/*
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  The ASF licenses this file
    * to you 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 org.apache.hadoop.chukwa.hicc;
  
  
  import javax.servlet.http.*;
  
  import org.apache.hadoop.chukwa.util.XssFilter;
  
  import java.util.Calendar;
  import java.util.TimeZone;
  import java.util.StringTokenizer;
  import java.text.SimpleDateFormat;
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import com.mdimension.jchronic.Chronic;
  import com.mdimension.jchronic.Options;
  import com.mdimension.jchronic.utils.Span;
  
  public class TimeHandler {
    private HttpSession session = null;
    private TimeZone tz = null;
    private long start = 0;
    private long end = 0;
    private String startDate = null;
    private String startHour = null;
    private String startMin = null;
    private String endDate = null;
    private String endHour = null;
    private String endMin = null;
    private String startS = null;
    private String endS = null;
    private XssFilter xf = null;
      private static Log log=LogFactory.getLog(TimeHandler.class);
    
    public TimeHandler(HttpServletRequest request) {
      this.tz = TimeZone.getTimeZone("UTC");
      init(request);
    }
  
    public TimeHandler(HttpServletRequest request, String tz) {
      if (tz != null) {
        this.tz = TimeZone.getTimeZone(tz);
      } else {
        this.tz = TimeZone.getTimeZone("UTC");
      }
      init(request);
    }
  
      /*
       * Using the Chronic library to parse the english string
       * and convert it to a long (millis seconds since 1970)
       */
      public long parseDateShorthand(String d) {
  	Calendar now = Calendar.getInstance();
  	long l=now.getTimeInMillis();
  	d=d.trim();
  	if (d.compareToIgnoreCase("now")!=0) {
  	    Options options= new Options(false);
  	    options.setCompatibilityMode(true);
  	    options.setNow(now);
  	    try {
  		Span span = Chronic.parse(d, options);
  		l = span.getBegin()*1000;
  	    } catch (Exception e) {
  		// exception when parsing
  		log.error("parse error for: "+d);		
  	    }
  	}
  
  	/*
  	 * debug 
  	 */
  	/*
          SimpleDateFormat sf =
              new SimpleDateFormat("yyyy/MM/dd HH:mm:ss");
  	Date ld=new Date(l);
  
  	log.error("Convert:"+d+" to "+Long.toString(l)+" - "+sf.format(ld)+ "-"+ld.getTime());
  	*/
  
  	return l;
      }
 
     public void parsePeriodValue(String period) {
 	Calendar now = Calendar.getInstance();
 	this.start = now.getTimeInMillis();
 	this.end = now.getTimeInMillis();
 	if (period.equals("last1hr")) {
 	    start = end - (60 * 60 * 1000);
 	} else if (period.equals("last2hr")) {
 	    start = end - (2 * 60 * 60 * 1000);
 	} else if (period.equals("last3hr")) {
 	    start = end - (3 * 60 * 60 * 1000);
 	} else if (period.equals("last6hr")) {
 	    start = end - (6 * 60 * 60 * 1000);
 	} else if (period.equals("last12hr")) {
 	    start = end - (12 * 60 * 60 * 1000);
 	} else if (period.equals("last24hr")) {
 	    start = end - (24 * 60 * 60 * 1000);
 	} else if (period.equals("last7d")) {
 	    start = end - (7 * 24 * 60 * 60 * 1000);
 	} else if (period.equals("last30d")) {
 	    start = end - (30L * 24 * 60 * 60 * 1000);
 	} else if (period.startsWith("custom;")) {
 	    
 	    // default value is between 2 days ago and now
 	    String startString="2 days ago";
 	    String endString="now";
 	    
 	    // tokenize the value to "custom;2 days ago;now" 
 	    StringTokenizer st=new StringTokenizer(period,";");
 	    if (st.hasMoreTokens()) {
 		st.nextToken(); // skip the first token
 		if (st.hasMoreTokens()) {
 		    startString=st.nextToken();
 		    if (st.hasMoreTokens()) {
 			endString=st.nextToken();
 		    }
 		}
 	    }
 	    
 	    // parse the parameter strings
 	    start = parseDateShorthand(startString);
 	    end = parseDateShorthand(endString);
 	}
     }
 
   public void init(HttpServletRequest request) {
     xf = new XssFilter(request);
     Calendar now = Calendar.getInstance();
     this.session = request.getSession();
     if (request.getParameter("time_type") == null
         && session.getAttribute("time_type") == null
         && session.getAttribute("period") == null
         && request.getParameter("period") == null) {
       end = now.getTimeInMillis();
       start = end - 60 * 60 * 1000;
       session.setAttribute("period", "last1hr");
       session.setAttribute("time_type", "last");
       session.setAttribute("start", "" + start);
       session.setAttribute("end", "" + end);
     } else if (request.getParameter("period") != null
         && !"".equals(request.getParameter("period"))) {
       String period = xf.getParameter("period");
       parsePeriodValue(period);
     } else if (request.getParameter("start") != null
         && request.getParameter("end") != null) {
       start = Long.parseLong(request.getParameter("start"));
       end = Long.parseLong(request.getParameter("end"));
     } else if ("range".equals(session.getAttribute("time_type"))) {
       start = Long.parseLong((String) session.getAttribute("start"));
       end = Long.parseLong((String) session.getAttribute("end"));
     } else if ("last".equals(session.getAttribute("time_type"))
         && session.getAttribute("period") != null) {
       String period = (String) session.getAttribute("period");
       parsePeriodValue(period);
     }
 
     SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd HH:mm");
     SimpleDateFormat formatDate = new SimpleDateFormat("yyyy-MM-dd");
     SimpleDateFormat formatHour = new SimpleDateFormat("HH");
     SimpleDateFormat formatMin = new SimpleDateFormat("mm");
 
     formatter.setTimeZone(this.tz);
     formatDate.setTimeZone(this.tz);
     formatHour.setTimeZone(this.tz);
     formatMin.setTimeZone(this.tz);
 
     startS = formatter.format(start);
     this.startDate = formatDate.format(start);
     this.startHour = formatHour.format(start);
     this.startMin = formatMin.format(start);
     endS = formatter.format(end);
     this.endDate = formatDate.format(end);
     this.endHour = formatHour.format(end);
     this.endMin = formatMin.format(end);
   }
 
   public String getStartDate(String format) {
     SimpleDateFormat formatter = new SimpleDateFormat(format);
     formatter.setTimeZone(this.tz);
     return formatter.format(this.start);
   }
 
   public String getStartDate() {
     return this.startDate;
   }
 
   public String getStartHour() {
     return this.startHour;
   }
 
   public String getStartMinute() {
     return this.startMin;
   }
 
   public String getStartTimeText() {
     return this.startS;
   }
 
   public long getStartTime() {
     return start;
   }
 
   public String getEndDate(String format) {
     SimpleDateFormat formatter = new SimpleDateFormat(format);
     formatter.setTimeZone(this.tz);
     return formatter.format(this.end);
   }
 
   public String getEndDate() {
     return this.endDate;
   }
 
   public String getEndHour() {
     return this.endHour;
   }
 
   public String getEndMinute() {
     return this.endMin;
   }
 
   public String getEndTimeText() {
     return this.endS;
   }
 
   public long getEndTime() {
     return end;
   }
 
 }