const pptxgen = require('pptxgenjs');
const fs = require('fs');
const { renderSlide } = require('./slide-renderer');

function render(pptxJson) {
  const pptx = new pptxgen();
  const data = typeof pptxJson === 'string' ? JSON.parse(pptxJson) : pptxJson;
  const pres = data.presentation || {};
  const slides = data.slides || [];

  if (pres.layout) pptx.layout = pres.layout;
  if (pres.author) pptx.author = pres.author;
  if (pres.title) pptx.title = pres.title;
  if (pres.subject) pptx.subject = pres.subject;
  if (pres.company) pptx.company = pres.company;
  if (pres.revision) pptx.revision = pres.revision;
  if (pres.rtlMode !== undefined) pptx.rtlMode = pres.rtlMode;
  if (pres.theme) pptx.theme = pres.theme;

  slides.forEach(slideData => renderSlide(pptx, slideData));

  return pptx;
}

async function renderFile(inputPath, outputPath) {
  const json = fs.readFileSync(inputPath, 'utf8');
  const pptx = render(json);
  return pptx.writeFile({ fileName: outputPath });
}

module.exports = { render, renderFile };