/*
 * 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.web;

import java.util.List;

import javax.servlet.http.HttpServletRequest;

import org.opendaylight.controller.sal.authorization.UserLevel;
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.usermanager.IUserManager;
import org.opendaylight.controller.usermanager.internal.UserConfig;
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("/admin")
public class DaylightWebAdmin {
    @RequestMapping("/users")
    @ResponseBody
    public List<UserConfig> getUsers() {
        IUserManager userManager = (IUserManager) ServiceHelper
                .getGlobalInstance(IUserManager.class, this);
        if (userManager == null) {
            return null;
        }

        List<UserConfig> userConfList = userManager.getLocalUserList();

        return userConfList;
    }

    /*
     * Password in clear text, moving to HTTP/SSL soon
     */
    @RequestMapping(value = "/users", method = RequestMethod.POST)
    @ResponseBody
    public String saveLocalUserConfig(
            @RequestParam(required = true) String json,
            @RequestParam(required = true) String action,
            HttpServletRequest request) {

        IUserManager userManager = (IUserManager) ServiceHelper
                .getGlobalInstance(IUserManager.class, this);
        if (userManager == null) {
            return "Internal Error";
        }

        if (!authorize(userManager, UserLevel.NETWORKADMIN, request)) {
            return "Operation not permitted";
        }

        Gson gson = new Gson();
        UserConfig config = gson.fromJson(json, UserConfig.class);

        Status result = (action.equals("add")) ? userManager
                .addLocalUser(config) : userManager.removeLocalUser(config);

        return result.getDescription();
    }

    @RequestMapping(value = "/users/{username}", method = RequestMethod.POST)
    @ResponseBody
    public String removeLocalUser(@PathVariable("username") String userName,
            HttpServletRequest request) {

        String username = request.getUserPrincipal().getName();
        if (username.equals(userName)) {
            return "Invalid Request: User cannot delete itself";
        }

        IUserManager userManager = (IUserManager) ServiceHelper
                .getGlobalInstance(IUserManager.class, this);
        if (userManager == null) {
            return "Internal Error";
        }

        if (!authorize(userManager, UserLevel.NETWORKADMIN, request)) {
            return "Operation not permitted";
        }

        return userManager.removeLocalUser(userName).getDescription();
    }
    
    @RequestMapping(value = "/users/password/{username}", method = RequestMethod.POST)
    @ResponseBody
    public Status changePassword(@PathVariable("username") String username, HttpServletRequest request,
            @RequestParam("currentPassword") String currentPassword, @RequestParam("newPassword") String newPassword) {
        String user = request.getUserPrincipal().getName();
        
        IUserManager userManager = (IUserManager) ServiceHelper
                .getGlobalInstance(IUserManager.class, this);
        if (userManager == null) {
            return new Status(StatusCode.GONE, "User Manager not found");
        }
        
        if (!authorize(userManager, UserLevel.NETWORKADMIN, request)) {
            return new Status(StatusCode.FORBIDDEN, "Operation not permitted");
        }
        
        if (newPassword.isEmpty()) {
            return new Status(StatusCode.BADREQUEST, "Empty passwords not allowed");
        }
        
        Status status = userManager.changeLocalUserPassword(user, currentPassword, newPassword);
        
        return status;
    }

    /**
     * Is the operation permitted for the given level
     * 
     * @param level
     */
    private boolean authorize(IUserManager userManager, UserLevel level,
            HttpServletRequest request) {
        String username = request.getUserPrincipal().getName();
        UserLevel userLevel = userManager.getUserLevel(username);
        return userLevel.toNumber() <= level.toNumber();
    }
}