require 'sprockets'
require 'sprockets-sass'
require 'sass'

class SprocketsCompiler
  # This is pretty much copy/paste from https://github.com/stevehodgkiss/guard-sprockets2/blob/master/lib/guard/sprockets2/compiler.rb
  # The only method added/changed is self.sprockets()

  def initialize(options = {})
    configure(options)
    @target = Pathname.new(@assets_path)
  end

  def clean
    FileUtils.rm_rf @assets_path, :secure => true
  end

  def compile
    @sprockets.send(:expire_index!)
    success = true
    @precompile.each do |path|
      @sprockets.each_logical_path do |logical_path|
        next unless path_matches?(path, logical_path)

        if asset = @sprockets.find_asset(logical_path)
          success = compile_asset(asset, false)
          success = compile_asset(asset, true) if @digest
          break unless success
        end
      end
    end
    success
  end

  protected

  def compile_asset(asset, digest)
    filename = digest ? @target.join(asset.digest_path) : @target.join(asset.logical_path)
    puts filename

    FileUtils.mkdir_p filename.dirname
    asset.write_to(filename)
    asset.write_to("#{filename}.gz") if @gz && filename.to_s =~ /\.(css|js)$/
    true
  rescue => e
    puts unless ENV['GUARD_ENV'] == 'test'
    UI.error e.message.gsub(/^Error: /, '')
    false
  end

  def path_matches?(path, logical_path)
    if path.is_a?(Regexp)
      path.match(logical_path)
    else
      File.fnmatch(path.to_s, logical_path)
    end
  end

  def configure(options)
    @sprockets = options[:sprockets]
    @assets_path = options[:assets_path]
    @precompile = options[:precompile]
    @digest = options[:digest]
    @gz = options[:gz]
    set_defaults
  end

  def set_defaults
    if defined?(Rails)
      @sprockets ||= Rails.application.assets
      @assets_path ||= File.join(Rails.public_path, Rails.application.config.assets.prefix)
      @precompile ||= Rails.application.config.assets.precompile
    else
      @assets_path ||= "#{Dir.pwd}/public/assets"
      @precompile ||= [ /\w+\.(?!js|css).+/, /application.(css|js)$/ ]
    end
    @digest = true if @digest.nil?
    @gz = true if @gz.nil?
  end

  def self.setup(base_dir)
    sprockets = ::Sprockets::Environment.new(base_dir)

    sprockets.append_path 'assets/img'
    sprockets.append_path 'assets/js'
    sprockets.append_path 'assets/css'
    sprockets.append_path 'assets/lib'

    default_assets_dir = File.dirname( File.expand_path( __FILE__ ) ) + '/..'
    sprockets.append_path default_assets_dir + '/assets/img'
    sprockets.append_path default_assets_dir + '/assets/js'
    sprockets.append_path default_assets_dir + '/assets/css'
    sprockets.append_path default_assets_dir + '/assets/lib'

    sprockets.append_path "#{Gem.loaded_specs['compass'].full_gem_path}/frameworks/compass/stylesheets"

    if ENV['RACK_ENV'] != 'development'
      require 'yui/compressor'
      require 'uglifier'
      sprockets.css_compressor = YUI::CssCompressor.new
      sprockets.js_compressor = Uglifier.new
    end

    return sprockets
  end

end