import infoboxParser from 'infobox-parser';
import { tokenize, constructTree } from 'hyntax';
import { aggregatePagination, pagination, api, parseContent } from './util.js';
import { parseCoordinates } from './coordinates.js';
import QueryChain from './chain.js';
const get = (obj, first, ...rest) => {
    if (obj === undefined || first === undefined)
        return obj;
    if (typeof first === 'function') {
        return get(first(obj), ...rest);
    }
    return get(obj[first], ...rest);
};
const firstValue = obj => {
    if (typeof obj === 'object')
        return obj[Object.keys(obj)[0]];
    return obj[0];
};
const getFileName = text => {
    if (Array.isArray(text))
        text = text[0];
    if (!text)
        return undefined;
    if (text.indexOf(':') !== -1) {
        const [, name] = text.split(':');
        return name;
    }
    return text;
};
/**
 * WikiPage
 * @namespace WikiPage
 */
export default function wikiPage(rawPageInfo, apiOptions) {
    const raw = rawPageInfo;
    /**
     * HTML from page
     * @example
     * wiki.page('batman').then(page => page.html()).then(console.log);
     * @method WikiPage#html
     * @return {Promise}
     */
    function html() {
        return api(apiOptions, {
            prop: 'revisions',
            rvprop: 'content',
            rvlimit: 1,
            rvparse: '',
            titles: raw.title
        }).then(res => res.query.pages[raw.pageid].revisions[0]['*']);
    }
    /**
     * @summary Useful for extracting structured section content from the page
     * @alias sections
     * @example
     * wiki.page('batman').then(page => page.content()).then(console.log);
     * @method WikiPage#content
     * @return {Promise}
     */
    function content() {
        return rawContent().then(parseContent);
    }
    /**
     * Raw content from page
     * @example
     * wiki.page('batman').then(page => page.rawContent()).then(console.log);
     * @method WikiPage#rawContent
     * @return {Promise}
     */
    function rawContent() {
        return chain()
            .content()
            .request()
            .then(res => res.extract);
    }
    /**
     * Text summary from page
     * @example
     * wiki.page('batman').then(page => page.summary()).then(console.log);
     * @method WikiPage#summary
     * @return {Promise}
     */
    function summary() {
        return chain()
            .summary()
            .request()
            .then(res => res.extract);
    }
    /**
     * Main page image directly from API
     * @method WikiPage#pageImage
     * @returns URL
     */
    function pageImage() {
        return chain()
            .image({ original: true, name: true })
            .request()
            .then(res => get(res, 'image', 'original', 'source'));
    }
    /**
     * Raw data from images from page
     * @example
     * wiki.page('batman').then(page => page.rawImages()).then(console.log);
     * @method WikiPage#rawImages
     * @return {Promise}
     */
    function rawImages() {
        return api(apiOptions, {
            generator: 'images',
            gimlimit: 'max',
            prop: 'imageinfo',
            iiprop: 'url',
            titles: raw.title
        }).then(res => {
            if (res.query) {
                return Object.keys(res.query.pages).map(id => res.query.pages[id]);
            }
            return [];
        });
    }
    /**
     * Main image URL from infobox on page
     * @example
     * wiki.page('batman').then(page => page.mainImage()).then(console.log);
     * @method WikiPage#mainImage
     * @return {Promise}
     */
    function mainImage() {
        return Promise.all([rawImages(), info()]).then(([images, info]) => {
            // Handle different translations of "image" here
            const mainImageName = getFileName(info.image ||
                info.bildname ||
                info.imagen ||
                info.Immagine ||
                info.badge ||
                info.logo);
            // Handle case where no info box exists
            if (!mainImageName) {
                return rawInfo().then(text => {
                    if (!images.length)
                        return undefined;
                    // Sort images by what is seen first in page's info text
                    images.sort((a, b) => text.indexOf(b.title) - text.indexOf(a.title));
                    const image = images[0];
                    const fallback = image && image.imageinfo.length > 0
                        ? image.imageinfo[0].url
                        : undefined;
                    // If no image could be found, fallback to page image api result
                    return pageImage().then(url => url || fallback);
                });
            }
            const image = images.find(({ title }) => {
                const filename = getFileName(title);
