require 'uri'

module VORuby

  module Simple

    # Classes representing the different sorts of parameters commonly used
    # in the REST-based services like SIAP, SSAP and SCS.
    module Parameters

      # Represents a search radius.
      class Radius
        def initialize(radius)
  	      @radius = radius(radius)
        end

        def radius(radius=nil)
  	      if radius == nil
  	        return @radius
  	      else
  	        @radius = radius.to_f()
  	      end
        end

        def to_s
  	      URI.escape(sprintf("SR=%.2f", @radius))
        end
      end
    
      # Represents astronomical longitude.
      class RightAscension
        def initialize(ra)
  	      ra(ra)
        end

        def ra(ra=nil)
  	      if ra == nil
  	        return @ra
  	      else
  	        if ra.instance_of?(String)
  	          if ra =~ /[-+]\d+:\d+:\d+(\.\d+)?/
  	            @ra = RightAscension.convert_to_decimal_degrees(ra)
  	          else
  	            @ra = ra.to_f()
  	          end
  	        else
  	          @ra = ra.to_f()
  	        end
  	      end
        end

        def to_s
  	      URI.escape(sprintf("RA=%.3f", @ra))
        end
      
        # Convert an RA in h:m:s format to decimal degrees.
        def self.convert_to_decimal_degrees(ra)
  	      hours, min, sec = ra.split(':')
	
  	      degrees =
  	        (hours.to_f() * 15.0) +
  	        (min.to_f() * 15.0 / 60.0) +
  	        (sec.to_f() * 15.0 / (60.0 * 60.0))
	
  	        return degrees
        end
      end
    
      # Represents astronomical latitude.
      class Declination
        def initialize(dec)
  	      dec(dec)
        end

        def dec(dec=nil)
  	      if dec == nil
  	        return @dec
  	      else
  	        if dec.instance_of?(String)
  	          @dec = Declination.convert_to_decimal_degrees(dec)
  	        else
  	          @dec = dec.to_f()
  	        end
  	      end
        end

        def to_s
  	      URI.escape(sprintf("DEC=%.3f", @dec))
        end

        # Convert a Dec in d:m:s format to decimal degrees.
        def self.convert_to_decimal_degrees(dec)
  	      degree, arcmin, arcsec = dec.split(':')
	
  	      degree_f = degree.to_f()
  	      arcmin_f = (arcmin.to_f() / 60.0)
  	      arcsec_f = (arcsec.to_f() / (60.0 * 60.0))
	
  	      return (degree_f - arcmin_f - arcsec_f) if degree_f < 0
  	      return degree_f + arcmin_f + arcsec_f
        end
      end
    
      # Represents an angular size on the sky.
      class Size
        def initialize(ra_width, dec_width=nil)
  	      if dec_width == nil
  	        ra_width(ra_width)
  	        dec_width(ra_width)
  	      else
  	        ra_width(ra_width)
  	        dec_width(dec_width)
  	      end
        end
      
        # Set or get the value of the RA width.
        # The width is specifed in decimal degrees.
        def ra_width(ra_width=nil)
  	      if ra_width == nil
  	        return @ra_width
  	      else
  	        @ra_width = ra_width.to_f()
  	      end
        end
      
        # Set or get the value of the declination width.
        # The width is specified in decimal degrees.
        def dec_width(dec_width=nil)
  	      if dec_width == nil
        	  return @dec_width
        	else
        	  @dec_width = dec_width.to_f()
        	end
        end
      
        #  Convert the size to its SIAP-compliant form.
        def to_s
        	if @ra_width == @dec_width
        	  # size = 0 is a special case--it test whether
        	  # the given point is in an image.
        	  if @ra_width == 0.0
        	    return URI.escape("SIZE=0")
        	  else
        	    return URI.escape(sprintf("SIZE=%.4f", @ra_width))
        	  end
        	else
        	  return URI.escape(sprintf("SIZE=%.4f,%.4f", @ra_width, @dec_width))
        	end
        end
      end
    
      # Represents a position on the sky.
      class Position
        def initialize(ra, dec)
  	      ra(ra)
  	      dec(dec)
        end
      
        # Set or get the value of the right ascension. 
        # The RA may be a decimal or a string in standard sexigesimal format.
        def ra(ra=nil)
  	      if ra == nil
  	        return @ra
  	      else
  	        if ra.instance_of?(RightAscension)
  	          @ra = ra
  	        else
  	          @ra = RightAscension.new(ra)
  	        end
  	      end
        end
      
        # Set or get the value of the declination.
        # The declination may be a decimal or a string in standard sexigesimal format.
        def dec(dec=nil)
  	      if dec == nil
  	        return @dec
  	      else
  	        if dec.instance_of?(Declination)
  	          @dec = dec
  	        else
  	          @dec = Declination.new(dec)
  	        end
  	      end
        end
			
        #  Convert the position to its SIAP-compliant form.
        def to_s
  	      URI.escape(sprintf("POS=%.3f,%.3f", @ra.ra(), @dec.dec()))
        end
      end
    
    end
  end
  
end