseObserver.onNext(verification.build());
            responseObserver.onCompleted();
        }

        /** Here start methods of NodeResource*/

        @Override
        public void getNodes(RequestID request, StreamObserver<NodeGrpc> responseObserver) {
            try{
                for (Node item : nodeService.getAllNodes(request.getIdGraph())) {
                    NodeGrpc nr = GrpcUtils.obtainNode(item);
                    responseObserver.onNext(nr);
                }
            }catch(ForbiddenException | DataNotFoundException ex){
                NodeGrpc nr = NodeGrpc.newBuilder().setErrorMessage(ex.getMessage()).build();
                responseObserver.onNext(nr);
                logger.log(Level.WARNING, ex.getMessage());
            }catch(Exception ex){
                NodeGrpc nr = NodeGrpc.newBuilder().setErrorMessage(internalError).build();
                responseObserver.onNext(nr);
                logger.log(Level.WARNING, ex.getMessage());
            }
            responseObserver.onCompleted();
        }

        @Override
        public void createNode(NodeGrpc request, StreamObserver<NewNode> responseObserver) {
            NewNode.Builder response = NewNode.newBuilder();
            try{
                Node node = GrpcUtils.deriveNode(request);
                Node newNode = nodeService.addNode(request.getIdGraph(), node);
                response.setSuccess(true).setNode(GrpcUtils.obtainNode(newNode));
            }catch(ForbiddenException | DataNotFoundException | BadRequestException ex){
                response.setSuccess(false).setErrorMessage(ex.getMessage());
                logger.log(Level.WARNING, ex.getMessage());
            }catch(Exception ex){
                response.setSuccess(false).setErrorMessage(internalError);
                logger.log(Level.WARNING, ex.getMessage());
            }
            responseObserver.onNext(response.build());
            responseObserver.onCompleted();
        }

        @Override
        public void deleteNode(RequestID request, StreamObserver<Status> responseObserver) {
            Status.Builder response = Status.newBuilder();
            try{
                nodeService.removeNode(request.getIdGraph(), request.getIdNode());
                response.setSuccess(true);
            }catch(ForbiddenException | DataNotFoundException ex){
                response.setSuccess(false).setErrorMessage(ex.getMessage());
                logger.log(Level.WARNING, ex.getMessage());
            }catch(Exception ex){
                response.setSuccess(false).setErrorMessage(internalError);
                logger.log(Level.WARNING, ex.getMessage());
            }
            responseObserver.onNext(response.build());
            responseObserver.onCompleted();
        }

        @Override
        public void getNode(RequestID request, StreamObserver<NodeGrpc> responseObserver) {
            NodeGrpc nr;
            try{
                Node node = nodeService.getNode(request.getIdGraph(), request.getIdNode());
                nr= GrpcUtils.obtainNode(node);
            }catch(ForbiddenException | DataNotFoundException ex){
                nr = NodeGrpc.newBuilder().setErrorMessage(ex.getMessage()).build();
                logger.log(Level.WARNING, ex.getMessage());
            }catch(Exception ex){
                nr = NodeGrpc.newBuilder().setErrorMessage(internalError).build();
                logger.log(Level.WARNING, ex.getMessage());
            }
            responseObserver.onNext(nr);
            responseObserver.onCompleted();
        }

        @Override
        public void updateNode(NodeGrpc request, StreamObserver<NewNode> responseObserver) {
            NewNode.Builder response = NewNode.newBuilder(); 
            try{
                Node node = GrpcUtils.deriveNode(request);
                node.setId(request.getId());
                Node newNode = nodeService.updateNode(request.getIdGraph(), node);
                response.setSuccess(true).setNode(GrpcUtils.obtainNode(newNode));
            }catch(ForbiddenException | DataNotFoundException | BadRequestException ex){
                response.setSuccess(false).setErrorMessage(ex.getMessage());
                logger.log(Level.WARNING, ex.getMessage());
            }catch(Exception ex){
                response.setSuccess(false).setErrorMessage(internalError);
                logger.log(Level.WARNING, ex.getMessage());
            }
            responseObserver.onNext(response.build());
            responseObserver.onCompleted();
        }

        @Override
        public void configureNode(ConfigurationGrpc request, StreamObserver<Status> responseObserver) {
            Status.Builder response = Status.newBuilder();
            try{
                if (request.getIdGraph() <= 0) {
                    throw new ForbiddenException("Illegal graph id: " + request.getIdGraph());
                }
                if (request.getIdNode() <= 0) {
                    throw new ForbiddenException("Illegal node id: " + request.getIdNode());
                }
                Graph graph = new GraphService().getGraph(request.getIdGraph());
                if (graph == null){
                    throw new BadRequestException("Graph with id " + request.getIdGraph() + " not found");
                }
                Node node = nodeService.getNode(request.getIdGraph(), request.getIdNode());
                if (node == null){
                    throw new BadRequestException("Node with id " + request.getIdNode() + " not found in graph with id " + request.getIdGraph());
                }
                Configuration nodeConfiguration = GrpcUtils.deriveConfiguration(request);
                Node nodeCopy = new Node();
                nodeCopy.setId(node.getId());
                nodeCopy.setName(node.getName());
                nodeCopy.setFunctional_type(node.getFunctional_type());
                Map<Long,Neighbour> nodes = new HashMap<Long,Neighbour>();
                nodes.putAll(node.getNeighbours());
                nodeCopy.setNeighbours(nodes);
                nodeConfiguration.setId(nodeCopy.getName());
                nodeCopy.setConfiguration(nodeConfiguration);
                Graph graphCopy = new Graph();
                graphCopy.setId(graph.getId());
                graphCopy.setNodes(new HashMap<Long, Node>(graph.getNodes()));
                graphCopy.getNodes().remove(node.getId());
                NodeService.validateNode(graphCopy, nodeCopy);
                graph.getNodes().put(request.getIdNode(), nodeCopy);
                response.setSuccess(true);
            }catch(ForbiddenException | BadRequestException ex){
                response.setSuccess(false).setErrorMessage(ex.getMessage());
                logger.log(Level.WARNING, ex.getMessage());
            }catch(Exception ex){
                response.setSuccess(false).setErrorMessage(internalError);
                logger.log(Level.WARNING, ex.getMessage());
            }
            responseObserver.onNext(response.build());
            responseObserver.onCompleted();
        }

