// import command line parsing from the std
import { parse } from "https://deno.land/std/flags/mod.ts";

// parse command line flags to get location and duration
const { lat, long, duration } = parse(Deno.args);

// lookup url for forecast specified at lat, long
let res = await fetch(`https://api.weather.gov/points/${lat},${long}`);
const json = await res.json();
const { city, state } = json.properties.relativeLocation.properties;
const url = json.properties.forecastHourly;

// fetch actual forecast data
res = await fetch(url);
const forecast = await res.json();

// limit console output to specified duration
const periods = forecast.properties.periods.slice(0, duration);

console.log(`The forecast for ${city}, ${state}` +
    `for the next ${periods.length} hours 🔮\n`);

// iterate through each hour's forecast
for (let p of periods) {
    const timestamp = new Date(p.startTime);
    const hours = `${timestamp.getHours() % 12 || 12}`.padStart(2);

    // convert 24h time to 12h
    const cycle = (timestamp.getHours() / 12) < 1 ? 'AM' : 'PM';
    const units = p.temperatureUnit === 'F' ? '℉' : '℃';

    // add padding to make thing print nicer
    const weather = p.shortForecast.padStart(12);
    const direction = p.windDirection.padEnd(3);

    console.log(`${hours} ${cycle}\t${weather}\t${p.temperature}` + 
        `${units}\t${p.windSpeed} ${direction} 🌬`);
}