'use strict';

const { JSDOM } = require('jsdom');
const moment = require('moment');
const http = require('./http');

function trim(str) {
    if (!str) return null;
    return str.trim().replace(/\s+/g, ' ');
}

function extractDate(dateString, format, match) {
    if (match) {
        const dateStamp = trim(dateString).match(match);

        if (dateStamp) {
            const date = moment.utc(dateStamp[0], format);

            return date.isValid() ? date.toDate() : null;
        }
        return null;
    }

    const date = moment.utc(trim(dateString), format);

    return date.isValid() ? date.toDate() : null;
}

function formatDate(date, format, inputFormat) {
    if (inputFormat) return moment(date, inputFormat).format(format);

    return moment(date).format(format);
}

function prefixProtocol(url, protocol = 'https') {
    if (protocol && /^\/\//.test(url)) {
        return `${protocol}:${url}`;
    }

    return url;
}

function q(context, selector, attrArg, applyTrim = true) {
    const attr = attrArg === true ? 'textContent' : attrArg;

    if (attr) {
        const value = selector
            ? context.querySelector(selector)?.[attr] || context.querySelector(selector)?.attributes[attr]?.value
            : context[attr] || context[attr]?.attributes[attr]?.value;

        return applyTrim && value ? trim(value) : value;
    }

    return selector ? context.querySelector(selector) : context;
}

function qall(context, selector, attrArg, applyTrim = true) {
    const attr = attrArg === true ? 'textContent' : attrArg;

    if (attr) {
        return Array.from(context.querySelectorAll(selector), el => (applyTrim && el[attr] ? trim(el[attr]) : el[attr]));
    }

    return Array.from(context.querySelectorAll(selector));
}

function qhtml(context, selector) {
    const el = q(context, selector, null, true);

    return el && el.innerHTML;
}

function qtexts(context, selector, applyTrim = true, filter = true) {
    const el = q(context, selector, null, applyTrim);
    if (!el) return null;

    const nodes = Array.from(el.childNodes)
        .filter(node => node.nodeName === '#text')
        .map(node => (applyTrim ? trim(node.textContent) : node.textContent));

    return filter ? nodes.filter(Boolean) : nodes;
}

function qtext(context, selector, applyTrim = true) {
    const nodes = qtexts(context, selector, applyTrim, true);
    if (!nodes) return null;

    const text = nodes.join(' ');

    return applyTrim ? trim(text) : text;
}

function qmeta(context, selector, attrArg = 'content', applyTrim = true) {
    if (/meta\[.*\]/.test(selector)) {
        return q(context, selector, attrArg, applyTrim);
    }

    return q(context, `meta[${selector}]`, attrArg, applyTrim);
}

function qdate(context, selector, format, match, attr = 'textContent') {
    const dateString = q(context, selector, attr, true);

    if (!dateString) return null;

    return extractDate(dateString, format, match);
}

function qimage(context, selector = 'img', attr = 'src', protocol = 'https') {
    const image = q(context, selector, attr);

    // no attribute means q output will be HTML element
    return attr ? prefixProtocol(image, protocol) : image;
}

function qimages(context, selector = 'img', attr = 'src', protocol = 'https') {
    const images = qall(context, selector, attr);

    return attr ? images.map(image => prefixProtocol(image, protocol)) : images;
}

function qurl(context, selector = 'a', attr = 'href', protocol = 'https') {
    const url = q(context, selector, attr);

    return attr ? prefixProtocol(url, protocol) : url;
}

function qurls(context, selector = 'a', attr = 'href', protocol = 'https') {
    const urls = qall(context, selector, attr);

    return attr ? urls.map(url => prefixProtocol(url, protocol)) : urls;
}

function qposter(context, selector = 'video', attr = 'poster', protocol = 'https') {
    const poster = q(context, selector, attr);

    return attr ? prefixProtocol(poster, protocol) : poster;
}

function qtrailer(context, selector = 'source', attr = 'src', protocol = 'https') {
    const trailer = q(context, selector, attr);

    return attr ? prefixProtocol(trailer, protocol) : trailer;
}

function qtrailers(context, selector = 'source', attr = 'src', protocol = 'https') {
    const trailers = qall(context, selector, attr);

    return attr ? trailers.map(trailer => prefixProtocol(trailer, protocol)) : trailers;
}

function qlength(context, selector, match, attr = 'textContent') {
    const durationString = q(context, selector, attr);

    if (!durationString) return null;
    const duration = durationString.match(match || /(\d+:)?\d+:\d+/);

    if (duration) {
        const segments = ['00'].concat(duration[0].split(':')).slice(-3);

        return moment.duration(segments.join(':')).asSeconds();
    }

    return null;
}

const funcs = {
    q,
    qa: qall,
    qall,
    qd: qdate,
    qdate,
    qh: qhtml,
    qhtml,
    qi: qimage,
    qimage,
    qimages,
    qis: qimages,
    ql: qlength,
    qlength,
    qm: qmeta,
    qmeta,
    qp: qposter,
    qposter,
    qs: qall,
    qt: qtrailer,
    qtext,
    qtexts,
    qtrailer,
    qtrailers,
    qts: qtrailers,
    qtx: qtext,
    qtxs: qtexts,
    qtxt: qtext,
    qtxts: qtexts,
    qu: qurl,
    qurl,
    qurls,
    qus: qurls,
};

function init(element, window) {
    if (!element) return null;

    const contextFuncs = Object.entries(funcs) // dynamically attach methods with context
        .reduce((acc, [key, func]) => ({
            ...acc,
            [key]: (...args) => (window && args[0] instanceof window.HTMLElement // allow for different context
                ? func(...args)
                : func(element, ...args)),
        }), {});

    return {
        element,
        el: element,
        html: element.outerHTML || element.body.outerHTML,
        text: trim(element.textContent),
        ...(window && {
            window,
            document: window.document,
        }),
        ...contextFuncs,
    };
}

function initAll(context, selector, window) {
    if (Array.isArray(context)) {
        return context.map(element => init(element, window));
    }

    return Array.from(context.querySelectorAll(selector))
        .map(element => init(element, window));
}

function extract(html, selector) {
    const { window } = new JSDOM(html);

    if (selector) {
        return init(window.document.querySelector(selector), window);
    }

    return init(window.document, window);
}

function extractAll(html, selector) {
    const { window } = new JSDOM(html);

    return initAll(window.document, selector, window);
}

async function get(url, selector, headers, all = false) {
    const res = await http.get(url, {
        headers,
    });

    if (res.statusCode === 200) {
        const item = all
            ? extractAll(res.body.toString(), selector)
            : extract(res.body.toString(), selector);

        return {
            item,
            items: all ? item : [item],
            res,
            ok: true,
            status: res.statusCode,
        };
    }

    return {
        item: null,
        items: [],
        res,
        ok: false,
        status: res.statusCode,
    };
}

async function getAll(url, selector, headers) {
    return get(url, selector, headers, true);
}

module.exports = {
    extractDate,
    extract,
    extractAll,
    init,
    initAll,
    formatDate,
    get,
    getAll,
    context: init,
    contextAll: initAll,
    ed: extractDate,
    ex: extract,
    exa: extractAll,
    fd: formatDate,
    ctx: init,
    ctxa: initAll,
    geta: getAll,
    edate: extractDate,
    fdate: formatDate,
    ...funcs,
};