const { Client } = require('pg');
const axios = require('axios');
require('dotenv').config();

const DATA_URL = 'https://raw.githubusercontent.com/nvkelso/natural-earth-vector/master/geojson/ne_10m_populated_places_simple.geojson';

async function importCities() {
  const client = new Client({
    connectionString: process.env.DATABASE_URL || 'postgresql://line_of_sight:line_of_sight_pass@localhost:5432/line_of_sight'
  });

  try {
    console.log('Connecting to database...');
    await client.connect();

    console.log('Downloading Natural Earth data (GeoJSON)...');
    const response = await axios.get(DATA_URL);
    const data = response.data;

    console.log(`Downloaded ${data.features.length} features. Preparing database...`);

    // Ensure table exists and is clean
    await client.query('TRUNCATE TABLE cities');

    let count = 0;
    const batchSize = 100;

    for (let i = 0; i < data.features.length; i += batchSize) {
      const batch = data.features.slice(i, i + batchSize);
      
      const values = [];
      const queryParts = [];
      
      batch.forEach((feature, index) => {
        const props = feature.properties;
        const coords = feature.geometry.coordinates; // [lon, lat]
        
        const name = props.NAME || 'Unknown';
        const population = props.POP_MAX || 0;
        const country = props.ADM0NAME || 'Unknown';
        const lon = coords[0];
        const lat = coords[1];

        const baseIndex = index * 4;
        queryParts.push(`($${baseIndex + 1}, $${baseIndex + 2}, $${baseIndex + 3}, ST_SetSRID(ST_MakePoint($${baseIndex + 4}, $${baseIndex + 1}), 4326)::geography)`);
        values.push(lat, name, population, country, lon); // Note: ST_MakePoint takes lon, lat
      });

      // Simple positional mapping for query (lat, name, pop, country, lon)
      // Actually let's refine the query to be clearer
      const refinedQueryParts = [];
      const refinedValues = [];
      
      batch.forEach((feature, index) => {
        const p = feature.properties;
        const c = feature.geometry.coordinates;
        const base = index * 5;
        refinedQueryParts.push(`($${base + 1}, $${base + 2}, $${base + 3}, ST_SetSRID(ST_MakePoint($${base + 4}, $${base + 5}), 4326)::geography)`);
        refinedValues.push(p.NAME || 'Unknown', p.POP_MAX || 0, p.ADM0NAME || 'Unknown', c[0], c[1]);
      });

      await client.query(
        `INSERT INTO cities (name, population, country, geom) VALUES ${refinedQueryParts.join(',')}`,
        refinedValues
      );
      
      count += batch.length;
      if (count % 1000 === 0 || count === data.features.length) {
        console.log(`Imported ${count}/${data.features.length} cities...`);
      }
    }

    console.log('SUCCESS: Natural Earth data import complete.');

  } catch (err) {
    console.error('ERROR during import:', err);
  } finally {
    await client.end();
  }
}

importCities();