/**
 * (C) Copyright IBM Corporation 2015.
 *
 * 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 com.ibm.websphere.samples.daytrader.web;

import java.io.IOException;
import java.io.PrintWriter;
import java.util.Collection;
import java.util.Iterator;

import javax.servlet.ServletConfig;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import com.ibm.websphere.samples.daytrader.entities.HoldingDataBean;
import com.ibm.websphere.samples.daytrader.util.Log;
import com.ibm.websphere.samples.daytrader.util.TradeConfig;

/**
 * TradeScenarioServlet emulates a population of web users by generating a
 * specific Trade operation for a randomly chosen user on each access to the
 * URL. Test this servlet by clicking Trade Scenario and hit "Reload" on your
 * browser to step through a Trade Scenario. To benchmark using this URL aim
 * your favorite web load generator (such as AKStress) at the Trade Scenario URL
 * and fire away.
 */
@WebServlet(name = "TradeScenarioServlet", urlPatterns = { "/scenario" })
public class TradeScenarioServlet extends HttpServlet {

  private static final long serialVersionUID = 1410005249314201829L;

  /**
   * Servlet initialization method.
   */
  @Override
  public void init(ServletConfig config) throws ServletException {
    super.init(config);
    java.util.Enumeration<String> en = config.getInitParameterNames();
    while (en.hasMoreElements()) {
      String parm = en.nextElement();
      String value = config.getInitParameter(parm);
      TradeConfig.setConfigParam(parm, value);
    }
  }

  /**
   * Returns a string that contains information about TradeScenarioServlet
   *
   * @return The servlet information
   */
  @Override
  public java.lang.String getServletInfo() {
    return "TradeScenarioServlet emulates a population of web users";
  }

  /**
   * Process incoming HTTP GET requests
   *
   * @param request  Object that encapsulates the request to the servlet
   * @param response Object that encapsulates the response from the servlet
   */
  @Override
  public void doGet(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response)
      throws ServletException, IOException {
    performTask(request, response);
  }

  /**
   * Process incoming HTTP POST requests
   *
   * @param request  Object that encapsulates the request to the servlet
   * @param response Object that encapsulates the response from the servlet
   */
  @Override
  public void doPost(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response)
      throws ServletException, IOException {
    performTask(request, response);
  }

  /**
   * Main service method for TradeScenarioServlet
   *
   * @param request  Object that encapsulates the request to the servlet
   * @param response Object that encapsulates the response from the servlet
   */
  public void performTask(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {

    // Scenario generator for Trade2
    char action = ' ';
    String userID = null;

    // String to create full dispatch path to TradeAppServlet w/ request
    // Parameters
    String dispPath = null; // Dispatch Path to TradeAppServlet

    resp.setContentType("text/html");

    String scenarioAction = req.getParameter("action");
    if ((scenarioAction != null) && (scenarioAction.length() >= 1)) {
      action = scenarioAction.charAt(0);
      if (action == 'n') { // null;
        try {
          // resp.setContentType("text/html");
          PrintWriter out = new PrintWriter(resp.getOutputStream());
          out.println("<HTML><HEAD>TradeScenarioServlet</HEAD><BODY>Hello</BODY></HTML>");
          out.close();
          return;

        } catch (Exception e) {
          Log.error("trade_client.TradeScenarioServlet.service(...)"
              + "error creating printwriter from responce.getOutputStream", e);

          resp.sendError(500,
              "trade_client.TradeScenarioServlet.service(...): erorr creating and writing to PrintStream created from response.getOutputStream()");
        } // end of catch

      } // end of action=='n'
    }

    ServletContext ctx = null;
    HttpSession session = null;
    try {
      ctx = getServletConfig().getServletContext();
      // These operations require the user to be logged in. Verify the
      // user and if not logged in
      // change the operation to a login
      session = req.getSession(true);
      userID = (String) session.getAttribute("uidBean");
    } catch (Exception e) {
      Log.error("trade_client.TradeScenarioServlet.service(...): performing " + scenarioAction
          + "error getting ServletContext,HttpSession, or UserID from session"
          + "will make scenarioAction a login and try to recover from there", e);
      userID = null;
      action = 'l';
    }

    if (userID == null) {
      action = 'l'; // change to login
      TradeConfig.incrementScenarioCount();
    } else if (action == ' ') {
      // action is not specified perform a random operation according to
      // current mix
      // Tell getScenarioAction if we are an original user or a registered
      // user
      // -- sellDeficits should only be compensated for with original
      // users.
      action = TradeConfig.getScenarioAction(userID.startsWith(TradeConfig.newUserPrefix));
    }
    switch (action) {

      case 'q': // quote
        dispPath = tasPathPrefix + "quotes&symbols=" + TradeConfig.rndSymbols();
        ctx.getRequestDispatcher(dispPath).include(req, resp);
        break;
      case 'a': // account
        dispPath = tasPathPrefix + "account";
        ctx.getRequestDispatcher(dispPath).include(req, resp);
        break;
      case 'u': // update account profile
        dispPath = tasPathPrefix + "account";
        ctx.getRequestDispatcher(dispPath).include(req, resp);

