Mini Project: Fetch & Display Data

// weather.js — Fetches weather from Open-Meteo (free, no API key)
// Run: node weather.js

async function getWeather(city) {
  // Step 1: Geocode the city name to coordinates
  const geoUrl = `https://geocoding-api.open-meteo.com/v1/search?name=${encodeURIComponent(city)}&count=1`;
  const geoRes = await fetch(geoUrl);
  const geoData = await geoRes.json();

  if (!geoData.results?.length) {
    throw new Error(`City not found: ${city}`);
  }

  const { latitude, longitude, name, country } = geoData.results[0];

  // Step 2: Fetch weather data
  const weatherUrl = `https://api.open-meteo.com/v1/forecast`
    + `?latitude=${latitude}&longitude=${longitude}`
    + `&current=temperature_2m,wind_speed_10m,weather_code`;

  const weatherRes = await fetch(weatherUrl);
  const weatherData = await weatherRes.json();

  const current = weatherData.current;

  return {
    city: `${name}, ${country}`,
    temp: current.temperature_2m,
    wind: current.wind_speed_10m,
  };
}

function formatWeather(data) {
  const lines = [
    `📍 ${data.city}`,
    `🌡  Temperature: ${data.temp}°C`,
    `💨  Wind: ${data.wind} km/h`,
  ];
  return lines.join("\n");
}

async function main() {
  const cities = process.argv.slice(2);

  if (cities.length === 0) {
    console.log("Usage: node weather.js <city> [city2] ...");
    console.log("Example: node weather.js London Paris Berlin");
    process.exit(1);
  }

  const results = await Promise.allSettled(
    cities.map(city => getWeather(city))
  );

  results.forEach((result, i) => {
    if (result.status === "fulfilled") {
      console.log(formatWeather(result.value));
    } else {
      console.error(`Error for ${cities[i]}: ${result.reason.message}`);
    }
    console.log("");
  });
}

main().catch(console.error);