module Asciidoctor
# A utility class for working with the built-in stylesheets.
#--
# QUESTION create methods for link_*_stylesheet?
# QUESTION create method for user stylesheet?
class Stylesheets
  DEFAULT_STYLESHEET_NAME = 'asciidoctor.css'
  #DEFAULT_CODERAY_STYLE = 'asciidoctor'
  DEFAULT_PYGMENTS_STYLE = 'default'
  STYLESHEETS_DATA_PATH = ::File.join DATA_PATH, 'stylesheets'

  @__instance__ = new

  def self.instance
    @__instance__
  end

  def primary_stylesheet_name
    DEFAULT_STYLESHEET_NAME
  end

  # Public: Read the contents of the default Asciidoctor stylesheet
  #
  # returns the [String] Asciidoctor stylesheet data
  def primary_stylesheet_data
    @primary_stylesheet_data ||= ::IO.read(::File.join(STYLESHEETS_DATA_PATH, 'asciidoctor-default.css')).chomp
  end

  def embed_primary_stylesheet
    %(<style>
#{primary_stylesheet_data}
</style>)
  end

  def write_primary_stylesheet target_dir
    ::File.open(::File.join(target_dir, primary_stylesheet_name), 'w') {|f| f.write primary_stylesheet_data }
  end

  def coderay_stylesheet_name
    'coderay-asciidoctor.css'
  end

  # Public: Read the contents of the default CodeRay stylesheet
  #
  # returns the [String] CodeRay stylesheet data
  def coderay_stylesheet_data
    # NOTE use the following two lines to load a built-in theme instead
    # Helpers.require_library 'coderay'
    # ::CodeRay::Encoders[:html]::CSS.new(:default).stylesheet
    @coderay_stylesheet_data ||= ::IO.read(::File.join(STYLESHEETS_DATA_PATH, 'coderay-asciidoctor.css')).chomp
  end

  def embed_coderay_stylesheet
    %(<style>
#{coderay_stylesheet_data}
</style>)
  end

  def write_coderay_stylesheet target_dir
    ::File.open(::File.join(target_dir, coderay_stylesheet_name), 'w') {|f| f.write coderay_stylesheet_data }
  end

  def pygments_stylesheet_name style = nil
    style ||= DEFAULT_PYGMENTS_STYLE
    %(pygments-#{style}.css)
  end

  # Public: Generate the Pygments stylesheet with the specified style.
  #
  # returns the [String] Pygments stylesheet data
  def pygments_stylesheet_data style = nil
    style ||= DEFAULT_PYGMENTS_STYLE
    (@pygments_stylesheet_data ||= load_pygments)[style] ||= ::Pygments.css '.listingblock .pygments', :classprefix => 'tok-', :style => style
  end

  def embed_pygments_stylesheet style = nil
    %(<style>
#{pygments_stylesheet_data style}
</style>)
  end

  def write_pygments_stylesheet target_dir, style = nil
    ::File.open(::File.join(target_dir, pygments_stylesheet_name(style)), 'w') {|f| f.write pygments_stylesheet_data(style) }
  end

  def load_pygments
    Helpers.require_library 'pygments', 'pygments.rb' unless defined? ::Pygments
    {}
  end
end
end