const fetch = require('node-fetch'); // Import node-fetch

async function getOdchodyData(url) {
  try {
    const response = await fetch(url);
    if (!response.ok) {
      throw new Error(`HTTP error! Status: ${response.status}`);
    }
    const csvData = await response.text();
    return parseOdchodyCSV(csvData);
  } catch (error) {
    console.error("Error fetching or processing data:", error);
    return []; // Or handle the error as appropriate for your application
  }
}

function parseOdchodyCSV(csvData) {
  const lines = csvData.split('\n');
  const odchod = [];
  let dataStart = -1;

  // Find the line where the actual data starts
  for (let i = 0; i < lines.length; i++) {
    if (lines[i].startsWith("Linka;Spoj;Čas odjezdu;Nástupiště;Cílová obec spoje;Kód datumové masky")) {
      dataStart = i + 1;
      break;
    }
  }

  if (dataStart === -1) {
    console.warn("Data header not found in CSV.");
    return []; // Or handle this error condition
  }

  for (let i = dataStart; i < lines.length; i++) {
    const line = lines[i].trim();
    if (line) { // Skip empty lines
      const values = line.split(';');
      if (values.length >= 6 && values[0] && values[2] && values[4]) {
        odchod.push([
          parseInt(values[0], 10), // Linka (parse to integer)
          values[2],              // Čas odjezdu
          values[4]               // Cílová obec spoje
        ]);
      }
    }
  }

  return odchod;
}

// --- Example Usage ---
const csvUrl = "https://bezpecne.sokolov.cz/zast/jedn_drogerie.csv";

getOdchodyData(csvUrl)
  .then(result => {
    console.log("Parsed Odchody Data:", result);
  })
  .catch(error => {
    // Error already handled in getOdchodyData, but you can add more specific handling here if needed
  });