adding basic season support. closes #22

src/main/antlr3/com/joestelmach/natty/generated/DateLexer.g

@@ -311,6 +311,14 @@ VALENTINE    : 'valentine' SINGLE_QUOTE? 's'?;
 VETERAN      : 'veteran' SINGLE_QUOTE? 's'?;
 fragment GROUND : 'ground';
 fragment HOG    : 'hog';
+
+// ********** season specific **********
+
+WINTER : 'winter' 's'?;
+FALL   : 'fall'   's'?;
+AUTUMN : 'autumn' 's'?;
+SPRING : 'spring' 's'?;
+SUMMER : 'summer' 's'?;
 
 UNKNOWN
   : UNKNOWN_CHAR

src/main/antlr3/com/joestelmach/natty/generated/DateParser.g

@@ -33,6 +33,7 @@ tokens {
   ZONE_OFFSET;
   RECURRENCE;
   HOLIDAY;
+  SEASON;
 }
 
 @header {
@@ -390,6 +391,10 @@ relative_date
   // next christmas, 2 thanksgivings ago
   | holiday
     -> ^(RELATIVE_DATE holiday)
+
+  // next fall, 2 summers from now
+  | season 
+    -> ^(RELATIVE_DATE season)
   ;
 
 // ********** explicit relative date rules **********
@@ -738,6 +743,30 @@ holiday_name
     -> HOLIDAY["VETERANS_DAY"]
   ;
 
+season
+  : spelled_or_int_optional_prefix WHITE_SPACE season_name WHITE_SPACE relative_date_suffix
+    -> ^(SEEK relative_date_suffix spelled_or_int_optional_prefix season_name)
+
+  | relative_date_prefix WHITE_SPACE season_name 
+    -> ^(SEEK relative_date_prefix season_name)
+
+  | season_name relaxed_year_prefix relaxed_year
+    -> ^(EXPLICIT_SEEK season_name relaxed_year)
+
+  | season_name
+    -> ^(SEEK DIRECTION[">"] SEEK_BY["by_day"] INT["1"] season_name)
+  ;
+
+season_name
+  :WINTER
+    -> SEASON["WINTER"]
+  | SPRING 
+    -> SEASON["SPRING"]
+  | SUMMER 
+    -> SEASON["SUMMER"]
+  | (FALL | AUTUMN)
+    -> SEASON["FALL"]
+  ;
 
 // ********** time rules **********
 

src/main/antlr3/com/joestelmach/natty/generated/DateWalker.g

@@ -99,6 +99,9 @@ seek
 
   | ^(SEEK DIRECTION SEEK_BY INT HOLIDAY)
     {_walkerState.seekToHoliday($HOLIDAY.text, $DIRECTION.text, $INT.text);}
+
+  | ^(SEEK DIRECTION SEEK_BY INT SEASON)
+    {_walkerState.seekToSeason($SEASON.text, $DIRECTION.text, $INT.text);}
   ;
 
 explicit_seek
@@ -120,6 +123,9 @@ explicit_seek
   | ^(EXPLICIT_SEEK HOLIDAY ^(YEAR_OF year=INT))
     {_walkerState.seekToHolidayYear($HOLIDAY.text, $year.text);}
 
+  | ^(EXPLICIT_SEEK SEASON ^(YEAR_OF year=INT))
+    {_walkerState.seekToSeasonYear($SEASON.text, $year.text);}
+
   | ^(EXPLICIT_SEEK index=INT ^(DAY_OF_WEEK day=INT))
     {_walkerState.setDayOfWeekIndex($index.text, $day.text);}
 

