const Discord = require("discord.js");
const TOKEN = require("./token.js");
const db = require("./db.js");
const RSSParser = require("rss-parser");
const interval = require("interval-promise");
const TurndownService = require("turndown");
const fs = require("fs");
const isImage = require("is-image");

const turndown = new TurndownService();
turndown.addRule("image", {
    filter: "img",
    replacement: () => ""
});
turndown.addRule("link", {
    filter: node => node.nodeName === "A" &&node.getAttribute("href"),
    replacement: (content, node) => node.getAttribute("href")
});

const statsFile = fs.openSync("./imagestats.csv", "a");

const client = new Discord.Client();
const parser = new RSSParser();
const RSS_UPDATE_INTERVAL_MIN = 5;

const REACT_PROBABILITY = 0.6;

async function checkFeeds() {
    let feeds = db.get("rssFeeds").value();
    let outlets = db.get("feedOutputs").value();
    let oldNews = db.get("postedNewsGuids");
    for(let feedEntry of feeds) {
        let feed = await parser.parseURL(feedEntry.url);
        if(feed.items.length == 0)
            continue;
        let printableItems = feed.items.filter(i => i.isoDate > feedEntry.lastUpdate).sort((a, b) => a.isoDate.localeCompare(b.isoDate));
        if(printableItems.length > 0) {
            printableItems.forEach(item => {
                if(oldNews.has(item.guid).value())
                    return;
                outlets.forEach(ch => {
                    client.channels.get(ch).send(`**${item.title}**\nPosted by ${item.creator}\n${item.link}\n\n${turndown.turndown(item[feedEntry.contentElement]).replace(/( {2}\n|\n\n){2,}/gm, "\n").replace(item.link, "")}`);
                });
                oldNews.set(item.guid, true).write();
            });
            let lastUpdateDate = printableItems[printableItems.length - 1].isoDate;
            console.log(`Setting last update marker on ${feedEntry.url} to ${lastUpdateDate}`);
            db.get("rssFeeds").find({ url: feedEntry.url}).assign({lastUpdate: lastUpdateDate}).write();
        }
    }
}

function isAuthorised(member) {
    if (db.get("editors.users").includes(member.id).value())
        return true;
    if (db.get("editors.roles").intersectionWith(member.roles.keyArray()).isEmpty().value())
        return false;
    return true;
}

const commands = {
    "make guide": msg => {
        if (!isAuthorised(msg.member)) return;
        let content = msg.content.substring(msg.content.indexOf("make guide") + "make guide ".length);
        let guideName = content.substring(0, content.indexOf("\n")).trim();
        let guideContent = content.substring(content.indexOf("\n")).trim();

        let guide = db.get("guides").find({ name: guideName });

        if (!guide.isUndefined().value()) {
            guide.assign({ content: guideContent }).write();
        } else {
            db.get("guides")
                .push({
                    name: guideName,
                    content: guideContent
                })
                .write();
        }

        msg.channel.send(
            `${msg.author.toString()} Added/updated "${guideName}"!`
        );
    },
    "delete guide": (msg, s) => {
        if (!isAuthorised(msg.member)) return;
        let guideName = s.substring("delete guide ".length).trim();
        let val = db.get("guides").find({ name: guideName });

        if (val.isUndefined().value()) {
            msg.channel.send(`${msg.author.toString()} No guide "${guideName}"!`);
            return;
        }

