const PDFDocument = require('pdfkit');

/**
 * Five-page PDF with two top-level outline entries.
 * @returns {Promise<Buffer>}
 */
function buildSamplePdf() {
  return new Promise((resolve, reject) => {
    const doc = new PDFDocument({ margin: 50 });
    const chunks = [];
    doc.on('data', (chunk) => chunks.push(chunk));
    doc.on('end', () => resolve(Buffer.concat(chunks)));
    doc.on('error', reject);

    doc.fontSize(18).text('Sample Book', { align: 'center' });
    doc.moveDown();
    doc.fontSize(12).text('A short booklet used to test outline detection.');

    doc.addPage();
    doc.outline.addItem('Chapter One');
    doc.fontSize(16).text('Chapter One');
    doc.moveDown();
    doc.fontSize(12).text('The first chapter begins with a river and a long road through the valley.');

    doc.addPage();
    doc.fontSize(12).text('The first chapter continues across the valley until the light changes.');

    doc.addPage();
    doc.outline.addItem('Chapter Two');
    doc.fontSize(16).text('Chapter Two');
    doc.moveDown();
    doc.fontSize(12).text('The second chapter starts in a city beside a harbor.');

    doc.addPage();
    doc.fontSize(12).text('The second chapter ends when the ship leaves the harbor.');
    doc.end();
  });
}

module.exports = { buildSamplePdf };