// ==UserScript==
// @name     Google Scholar Wiktionary Citation
// @version  1
// @grant    GM.xmlHttpRequest
// @require https://cdn.jsdelivr.net/npm/citation-js@0.5
// @include https://scholar.google.com/scholar?*
// ==/UserScript==
var Cite = require('citation-js');

function displayCitationScholar(id, data) {
    var target = document.getElementById(id).href;

    var popup = document.getElementById("gs_citd");
    var tool = document.getElementsByClassName('wikt-citation-tool');
    if (tool.length)
        tool[0].remove();

    var div = document.createElement('div');
    div.classList.add('wikt-citation-tool');
    popup.insertBefore(div, popup.firstChild);

    var subdiv1 = document.createElement('div');

    var textarea = document.createElement('textarea');
    textarea.setAttribute('rows', 10);
    textarea.setAttribute('cols', 50);

    var button = document.createElement('button');
    var buttonText = document.createTextNode("[minify]");
    button.appendChild(buttonText);
    button.onclick = minify;
    var crbutton = document.createElement('button');
    var crbuttonText = document.createTextNode("[check crossref; will overwrite]");
    crbutton.appendChild(crbuttonText);

    subdiv1.append(textarea);
    subdiv1.append(button);
    subdiv1.style.display = 'none';
    var subdiv2 = document.createElement('div');
    subdiv2.style.display = 'none';
    div.append(subdiv1);
    div.append(subdiv2);

    var title = data.title,
        containerTitle = data["container-title"];
    var volume = data.volume,
        issue = data.issue;
    var publisher = data.publisher;

    var isbn = data.ISBN,
        issn = data.ISSN,
        doi = data.DOI,
        pmid = data.PMID;
    var language = data.language;
    var page = data.page;
    var pageType = page && (page.includes("-") ? "pages" : "page");
    var result = document.getElementById(id).closest('.gs_or');
    var snippet = result && result.getElementsByClassName('gs_rs');
    snippet = snippet.length && snippet[0].textContent.replace(/\s*\n\s*/g, " ");

    var date = data.issued,
        dateType = "date";

    if (date && date["date-parts"]) {
        var parts = date["date-parts"][date["date-parts"].length - 1];
        var year = parts[0],
            month = parts[1],
            day = parts[2];

        if (month === undefined) date = "" + year, dateType = "year";
        else if (day === undefined) date = "" + year + "-" + ("0" + month).slice(-2);
        else date = "" + year + "-" + ("0" + month).slice(-2) + "-" + ("0" + day).slice(-2);
    }

    var journalTypes = ['article-journal', 'article-magazine', 'article-newspaper'];
    var template = "quote-book",
        container = "title",
        entry = "chapter";
    if (!containerTitle) entry = "title";

    var authorialFields = ["original-author", "author", "composer", "contributor", "director", "guest", "host", "illustrator", "interviewer", "narrator", "performer", "script-writer", "series-creator"];
    var editorialFields = ["container-author", "editor", "compiler", "chair", "collection-editor", "curator", "editorial-director", "editor-translator", "producer", "executive-producer", "organizer", "translator"];

    var f = function(x) {
        return x.literal || ((x.given || "") + " " + (x.family || "")).replace(/^\s+|\s+$/g, '');
    };

    var author = [];
    for (var i = 0; i < authorialFields.length; i++) {
        var field = authorialFields[i];
        if (field in data) {
            author = author.concat(data[field].map(f));
        }
    }

    var editor = [];
    for (var i = 0; i < editorialFields.length; i++) {
        var field = editorialFields[i];
        if (field in data) {
            editor = editor.concat(data[field].map(f));
        }
    }

    author = author.join(", "), editor = editor.join(", ");

    if (journalTypes.includes(data.type)) {
        template = "quote-journal", container = "journal", entry = "title";
    }

