app.js

//request 用来 make http calls
const request = require('request');
const yargs = require('yargs');

const geocode = require('./geocode/geocode');
const weather = require('./weather/weather');

const input = yargs.options({
    address:{
        demand: true, //在terminal里输入true的时候，必须要有这个
        alias: 'a',
        describe: 'address to fetch weather for',
        string: true //ask yargs always to parse the address as a string. 'true' make sure we will get the data, not blank
    },
    // latitude:{
    //     demand: true,
    //     alias: 't',
    //     describe: 'latitude for weather address',
    //     string: true,
    // },
    // longitude:{
    //     demand: true,
    //     alias: 'g',
    //     describe: 'longitude for weather address',
    //     stirng: true,
    // }
})
.help()
.alias('help', 'h')
.argv;

//在geocode文件里，geocodeAddress = (address, callback)， input.address 等于address; (errowMessage, result)=callback
geocode.geocodeAddress(input.address,(errowMessage, result)=>{
    if(errowMessage){
        console.log(errowMessage);
    }
    else{
        console.log(result.address);
        weather.getWeather(result.latitude, result.longitude, (errMessage, result)=>{
            if(errMessage){
                console.log(errMessage);
            }
            else{
                console.log(`it's currently ${result.temperature}, but it feels like ${result.apparentTemperature}.`);
            }
        });
    }
});