#!/usr/bin/env node
'use strict';

var fs = require('fs');
var https = require('https');
var { URL } = require('url');

var slug = process.argv[2];

if(typeof slug === 'undefined') {
    console.log('Usage: snatch-catalog.js <board-name>');
    return;
}

function get(url, callback) {
    https.request(new URL(url), res => {
        var data = Buffer.from([]);

        res.on('data', chunk => {
            data = Buffer.concat([data, chunk]);
        });

        res.on('end', () => {
            if(callback) callback(data);
        });
    }).end();
}

get('https://8ch.net/' + slug + '/catalog.html', data => {
    fs.mkdir(slug, err => {
        var m;
        var r = /class="thread.*?href="(.*?\.html)"/g;
        while((m = r.exec(data)) !== null) {
            if(m.index === r.lastIndex) r.lastIndex++;
            const board_url = 'https://8ch.net' + m[1];
            get(board_url, data => {
                var m;
                var r = /postfilename">(.+?)<\/span>.+?href="(.+?)" target="_blank"/g;

                while((m = r.exec(data)) !== null) {
                    if(m.index === r.lastIndex) r.lastIndex++;

                    const file_name = m[1];
                    const file_url = m[2];

                    console.log('Downloading ' + file_name + '...');

                    get(file_url, data => {
                        fs.writeFile(slug + '/' + file_name, data, err => {
                            if(err) console.error(err);
                        });
                    });
                }
            });
        }
    });
});