/*
 * Copyright 2016-present Open Networking Foundation
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.opencord.cordvtn.rest;

import com.fasterxml.jackson.databind.JsonNode;
import org.onlab.osgi.DefaultServiceDirectory;
import org.onosproject.rest.AbstractWebResource;
import org.opencord.cordvtn.api.core.ServiceNetworkAdminService;
import org.opencord.cordvtn.api.net.NetworkId;
import org.opencord.cordvtn.api.net.SegmentId;
import org.opencord.cordvtn.api.net.ServiceNetwork;
import org.opencord.cordvtn.api.net.ServiceNetwork.NetworkType;
import org.opencord.cordvtn.impl.DefaultServiceNetwork;
import org.openstack4j.core.transport.ObjectMapperSingleton;
import org.openstack4j.openstack.networking.domain.NeutronNetwork;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import javax.ws.rs.Consumes;
import javax.ws.rs.DELETE;
import javax.ws.rs.POST;
import javax.ws.rs.PUT;
import javax.ws.rs.Path;
import javax.ws.rs.PathParam;
import javax.ws.rs.Produces;
import javax.ws.rs.core.Context;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.Response;
import javax.ws.rs.core.UriBuilder;
import javax.ws.rs.core.UriInfo;
import java.io.InputStream;

import static com.fasterxml.jackson.databind.SerializationFeature.INDENT_OUTPUT;
import static javax.ws.rs.core.Response.Status.OK;
import static javax.ws.rs.core.Response.created;
import static javax.ws.rs.core.Response.noContent;
import static javax.ws.rs.core.Response.status;

/**
 * Neutron ML2 mechanism driver implementation for the network resource.
 */
@Path("networks")
public class NeutronMl2NetworksWebResource extends AbstractWebResource {
    protected final Logger log = LoggerFactory.getLogger(getClass());

    private static final String MESSAGE = "Received networks %s request";
    private static final String NETWORKS = "networks";

    private final ServiceNetworkAdminService adminService =
            DefaultServiceDirectory.getService(ServiceNetworkAdminService.class);

    @Context
    private UriInfo uriInfo;

    /**
     * Creates a network from the JSON input stream.
     *
     * @param input network JSON input stream
     * @return 201 CREATED if the JSON is correct, 400 BAD_REQUEST if the JSON
     * is invalid or duplicated network already exists
     */
    @POST
    @Consumes(MediaType.APPLICATION_JSON)
    @Produces(MediaType.APPLICATION_JSON)
    public Response createNetwork(InputStream input) {
        log.trace(String.format(MESSAGE, "CREATE"));

        final ServiceNetwork snet = readNetwork(input);
        adminService.createServiceNetwork(snet);

        UriBuilder locationBuilder = uriInfo.getBaseUriBuilder()
                .path(NETWORKS)
                .path(snet.id().id());

        return created(locationBuilder.build()).build();
    }

    /**
     * Updates the network with the specified identifier.
     *
     * @param id network identifier
     * @param input network JSON input stream
     * @return 200 OK with the updated network, 400 BAD_REQUEST if the requested
     * network does not exist
     */
    @PUT
    @Path("{id}")
    @Consumes(MediaType.APPLICATION_JSON)
    @Produces(MediaType.APPLICATION_JSON)
    public Response updateNetwork(@PathParam("id") String id, InputStream input) {
        log.trace(String.format(MESSAGE, "UPDATE " + id));

        final ServiceNetwork snet = readNetwork(input);
        adminService.updateServiceNetwork(snet);

        return status(OK).build();
    }

    /**
     * Removes the service network.
     *
     * @param id network identifier
     * @return 204 NO_CONTENT, 400 BAD_REQUEST if the network does not exist
     */
    @DELETE
    @Path("{id}")
    @Consumes(MediaType.APPLICATION_JSON)
    @Produces(MediaType.APPLICATION_JSON)
    public Response deleteNetwork(@PathParam("id") String id) {
        log.trace(String.format(MESSAGE, "DELETE " + id));

        adminService.removeServiceNetwork(NetworkId.of(id));
        return noContent().build();
    }

    private ServiceNetwork readNetwork(InputStream input) {
        try {
            JsonNode jsonTree = mapper().enable(INDENT_OUTPUT).readTree(input);
            log.trace(mapper().writeValueAsString(jsonTree));
            NeutronNetwork osNet = ObjectMapperSingleton.getContext(NeutronNetwork.class)
                    .readerFor(NeutronNetwork.class)
                    .readValue(jsonTree);

            return DefaultServiceNetwork.builder()
                    .id(NetworkId.of(osNet.getId()))
                    .name(osNet.getName())
                    .type(NetworkType.PRIVATE)
                    .segmentId(SegmentId.of(Long.valueOf(osNet.getProviderSegID())))
                    .build();
        } catch (Exception e) {
            throw new IllegalArgumentException();
        }
    }
}