require 'awestruct/util/exception_helper'

require 'listen'
require 'guard/livereload'
require 'compass'
require 'compass/commands'

module Awestruct
  module CLI
    class Auto

      def initialize(config, base_url)
        @config = config
        @base_url = base_url
      end

      def run()
        generate_thread = nil
        current_path = nil

        guard = if ( @config.options.livereload )
          guard = Guard::LiveReload.new
          guard.start
          guard
        else
          nil
        end

        force_polling = ( RUBY_PLATFORM =~ /mingw/ ? true : false )
        listener = Listen.to( @config.dir, :latency=>0.5, :force_polling=>force_polling ) do |modified, added, removed|
          modified.each do |path| # path is absolute path
            engine = ::Awestruct::Engine.instance

            begin
              $LOG.info "Change detected for file #{path}" if $LOG.info?
              if path.eql? current_path
                unless generate_thread.nil?
                  $LOG.info "Same path triggered, stopping previous generation" if generate_thread.alive? && $LOG.info?
                  generate_thread.kill
                end
              else
                generate_thread.join unless generate_thread.nil?
                current_path = path
              end

              generate_thread = Thread.new {
                begin
                  if ( File.extname(path) == '.sass' || File.extname(path) == '.scss' )
                    # TODO use sass here, eventually, as soon as I can figure out how to get it and sprites to work
                    ::Compass::Commands::UpdateProject.new(engine.site.dir, {}).perform
                    # fixes the nil later on, there's an outstanding bug that css 
                    # pages aren't output in the correct directory
                    pages = [] 
                  else
                    page = engine.page_by_source_path(path)
                    pages = []
                    if ( page )
                      pages = engine.generate_page_and_dependencies( page )
                    else
                      if File.exist? path
                      # chances are this is an extension or yaml file
                        pages = engine.run_auto_for_non_page(path)
                      end
                    end
                  end

                  $LOG.info "Regeneration finished." if $LOG.info?

                  if ( guard )
                    urls = pages.map do |p|
                      @base_url + p.url.to_s
                    end

                    guard.run_on_modifications(urls)
                  end

                rescue => e
                  ExceptionHelper.log_building_error e, path
                end
              }
            rescue => e
              ExceptionHelper.log_building_error e, path
            end
          end
        end
        listener.ignore( %r(\.awestruct) )
        listener.ignore( %r(^#{File.basename( @config.tmp_dir )}) )
        listener.ignore( %r(\.sass-cache) )
        listener.ignore( %r(^#{File.basename( @config.output_dir )}) )

        @config.ignore.each do |i|
          listener.ignore( %r(^#{i}) )
        end

        listener.start
      end

    end

  end
end