import PDFKit from 'pdfkit';
import { Invoice } from '../../types/invoice.types';

export class EInvoiceSection {
  private doc: PDFKit.PDFDocument;
  private currentY: number;
  private pageHeight: number = 842; // A4 Höhe in Punkten
  private footerHeight: number = 120; // Platz für Footer

  constructor(doc: PDFKit.PDFDocument, currentY: number) {
    this.doc = doc;
    this.currentY = currentY;
  }

  /**
   * E-Rechnung Sektion
   * Strukturierte elektronische Rechnung nach XRechnung-Standard
   */
  public draw(invoice: Invoice): number {
    // E-Rechnung Header
    this.drawEInvoiceHeader();
    
    // Rechnungssteller (Seller)
    this.drawSellerSection(invoice);
    
    // Rechnungsempfänger (Buyer)
    this.drawBuyerSection(invoice);
    
    // Rechnungsdetails
    this.drawInvoiceDetails(invoice);
    
    // Positionen in strukturierter Form
    this.drawStructuredItems(invoice);
    
    // Summen und Steuern
    this.drawStructuredTotals(invoice);
    
    // Zahlungsinformationen
    this.drawPaymentInformation(invoice);
    
    return this.currentY;
  }

  private drawEInvoiceHeader(): void {
    // E-Rechnung Titel
    this.doc.font('Helvetica-Bold')
      .fontSize(18)
      .fillColor('#008080')
      .text('E-RECHNUNG', 50, this.currentY, { continued: false });
    
    this.currentY += 25;
    
    // XRechnung-konforme Metadaten
    this.doc.font('Helvetica-Bold')
      .fontSize(12)
      .fillColor('black')
      .text('Elektronische Rechnung nach XRechnung-Standard', 50, this.currentY, { continued: false });
    
    this.currentY += 20;
    
    // Trennlinie
    this.doc.moveTo(50, this.currentY)
      .lineTo(550, this.currentY)
      .lineWidth(2)
      .strokeColor('#008080')
      .stroke();
    
    this.currentY += 20;
  }

  private drawSellerSection(invoice: Invoice): void {
    this.doc.font('Helvetica-Bold')
      .fontSize(14)
      .text('Rechnungssteller (Seller)', 50, this.currentY, { continued: false });
    
    this.currentY += 20;
    
    // Strukturierte Seller-Informationen
    this.doc.font('Helvetica')
      .fontSize(10);
    
    this.drawInfoRow('Name:', invoice.sender.name, 50);
    this.drawInfoRow('Firma:', invoice.sender.company || '', 50);
    this.drawInfoRow('Straße:', invoice.sender.address.street, 50);
    this.drawInfoRow('PLZ/Ort:', `${invoice.sender.address.postalCode} ${invoice.sender.address.city}`, 50);
    this.drawInfoRow('Telefon:', invoice.sender.contactInfo.phone, 50);
    this.drawInfoRow('E-Mail:', invoice.sender.contactInfo.email, 50);
    this.drawInfoRow('Website:', invoice.sender.contactInfo.website || '', 50);
    this.drawInfoRow('Geschäftsinhaber:', invoice.sender.businessOwner || '', 50);
    this.drawInfoRow('USt-IdNr.:', invoice.sender.vatId || '', 50);
    
    this.currentY += 20;
  }

  private drawBuyerSection(invoice: Invoice): void {
    this.doc.font('Helvetica-Bold')
      .fontSize(14)
      .text('Rechnungsempfänger (Buyer)', 50, this.currentY, { continued: false });
    
    this.currentY += 20;
    
    // Strukturierte Buyer-Informationen
    this.doc.font('Helvetica')
      .fontSize(10);
    
    this.drawInfoRow('Name:', invoice.recipient.name, 50);
    this.drawInfoRow('Straße:', invoice.recipient.address.street, 50);
    this.drawInfoRow('PLZ/Ort:', `${invoice.recipient.address.postalCode} ${invoice.recipient.address.city}`, 50);
    
    this.currentY += 20;
  }

  private drawInvoiceDetails(invoice: Invoice): void {
    this.doc.font('Helvetica-Bold')
      .fontSize(14)
      .text('Rechnungsdetails', 50, this.currentY, { continued: false });
    
    this.currentY += 20;
    
    // Strukturierte Rechnungsdetails
    this.doc.font('Helvetica')
      .fontSize(10);
    
    this.drawInfoRow('Rechnungsnummer:', invoice.details.invoiceNumber, 50);
    this.drawInfoRow('Kundennummer:', invoice.details.customerNumber, 50);
    this.drawInfoRow('Rechnungsdatum:', invoice.details.invoiceDate, 50);
    this.drawInfoRow('Lieferdatum:', invoice.details.deliveryDate, 50);
    this.drawInfoRow('Leistungszeitraum:', invoice.details.servicePeriod, 50);
    
    this.currentY += 20;
  }

  private drawStructuredItems(invoice: Invoice): void {
    this.doc.font('Helvetica-Bold')
      .fontSize(14)
      .text('Rechnungspositionen', 50, this.currentY, { continued: false });
    
    this.currentY += 20;
    
