module DockerfileRails
  module Scanner
    def scan_rails_app

      ### ruby gems ###

      @gemfile = []
      @git = false

      if File.exist? 'Gemfile.lock'
        parser = Bundler::LockfileParser.new(Bundler.read_file('Gemfile.lock'))
        @gemfile += parser.specs.map { |spec, version| spec.name }
        @git ||= ENV['RAILS_ENV'] != 'test' && parser.specs.any? do |spec|
          spec.source.instance_of? Bundler::Source::Git
        end
      end
      
      if File.exist? 'Gemfile'
        begin
          gemfile_definition = Bundler::Definition.build('Gemfile', nil, [])
          @gemfile += gemfile_definition.dependencies.map(&:name)

          unless ENV['RAILS_ENV'] == 'test'
            @git = !gemfile_definition.spec_git_paths.empty?
          end
        rescue => error
          STDERR.puts error.message
        end
      end

      @anycable = @gemfile.include? 'anycable-rails'
      @vips = @gemfile.include? 'ruby-vips'
      @bootstrap = @gemfile.include? 'bootstrap'
      @puppeteer = @gemfile.include? 'puppeteer'
      @bootsnap = @gemfile.include? 'bootsnap'

      ### database ###

      database = YAML.load_file('config/database.yml', aliases: true).
        dig('production', 'adapter') rescue nil

      if database == 'sqlite3'
        @sqlite3 = true
      elsif database == 'postgresql'
        @postgresql = true
      elsif database == 'mysql' or database == 'mysql2'
        @mysql = true
      elsif database == 'sqlserver'
        @sqlserver = true
      end

      @sqlite3 = true if @gemfile.include? 'sqlite3'
      @postgresql = true if @gemfile.include? 'pg'
      @mysql = true if @gemfile.include? 'mysql2'

      ### node modules ###

      @package_json = []

      if File.exist? 'package.json'
        @package_json += JSON.load_file('package.json')['dependencies'].keys rescue []
      end

      @puppeteer ||= @package_json.include? 'puppeteer'

      ### cable/redis ###

      @cable = ! Dir['app/channels/*.rb'].empty?

      if @cable
        @redis_cable = true
        if (YAML.load_file('config/cable.yml').dig('production', 'adapter') rescue '').include? 'any_cable'
          @anycable = true
        end
      end

      if (IO.read('config/environments/production.rb') =~ /redis/i rescue false)
        @redis_cache = true
      end

      @redis = @redis_cable || @redis_cache
    end
  end
end