module IsoDoc
  class Convert < ::IsoDoc::Common
    # Check if already compiled version(.css) exists,
    #   if not, return original scss file. During release
    #   we compile scss into css files in order to not depend on scss
    def precompiled_style_or_original(stylesheet_path)
      # Already have compiled stylesheet, use it
      return stylesheet_path if stylesheet_path.nil? ||
        File.extname(stylesheet_path) == ".css"

      basename = File.basename(stylesheet_path, ".*")
      compiled_path = File.join(File.dirname(stylesheet_path),
                                "#{basename}.css")
      return stylesheet_path unless File.file?(compiled_path)

      compiled_path
    end

    def localpath(path)
      return path if %r{^[A-Z]:|^/|^file:/}.match?(path)
      return path unless (@sourcedir || @localdir) && path

      File.expand_path(File.join((@sourcedir || @localdir), path))
    end

    # run this after @meta is populated
    def populate_css
      @htmlstylesheet = generate_css(localpath(@htmlstylesheet_name), true)
      @wordstylesheet = generate_css(localpath(@wordstylesheet_name), false)
      @standardstylesheet =
        generate_css(localpath(@standardstylesheet_name), false)
      @htmlstylesheet_override_name and
        @htmlstylesheet_override = File.open(localpath(@htmlstylesheet_override_name))
      @wordstylesheet_override_name and
        @wordstylesheet_override = File.open(localpath(@wordstylesheet_override_name))
    end

    def default_fonts(_options)
      {
        bodyfont: "Arial",
        headerfont: "Arial",
        monospacefont: "Courier New",
      }
    end

    # none for this parent gem, but will be populated in child gems
    # which have access to stylesheets &c
    def default_file_locations(_options)
      {}
    end

    def fonts_options
      {
        "bodyfont" => options[:bodyfont] || "Arial",
        "headerfont" => options[:headerfont] || "Arial",
        "monospacefont" => options[:monospacefont] || "Courier New",
        "normalfontsize" => options[:normalfontsize],
        "monospacefontsize" => options[:monospacefontsize],
        "smallerfontsize" => options[:smallerfontsize],
        "footnotefontsize" => options[:footnotefontsize],
      }
    end

    def scss_fontheader(is_html_css)
      b = options[:bodyfont] || "Arial"
      h = options[:headerfont] || "Arial"
      m = options[:monospacefont] || "Courier New"
      ns = options[:normalfontsize] || (is_html_css ? "1.0em" : "12.0pt")
      ms = options[:monospacefontsize] || (is_html_css ? "0.8em" : "11.0pt")
      ss = options[:smallerfontsize] || (is_html_css ? "0.9em" : "10.0pt")
      fs = options[:footnotefontsize] || (is_html_css ? "0.9em" : "9.0pt")
      "$bodyfont: #{b};\n$headerfont: #{h};\n$monospacefont: #{m};\n"\
        "$normalfontsize: #{ns};\n$monospacefontsize: #{ms};\n"\
        "$smallerfontsize: #{ss};\n$footnotefontsize: #{fs};\n"
    end

    def convert_scss(filename, stylesheet, stripwordcss)
      require "sassc"
      require "isodoc/sassc_importer"

      [File.join(Gem.loaded_specs["isodoc"].full_gem_path,
                 "lib", "isodoc"),
       File.dirname(filename)].each do |name|
        SassC.load_paths << name
      end
      SassC::Engine.new(scss_fontheader(stripwordcss) + stylesheet,
                        syntax: :scss, importer: SasscImporter)
        .render
    end

    # stripwordcss if HTML stylesheet, !stripwordcss if DOC stylesheet
    def generate_css(filename, stripwordcss)
      return nil if filename.nil?

      filename = precompiled_style_or_original(filename)
      stylesheet = File.read(filename, encoding: "UTF-8")
      stylesheet = populate_template(stylesheet, :word)
      stylesheet.gsub!(/(\s|\{)mso-[^:]+:[^;]+;/m, "\\1") if stripwordcss
      stylesheet.gsub!(/--/, "-DOUBLE_HYPHEN_ESCAPE-") unless stripwordcss
      if File.extname(filename) == ".scss"
        stylesheet = convert_scss(filename, stylesheet, stripwordcss)
      end
      Tempfile.open([File.basename(filename, ".*"), "css"],
                    encoding: "utf-8") do |f|
        f.write(stylesheet)
        f
      end
    end
  end
end