/*
 * Copyright (c) 2013 Cisco Systems, Inc. and others.  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.controller.flows.web;

import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;

import javax.servlet.http.HttpServletRequest;

import org.opendaylight.controller.forwardingrulesmanager.FlowConfig;
import org.opendaylight.controller.forwardingrulesmanager.IForwardingRulesManager;
import org.opendaylight.controller.sal.authorization.UserLevel;
import org.opendaylight.controller.sal.core.Name;
import org.opendaylight.controller.sal.core.Node;
import org.opendaylight.controller.sal.core.NodeConnector;
import org.opendaylight.controller.sal.utils.ServiceHelper;
import org.opendaylight.controller.sal.utils.Status;
import org.opendaylight.controller.sal.utils.StatusCode;
import org.opendaylight.controller.switchmanager.ISwitchManager;
import org.opendaylight.controller.switchmanager.Switch;
import org.opendaylight.controller.switchmanager.SwitchConfig;
import org.opendaylight.controller.usermanager.IUserManager;
import org.opendaylight.controller.web.DaylightWebUtil;
import org.opendaylight.controller.web.IDaylightWeb;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.ResponseBody;

import com.google.gson.Gson;

@Controller
@RequestMapping("/")
public class Flows implements IDaylightWeb {
    private static final UserLevel AUTH_LEVEL = UserLevel.CONTAINERUSER;
    private static final String WEB_NAME = "Flows";
    private static final String WEB_ID = "flows";
    private static final short WEB_ORDER = 2;

    public Flows() {
        ServiceHelper.registerGlobalService(IDaylightWeb.class, this, null);
    }

    @Override
    public String getWebName() {
        return WEB_NAME;
    }

    @Override
    public String getWebId() {
        return WEB_ID;
    }

    @Override
    public short getWebOrder() {
        return WEB_ORDER;
    }

    @Override
    public boolean isAuthorized(UserLevel userLevel) {
        return userLevel.ordinal() <= AUTH_LEVEL.ordinal();
    }

    @RequestMapping(value = "/main")
    @ResponseBody
    public Set<Map<String, Object>> getFlows(HttpServletRequest request, @RequestParam(required = false) String container) {
        String containerName = DaylightWebUtil.getAuthorizedContainer(request, container, this);

        // fetch frm
        IForwardingRulesManager frm = (IForwardingRulesManager) ServiceHelper
                .getInstance(IForwardingRulesManager.class, containerName, this);
        if (frm == null) {
            return null;
        }

        // fetch sm
        ISwitchManager switchManager = (ISwitchManager) ServiceHelper
                .getInstance(ISwitchManager.class, containerName, this);
        if (switchManager == null) {
            return null;
        }

        // get static flow list
        List<FlowConfig> staticFlowList = frm.getStaticFlows();
        Set<Map<String, Object>> output = new HashSet<Map<String, Object>>();
        for (FlowConfig flowConfig : staticFlowList) {
            Map<String, Object> entry = new HashMap<String, Object>();
            entry.put("flow", flowConfig);
            entry.put("name", flowConfig.getName());
            Node node = flowConfig.getNode();
            String description = switchManager.getNodeDescription(node);
            entry.put("node", (description.isEmpty() || description
                    .equalsIgnoreCase("none")) ? node.toString() : description);
            entry.put("nodeId", node.toString());
            output.add(entry);
        }

        return output;
    }

    @RequestMapping(value = "/node-ports")
    @ResponseBody
    public Map<String, Object> getNodePorts(HttpServletRequest request, @RequestParam(required = false) String container) {
        String containerName = DaylightWebUtil.getAuthorizedContainer(request, container, this);

        ISwitchManager switchManager = (ISwitchManager) ServiceHelper
                .getInstance(ISwitchManager.class, containerName, this);
        if (switchManager == null) {
            return null;
        }

        Map<String, Object> nodes = new HashMap<String, Object>();
        Map<Short, String> port;

        for (Switch node : switchManager.getNetworkDevices()) {
            port = new HashMap<Short, String>(); // new port
            Set<NodeConnector> nodeConnectorSet = node.getNodeConnectors();

            if (nodeConnectorSet != null) {
                for (NodeConnector nodeConnector : nodeConnectorSet) {
                    String nodeConnectorName = ((Name) switchManager
                            .getNodeConnectorProp(nodeConnector,
                                    Name.NamePropName)).getValue();
                    port.put((Short) nodeConnector.getID(), nodeConnectorName
                            + "(" + nodeConnector.getNodeConnectorIDString()
                            + ")");
                }
            }