        String fullName = "rnd" + System.currentTimeMillis();
        String address = "rndAddress";
        String password = "xxx";
        String email = "rndEmail";
        String creditcard = "rndCC";
        dispPath = tasPathPrefix + "update_profile&fullname=" + fullName + "&password=" + password + "&cpassword="
            + password + "&address=" + address + "&email=" + email + "&creditcard=" + creditcard;
        ctx.getRequestDispatcher(dispPath).include(req, resp);
        break;
      case 'h': // home
        dispPath = tasPathPrefix + "home";
        ctx.getRequestDispatcher(dispPath).include(req, resp);
        break;
      case 'l': // login
        userID = TradeConfig.getUserID();
        String password2 = "xxx";
        dispPath = tasPathPrefix + "login&inScenario=true&uid=" + userID + "&passwd=" + password2;
        ctx.getRequestDispatcher(dispPath).include(req, resp);

        // login is successful if the userID is written to the HTTP session
        if (session.getAttribute("uidBean") == null) {
          System.out.println("TradeScenario login failed. Reset DB between runs");
        }
        break;
      case 'o': // logout
        dispPath = tasPathPrefix + "logout";
        ctx.getRequestDispatcher(dispPath).include(req, resp);
        break;
      case 'p': // portfolio
        dispPath = tasPathPrefix + "portfolio";
        ctx.getRequestDispatcher(dispPath).include(req, resp);
        break;
      case 'r': // register
        // Logout the current user to become a new user
        // see note in TradeServletAction
        req.setAttribute("TSS-RecreateSessionInLogout", Boolean.TRUE);
        dispPath = tasPathPrefix + "logout";
        ctx.getRequestDispatcher(dispPath).include(req, resp);

        userID = TradeConfig.rndNewUserID();
        String passwd = "yyy";
        fullName = TradeConfig.rndFullName();
        creditcard = TradeConfig.rndCreditCard();
        String money = TradeConfig.rndBalance();
        email = TradeConfig.rndEmail(userID);
        String smail = TradeConfig.rndAddress();
        dispPath = tasPathPrefix + "register&Full Name=" + fullName + "&snail mail=" + smail + "&email=" + email
            + "&user id=" + userID + "&passwd=" + passwd + "&confirm passwd=" + passwd + "&money=" + money
            + "&Credit Card Number=" + creditcard;
        ctx.getRequestDispatcher(dispPath).include(req, resp);
        break;
      case 's': // sell
        dispPath = tasPathPrefix + "portfolioNoEdge";
        ctx.getRequestDispatcher(dispPath).include(req, resp);

        Collection<?> holdings = (Collection<?>) req.getAttribute("holdingDataBeans");
        int numHoldings = holdings.size();
        if (numHoldings > 0) {
          // sell first available security out of holding

          Iterator<?> it = holdings.iterator();
          boolean foundHoldingToSell = false;
          while (it.hasNext()) {
            HoldingDataBean holdingData = (HoldingDataBean) it.next();
            if (!(holdingData.getPurchaseDate().equals(new java.util.Date(0)))) {
              Integer holdingID = holdingData.getHoldingID();

              dispPath = tasPathPrefix + "sell&holdingID=" + holdingID;
              ctx.getRequestDispatcher(dispPath).include(req, resp);
              foundHoldingToSell = true;
              break;
            }
          }
          if (foundHoldingToSell) {
            break;
          }
          if (Log.doTrace()) {
            Log.trace("TradeScenario: No holding to sell -switch to buy -- userID = " + userID + "  Collection count = "
                + numHoldings);
          }

        }
        // At this point: A TradeScenario Sell was requested with No Stocks
        // in Portfolio
        // This can happen when a new registered user happens to request a
        // sell before a buy
        // In this case, fall through and perform a buy instead

        /*
         * Trade 2.037: Added sell_deficit counter to maintain correct buy/sell mix.
         * When a users portfolio is reduced to 0 holdings, a buy is requested instead
         * of a sell. This throws off the buy/sell mix by 1. This results in unwanted
         * holding table growth To fix this we increment a sell deficit counter to
         * maintain the correct ratio in getScenarioAction The 'z' action from
         * getScenario denotes that this is a sell action that was switched from a buy
         * to reduce a sellDeficit
         */
        if (userID.startsWith(TradeConfig.newUserPrefix) == false) {
          TradeConfig.incrementSellDeficit();
        }
      case 'b': // buy
        String symbol = TradeConfig.rndSymbol();
        String amount = TradeConfig.rndQuantity() + "";

        dispPath = tasPathPrefix + "quotes&symbols=" + symbol;
        ctx.getRequestDispatcher(dispPath).include(req, resp);

        dispPath = tasPathPrefix + "buy&quantity=" + amount + "&symbol=" + symbol;
        ctx.getRequestDispatcher(dispPath).include(req, resp);
        break;
    } // end of switch statement
  }

  // URL Path Prefix for dispatching to TradeAppServlet
  private static final String tasPathPrefix = "/app?action=";

}
