const fs = require('fs');
const Parser = require('rss-parser');
const parser = new Parser();

const Markup = require('telegraf/markup');
const Extra = require('telegraf/extra');

const db_js = require('./db.js');


var db = new db_js("rss_chan");

//=== TOOL FUNCTIONS

const get_rss = function(url,min_id){
	return parser.parseURL(url).then(feed=>feed.items).then(items=>{
		let idx = items.findIndex(i => parseInt(i.guid) === min_id);
		if(idx>=0) return items.slice(0,idx);
		else return items;
	});
}

const article_to_mess = function(art){
	return `*${art.title.replace('\r\n','').trim()}*\n\n${art.content}\n\n[Read More](${art.link})`;
}

//=== MAIN MODULE CONFIG

const rssi_ex = [
	{
		chat:'CHAT_ID',
		url: 'RSS_URL',
	}
];

module.exports = function(rssi){
	this.rssi = rssi;
	return {
		name : "RSS-FEED",
		key : "rssf",
		version : 0.1,
		requirements : {
			gps : false,
		},
		text : [
			{
			trigger : ["/refresh"],
			public : false,
			desc : {
				0: "Force refresh the feeds",
			},
			requirements : (bot,event,message)=>{ 
				return new Promise((resolve, reject)=>{
					if(event.from && bot.admin.indexOf(event.from.id) == -1)
						return reject(403);
					return resolve(200);
				});
			},
			action : (bot,event,message)=>{
				return Promise.all(this.rssi.map(entry=>
					db.get_v(entry.chat).then(v=>
						get_rss(entry.url,v).then(articles=>
							Promise.all(articles.map(art=>
								this.bot.telegram.sendMessage(entry.chat,article_to_mess(art),{"parse_mode":"Markdown"})
							)).then(rr=>
								(articles.length == 0) || db.set_v(entry.chat,parseInt(articles.pop().guid))
							)
						)
					)
				)).then(r=>event.reply("Refreshed all Feeds"));
			}
		}
		],
		reply : [],
		regex : [],
		media : [],
		callback : [],
		inline : [],
		new_member : (bot,event)=>{},
		weburl : [],
		cron : [
			{
			cstr : '0 0,30 */1 * * *',
			public : true,
			desc: {
				0: "Informs Group using RSS feed",
				1: "Informe le Groupe avec le feed RSS",
				4: "Informiert die Gruppe durch dem RSS feed",
			},
			params : [ null, true],
			timezone : 'Europe/Zurich',
			action : (bot)=> {
					this.bot = bot;
					return ()=>{
						return Promise.all(this.rssi.map(entry=>
							db.get_v(entry.chat).then(v=>
								get_rss(entry.url,v).then(articles=>
									Promise.all(articles.map(art=>
										this.bot.telegram.sendMessage(entry.chat,article_to_mess(art),{"parse_mode":"Markdown"})
									)).then(rr=>
										(articles.length == 0) || db.set_v(entry.chat,parseInt(articles.pop().guid))
									)
								)
							)
						));
					};
				}
			}
		]
	}
}