module Sablon
  class HTMLConverter
    class Node
      def accept(visitor)
        visitor.visit(self)
      end

      def self.node_name
        @node_name ||= name.split('::').last
      end
    end

    class Collection < Node
      attr_reader :nodes
      def initialize(nodes)
        @nodes = nodes
      end

      def accept(visitor)
        super
        @nodes.each do |node|
          node.accept(visitor)
        end
      end

      def to_docx
        nodes.map(&:to_docx).join
      end
    end

    class Root < Collection
      def to_a
        nodes
      end

      def grep(pattern)
        visitor = GrepVisitor.new(pattern)
        accept(visitor)
        visitor.result
      end
    end

    class Paragraph < Node
      attr_accessor :style, :runs
      def initialize(style, runs)
        @style, @runs = style, runs
      end

      PATTERN = <<-XML.gsub("\n", "")
<w:p>
<w:pPr>
<w:pStyle w:val="%s" />
%s
</w:pPr>
%s
</w:p>
XML

      def to_docx
        PATTERN % [style, ppr_docx, runs.to_docx]
      end

      def accept(visitor)
        super
        runs.accept(visitor)
      end

      private
      def ppr_docx
      end
    end

    class ListParagraph < Paragraph
      LIST_STYLE = <<-XML.gsub("\n", "")
<w:numPr>
<w:ilvl w:val="%s" />
<w:numId w:val="%s" />
</w:numPr>
XML
      attr_accessor :numid, :ilvl
      def initialize(style, runs, numid, ilvl)
        super style, runs
        @numid = numid
        @ilvl = ilvl
      end

      private
      def ppr_docx
        LIST_STYLE % [@ilvl, numid]
      end
    end

    class Text < Node
      attr_reader :string
      def initialize(string)
        @string = string
      end

      def to_docx
        "<w:r>#{style_docx}<w:t xml:space=\"preserve\">#{normalized_string}</w:t></w:r>"
      end

      private
      def style_docx
      end

      def normalized_string
        string.tr("\u00A0", ' ')
      end
    end

    class Bold < Text
      def style_docx
        '<w:rPr><w:b /></w:rPr>'
      end
    end

    class Italic < Text
      def style_docx
        '<w:rPr><w:i /></w:rPr>'
      end
    end

    class Newline < Node
      def to_docx
        "<w:r><w:br/></w:r>"
      end
    end
  end
end