            // add ports
            Map<String, Object> entry = new HashMap<String, Object>();
            entry.put("ports", port);

            // add name
            String description = switchManager.getNodeDescription(node
                    .getNode());
            entry.put("name", (description.isEmpty() || description
                    .equalsIgnoreCase("none")) ? node.getNode().toString()
                    : description);

            // add to the node
            nodes.put(node.getNode().toString(), entry);
        }

        return nodes;
    }

    @RequestMapping(value = "/node-flows")
    @ResponseBody
    public Map<String, Object> getNodeFlows(HttpServletRequest request, @RequestParam(required = false) String container) {
        String containerName = DaylightWebUtil.getAuthorizedContainer(request, container, this);

        ISwitchManager switchManager = (ISwitchManager) ServiceHelper
                .getInstance(ISwitchManager.class, containerName, this);
        if (switchManager == null) {
            return null;
        }
        IForwardingRulesManager frm = (IForwardingRulesManager) ServiceHelper
                .getInstance(IForwardingRulesManager.class, containerName, this);
        if (frm == null) {
            return null;
        }

        Map<String, Object> nodes = new HashMap<String, Object>();

        for (Switch sw : switchManager.getNetworkDevices()) {
            Node node = sw.getNode();

            List<FlowConfig> flows = frm.getStaticFlows(node);

            String nodeDesc = node.toString();
            SwitchConfig config = switchManager.getSwitchConfig(node
                    .toString());
            if (config != null) {
                nodeDesc = config.getNodeDescription();
            }

            nodes.put(nodeDesc, flows.size());
        }

        return nodes;
    }

    @RequestMapping(value = "/flow", method = RequestMethod.POST)
    @ResponseBody
    public String actionFlow(@RequestParam(required = true) String action,
            @RequestParam(required = false) String body,
            @RequestParam(required = true) String nodeId,
            HttpServletRequest request, @RequestParam(required = false) String container) {
        if (!isUserAuthorized(UserLevel.NETWORKADMIN, request)) {
            return "Operation not authorized";
        }

        String containerName = DaylightWebUtil.getAuthorizedContainer(request, container, this);

        IForwardingRulesManager frm = (IForwardingRulesManager) ServiceHelper
                .getInstance(IForwardingRulesManager.class, containerName, this);
        if (frm == null) {
            return null;
        }

        Gson gson = new Gson();
        FlowConfig flow = gson.fromJson(body, FlowConfig.class);
        Node node = Node.fromString(nodeId);
        flow.setNode(node);
        Status result = new Status(StatusCode.BADREQUEST, "Invalid request");
        if (action.equals("add")) {
            result = frm.addStaticFlow(flow, false);
        }

        return (result.isSuccess()) ? StatusCode.SUCCESS.toString() : result
                .getDescription();
    }

    @RequestMapping(value = "/flow/{nodeId}/{name}", method = RequestMethod.POST)
    @ResponseBody
    public String removeFlow(@PathVariable("nodeId") String nodeId,
            @PathVariable("name") String name,
            @RequestParam(required = true) String action,
            HttpServletRequest request, @RequestParam(required = false) String container) {
        if (!isUserAuthorized(UserLevel.NETWORKADMIN, request)) {
            return "Operation not authorized";
        }

        String containerName = DaylightWebUtil.getAuthorizedContainer(request, container, this);

        IForwardingRulesManager frm = (IForwardingRulesManager) ServiceHelper
                .getInstance(IForwardingRulesManager.class, containerName, this);
        if (frm == null) {
            return null;
        }

        Status result = null;
        Node node = Node.fromString(nodeId);
        if (node == null) {
            return null;
        }
        if (action.equals("remove")) {
            result = frm.removeStaticFlow(name, node);
        } else if (action.equals("toggle")) {
            result = frm.toggleStaticFlowStatus(name, node);
        } else {
            result = new Status(StatusCode.BADREQUEST, "Unknown action");
        }

        return (result.isSuccess()) ? StatusCode.SUCCESS.toString() : result
                .getDescription();
    }

    /**
     * Returns whether the current user's level is same or above the required
     * authorization level.
     *
     * @param requiredLevel
     *            the authorization level required
     */
    private boolean isUserAuthorized(UserLevel requiredLevel,
            HttpServletRequest request) {
        IUserManager userManager = (IUserManager) ServiceHelper
                .getGlobalInstance(IUserManager.class, this);
        if (userManager == null) {
            return false;
        }

        String username = request.getUserPrincipal().getName();
        UserLevel userLevel = userManager.getUserLevel(username);
        return (userLevel.ordinal() <= requiredLevel.ordinal());
    }

}