Invoice = Struct.new(:number, :customer, :total)

class PdfRenderer
  def initialize(invoice)
    @invoice = invoice
  end

  def render
    "PDF invoice #{@invoice.number} for #{@invoice.customer}"
  end
end

class CsvRenderer
  def initialize(invoice)
    @invoice = invoice
  end

  def render
    [
      @invoice.number,
      @invoice.customer,
      @invoice.total,
    ].join(",")
  end
end

class InvoiceExporter
  def initialize(renderer_classes)
    @renderer_classes = renderer_classes
  end

  def export(invoice)
    @renderer_classes.map do |renderer_class|
      renderer_class.new(invoice).render
    end
  end
end

invoice = Invoice.new(
  number: "INV-123",
  customer: "Acme AB",
  total: 1200,
)

exporter = InvoiceExporter.new([PdfRenderer, CsvRenderer])
puts exporter.export(invoice)

# Output:
# PDF invoice INV-123 for Acme AB
# INV-123,Acme AB,1200
      

import java.util.ArrayList;
import java.util.List;

class Invoice {
  final String number;
  final String customer;
  final int total;

  Invoice(String number, String customer, int total) {
    this.number = number;
    this.customer = customer;
    this.total = total;
  }
}

interface InvoiceRenderer {
  String render();
}

interface InvoiceRendererFactory {
  InvoiceRenderer create(Invoice invoice);
}

class PdfRenderer implements InvoiceRenderer {
  private final Invoice invoice;

  PdfRenderer(Invoice invoice) {
    this.invoice = invoice;
  }

  public String render() {
    return "PDF invoice " + invoice.number + " for " + invoice.customer;
  }
}

class CsvRenderer implements InvoiceRenderer {
  private final Invoice invoice;

  CsvRenderer(Invoice invoice) {
    this.invoice = invoice;
  }

  public String render() {
    return invoice.number + "," + invoice.customer + "," + invoice.total;
  }
}

class PdfRendererFactory implements InvoiceRendererFactory {
  public InvoiceRenderer create(Invoice invoice) {
    return new PdfRenderer(invoice);
  }
}

class CsvRendererFactory implements InvoiceRendererFactory {
  public InvoiceRenderer create(Invoice invoice) {
    return new CsvRenderer(invoice);
  }
}

class InvoiceExporter {
  private final List<InvoiceRendererFactory> factories;

  InvoiceExporter(List<InvoiceRendererFactory> factories) {
    this.factories = factories;
  }

  List<String> export(Invoice invoice) {
    List<String> files = new ArrayList<>();

    for (InvoiceRendererFactory factory : factories) {
      files.add(factory.create(invoice).render());
    }

    return files;
  }
}

public class Main {
  public static void main(String[] args) {
    Invoice invoice = new Invoice("INV-123", "Acme AB", 1200);

    InvoiceExporter exporter = new InvoiceExporter(List.of(
      new PdfRendererFactory(),
      new CsvRendererFactory()
    ));

    for (String file : exporter.export(invoice)) {
      System.out.println(file);
    }

    // Output:
    // PDF invoice INV-123 for Acme AB
    // INV-123,Acme AB,1200
  }
}