const config = require('./config');

function pad(n) {
  return String(n).padStart(2, '0');
}

function buildFileName(originalName, ext) {
  if (originalName) return originalName;
  const now = new Date();
  const base = `${now.getFullYear()}${pad(now.getMonth() + 1)}${pad(now.getDate())}_` +
      `${pad(now.getHours())}${pad(now.getMinutes())}${pad(now.getSeconds())}`;
  return ext ? `${base}.${ext}` : base;
}

async function uploadMedia(base64Data, mimeType, ext, originalName) {
  const url = config.appsScriptUrl;
  if (!url) throw new Error('Missing Apps Script URL');

  const fileName = buildFileName(originalName, ext);

  const payload = JSON.stringify({
    fileBase64: base64Data,
    mimeType,
    fileName,
  });

  try {
    // Native fetch handles Google's 302 redirects cleanly
    const response = await fetch(url, {
      method: 'POST',
      headers: {
        'Content-Type': 'application/json',
      },
      body: payload,
    });

    // Google Apps Script text output comes back as text first
    const body = await response.text();
    console.log('[GDRIVE] Raw response:', body);

    const result = JSON.parse(body);

    if (!result.success) {
      throw new Error(result.error || 'Upload failed');
    }

    return result.url;
  } catch (error) {
    throw new Error('Apps Script communication failed: ' + error.message);
  }
}

module.exports = { uploadMedia };