src/main/java/com/joestelmach/natty/IcsSearcher.java

@@ -0,0 +1,92 @@
+package com.joestelmach.natty;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.text.ParseException;
+import java.util.Calendar;
+import java.util.Date;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.TimeZone;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+import net.fortuna.ical4j.data.CalendarBuilder;
+import net.fortuna.ical4j.data.ParserException;
+import net.fortuna.ical4j.model.Component;
+import net.fortuna.ical4j.model.DateTime;
+import net.fortuna.ical4j.model.Period;
+import net.fortuna.ical4j.model.PeriodList;
+
+public class IcsSearcher {
+  private static final String GMT = "GMT";
+  private static final String VEVENT = "VEVENT";
+  private static final String SUMMARY = "SUMMARY";
+  private static final Logger _logger = Logger.getLogger("com.joestelmach.natty");
+  private net.fortuna.ical4j.model.Calendar _holidayCalendar;
+  private String _calendarFileName;
+  private TimeZone _timeZone;
+
+  public IcsSearcher(String calendarFileName, TimeZone timeZone) {
+    _calendarFileName = calendarFileName;
+    _timeZone = timeZone;
+  }
+
+  public Map<Integer, Date> findDates(int startYear, int endYear, String eventSummary) {
+    Map<Integer, Date> holidays = new HashMap<Integer, Date>(); 
+
+    if(_holidayCalendar == null) {
+      InputStream fin = WalkerState.class.getResourceAsStream(_calendarFileName);
+      try {
+        _holidayCalendar = new CalendarBuilder().build(fin);
+
+      } catch (IOException e) {
+        _logger.severe("Couln't open " + _calendarFileName);
+        return holidays;
+
+      } catch (ParserException e) {
+        _logger.severe("Couln't parse " + _calendarFileName);
+        return holidays;
+      }
+    }
+
+    Period period = null;
+    try {
+      DateTime from = new DateTime(startYear + "0101T000000Z");
+      DateTime to = new DateTime(endYear + "1231T000000Z");;
+      period = new Period(from, to);
+
+    } catch (ParseException e) {
+      _logger.log(Level.SEVERE, "Invalid start or end year: " + startYear + ", " + endYear, e);
+      return holidays;
+    }
+
+    for (Object  component : _holidayCalendar.getComponents(VEVENT)) {
+      Component vevent = (Component) component;
+      String summary = vevent.getProperty(SUMMARY).getValue();
+      if(summary.equals(eventSummary)) {
+        PeriodList list = vevent.calculateRecurrenceSet(period);
+        for(Object p : list) {
+          DateTime date = ((Period) p).getStart();
+
+          // this date is at the date of the holiday at 12 AM UTC
+          Calendar utcCal = CalendarSource.getCurrentCalendar();
+          utcCal.setTimeZone(TimeZone.getTimeZone(GMT));
+          utcCal.setTime(date);
+
+          // use the year, month and day components of our UTC date to form a new local date
+          Calendar localCal = CalendarSource.getCurrentCalendar();
+          localCal.setTimeZone(_timeZone);
+          localCal.set(Calendar.YEAR, utcCal.get(Calendar.YEAR));
+          localCal.set(Calendar.MONTH, utcCal.get(Calendar.MONTH));
+          localCal.set(Calendar.DAY_OF_MONTH, utcCal.get(Calendar.DAY_OF_MONTH));
+
+          holidays.put(localCal.get(Calendar.YEAR), localCal.getTime());
+        }
+      }
+    }
+
+    return holidays;
+  }
+
+}

src/main/java/com/joestelmach/natty/Parser.java

@@ -102,7 +102,7 @@ public List<DateGroup> parse(String value) {
               Iterator<Token> iter = tokens.iterator();
               while(iter.hasNext()) {
                 Token token = iter.next();
-                if(!DateParser.FOLLOW_empty_in_parse181.member(token.getType())) {
+                if(!DateParser.FOLLOW_empty_in_parse186.member(token.getType())) {
                   iter.remove();
                 }
                 else {
@@ -209,7 +209,7 @@ private List<TokenStream> collectTokenStreams(TokenStream stream) {
         // ignore white space in-between possible rules
         if(currentToken.getType() != DateLexer.WHITE_SPACE) {
           // if the token is a possible date start token, we start a new collection
-          if(DateParser.FOLLOW_empty_in_parse181.member(currentToken.getType())) {
+          if(DateParser.FOLLOW_empty_in_parse186.member(currentToken.getType())) {
             currentGroup = new ArrayList<Token>();
             currentGroup.add(currentToken);
           }

src/main/java/com/joestelmach/natty/Season.java

@@ -0,0 +1,33 @@
+package com.joestelmach.natty;
+
+import java.util.HashMap;
+import java.util.Map;
+
+public enum Season {
+  WINTER("Winter Solstice"),
+  SPRING("Vernal Equinox"),
+  SUMMER("Summer Solstice"),
+  FALL("Autumnal Equinox");
+
+  private String summary;
+  private static final Map<String, Season> lookup;
+  static {
+    lookup = new HashMap<String, Season>();
+    for(Season h:values()) {
+      lookup.put(h.getSummary(), h);
+    }
+  }
+
+  Season(String summary) {
+    this.summary = summary;
+  }
+
+  public String getSummary() {
+    return summary;
+  }
+
+  public static Season fromSummary(String summary) {
+    if(summary == null) return null;
+    return lookup.get(summary);
+  }
+}