const express = require('express')
const app = express();
const axios = require('axios');
const querystring = require('querystring');

app.use(express.static('public'))

let tokenExpirationDate = false;
let bearerToken;

const data = {
	grant_type:'password',
	username:process.env.REDDITUSR,
	password:process.env.REDDITPWD
}
const auth = {
	username: process.env.APPID,
	password: process.env.APPSECRET
}

const getToken = async ()=>{
	if(tokenExpirationDate === false || Date.now() > tokenExpirationDate){
		const response = await axios({
			url:'https://www.reddit.com/api/v1/access_token',
			method:'post',
			auth:auth, 
			data:querystring.stringify(data)
		})
		bearerToken = response.data.access_token
		tokenExpirationDate = Date.now()+(response.data.expires_in*1000)
	}

	const config = {
		headers:{
			Authorization: 'bearer '+ bearerToken
		}
	}
	return config
}

const generate = async (req, res)=>{
	
	let url = `https://oauth.reddit.com/user/mahuntington/saved?count=100`;
	
	if(req.params.direction){
		url += `&${req.params.direction}=${req.params.page}`
	}

	const config = await getToken()
	const response = await axios.get(url, config)
	const next = response.data.data.after;
	const posts = response.data.data.children.filter(post => {
		return post.data.subreddit === 'ProgrammerHumor' && post.data.removed_by_category === null
	}).map(post => {
		return post.data.permalink
	})

	res.json({ 
		posts,
		next
	})

}

getToken();

app.get('/posts/', generate)

app.get('/posts/:direction/:page', generate) 

app.listen(3002, ()=>{
	console.log('listening');
})