module Jets::Builders
  class GemReplacer
    extend Memoist
    def initialize(options)
      @options = options
    end

    def run
      # use_gemspec to resolve http-parser gem issue
      use_gemspec = !Jets::Turbo.afterburner? # gemspec approach breaks afterburner mode
      check = Jets::Gems::Check.new(use_gemspec: use_gemspec)
      if Jets.config.lambda.layers.empty?
        found_gems = check.run! # exits early if missing gems found
      else
        # assumes missing gems are in the provided custom layer by the user
        found_gems = check.run # does not exist early
      end

      # found gems will only have gems that were found
      found_gems.each do |gem_name|
        gem_extractor = Jets::Gems::Extract::Gem.new(gem_name, @options)
        gem_extractor.run
        rename_gem(gem_name)
      end

      tidy
    end

    def rename_gem(gem_name)
      ruby_folder = "#{Jets.build_root}/stage/opt/ruby/gems/#{Jets::Gems.ruby_folder}"
      gems_folder = "#{ruby_folder}/gems"
      expr = "#{gems_folder}/#{gem_name}-x*-{darwin,linux}"
      src = Dir.glob(expr).first
      return unless src

      dest = src.sub("-darwin", "-linux")
      FileUtils.mv(src, dest) unless File.exist?(dest) # looks like rename_gem actually runs twice
    end

    def sh(command)
      puts "=> #{command}".color(:green)
      success = system(command)
      abort("Command Failed: #{command}") unless success
      success
    end

    def ruby_folder
      Jets::Gems.ruby_folder
    end

    # remove unnecessary files to reduce package size
    def tidy
      # project_root: /tmp/jets/demo/stage/code/
      # /tmp/jets/demo/stage/code/bundled
      tidy_gems("#{@options[:project_root]}/ruby/gems/#{ruby_folder}/*/gems/*")
      tidy_gems("#{@options[:project_root]}/ruby/gems/#{ruby_folder}/*/bundler/gems/*")
    end

    def tidy_gems(gems_path)
      Dir.glob(gems_path).each do |gem_path|
        tidy_gem(gem_path)
      end
    end

    # Clean up some unneeded files to try to keep the package size down
    # In a generated jets app this made a decent 9% difference:
    #  175M test2
    #  191M test3
    def tidy_gem(path)
      # remove top level tests and cache folders
      Dir.glob("#{path}/*").each do |path|
        next unless File.directory?(path)
        folder = File.basename(path)
        if %w[test tests spec features benchmark cache doc].include?(folder)
          FileUtils.rm_rf(path)
        end
      end

      Dir.glob("#{path}/**/*").each do |path|
        next unless File.file?(path)
        ext = File.extname(path)
        if %w[.rdoc .md .markdown].include?(ext) or
           path =~ /LICENSE|CHANGELOG|README/
          FileUtils.rm_f(path)
        end
      end
    end
  end
end