/*
 * Copyright IBM Corporation and others, 2013.  All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v1.0 which accompanies this distribution,
 * and is available at http://www.eclipse.org/legal/epl-v10.html
 */

package org.opendaylight.neutron.northbound.api;

import java.net.HttpURLConnection;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

import javax.ws.rs.Consumes;
import javax.ws.rs.DELETE;
import javax.ws.rs.DefaultValue;
import javax.ws.rs.GET;
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.QueryParam;
import javax.ws.rs.core.Context;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.Response;
import javax.ws.rs.core.UriInfo;

import org.codehaus.enunciate.jaxrs.ResponseCode;
import org.codehaus.enunciate.jaxrs.StatusCodes;
import org.opendaylight.neutron.spi.INeutronNetworkCRUD;
import org.opendaylight.neutron.spi.INeutronSubnetAware;
import org.opendaylight.neutron.spi.INeutronSubnetCRUD;
import org.opendaylight.neutron.spi.NeutronCRUDInterfaces;
import org.opendaylight.neutron.spi.NeutronSubnet;

/**
 * Neutron Northbound REST APIs for Subnets.<br>
 * This class provides REST APIs for managing neutron Subnets
 *
 * <br>
 * <br>
 * Authentication scheme : <b>HTTP Basic</b><br>
 * Authentication realm : <b>opendaylight</b><br>
 * Transport : <b>HTTP and HTTPS</b><br>
 * <br>
 * HTTPS Authentication is disabled by default. Administrator can enable it in
 * tomcat-server.xml after adding a proper keystore / SSL certificate from a
 * trusted authority.<br>
 * More info :
 * http://tomcat.apache.org/tomcat-7.0-doc/ssl-howto.html#Configuration
 *
 */

@Path("/subnets")
public class NeutronSubnetsNorthbound {
    private static final int HTTP_OK_BOTTOM = 200;
    private static final int HTTP_OK_TOP = 299;
    private static final String INTERFACE_NAME = "Subnet CRUD Interface";
    private static final String UUID_NO_EXIST = "Subnet UUID does not exist.";
    private static final String UUID_EXISTS = "Subnet UUID already exists.";
    private static final String NO_PROVIDERS = "No providers registered.  Please try again later";
    private static final String NO_PROVIDER_LIST = "Couldn't get providers list.  Please try again later";

    private NeutronSubnet extractFields(NeutronSubnet o, List<String> fields) {
        return o.extractFields(fields);
    }

    private NeutronCRUDInterfaces getNeutronInterfaces(boolean needNetwork) {
        NeutronCRUDInterfaces answer = new NeutronCRUDInterfaces().fetchINeutronSubnetCRUD(this);
        if (answer.getSubnetInterface() == null) {
            throw new ServiceUnavailableException(INTERFACE_NAME
                + RestMessages.SERVICEUNAVAILABLE.toString());
        }
        if (needNetwork) {
            answer = answer.fetchINeutronNetworkCRUD(this);
            if (answer.getNetworkInterface() == null) {
                throw new ServiceUnavailableException("Network CRUD Interface "
                    + RestMessages.SERVICEUNAVAILABLE.toString());
            }
        }
        return answer;
    }

    @Context
    UriInfo uriInfo;

