/**
 *    Copyright 2011, Big Switch Networks, Inc.
 *    Originally created by David Erickson, Stanford University
 *
 *    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 net.floodlightcontroller.core.web;

import java.util.Collections;
import java.util.Iterator;

import net.floodlightcontroller.core.IFloodlightProviderService;
import net.floodlightcontroller.core.IOFSwitch;
import net.floodlightcontroller.util.FilterIterator;

import org.projectfloodlight.openflow.util.HexString;
import org.restlet.data.Form;
import org.restlet.data.Status;
import org.restlet.resource.Get;
import org.restlet.resource.ServerResource;

/**
 * Get a list of switches connected to the controller
 *
 * @author readams
 */
public class ControllerSwitchesResource extends ServerResource {
    public static final String DPID_ERROR =
            "Invalid Switch DPID: must be a 64-bit quantity, expressed in " +
                    "hex as AA:BB:CC:DD:EE:FF:00:11";

    @Get("json")
    public Iterator<IOFSwitch> retrieve() {
        IFloodlightProviderService floodlightProvider =
                (IFloodlightProviderService) getContext().getAttributes().
                        get(IFloodlightProviderService.class.getCanonicalName());

        Long switchDPID = null;

        Form form = getQuery();
        String dpid = form.getFirstValue("dpid", true);
        if (dpid != null) {
            try {
                switchDPID = HexString.toLong(dpid);
            } catch (Exception e) {
                setStatus(Status.CLIENT_ERROR_BAD_REQUEST, DPID_ERROR);
                return null;
            }
        }
        if (switchDPID != null) {
            IOFSwitch sw =
                    floodlightProvider.getSwitches().get(switchDPID);
            if (sw != null)
                return Collections.singleton(sw).iterator();
            return Collections.<IOFSwitch>emptySet().iterator();
        }
        final String dpidStartsWith =
                form.getFirstValue("dpid__startswith", true);
        Iterator<IOFSwitch> switer =
                floodlightProvider.getSwitches().values().iterator();
        if (dpidStartsWith != null) {
            return new FilterIterator<IOFSwitch>(switer) {
                @Override
                protected boolean matches(IOFSwitch value) {
                    return value.getStringId().startsWith(dpidStartsWith);
                }
            };
        }
        return switer;
    }
}