module X12

  grammar X12syntax

    # $Id: x12syntax.treetop 36 2008-11-13 18:36:36Z ikk $
    # This is a syntax definition for the X12-syntax files.
  
    rule x12syntax
      (table / segment / composite / loop )+
      {
        def get
          elements.inject({}){|s, i| 
            if i.nonterminal?
              r = i.get
              s[r.class] ||= {}
              s[r.class][r.name]=r
            end
            s
          }
        end  
      }
    end

    # LOOP

    rule loop
      space? 'loop' space loop_name space repeat space? '{' space? loop_components space? '}' space?
      {
        def get
          Loop.new(loop_name.text_value, loop_components.get, repeat.get)
        end  
      }
    end

    rule loop_components
      loop_component+
      {
        def get
          elements.map{|i| i.get}
        end
      }
    end

    rule loop_component
      loop_segment / loop
    end

    rule loop_segment
      space? 'segment' space identifier space repeat space? '{' space? fields space? '}'
      {
        def get
          Segment.new(identifier.text_value, fields.get, repeat.get)
        end  
      }
      /
      space? 'segment' space identifier space repeat space?
      {
        def get
          Segment.new(identifier.text_value, [], repeat.get)
        end  
      }
    end

    # COMPOSITE
    rule composite
      space? 'composite' space composite_name space? '{' space? fields space? '}' space?
      {
        def get
          Composite.new(composite_name.text_value, fields.get)
        end  
      }
    end

    # SEGMENT

    rule segment
      space? 'segment' space identifier space? '{' space? fields space? '}' space?
      {
        def get
          Segment.new(identifier.text_value, fields.get)
        end  
      }
    end

    rule fields
      field+
      {
        def get
          elements.map{|i| i.get}
        end
      }
    end

    rule field
      space? field_name space field_type space field_required space field_min_length '-' field_max_length field_validation space?
      {
        def get
           #elements.each{|i| puts "*** [#{i.text_value}] #{i.inspect}"}
          Field.new(*[field_name.text_value, 
           field_type.text_value,
           field_required.text_value,
           field_min_length.text_value,
           field_max_length.text_value,
           field_validation.get,
           ])
        end
      }
    end

    rule field_name
      identifier
    end

    rule field_type
      'I' / 'S' / composite_name / constant
    end

    rule composite_name
      'C' numeric_char+
    end

    rule field_required
      'R' / 'O'
    end

    rule field_min_length
      numeric_char+
    end

    rule field_max_length
      numeric_char+
    end

    rule field_validation
      [ ]+ identifier
      {
        def get
          identifier.text_value
        end  
      }
      / space
      {
        def get
          nil
        end  
      }
    end

    # TABLE

    rule table
      space? 'table' space identifier space? '{' space? name_value_lines space? '}' space?
      {
        def get
          Table.new(identifier.text_value, name_value_lines.get)
        end  
      }
    end

    rule name_value_lines
      name_value_line+
      {
        def get
          elements.inject({}){|s, i| s[i.get_name] = i.get_value; s}
        end
      }
    end

    rule name_value_line
      space? name space value
      {
        def get_name
          name.text_value
        end
        def get_value
          value.text_value
        end
      }
    end

    rule name
      alphanumeric_char+
    end 

    rule value
      [^\r\n]+
    end 

    rule repeat
      min_required ':' max_allowed 
      {
        def get
          Range.new(min_required.text_value.to_i, max_allowed.text_value.to_i)
        end
      }
    end

    rule min_required
      numeric_char+
    end

    rule max_allowed
      numeric_char+
    end

    rule loop_name
      alphanumeric_char+
    end

    # UTILITY

    rule constant
      '"' [^"]* '"'
    end 

    rule identifier
      alpha_char alphanumeric_char*
    end 

    rule non_space_char
      !space .
    end

    rule alpha_char
      [A-Za-z_]
    end

    rule alphanumeric_char
      alpha_char / numeric_char
    end

    rule numeric_char
      [0-9]
    end

    rule space
      (white / comment_c_style / comment_to_eol)+
    end

    rule comment_c_style
    '/*' (!'*/' . )* '*/'
    end

    rule comment_to_eol
      '#' (!"\n" .)+
    end

    rule white
      [ \t\n\r]
    end

    rule eol
      "\n" / "\r"
    end
  end
end