    /**
     * Returns a list of all Subnets */
    @GET
    @Produces({ MediaType.APPLICATION_JSON })
    //@TypeHint(OpenStackSubnets.class)
    @StatusCodes({
            @ResponseCode(code = HttpURLConnection.HTTP_OK, condition = "Operation successful"),
            @ResponseCode(code = HttpURLConnection.HTTP_UNAUTHORIZED, condition = "Unauthorized"),
            @ResponseCode(code = HttpURLConnection.HTTP_NOT_IMPLEMENTED, condition = "Not Implemented"),
            @ResponseCode(code = HttpURLConnection.HTTP_UNAVAILABLE, condition = "No providers available") })
    public Response listSubnets(
            // return fields
            @QueryParam("fields") List<String> fields,
            // note: openstack isn't clear about filtering on lists, so we aren't handling them
            @QueryParam("id") String queryID,
            @QueryParam("network_id") String queryNetworkID,
            @QueryParam("name") String queryName,
            @QueryParam("ip_version") String queryIPVersion,
            @QueryParam("cidr") String queryCIDR,
            @QueryParam("gateway_ip") String queryGatewayIP,
            @QueryParam("enable_dhcp") String queryEnableDHCP,
            @QueryParam("tenant_id") String queryTenantID,
            @QueryParam("ipv6_address_mode") String queryIpV6AddressMode,
            @QueryParam("ipv6_ra_mode") String queryIpV6RaMode,
            // linkTitle
            @QueryParam("limit") Integer limit,
            @QueryParam("marker") String marker,
            @DefaultValue("false") @QueryParam("page_reverse") Boolean pageReverse
            // sorting not supported
            ) {
        INeutronSubnetCRUD subnetInterface = getNeutronInterfaces(false).getSubnetInterface();
        List<NeutronSubnet> allNetworks = subnetInterface.getAllSubnets();
        List<NeutronSubnet> ans = new ArrayList<NeutronSubnet>();
        Iterator<NeutronSubnet> i = allNetworks.iterator();
        while (i.hasNext()) {
            NeutronSubnet oSS = i.next();
            if ((queryID == null || queryID.equals(oSS.getID())) &&
                    (queryNetworkID == null || queryNetworkID.equals(oSS.getNetworkUUID())) &&
                    (queryName == null || queryName.equals(oSS.getName())) &&
                    (queryIPVersion == null || queryIPVersion.equals(oSS.getIpVersion())) &&
                    (queryCIDR == null || queryCIDR.equals(oSS.getCidr())) &&
                    (queryGatewayIP == null || queryGatewayIP.equals(oSS.getGatewayIP())) &&
                    (queryEnableDHCP == null || queryEnableDHCP.equals(oSS.getEnableDHCP())) &&
                    (queryTenantID == null || queryTenantID.equals(oSS.getTenantID())) &&
                    (queryIpV6AddressMode == null || queryIpV6AddressMode.equals(oSS.getIpV6AddressMode())) &&
                    (queryIpV6RaMode == null || queryIpV6RaMode.equals(oSS.getIpV6RaMode()))){
                if (fields.size() > 0) {
                    ans.add(extractFields(oSS,fields));
                } else {
                    ans.add(oSS);
                }
            }
        }

        if (limit != null && ans.size() > 1) {
            // Return a paginated request
            NeutronSubnetRequest request = (NeutronSubnetRequest) PaginatedRequestFactory.createRequest(limit,
                    marker, pageReverse, uriInfo, ans, NeutronSubnet.class);
            return Response.status(HttpURLConnection.HTTP_OK).entity(request).build();
        }

        return Response.status(HttpURLConnection.HTTP_OK).entity(
                new NeutronSubnetRequest(ans)).build();
    }

    /**
     * Returns a specific Subnet */

    @Path("{subnetUUID}")
    @GET
    @Produces({ MediaType.APPLICATION_JSON })
    //@TypeHint(OpenStackSubnets.class)
    @StatusCodes({
            @ResponseCode(code = HttpURLConnection.HTTP_OK, condition = "Operation successful"),
            @ResponseCode(code = HttpURLConnection.HTTP_UNAUTHORIZED, condition = "Unauthorized"),
            @ResponseCode(code = HttpURLConnection.HTTP_NOT_FOUND, condition = "Not Found"),
            @ResponseCode(code = HttpURLConnection.HTTP_NOT_IMPLEMENTED, condition = "Not Implemented"),
            @ResponseCode(code = HttpURLConnection.HTTP_UNAVAILABLE, condition = "No providers available") })
    public Response showSubnet(
            @PathParam("subnetUUID") String subnetUUID,
            // return fields
            @QueryParam("fields") List<String> fields) {
        INeutronSubnetCRUD subnetInterface = getNeutronInterfaces(false).getSubnetInterface();
        if (!subnetInterface.subnetExists(subnetUUID)) {
            throw new ResourceNotFoundException(UUID_NO_EXIST);
        }
        if (fields.size() > 0) {
            NeutronSubnet ans = subnetInterface.getSubnet(subnetUUID);
            return Response.status(HttpURLConnection.HTTP_OK).entity(
                    new NeutronSubnetRequest(extractFields(ans, fields))).build();
        } else {
            return Response.status(HttpURLConnection.HTTP_OK).entity(
                    new NeutronSubnetRequest(subnetInterface.getSubnet(subnetUUID))).build();
        }
    }

