package au.gov.amsa.geo.model;
   
   import au.gov.amsa.risky.format.HasFix;
   import au.gov.amsa.util.navigation.Position;
   
   /**
    * Geographic bounds using a latitude, longitude rectangle.
    */
   public class Bounds {
  
      private final double topLeftLat, topLeftLon, bottomRightLat, bottomRightLon;
  
      public Bounds(double topLeftLat, double topLeftLon, double bottomRightLat, double bottomRightLon) {
          this.topLeftLat = topLeftLat;
          this.topLeftLon = Position.to180(topLeftLon);
          this.bottomRightLat = bottomRightLat;
          this.bottomRightLon = Position.to180(bottomRightLon);
      }
  
      public double getTopLeftLat() {
          return topLeftLat;
      }
  
      public double getTopLeftLon() {
          return topLeftLon;
      }
  
      public double getBottomRightLat() {
          return bottomRightLat;
      }
  
      public double getBottomRightLon() {
          return bottomRightLon;
      }
  
      public double getWidthDegrees() {
          if (bottomRightLon < topLeftLon)
              return bottomRightLon + 360 - topLeftLon;
          else
              return bottomRightLon - topLeftLon;
      }
  
      public double getHeightDegrees() {
          return topLeftLat - bottomRightLat;
      }
  
      public boolean contains(HasFix p) {
          return contains(p.fix().lat(), p.fix().lon());
      }
  
      public boolean contains(double lat, double lon) {
          return topLeftLat >= lat && bottomRightLat <= lat
                  && betweenLongitudes(topLeftLon, bottomRightLon, Position.to180(lon));
      }
  
      /**
       * Returns true if and only if lon is between the longitudes topLeftLon and
       * bottomRightLon.
       * 
       * @param topLeftLon
       *            must be between -180 and 180
       * @param bottomRightLon
       *            must be between -180 and 180
       * @param lon
       *            must be between -180 and 180
       * @return
       */
      private static boolean betweenLongitudes(double topLeftLon, double bottomRightLon, double lon) {
          if (topLeftLon <= bottomRightLon)
              return lon >= topLeftLon && lon <= bottomRightLon;
          else
              return lon >= topLeftLon || lon <= bottomRightLon;
      }
  
      @Override
      public String toString() {
          StringBuilder builder = new StringBuilder();
          builder.append("Bounds [topLeftLat=");
          builder.append(topLeftLat);
          builder.append(", topLeftLon=");
          builder.append(topLeftLon);
          builder.append(", bottomRightLat=");
          builder.append(bottomRightLat);
          builder.append(", bottomRightLon=");
          builder.append(bottomRightLon);
          builder.append("]");
          return builder.toString();
      }
  
      public Bounds expand(double latExpansionDegrees, double lonExpansionDegrees) {
          return new Bounds(Math.min(90, topLeftLat + latExpansionDegrees), topLeftLon
                  - lonExpansionDegrees, Math.max(-90, bottomRightLat - latExpansionDegrees),
                  bottomRightLon + lonExpansionDegrees);
      }
  
  }