import { writeFile, readFile } from "fs/promises";
import { rankCalc } from "./rank.js";
import * as cheerio from 'cheerio';

let cache = {};
let site = process.env.site || 'darflen';
let route = process.env.route || './test.txt';
let pageLimit = process.env.pageLimit || Infinity;
let blacklist = (process.env.blacklist + '').split(',') || [];
let greylist = (process.env.greylist + '').split(',') || [];
let hh;
let percent = 0;
let d = process.env.depth || 1;

async function urlCollector(url, path, file, useLimit, data2) {
    let urls = data2[url] ? (data2[url][path] || []) : [];
    urls = [...urls];
    if (path != 'following') return urls;

    let data;
    try {
        data = await fetch(url);
        data = await data.text();
        console.log(`User ${url} was fetched`);
    } catch (err) {
        console.warn(`User ${url} did not fetch`);
        return urls;
    }

    let body = cheerio.load(data);
    let links = body('a');
    let ll = urls.length;
    links.each(function (i, link) {
        if (useLimit && urls.length >= pageLimit * 40 + ll) {
            return false;
        }
        let h = body(link).attr('href');
        if (!h) return true;
        h = h.trim();
        if (h.startsWith('./') || h.startsWith('../') || h.startsWith('/')) {
            let u = new URL(url);
            u.pathname = h;
            h = u.toString();
        }
        let h2;
        try {
            h2 = new URL(h);
        } catch (err) {
            
        }
        if (!h2) return true;
        for (let g of greylist) {
            if (h2.toString().includes(g) && g != '') return true;
        }
        if (blacklist.indexOf(h2.toString()) != -1) return true;
        urls.push(h2.toString());
        urls = [...new Set(urls)];
        console.log(`User ${url} has ${urls.length} pages calculated`);
        return true;
    })

    let h3;
    try {
        h3 = new URL(new URL(url).origin);
    } catch (err) {

    }
    urls.push(h3.toString())
    if (!data2[url]) data2[url] = { following: [], followers: [] };
    data2[url][path] = [...new Set(urls)];

    return data2[url][path];
}

async function rounder(users, data, mode) {
    let p = [];
    let congested = [];
    let timeout = false;

    let pr = new Promise(resolve => setTimeout(function (...ag) {
        timeout = true;
        resolve(ag);
    }, (process.env.delay * 1000) || (60 * 1000)))

    let ul = 0;
    for (let u of users) {
        let it = 0;
        while (p.length >= (process.env.maxRate || 15)) {
            p = p.filter(x => x != 'hi');
            if (p.length == 0) break;
            let pv = await Promise.any([...p, pr]);

            if (timeout) {
                console.warn(`Somehow, this is stuck.`);
                break;
            }
            it++;
            if (it > 10) {
                console.warn(`Promises got congested. Moving to another array...`)
                congested = congested.concat(p);
                p = [];
                break;
            }
        }
        if (timeout) break;
        if (!data[u]) data[u] = { followers: [], following: [] };
        p.push(async function (k) {
            await siteCollector(u, 'followers', site, mode, data);
            
            percent += 50 / d / users.length;
            console.log(`User ${u} followers is fully calculated (${percent}% total)`);

            p[k] = 'hi';
        }(p.length));

        p.push(async function (k) {
            await siteCollector(u, 'following', site, mode, data);

            percent += 50 / d / users.length;
            console.log(`User ${u} following is fully calculated (${percent}% total)`);

            p[k] = 'hi';
        }(p.length));
    }

    if (!timeout) {
        p = p.concat(congested);
        await Promise.all(p);
    } else {
        console.warn('Took too long...')
    }

    let endn = [...users];
    let oldLength = endn.length;
    for (let h in data) {
        endn.push(h);
        if (endn.length > oldLength * 1.25 ) {
            endn = [...new Set(endn)];
        }
    }
    //let fcg = ((a, b) => ((data[a] ? -data[a].followers.length : 0) - (data[b] ? -data[b].followers.length : 0)));
    //endn = endn.sort(fcg);

    return endn;
}

async function textCollector(word, path, file) {
    if (!hh) hh = await readFile(file, 'utf8');

