import PDFDocument from 'pdfkit';
import type { InteracTransaction } from '@icc/shared';

const ICC_BLUE = '#1773cf';
const GRAY_TEXT = '#4B5563';
const LIGHT_GRAY = '#F3F4F6';

function formatCurrencyPdf(amount: number): string {
  return new Intl.NumberFormat('fr-CA', {
    style: 'currency',
    currency: 'CAD',
    minimumFractionDigits: 2,
  }).format(amount);
}

function formatDatePdf(dateStr: string): string {
  try {
    return new Intl.DateTimeFormat('fr-CA', {
      year: 'numeric',
      month: '2-digit',
      day: '2-digit',
      hour: '2-digit',
      minute: '2-digit',
    }).format(new Date(dateStr));
  } catch {
    return dateStr;
  }
}

const STATUS_LABELS: Record<string, string> = {
  deposited: 'Déposé ✓',
  pending: 'En attente',
  expired: 'Expiré',
  cancelled: 'Annulé',
};

export function generateReceipt(transaction: InteracTransaction): Promise<Buffer> {
  return new Promise((resolve, reject) => {
    const doc = new PDFDocument({
      size: 'A4',
      margin: 50,
      info: {
        Title: `Reçu - ${transaction.reference || 'N/A'}`,
        Author: 'ICC Interac Manager',
      },
    });

    const chunks: Buffer[] = [];
    doc.on('data', (chunk: Buffer) => chunks.push(chunk));
    doc.on('end', () => resolve(Buffer.concat(chunks)));
    doc.on('error', reject);

    const pageWidth = doc.page.width - 100;
    const startX = 50;
    let y = 50;

    // Header background
    doc.rect(startX, y, pageWidth, 80).fill(ICC_BLUE);

    // Header text
    doc.fillColor('#FFFFFF')
      .font('Helvetica-Bold')
      .fontSize(22)
      .text('ICC AMÉRIQUES', startX, y + 15, { width: pageWidth, align: 'center' });

    doc.fontSize(12)
      .font('Helvetica')
      .text('Reçu de virement Interac', startX, y + 45, { width: pageWidth, align: 'center' });

    y += 100;

    // Separator line
    doc.moveTo(startX, y).lineTo(startX + pageWidth, y).strokeColor(ICC_BLUE).lineWidth(2).stroke();
    y += 20;

    // Transaction details
    const fields: [string, string][] = [
      ['Date', formatDatePdf(transaction.date)],
      ['Expéditeur', transaction.sender],
      ['Montant', formatCurrencyPdf(transaction.amount)],
      ['Devise', transaction.currency || 'CAD'],
      ['Référence', transaction.reference || 'N/A'],
      ['Message', transaction.message || '—'],
      ['Succursale', (transaction as any).branch || 'Montreal'],
      ['Statut', STATUS_LABELS[transaction.status] || transaction.status],
    ];

    for (const [label, value] of fields) {
      // Alternating row background
      if (fields.indexOf([label, value] as any) % 2 === 0) {
        doc.rect(startX, y - 5, pageWidth, 30).fill(LIGHT_GRAY);
      }

      doc.fillColor(GRAY_TEXT)
        .font('Helvetica-Bold')
        .fontSize(11)
        .text(`${label}:`, startX + 15, y, { width: 150 });

      doc.fillColor('#111827')
        .font('Helvetica')
        .fontSize(11)
        .text(value, startX + 170, y, { width: pageWidth - 185 });

      y += 30;
    }

    y += 10;

    // Footer separator
    doc.moveTo(startX, y).lineTo(startX + pageWidth, y).strokeColor('#E5E7EB').lineWidth(1).stroke();
    y += 15;

    // Footer
    doc.fillColor(GRAY_TEXT)
      .font('Helvetica')
      .fontSize(9)
      .text('Reçu généré automatiquement par ICC Interac Manager', startX, y, { width: pageWidth, align: 'center' });

    y += 15;
    doc.text(`Date de génération: ${new Date().toISOString().split('T')[0]}`, startX, y, { width: pageWidth, align: 'center' });

    doc.end();
  });
}

export async function generateBatchReceipts(txns: InteracTransaction[]): Promise<Buffer> {
  const doc = new PDFDocument({ size: 'A4', margin: 50 });
  const chunks: Buffer[] = [];

  return new Promise((resolve, reject) => {
    doc.on('data', (chunk: Buffer) => chunks.push(chunk));
    doc.on('end', () => resolve(Buffer.concat(chunks)));
    doc.on('error', reject);

    for (let i = 0; i < txns.length; i++) {
      if (i > 0) doc.addPage();

      const tx = txns[i];
      const pageWidth = doc.page.width - 100;
      const startX = 50;
      let y = 50;

      // Header
      doc.rect(startX, y, pageWidth, 60).fill(ICC_BLUE);
      doc.fillColor('#FFFFFF').font('Helvetica-Bold').fontSize(18)
        .text('ICC AMÉRIQUES', startX, y + 10, { width: pageWidth, align: 'center' });
      doc.fontSize(10).font('Helvetica')
        .text('Reçu de virement Interac', startX, y + 35, { width: pageWidth, align: 'center' });

      y += 75;

      const fields: [string, string][] = [
        ['Date', formatDatePdf(tx.date)],
        ['Expéditeur', tx.sender],
        ['Montant', formatCurrencyPdf(tx.amount)],
        ['Référence', tx.reference || 'N/A'],
        ['Message', tx.message || '—'],
        ['Succursale', (tx as any).branch || 'Montreal'],
        ['Statut', STATUS_LABELS[tx.status] || tx.status],
      ];

      for (const [label, value] of fields) {
        doc.fillColor(GRAY_TEXT).font('Helvetica-Bold').fontSize(10)
          .text(`${label}:`, startX + 15, y, { width: 130 });
        doc.fillColor('#111827').font('Helvetica').fontSize(10)
          .text(value, startX + 150, y, { width: pageWidth - 165 });
        y += 25;
      }

      y += 10;
      doc.fillColor(GRAY_TEXT).font('Helvetica').fontSize(8)
        .text(`Reçu ${i + 1}/${txns.length} — Généré le ${new Date().toISOString().split('T')[0]}`,
          startX, y, { width: pageWidth, align: 'center' });
    }

    doc.end();
  });
}