        db.get("guides")
            .remove({ name: guideName })
            .write();
        msg.channel.send(
            `${msg.author.toString()} Removed guide "${guideName}"!`
        );
    },
    "react to": (msg, s) => {
        if (!isAuthorised(msg.member)) return;
        const pattern = /^react to\s+"([^"]+)"\s+with\s+\<:[^:]+:([^\>]+)\>$/i;
        let contents = pattern.exec(s);
        if(contents != null) {
            let reactable = contents[1].trim().toLowerCase();
            let reactionEmoji = contents[2];
            if(!client.emojis.has(reactionEmoji)){
                msg.channel.send(`${msg.author.toString()} I cannot react with this emoji :(`);
                return;
            }
            db.get("messageReactions").set(reactable, reactionEmoji).write();
            msg.channel.send(`${msg.author.toString()} Added reaction!`);
        }
    },
    "remove reaction to": (msg, s) => {
        if (!isAuthorised(msg.member)) return;
        let content = s.substring("remove reaction to ".length).trim().toLowerCase();
        if(!db.get("messageReactions").has(content).value()) {
            msg.channel.send(`${msg.author.toString()} No such reaction available!`);
            return;
        }
        db.get("messageReactions").unset(content).write();
        msg.channel.send(`${msg.author.toString()} Removed reaction!`);
    },
    "reactions": msg => {
        let reactions = db.get("messageReactions").keys().value().reduce((p, c) => `${p}\n${c}`, "");
        msg.channel.send(`I'll react to the following messages:\n\`\`\`${reactions}\`\`\``);
    },
    "help": msg => {
        let guides = db
            .get("guides")
            .map(g => g.name)
            .reduce((p, c) => `${p}\n${c}`, "")
            .value();
        msg.channel.send(
            `Hello! I am NoctBot! I have answers for the most common C(O)M-related questions.\nJust ping me with one of the following keywords:\n\`\`\`${guides}\`\`\``
        );
    }
};

client.on("ready", () => {
    console.log("Ready!");
    client.user.setActivity("@NoctBot help", { type: "PLAYING" });
    interval(checkFeeds, RSS_UPDATE_INTERVAL_MIN * 60 * 1000);
});

client.on("message", m => {
    let imagesCount = m.attachments.filter(v => isImage(v.filename)).size;

    if(imagesCount > 0) {
        let now = new Date();
        fs.writeSync(statsFile, `${now.getUTCFullYear()}-${now.getUTCMonth()+1}-${now.getUTCDate()} ${now.getUTCHours()}:${now.getUTCMinutes()};${imagesCount}\n`);
    }

    if (m.author.id == client.user.id) return;

    let content = m.cleanContent.trim();
    let lowerContent = content.toLowerCase();
    if(db.get("messageReactions").has(lowerContent).value()) {
        m.react(client.emojis.get(db.get("messageReactions").get(lowerContent).value()));
        return;
    }

    if(m.mentions.users.size == 0)
        return;

    if (!db.get("reactableMentionedUsers").intersectionWith(m.mentions.users.map(u => u.id)).isEmpty().value()) {
        const emoteId = db
            .get("emotes")
            .get("angery")
            .randomElement()
            .value();
        m.react(client.emojis.find(e => e.id == emoteId));
        return;
    }

    if (m.mentions.users.first().id == client.user.id) {
        if(content.startsWith(`@${client.user.username}`)) {
            content = content
                .substring(`@${client.user.username} `.length);
            let lowerCaseContent = content.toLowerCase().trim();
            for (let c in commands) {
                if (lowerCaseContent.startsWith(c)) {
                    commands[c](m, content);
                    return;
                }
            }

            if (lowerCaseContent.length > 0) {
                let parts = lowerCaseContent.trim().split(" ");
                let guide = db
                    .get("guides")
                    .map(g => Object.assign({parts: g.name.toLowerCase().split(" ")}, g))
                    .sortBy(g => g.parts.length)
                    .maxBy(k => db._.intersection(parts, k.parts).length)
                    .value();
                let hits =
                    guide !== undefined &&
                    db._.intersection(guide.name.toLowerCase().split(" "), parts).length > 0;
                if (hits) {
                    m.channel.send(guide.content);
                    return;
                }
            }
        }

        let emoteType = "angery";
        if(db.get("specialUsers").includes(m.author.id).value())
            emoteType = "hug";
        else if(db.get("bigUsers").includes(m.author.id).value())
            emoteType = "big";
        else if(db.get("dedUsers").includes(m.author.id).value())
            emoteType = "ded";

        const id = db
            .get("emotes")
            .get(emoteType)
            .randomElement()
            .value();
        m.channel.send(client.emojis.find(e => e.id == id).toString());
    } else if (m.content.includes("Noct")) {
        m.channel.send(
            client.emojis.find(e => e.name == "mukuNeighWaaaaaa").toString()
        );
    }
});

client.on("messageReactionAdd", (r, u) => {
    if(Math.random() <= REACT_PROBABILITY && !r.me)
        r.message.react(r.emoji);
});

client.login(TOKEN);