    // Tabellenkopf
    const tableWidth = 500;
    const colWidths = [250, 50, 50, 50, 100]; // Description, Qty, Unit, VAT, Total
    
    this.doc.rect(50, this.currentY, tableWidth, 25)
      .fill('#f0f0f0')
      .stroke();
    
    this.doc.font('Helvetica-Bold')
      .fontSize(9)
      .fillColor('black')
      .text('Beschreibung', 55, this.currentY + 8, { width: colWidths[0], continued: false })
      .text('Menge', 305, this.currentY + 8, { width: colWidths[1], align: 'center', continued: false })
      .text('Einh.', 355, this.currentY + 8, { width: colWidths[2], align: 'center', continued: false })
      .text('MwSt.', 405, this.currentY + 8, { width: colWidths[3], align: 'center', continued: false })
      .text('Gesamt', 455, this.currentY + 8, { width: colWidths[4], align: 'right', continued: false });

    this.currentY += 25;

    // Positionen
    invoice.items.forEach((item, index) => {
      // Prüfe ob genug Platz auf der aktuellen Seite ist
      if (this.currentY + 20 > this.pageHeight - this.footerHeight) {
        this.addNewPage();
      }
      
      const rowColor = index % 2 === 0 ? '#ffffff' : '#f8f8f8';
      const rowHeight = 20; // Feste Höhe für E-Rechnung-Tabelle
      
      // Zeilen-Hintergrund - exakt mit Zeilenhöhe
      this.doc.rect(50, this.currentY, tableWidth, rowHeight)
        .fill(rowColor)
        .stroke();
      
      this.doc.font('Helvetica')
        .fontSize(8)
        .fillColor('black')
        .text(item.description, 55, this.currentY + 6, { width: colWidths[0], continued: false })
        .text(item.quantity.toString(), 305, this.currentY + 6, { width: colWidths[1], align: 'center', continued: false })
        .text(item.unit, 355, this.currentY + 6, { width: colWidths[2], align: 'center', continued: false })
        .text(`${item.vatRate}%`, 405, this.currentY + 6, { width: colWidths[3], align: 'center', continued: false })
        .font('Helvetica-Bold')
        .text(`${item.total.toFixed(2).replace('.', ',')} ${item.currency}`, 455, this.currentY + 6, { width: colWidths[4], align: 'right', continued: false });

      this.currentY += rowHeight;
    });
    
    this.currentY += 20;
  }

  private drawStructuredTotals(invoice: Invoice): void {
    this.doc.font('Helvetica-Bold')
      .fontSize(14)
      .text('Summen und Steuern', 50, this.currentY, { continued: false });
    
    this.currentY += 20;
    
    // Strukturierte Summen
    this.doc.font('Helvetica')
      .fontSize(10);
    
    this.drawInfoRow('Nettobetrag:', `${invoice.totals.netAmount.toFixed(2).replace('.', ',')} ${invoice.totals.currency}`, 50);
    this.drawInfoRow('MwSt.-Satz:', `${invoice.totals.vatRate.toFixed(2).replace('.', ',')}%`, 50);
    this.drawInfoRow('MwSt.-Betrag:', `${invoice.totals.vatAmount.toFixed(2).replace('.', ',')} ${invoice.totals.currency}`, 50);
    
    this.currentY += 15;
    
    // Gesamtbetrag hervorgehoben
    this.doc.font('Helvetica-Bold')
      .fontSize(16)
      .text(`Gesamtbetrag: ${invoice.totals.grossAmount.toFixed(2).replace('.', ',')} ${invoice.totals.currency}`, 50, this.currentY, { continued: false });
    
    this.currentY += 30;
  }

  private drawPaymentInformation(invoice: Invoice): void {
    this.doc.font('Helvetica-Bold')
      .fontSize(14)
      .text('Zahlungsinformationen', 50, this.currentY, { continued: false });
    
    this.currentY += 20;
    
    // Strukturierte Zahlungsinformationen
    this.doc.font('Helvetica')
      .fontSize(10);
    
    const paymentText = `Zahlbar ohne Abzug bis zum ${invoice.paymentInfo.dueDate}.`;
    this.drawInfoRow('Zahlungsziel:', paymentText, 50);
    this.drawInfoRow('Bank:', invoice.paymentInfo.bank, 50);
    this.drawInfoRow('Kontoinhaber:', invoice.paymentInfo.accountHolder, 50);
    this.drawInfoRow('IBAN:', invoice.paymentInfo.iban, 50);
    this.drawInfoRow('BIC/SWIFT:', invoice.paymentInfo.bic, 50);
    
    this.currentY += 20;
  }

  private drawInfoRow(label: string, value: string, x: number): void {
    if (!value) return; // Überspringe leere Werte
    
    this.doc.font('Helvetica-Bold')
      .fontSize(10)
      .text(label, x, this.currentY, { width: 150, continued: false })
      .font('Helvetica')
      .text(value, x + 160, this.currentY, { continued: false });
    
    this.currentY += 15;
  }

  private addNewPage(): void {
    this.doc.addPage();
    this.currentY = 50;
  }
}