        /** Here start methods of NeighbourResource*/
        @Override
        public void getNeighbours(RequestID request, StreamObserver<NeighbourGrpc> responseObserver) {
            try{
                for(Neighbour item : neighboursService.getAllNeighbours(request.getIdGraph(), request.getIdNode())) {
                    NeighbourGrpc nr = GrpcUtils.obtainNeighbour(item);
                    responseObserver.onNext(nr);
                }
            }catch(ForbiddenException | DataNotFoundException ex){
                NeighbourGrpc nr = NeighbourGrpc.newBuilder().setErrorMessage(ex.getMessage()).build();
                responseObserver.onNext(nr);
                logger.log(Level.WARNING, ex.getMessage());
            }catch(Exception ex){
                NeighbourGrpc nr = NeighbourGrpc.newBuilder().setErrorMessage(internalError).build();
                responseObserver.onNext(nr);
                logger.log(Level.WARNING, ex.getMessage());
            }           
            responseObserver.onCompleted();
        }

        @Override
        public void createNeighbour(NeighbourGrpc request, StreamObserver<NewNeighbour> responseObserver) {
            NewNeighbour.Builder response = NewNeighbour.newBuilder();
            try{
                Neighbour neighbour = GrpcUtils.deriveNeighbour(request);
                Neighbour newNeighbour = neighboursService.addNeighbour(request.getIdGraph(), request.getIdNode(), neighbour);
                response.setSuccess(true).setNeighbour(GrpcUtils.obtainNeighbour(newNeighbour));
            }catch(ForbiddenException | DataNotFoundException | BadRequestException ex){
                response.setSuccess(false).setErrorMessage(ex.getMessage());
                logger.log(Level.WARNING, ex.getMessage());
            }catch(Exception ex){
                response.setSuccess(false).setErrorMessage(ex.getMessage());
                logger.log(Level.WARNING, ex.getMessage());
            }
            responseObserver.onNext(response.build());
            responseObserver.onCompleted();
        }

        @Override
        public void deleteNeighbour(RequestID request, StreamObserver<Status> responseObserver) {
            Status.Builder response = Status.newBuilder();
            try{
                neighboursService.removeNeighbour(request.getIdGraph(), request.getIdNode(), request.getIdNeighbour());
                response.setSuccess(true);
            }catch(ForbiddenException | DataNotFoundException ex){
                response.setSuccess(false).setErrorMessage(ex.getMessage());
                logger.log(Level.WARNING, ex.getMessage());
            }catch(Exception ex){
                response.setSuccess(false).setErrorMessage(ex.getMessage());
                logger.log(Level.WARNING, ex.getMessage());
            }
            responseObserver.onNext(response.build());
            responseObserver.onCompleted();
        }

        @Override
        public void getNeighbour(RequestID request, StreamObserver<NeighbourGrpc> responseObserver) {
            NeighbourGrpc nr;
            try{
                Neighbour neighbour = neighboursService.getNeighbour(request.getIdGraph(),
                        request.getIdNode(), request.getIdNeighbour());
                nr = GrpcUtils.obtainNeighbour(neighbour);

            }catch(ForbiddenException | DataNotFoundException ex){
                nr = NeighbourGrpc.newBuilder().setErrorMessage(ex.getMessage()).build();
                logger.log(Level.WARNING, ex.getMessage());
            }catch(Exception ex){
                nr = NeighbourGrpc.newBuilder().setErrorMessage(internalError).build();
                logger.log(Level.WARNING, ex.getMessage());
            }
            responseObserver.onNext(nr);
            responseObserver.onCompleted();
        }

        @Override
        public void updateNeighbour(NeighbourGrpc request, StreamObserver<NewNeighbour> responseObserver) {
            NewNeighbour.Builder response = NewNeighbour.newBuilder();
            try{
                Neighbour neighbour = GrpcUtils.deriveNeighbour(request);
                neighbour.setId(request.getId());
                Neighbour newNeighbour = neighboursService.updateNeighbour(request.getIdGraph(), request.getIdNode(), neighbour);
                response.setSuccess(true).setNeighbour(GrpcUtils.obtainNeighbour(newNeighbour));
            }catch(ForbiddenException | DataNotFoundException | BadRequestException ex){
                response.setSuccess(false).setErrorMessage(ex.getMessage());
                logger.log(Level.WARNING, ex.getMessage());
            }catch(Exception ex){
                response.setSuccess(false).setErrorMessage(ex.getMessage());
                logger.log(Level.WARNING, ex.getMessage());
            }
            responseObserver.onNext(response.build());
            responseObserver.onCompleted();
        }
    }
}