    var displayCitation = function(event) {
        subdiv1.style.display = 'block';
        subdiv2.style.display = 'none';
        var citation = "{{" + template + "|" + (language || "languagecode") +
            (target && ("\n|url=" + target) || "") +
            (title && ("\n|" + entry + "=" + title) || "") +
            (containerTitle && ("\n|" + container + "=" + containerTitle) || "") +
            (author && ("\n|author=" + author) || "") +
            (editor && ("\n|editor=" + editor) || "") +
            (publisher && ("\n|publisher=" + publisher) || "") +
            (isbn && ("\n|isbn=" + isbn) || "") +
            (issn && ("\n|issn=" + issn) || "") +
            (doi && ("\n|doi=" + doi) || "") +
            (pmid && ("\n|pmid=" + pmid) || "") +
            (date && ("\n|" + dateType + "=" + date) || "") +
            (volume && ("\n|volume=" + volume) || "") +
            (issue && ("\n|issue=" + issue) || "") +
            (page && ("\n|" + pageType + "=" + page) || "") +
            (snippet && ("\n|passage=" + snippet) || "") +
            (snippet && language && (language != "en") && "\n|t=" || "") +
            "\n}}";
        textarea.value = citation;
    };

    displayCitation();

    var crossrefCheck = function() {
        GM.xmlHttpRequest({
            method: "GET",
            url: "https://api.crossref.org/works?rows=2&query.bibliographic=" + encodeURIComponent(document.getElementsByClassName('gs_citr')[0].textContent),
            onload: function(response) {
                crbutton.style.display = 'none';
                var results = JSON.parse(response.responseText);
                var items = results.message.items;
                if (items.length) {
                    subdiv1.style.display = 'none';
                    subdiv2.style.display = 'block';
                    var p = document.createElement('p');
                    p.innerText = "Check carefully. If any of these is the *exact same* publication/work, select it (there may be duplicates; do *not* select reviews):";
                    subdiv2.append(p);

                    for (var i = 0; i < items.length; i++) {
                        var c = new Cite(items[i]);
                        var itemdiv = document.createElement('div');
                        var input = document.createElement('input');
                        input.setAttribute('name', 'crossref');
                        input.setAttribute('type', 'radio');
                        input.setAttribute('value', 'crossref' + i);
                        input.setAttribute('id', 'crossref' + i);
                        var label = document.createElement('label');
                        label.setAttribute('for', 'crossref' + i);
                        label.innerText = c.get({
                            'format': 'string',
                            'lang': 'en',
                            'style': 'citation-apa',
                            'type': 'string'
                        });
                        itemdiv.append(input);
                        itemdiv.append(label);
                        subdiv2.append(itemdiv);
                    }

                    var button1 = document.createElement('button');
                    var button2 = document.createElement('button');
                    button1.innerText = 'select';
                    button2.innerText = 'none match';
                    subdiv2.append(button1);
                    subdiv2.append(button2);
                    subdiv2.append(document.createElement('hr'));
                    button1.onclick = function() {
                        var selected = +document.querySelector('input[name="crossref"]:checked').value.slice(-1);
                        pmid = items[selected].PMID;
                        doi = items[selected].DOI;
                        language = items[selected].language;
                        displayCitation();
                    }
                    button2.onclick = displayCitation;
                } else displayCitation();
            }
        });
    };
    crbutton.onclick = crossrefCheck;
    subdiv1.append(crbutton);
    subdiv1.append(document.createElement('hr'));
}

var observer = new MutationObserver(function(mutations) {
    mutations.forEach(function(mutation) {
        if (!mutation.addedNodes) return;

        for (var i = 0; i < mutation.addedNodes.length; i++) {
            var node = mutation.addedNodes[i];

            if (node.id == 'gs_citi') {
                for (var j = 0; j < node.childNodes.length; j++) {
                    var subnode = node.childNodes[j];

                    if (subnode.textContent == "RefMan") {
                        var url = subnode.href;
                        var id = /q=info:(.*?):/.exec(url)[1];

                        GM.xmlHttpRequest({
                            method: "GET",
                            url: url,
                            onload: function(response) {
                                var cite = new Cite(response.responseText);
                                displayCitationScholar(id, cite.data[0]);
                            }
                        });
                    }
                }
            }
        }
    });
})

observer.observe(document.body, {
    childList: true,
    subtree: true,
    attributes: false,
    characterData: false
});

function minify() {
    var textarea = this.parentNode.getElementsByTagName('textarea')[0];
    textarea.value = textarea.value.replace(/\n/g, "");
}