#!/usr/bin/env node
//
// # Description
//
// Summarize the current page in a new tab, by processing it with the standalone readability
// library used for Firefox Reader View.
//
// # Prerequisites
//
// - Mozilla's readability library (npm install -g @mozilla/readability)
//     - Also available in the AUR as nodejs-readability-git
// - jsdom (npm install -g jsdom)
// - qutejs (npm install -g qutejs)
//
// - Ensure that node knows where to find your globally installed modules by adding
//   the following to ~/.profile or /etc/profile:
//     
//   export NODE_PATH=$NODE_PATH:$(npm root -g)
//
// *Note*: On some Linux distros and macOS, it may be easier to set NODE_PATH using qutebrowser's
// qt.environ setting. For instance, if 'npm root -g' returns /usr/lib/node_modules, then run:
//
//   :set qt.environ '{"NODE_PATH": "/usr/lib/node_modules"}'
//
// # Usage
//
// :spawn --userscript readability-js
//
// One may wish to define an easy to type command alias in qutebrowser's configuration file:
// c.aliases = {"readability" : "spawn --userscript readability-js", ...}

const { Readability } = require('@mozilla/readability');
const qute = require('qutejs');
const JSDOM = require('jsdom').JSDOM;
const fs = require('fs');
const path = require('path');
const util = require('util');

const HEADER = `
<!DOCTYPE html>
<html>
<head>
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <meta charset="UTF-8">
    <title>%s</title>
    <style type="text/css">
        body {
            margin: 30px auto;
            max-width: 650px;
            line-height: 1.4;
            padding: 0 10px;
        }
        h1, h2, h3 {
            line-height: 1.2;
        }
        h1.reader-title {
            font-size: 1.85em;
            line-height: 1.25em;
            width: 100%;
            margin: 0 0;
        }
        img {
            max-width:100%;
            height:auto;
        }
        p > img:only-child,
        p > a:only-child > img:only-child,
        .wp-caption img,
        figure img {
            display: block;
        }
        table,
        th,
        td {
            border: 1px solid grey;
            border-collapse: collapse;
            padding: 6px;
            vertical-align: top;
        }
        table {
            margin: 5px;
        }
        pre {
            padding: 16px;
            overflow: auto;
            line-height: 1.45;
            background-color: #dddddd;
        }
        code { 
            padding: .2em .4em;
            margin: 0;
            background-color: #dddddd;
        }
        pre > code {
            padding-right: 0;
            padding-left: 0;
        }
        blockquote {
            border-inline-start: 2px solid grey !important;
            padding: 0;
            padding-inline-start: 16px;
            margin-inline-start: 24px;
            border-radius: 5px;
        }
    </style>
    <!-- This icon is licensed under the Mozilla Public License 2.0 (available at: https://www.mozilla.org/en-US/MPL/2.0/).
    The original icon can be found here: https://dxr.mozilla.org/mozilla-central/source/browser/themes/shared/reader/readerMode.svg -->
    <link rel="shortcut icon" href="data:image/svg+xml;base64,PHN2ZyB3aWR0aD0iNjRweCIgaGVpZ2h0PSI2NHB4IiB2ZXJzaW9uPSIxLjEiI
    HZpZXdCb3g9IjAgMCA2NCA2NCIgeG1sbnM9Imh0dHA6Ly93d3cudzMub3JnLzIwMDAvc3ZnIj4KPGcgZmlsbD0iI2ZmZiI+CjxwYXRoIGQ9Im01MiAwaC00
    MGMtNC40MiAwLTggMy41OC04IDh2NDhjMCA0LjQyIDMuNTggOCA4IDhoNDBjNC40MiAwIDgtMy41OCA4LTh2LTQ4YzAtNC40Mi0zLjU4LTgtOC04em0wIDU
    yYzAgMi4yMS0xLjc5IDQtNCA0aC0zMmMtMi4yMSAwLTQtMS43OS00LTR2LTQwYzAtMi4yMSAxLjc5LTQgNC00aDMyYzIuMjEgMCA0IDEuNzkgNCA0em0tMT
    AtMzZoLTIwYy0xLjExIDAtMiAwLjg5NS0yIDJzMC44OTUgMiAyIDJoMjBjMS4xMSAwIDItMC44OTUgMi0ycy0wLjg5NS0yLTItMnptMCA4aC0yMGMtMS4xM
    SAwLTIgMC44OTUtMiAyczAuODk1IDIgMiAyaDIwYzEuMTEgMCAyLTAuODk1IDItMnMtMC44OTUtMi0yLTJ6bTAgOGgtMjBjLTEuMTEgMC0yIDAuODk1LTIg
    MnMwLjg5NSAyIDIgMmgyMGMxLjExIDAgMi0wLjg5NSAyLTJzLTAuODk1LTItMi0yem0tMTIgOGgtOGMtMS4xMSAwLTIgMC44OTUtMiAyczAuODk1IDIgMiA
    yaDhjMS4xMSAwIDItMC44OTUgMi0ycy0wLjg5NS0yLTItMnoiIGZpbGw9IiNmZmYiLz4KPC9nPgo8L3N2Zz4K"/>
</head>
<body class="qute-readability">
    <h1 class="reader-title">%s</h1>
    <div>From <a class="reader-title" href="%s">%s</a></div>
    <hr>
    %s
</body>
</html>
`;
const scriptsDir = path.join(process.env.QUTE_DATA_DIR, 'userscripts');
const tmpFile = path.join(scriptsDir, '/readability.html');

if (!fs.existsSync(scriptsDir)) {
    fs.mkdirSync(scriptsDir);
}

let getDOM, domOpts, target;
// When hinting, use the selected hint instead of the current page
if (process.env.QUTE_MODE === 'hints') {
    getDOM = JSDOM.fromURL;
    target = process.env.QUTE_URL;
}
else {
    getDOM = JSDOM.fromFile;
    domOpts = {url: process.env.QUTE_URL, contentType: "text/html; charset=utf-8"};
    target = process.env.QUTE_HTML;
}

getDOM(target, domOpts).then(dom => {
    let reader = new Readability(dom.window.document);
    let article = reader.parse();
    let subtitle = (article.siteName == null) ? new URL(process.env.QUTE_URL).hostname : article.siteName;
    let content = util.format(HEADER, article.title, article.title, process.env.QUTE_URL, subtitle, article.content);

    fs.writeFile(tmpFile, content, (err) => {
        if (err) {
            qute.messageError([`"${err}"`])
            return 1;
        }
        // Success
        qute.open(['-t', '-r', tmpFile]);
    })
});