    hh = hh.toLowerCase();

    let words = hh.split(/[\n.]+/g).filter(x => word.length == 0 || ` ${x} `.includes(` ${word} `));
    words = words.join(' ').split(/[^a-zA-Z0-9']+/g);
    words = [...new Set(words)];

    if (!data2[word]) data2[word] = { following: [], followers: [] };
    data2[word][path] = words;
    return words;
}

async function siteCollector(user, path, site, useLimit, data2) {
    let users = [];
    let urls = data2[user] ? (data2[user][path] || []) : [];
    let ul = urls.length;
    let i = 1 + (ul || 0);
    let out = [];

    if (site == 'file') {
        return await textCollector(user, path, route, data2);
    }

    if (site == 'url') {
        return await urlCollector(user, path, route, useLimit, data2);
    }

    while (true) {
        let p;

        if (site == 'darflen') {
            p = `https://api.darflen.com/users/${user}/${path}/${i}`;
        } else if (site == 'scratch') {
            p = `https://api.scratch.mit.edu/users/${user}/${path}/?limit=40&offset=${(i - 1) * 40}`;
        } else {
            throw 'That site is not supported.';
        }

        let j1 = cache[p];
        if (!j1) {
            let h1 = await fetch(p);
            try {
                j1 = await h1.json();
            } catch (err) {
                j1 = [];
            }
        }
        cache[p] = j1;

        if (!j1 || ((i - ul - 1) >= pageLimit && useLimit)) break;

        let users2;
        try {
            if (site == 'darflen') {
                users2 = j1[path].map(x => x.profile.username);
            } else if (site == 'scratch') {
                users2 = j1.map(x => x.username);
            }
        } catch (err) {
            users2 = [];
        }

        users.push(users2);

        if (users2.length == 0) break;

        i++;

        console.log(`User ${user} has ${i} pages calculated`);
    }
    out = out.concat(...users);
    if (useLimit) {
        out.length = Math.min(out.length, pageLimit * 40);
    }

    if (!data2[user]) data2[user] = { following: [], followers: [] };
    data2[user][path] = out;
    return out;
}

(async function () {
    let penv = process.env.user || 'paradock';
    penv = penv.split(',');

    let users = [];
    let data = {};

    users = await rounder(penv, data, false);

    users = [...new Set(users)];

    let dat;
    for (let i = 0; i < d; i++) {
        if (i != 0) {
            let tempSet = dat.map(x => x[0]);
            users = tempSet.concat(await rounder(tempSet, data, true));
            users = [...new Set(users)];
        }
        for (let uf of users) {
            let u = data[uf];
            if (!u) {
                data[uf] = {following: [], followers: []}
            }
            let { following, followers } = u;
            if (!following || !followers) continue;

            try {
                if (site == 'url') {
                    let o = new URL(new URL(uf).origin).toString();

                    if (followers.indexOf(o) == -1) {
                        followers.push(o)
                    }
                }
            } catch (err) {
            }

            for (let f of followers) {
                if (!data[f]) data[f] = { followers: [] };
                if (!data[f].following) data[f].following = [];
                if (data[f].following.indexOf(uf) == -1) {
                    data[f].following.push(uf);
                }
            }
            for (let f of following) {
                if (!data[f]) data[f] = { following: [] };
                if (!data[f].followers) data[f].followers = [];
                if (data[f].followers.indexOf(uf) == -1) {
                    data[f].followers.push(uf);
                }
            }
        }
        console.log(`Graph is fully repaired`);
        dat = Object.entries(rankCalc(data, (i == d - 1) ? process.env.matrixIterations : 3, penv, site == 'url'));
        dat = dat.sort((a, b) => b[1] - a[1]);  
        console.log(`Graph is calculated with ${dat.length} entries`);  
        let dat2 = {};
        for (let d of dat) {
            dat2[d[0]] = d[1] * 100 + "%";
        }
    
        let srz = JSON.stringify(dat2);
        let ff = `./users_${i}.json`;
        await writeFile(ff, srz, 'utf8');
        console.log(`Temporary file ${ff} is written`);
    }

    console.log(`Graph is complete (${Object.keys(users).length} entries)`);
    
})()