package com.bradmcevoy.http;
   
   import java.io.Serializable;
   import java.util.ArrayList;
   import java.util.Calendar;
   import java.util.Date;
   import java.util.List;
   
   import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  public class LockTimeout implements Serializable{
  
      private static final long serialVersionUID = 1L;
  
  
      private static Logger log = LoggerFactory.getLogger(LockTimeout.class);
      private static final String INFINITE = "Infinite";
      
              
      public static LockTimeout parseTimeout(Request request) {
          String sTimeout = request.getTimeoutHeader();
          log.debug("..requested timeout: " + sTimeout);
          return parseTimeout(sTimeout);
      }
      
      public static LockTimeout parseTimeout(String s) {      
          if ( s==null ) return new LockTimeout((List<Long>)null);
          s = s.trim();
          if( s.length() == 0 ) return new LockTimeout((List<Long>)null);
  
          List<Long> list = new ArrayList<Long>();
          for( String part : s.split(",")) {
              part = part.trim();
              if( part.equalsIgnoreCase(INFINITE)) {
                  list.add(Long.MAX_VALUE);
              } else {
                  Long seconds = parseTimeoutPart(part);
                  if(seconds != null ) {
                      list.add(seconds);
                  }
              }
          }
          
          LockTimeout timeout = new LockTimeout(list);
          return timeout;
      }
  
      static String trim(String s) {
          if( s == null ) return "";
          return s.trim();
      }
      
      static boolean isPresent(String s) {
          return s != null && s.length()>0;
      }
  
      private static Long parseTimeoutPart(String part) {
          if( part == null || part.length() == 0 ) return null;
          int pos = part.indexOf("-");
          if( pos <= 0 ) {
              return null;
          }
          String s = part.substring(pos+1, part.length());
          long l = 0;
          try {
              l = Long.parseLong(s);
              return l;
          } catch (NumberFormatException numberFormatException) {
              log.error("Number format exception parsing timeout: " + s);
              return null;
          }        
      }
      
      final Long seconds;
      final Long[] otherSeconds;
  
      public LockTimeout(Long timeout) {
          this.seconds = timeout;
          this.otherSeconds = null;
      }
      
      private LockTimeout(List<Long> timeouts) {
          if( timeouts == null || timeouts.isEmpty() ) {
              this.seconds = null;
              this.otherSeconds = null;
          } else {
              this.seconds = timeouts.get(0);
              timeouts.remove(0);
              otherSeconds = new Long[timeouts.size()];
              timeouts.toArray(otherSeconds);
          }
      }
      
      /**
       * 
       * @return - the preferred timeout. Infinite is represents as Long.MAX_VALUE. Maybe null if no timeout provided
       */
      public Long getSeconds() {
         return seconds;
     }
 
     /**
      * 
      * @return - an array of less preferred timeouts
      */
     public Long[] getOtherSeconds() {
         return otherSeconds;
     }
 
     @Override
     public String toString() {
         if( this.seconds == null ) {
             return INFINITE;
         } else if(this.seconds.equals( Long.MAX_VALUE )) {
             return INFINITE;
         } else {
             return "Second-" + this.seconds;
         }
     }
 
 
     
 
     /**
      * Returns a current object which holds the expected end date/time, based
      * on defaultSeconds and maxSeconds, as well as the actual seconds used
      * in that calculation.
      *
      * This is handy for locking because we generally want to lock a resource
      * until a specific date/time, but we also want to report back the timeout
      * actually locked in terms of seconds
      * 
      * @return - the current time + getSeconds()
      */
     public DateAndSeconds getLockedUntil(Long defaultSeconds, Long maxSeconds) {
         Long l = getSeconds();        
         if( l == null ) {
             if( defaultSeconds != null ) {
                 return addSeconds(defaultSeconds);
             } else if( maxSeconds != null ) {
                 return addSeconds( maxSeconds);
             } else {
                 return addSeconds(60l); // default default
             }
         } else {
             if( maxSeconds != null ) {
                 if( getSeconds() > maxSeconds ) {
                     return addSeconds(maxSeconds);
                 } else {
                     return addSeconds(l);
                 }
             } else {
                 return addSeconds(l);
             }
         }
     }
     
     public static DateAndSeconds addSeconds( Long l) {
         Calendar cal = Calendar.getInstance();
         cal.setTimeInMillis(System.currentTimeMillis());
         int secs = (int)l.longValue();
         cal.add(Calendar.SECOND, secs);
         DateAndSeconds das = new DateAndSeconds();
         das.date = cal.getTime();        
         das.seconds = l;
         return das;
     }
         
     public static class DateAndSeconds {
         public Date date;
         public Long seconds;
     }
 }