    /**
     * Creates new Subnets */

    @POST
    @Produces({ MediaType.APPLICATION_JSON })
    @Consumes({ MediaType.APPLICATION_JSON })
    //@TypeHint(OpenStackSubnets.class)
    @StatusCodes({
            @ResponseCode(code = HttpURLConnection.HTTP_CREATED, condition = "Created"),
            @ResponseCode(code = HttpURLConnection.HTTP_BAD_REQUEST, condition = "Bad Request"),
            @ResponseCode(code = HttpURLConnection.HTTP_UNAUTHORIZED, condition = "Unauthorized"),
            @ResponseCode(code = HttpURLConnection.HTTP_FORBIDDEN, condition = "Forbidden"),
            @ResponseCode(code = HttpURLConnection.HTTP_NOT_FOUND, condition = "Not Found"),
            @ResponseCode(code = HttpURLConnection.HTTP_CONFLICT, condition = "Conflict"),
            @ResponseCode(code = HttpURLConnection.HTTP_NOT_IMPLEMENTED, condition = "Not Implemented"),
            @ResponseCode(code = HttpURLConnection.HTTP_UNAVAILABLE, condition = "No providers available") })
    public Response createSubnets(final NeutronSubnetRequest input) {
        NeutronCRUDInterfaces interfaces = getNeutronInterfaces(true);
        INeutronSubnetCRUD subnetInterface = interfaces.getSubnetInterface();
        INeutronNetworkCRUD networkInterface = interfaces.getNetworkInterface();
        if (input.isSingleton()) {
            NeutronSubnet singleton = input.getSingleton();

            Object[] instances = NeutronUtil.getInstances(INeutronSubnetAware.class, this);
            if (instances != null) {
                if (instances.length > 0) {
                    for (Object instance : instances) {
                        INeutronSubnetAware service = (INeutronSubnetAware) instance;
                        int status = service.canCreateSubnet(singleton);
                        if (status < HTTP_OK_BOTTOM || status > HTTP_OK_TOP) {
                            return Response.status(status).build();
                        }
                    }
                } else {
                    throw new ServiceUnavailableException(NO_PROVIDERS);
                }
            } else {
                throw new ServiceUnavailableException(NO_PROVIDER_LIST);
            }
            subnetInterface.addSubnet(singleton);
            if (instances != null) {
                for (Object instance : instances) {
                    INeutronSubnetAware service = (INeutronSubnetAware) instance;
                    service.neutronSubnetCreated(singleton);
                }
            }
        } else {
            Object[] instances = NeutronUtil.getInstances(INeutronSubnetAware.class, this);
            for (NeutronSubnet test : input.getBulk()) {
                if (instances != null) {
                    if (instances.length > 0) {
                        for (Object instance : instances) {
                            INeutronSubnetAware service = (INeutronSubnetAware) instance;
                            int status = service.canCreateSubnet(test);
                            if (status < HTTP_OK_BOTTOM || status > HTTP_OK_TOP) {
                                return Response.status(status).build();
                            }
                        }
                    } else {
                        throw new ServiceUnavailableException(NO_PROVIDERS);
                    }
                } else {
                    throw new ServiceUnavailableException(NO_PROVIDER_LIST);
                }
            }

            /*
             * now, each element of the bulk request can be added to the cache
             */
            for (NeutronSubnet test : input.getBulk()) {
                subnetInterface.addSubnet(test);
                if (instances != null) {
                    for (Object instance : instances) {
                        INeutronSubnetAware service = (INeutronSubnetAware) instance;
                        service.neutronSubnetCreated(test);
                    }
                }
            }
        }
        return Response.status(HttpURLConnection.HTTP_CREATED).entity(input).build();
    }

