module EacLauncher
  module Ruby
    module Gem
      class Build
        include ::EacRubyUtils::Console::Speaker

        def initialize(original_gem_root)
          @original_gem_root = original_gem_root
        end

        def output_file
          return nil unless @gem_root
          @gem_root.find_files_with_extension('.gem').first
        end

        def builded?
          output_file.present? && ::File.exist?(output_file)
        end

        def build
          return if builded?
          copy_gem_files
          build_gem
          check_gem_empty_size
          check_gem_version
        end

        def close
          ::FileUtils.remove_entry(@gem_root) if @gem_root && ::File.directory?(@gem_root)
          @gem_root = nil
        end

        private

        def copy_gem_files
          @gem_root = ::EacLauncher::Paths::Real.new(::Dir.mktmpdir)
          FileUtils.cp_r "#{@original_gem_root}/.", @gem_root
        end

        def build_gem
          info("Building gemspec #{gemspec_file}...")
          clear_gems
          Dir.chdir @gem_root do
            isolated_build_gem
          end
        end

        def isolated_build_gem
          old_bundle_gemfile = ENV['BUNDLE_GEMFILE']
          ENV['BUNDLE_GEMFILE'] = nil
          EacRubyUtils::Envs.local.command('gem', 'build', gemspec_file).execute!
        ensure
          ENV['BUNDLE_GEMFILE'] = old_bundle_gemfile
        end

        def check_gem_empty_size
          Dir.mktmpdir do |dir|
            Dir.chdir dir do
              EacRubyUtils::Envs.local.command('gem', 'unpack', gem).system
              gs = File.join(dir, File.basename(gem, '.gem'))
              if (Dir.entries(gs) - %w[. ..]).empty?
                raise "\"#{dir}\" (Unpacked from #{gem}) has no source code"
              end
            end
          end
        end

        def clear_gems
          @gem_root.find_files_with_extension('.gem').each do |f|
            FileUtils.rm_rf(f)
          end
        end

        def gemspec_file
          @gem_root.find_file_with_extension('.gemspec')
        end

        def gem
          @gem_root.find_file_with_extension('.gem')
        end

        def check_gem_version
          spec = ::EacLauncher::Ruby::Gem::Specification.new(gemspec_file)
          return if ::File.basename(output_file, '.gem') == spec.full_name
          raise("Builded gem is not the same version of gemspec (#{spec}, #{output_file})")
        end
      end
    end
  end
end