class Haml::Exec::Sass

def initialize(args)
  super
  @name = "Sass"
  @options[:for_engine][:load_paths] = ['.'] + (ENV['SASSPATH'] || '').split(File::PATH_SEPARATOR)
end

def interactive
  require 'sass'
  require 'sass/repl'
  ::Sass::Repl.new(@options).run
end

def process_result
  if !@options[:update] && !@options[:watch] &&
      @args.first && @args.first.include?(':')
    if @args.size == 1
      @args = @args.first.split(':', 2)
    else
      @options[:update] = true
    end
  end
  return interactive if @options[:interactive]
  return watch_or_update if @options[:watch] || @options[:update]
  super
  begin
    input = @options[:input]
    output = @options[:output]
    @options[:syntax] ||= :scss if input.is_a?(File) && input.path =~ /\.scss$/
    tree =
      if input.is_a?(File) && !@options[:check_syntax]
        ::Sass::Files.tree_for(input.path, @options[:for_engine])
      else
        # We don't need to do any special handling of @options[:check_syntax] here,
        # because the Sass syntax checking happens alongside evaluation
        # and evaluation doesn't actually evaluate any code anyway.
        ::Sass::Engine.new(input.read(), @options[:for_engine]).to_tree
      end
    input.close() if input.is_a?(File)
    output.write(tree.render)
    output.close() if output.is_a? File
  rescue ::Sass::SyntaxError => e
    raise e if @options[:trace]
    raise e.sass_backtrace_str("standard input")
  end
end

def set_opts(opts)
  super
  opts.on('--scss',
          'Use the CSS-superset SCSS syntax.') do
    @options[:for_engine][:syntax] = :scss
  end
  opts.on('--watch', 'Watch files or directories for changes.',
                     'The location of the generated CSS can be set using a colon:',
                     '  sass --watch input.sass:output.css',
                     '  sass --watch input-dir:output-dir') do
    @options[:watch] = true
  end
  opts.on('--update', 'Compile files or directories to CSS.',
                      'Locations are set like --watch.') do
    @options[:update] = true
  end
  opts.on('-t', '--style NAME',
          'Output style. Can be nested (default), compact, compressed, or expanded.') do |name|
    @options[:for_engine][:style] = name.to_sym
  end
  opts.on('-q', '--quiet', 'Silence warnings during compilation.') do
    @options[:for_engine][:quiet] = true
  end
  opts.on('-g', '--debug-info',
          'Emit extra information in the generated CSS that can be used by the FireSass Firebug plugin.') do
    @options[:for_engine][:debug_info] = true
  end
  opts.on('-l', '--line-numbers', '--line-comments',
          'Emit comments in the generated CSS indicating the corresponding sass line.') do
    @options[:for_engine][:line_numbers] = true
  end
  opts.on('-i', '--interactive',
          'Run an interactive SassScript shell.') do
    @options[:interactive] = true
  end
  opts.on('-I', '--load-path PATH', 'Add a sass import path.') do |path|
    @options[:for_engine][:load_paths] << path
  end
  opts.on('--cache-location PATH', 'The path to put cached Sass files. Defaults to .sass-cache.') do |loc|
    @options[:for_engine][:cache_location] = loc
  end
  opts.on('-C', '--no-cache', "Don't cache to sassc files.") do
    @options[:for_engine][:cache] = false
  end
  unless ::Haml::Util.ruby1_8?
    opts.on('-E encoding', 'Specify the default encoding for Sass files.') do |encoding|
      Encoding.default_external = encoding
    end
  end
end

def watch_or_update
  require 'sass'
  require 'sass/plugin'
  ::Sass::Plugin.options.merge! @options[:for_engine]
  ::Sass::Plugin.options[:unix_newlines] = @options[:unix_newlines]
  if @args[1] && !@args[0].include?(':')
    flag = @options[:update] ? "--update" : "--watch"
    err =
      if !File.exist?(@args[1])
        "doesn't exist"
      elsif @args[1] =~ /\.css$/
        "is a CSS file"
      end
    raise <<MSG if err
{@args[1]} #{err}.
you mean: sass #{flag} #{@args[0]}:#{@args[1]}
  end
  dirs, files = @args.map {|name| name.split(':', 2)}.
    partition {|i, _| File.directory? i}
  files.map! {|from, to| [from, to || from.gsub(/\..*?$/, '.css')]}
  dirs.map! {|from, to| [from, to || from]}
  ::Sass::Plugin.options[:template_location] = dirs
  ::Sass::Plugin.on_updating_stylesheet do |_, css|
    if File.exists? css
      puts_action :overwrite, :yellow, css
    else
      puts_action :create, :green, css
    end
  end
  ::Sass::Plugin.on_creating_directory {|dirname| puts_action :directory, :green, dirname}
  ::Sass::Plugin.on_deleting_css {|filename| puts_action :delete, :yellow, filename}
  ::Sass::Plugin.on_compilation_error do |error, _, _|
    raise error unless error.is_a?(::Sass::SyntaxError)
    puts_action :error, :red, "#{error.sass_filename} (Line #{error.sass_line}: #{error.message})"
  end
  if @options[:update]
    ::Sass::Plugin.update_stylesheets(files)
    return
  end
  puts ">>> Sass is watching for changes. Press Ctrl-C to stop."
  ::Sass::Plugin.on_template_modified {|template| puts ">>> Change detected to: #{template}"}
  ::Sass::Plugin.on_template_created {|template| puts ">>> New template detected: #{template}"}
  ::Sass::Plugin.on_template_deleted {|template| puts ">>> Deleted template detected: #{template}"}
  ::Sass::Plugin.watch(files)
end