    /**
     * Updates a Subnet */

    @Path("{subnetUUID}")
    @PUT
    @Produces({ MediaType.APPLICATION_JSON })
    @Consumes({ MediaType.APPLICATION_JSON })
    //@TypeHint(OpenStackSubnets.class)
    @StatusCodes({
            @ResponseCode(code = HttpURLConnection.HTTP_OK, condition = "Operation successful"),
            @ResponseCode(code = HttpURLConnection.HTTP_BAD_REQUEST, condition = "Bad Request"),
            @ResponseCode(code = HttpURLConnection.HTTP_UNAUTHORIZED, condition = "Unauthorized"),
            @ResponseCode(code = HttpURLConnection.HTTP_FORBIDDEN, condition = "Forbidden"),
            @ResponseCode(code = HttpURLConnection.HTTP_NOT_FOUND, condition = "Not Found"),
            @ResponseCode(code = HttpURLConnection.HTTP_NOT_IMPLEMENTED, condition = "Not Implemented"),
            @ResponseCode(code = HttpURLConnection.HTTP_UNAVAILABLE, condition = "No providers available") })
    public Response updateSubnet(
            @PathParam("subnetUUID") String subnetUUID, final NeutronSubnetRequest input
            ) {
        INeutronSubnetCRUD subnetInterface = getNeutronInterfaces(false).getSubnetInterface();

        /*
         * note: what we get appears to not be a delta, but rather a
         * complete updated object.  So, that needs to be sent down to
         * folks to check 
         */

        NeutronSubnet updatedObject = input.getSingleton();

        Object[] instances = NeutronUtil.getInstances(INeutronSubnetAware.class, this);
        if (instances != null) {
            if (instances.length > 0) {
                for (Object instance : instances) {
                    INeutronSubnetAware service = (INeutronSubnetAware) instance;
                    NeutronSubnet original = subnetInterface.getSubnet(subnetUUID);
                    int status = service.canUpdateSubnet(updatedObject, original);
                    if (status < HTTP_OK_BOTTOM || status > HTTP_OK_TOP) {
                        return Response.status(status).build();
                    }
                }
            } else {
                throw new ServiceUnavailableException(NO_PROVIDERS);
            }
        } else {
            throw new ServiceUnavailableException(NO_PROVIDER_LIST);
        }

        /*
         * update the object and return it
         */
        subnetInterface.updateSubnet(subnetUUID, updatedObject);
        if (instances != null) {
            for (Object instance : instances) {
                INeutronSubnetAware service = (INeutronSubnetAware) instance;
                service.neutronSubnetUpdated(updatedObject);
            }
        }
        return Response.status(HttpURLConnection.HTTP_OK).entity(
                new NeutronSubnetRequest(subnetInterface.getSubnet(subnetUUID))).build();
    }

    /**
     * Deletes a Subnet */

    @Path("{subnetUUID}")
    @DELETE
    @StatusCodes({
            @ResponseCode(code = HttpURLConnection.HTTP_NO_CONTENT, condition = "No Content"),
            @ResponseCode(code = HttpURLConnection.HTTP_UNAUTHORIZED, condition = "Unauthorized"),
            @ResponseCode(code = HttpURLConnection.HTTP_NOT_FOUND, condition = "Not Found"),
            @ResponseCode(code = HttpURLConnection.HTTP_CONFLICT, condition = "Conflict"),
            @ResponseCode(code = HttpURLConnection.HTTP_NOT_IMPLEMENTED, condition = "Not Implemented"),
            @ResponseCode(code = HttpURLConnection.HTTP_UNAVAILABLE, condition = "No providers available") })
    public Response deleteSubnet(
            @PathParam("subnetUUID") String subnetUUID) {
        INeutronSubnetCRUD subnetInterface = getNeutronInterfaces(false).getSubnetInterface();

        NeutronSubnet singleton = subnetInterface.getSubnet(subnetUUID);
        Object[] instances = NeutronUtil.getInstances(INeutronSubnetAware.class, this);
        if (instances != null) {
            if (instances.length > 0) {
                for (Object instance : instances) {
                    INeutronSubnetAware service = (INeutronSubnetAware) instance;
                    int status = service.canDeleteSubnet(singleton);
                    if (status < HTTP_OK_BOTTOM || status > HTTP_OK_TOP) {
                        return Response.status(status).build();
                    }
                }
            } else {
                throw new ServiceUnavailableException(NO_PROVIDERS);
            }
        } else {
            throw new ServiceUnavailableException(NO_PROVIDER_LIST);
        }

        /*
         * remove it and return 204 status
         */
        subnetInterface.removeSubnet(subnetUUID);
        if (instances != null) {
            for (Object instance : instances) {
                INeutronSubnetAware service = (INeutronSubnetAware) instance;
                service.neutronSubnetDeleted(singleton);
            }
        }
        return Response.status(HttpURLConnection.HTTP_NO_CONTENT).build();
    }
}