dbmedialab/reader-critics

//
// LESERKRITIKK v2 (aka Reader Critics)
// Copyright (C) 2017 DB Medialab/Aller Media AS, Oslo, Norway
// https://github.com/dbmedialab/reader-critics/
//
// This program is free software: you can redistribute it and/or modify it under
// the terms of the GNU General Public License as published by the Free Software
// Foundation, either version 3 of the License, or (at your option) any later
// version.
//
// This program is distributed in the hope that it will be useful, but WITHOUT
// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
// FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License along with
// this program. If not, see <http://www.gnu.org/licenses/>.
//

import * as Promise from 'bluebird';

import Article from 'base/Article';
import ArticleURL from 'base/ArticleURL';
import ParserFactory from 'base/ParserFactory';
import Website from 'base/Website';

import {
    articleService,
    parserService,
} from 'app/services';

import emptyCheck from 'app/util/emptyCheck';

import * as app from 'app/util/applib';

const log = app.createLog();

/**
 * @param website Needed to determine the parser for this article
 * @param url The source of the article
 */
export default function(website : Website, url : ArticleURL) : Promise <Article> {
    emptyCheck(website, url);

    let parserFactory : ParserFactory;
    let downloadURL : ArticleURL;
    let rawArticle : string;

    log('Initiating fetch of', url.toString());

    // TODO convert download url if custom parser needs to download from
    // a different location
    // Example LabradorParser, retrieve article ID from URL and create
    // URL for the JSON API:
    // ${labradorHost}/api/v1/article/${articleID}.json?content=full
    // So something like:
    // https://labrador.dagbladet.no/api/v1/article/12345678.json?content=full

    const parserPromise = parserService.getParserFor(website)
        .then((fact : ParserFactory) => parserFactory = fact);

    const fetchPromise = determineLocation(website, url)
        .then((realLocation : ArticleURL) => {
            downloadURL = realLocation;
            return articleService.download(downloadURL);
        })
        .then((data : string) => {
            rawArticle = data;
        });

    return Promise.all([parserPromise, fetchPromise])
    .then(() => parserFactory.newInstance(rawArticle, downloadURL).parse());
}

function determineLocation(website : Website, url : ArticleURL) : Promise <ArticleURL> {
    if (app.isTest) {
        // Shortcut: test URLs are shortened to refer to static local files in the repo.
        return Promise.resolve(url);
    }

    switch (website.parserClass) {
        case 'AMP Parser':
            return Promise.resolve(ArticleURL.from(`${url.toString()}/amp/`));
        case 'Nettavisen Parser':
            return Promise.resolve(ArticleURL.from(url.toString().
            replace(/m.nettavisen.no/, 'www.nettavisen.no')));
    }

    return Promise.resolve(url);
}