const fs = require('fs');
const path = require('path');

// Base URL for the WFS service
const baseUrl = 'https://kartta.hel.fi/ws/geoserver/avoindata/wfs';

// List of layers to download (extendable by adding more items to this array)
const layers = [
  'Aluesarjat_avainluvut_2024',
  'Seutukartta_liikenne_paatiet',
  'Seutukartta_liikenne_metroasemat',
  'Seutukartta_liikenne_metro_rata',
  'Seutukartta_liikenne_juna_rata',
  'Seutukartta_liikenne_juna_asema',
  'Seutukartta_aluejako_pienalue',
  'Seutukartta_aluejako_kuntarajat',
  'Seutukartta_maankaytto_jarvet',
  'Seutukartta_maankaytto_joet',
  'Seutukartta_meren_rantaviiva',
  'Toimipisterekisteri_palvelut'
];

// Output directory
const outputDir = path.join(__dirname, 'app', 'data');

// Create output directory if it doesn't exist
if (!fs.existsSync(outputDir)) {
  fs.mkdirSync(outputDir, { recursive: true });
}

// Function to download and save layer data
async function downloadLayer(layer) {
  const url = `${baseUrl}?service=WFS&version=2.0.0&request=GetFeature&typeName=avoindata:${layer}&outputFormat=application/json&srsname=EPSG:4326`;

  try {
    const response = await fetch(url);
    if (!response.ok) {
      throw new Error(`Failed to fetch ${layer}: ${response.statusText}`);
    }
    const data = await response.json();

    const filePath = path.join(outputDir, `${layer}.json`);
    fs.writeFileSync(filePath, JSON.stringify(data, null, '\t'));
    console.log(`Downloaded and saved: ${layer}.json`);
  } catch (error) {
    console.error(`Error downloading ${layer}: ${error.message}`);
  }
}

// Download all layers sequentially
async function main() {
  for (const layer of layers) {
    await downloadLayer(layer);
  }
}

main();