                // Some wikis use underscores for spaces, some don't
                return (filename.toUpperCase() === mainImageName.toUpperCase() ||
                    filename.replace(/\s/g, '_') === mainImageName);
            });
            const fallback = image && image.imageinfo.length > 0
                ? image.imageinfo[0].url
                : undefined;
            // If no image could be found, fallback to page image api result
            return pageImage().then(url => url || fallback);
        });
    }
    /**
     * Image URL's from page
     * @example
     * wiki.page('batman').then(page => page.image()).then(console.log);
     * @method WikiPage#images
     * @return {Promise}
     */
    function images() {
        return rawImages().then(images => {
            return images
                .map(image => image.imageinfo)
                .reduce((imageInfos, list) => [...imageInfos, ...list], [])
                .map(info => info.url);
        });
    }
    /**
     * External links from page
     * @example
     * wiki().page('batman').then(page => page.externalLinks()).then(console.log);
     * // or
     * wiki().chain().search('batman').extlinks().request()
     * @method WikiPage#externalLinks
     * @return {Promise}
     */
    function externalLinks() {
        return chain().direct('extlinks');
    }
    function hasClass(node, className) {
        return (node.content.attributes &&
            node.content.attributes.some(attr => attr.key.content === 'class' &&
                attr.value.content.indexOf(className) !== -1));
    }
    function isTag(node) {
        return node.nodeType === 'tag';
    }
    function hasName(node, name) {
        return node.content.name === name;
    }
    function findNode(node, predicate) {
        if (predicate(node))
            return node;
        // search through children as well
        if (node.content.children) {
            for (let child of node.content.children) {
                const found = findNode(child, predicate);
                if (found) {
                    return found;
                }
            }
        }
        return null;
    }
    function findNodes(node, predicate, nodes) {
        if (predicate(node)) {
            nodes.push(node);
        }
        if (node.content.children) {
            for (let child of node.content.children) {
                findNodes(child, predicate, nodes);
            }
        }
    }
    /**
     * References from page
     * @example
     * wiki().page('batman').then(page => page.references()).then(console.log);
     * @method WikiPage#references
     * @return {Promise}
     */
    function references() {
        return html()
            .then(inputHTML => {
            const { tokens } = tokenize(inputHTML);
            const { ast } = constructTree(tokens);
            return ast;
        })
            .then(ast => {
            const links = [];
            const refs = [];
            // There can be mulitple reference sections
            findNodes(ast, node => isTag(node) && hasName(node, 'ol') && hasClass(node, 'references'), refs);
            for (let ref of refs) {
                const items = ref.content.children.filter(el => isTag(el) && hasName(el, 'li') && el.content.children);
                for (let item of items) {
                    // The reference was moved under a span under li
                    const span = item.content.children[2];
                    const cite = findNode(span, node => isTag(node) && hasName(node, 'cite'));
                    if (cite) {
                        for (let el of cite.content.children) {
                            if (isTag(el) && hasName(el, 'a') && hasClass(el, 'external')) {
                                const linkAttr = el.content.attributes.find(attr => attr.key.content === 'href');
                                links.push(linkAttr.value.content);
                            }
                        }
                    }
                }
            }
            return links;
        });
    }
    /**
     * Paginated links from page
     * @example
     * wiki().page('batman').then(page => page.links()).then(console.log);
     * @method WikiPage#links
     * @param  {Boolean} [aggregated] - return all links (default is true)
     * @param  {Number} [limit] - number of links per page
     * @return {Promise} - returns results if aggregated [and next function for more results if not aggregated]
     */
    function links(aggregated = true, limit = 100) {
        const _pagination = pagination(apiOptions, {
            prop: 'links',
            plnamespace: 0,
            pllimit: limit,
            titles: raw.title
        }, res => (res.query.pages[raw.pageid].links || []).map(link => link.title));
        if (aggregated) {
            return aggregatePagination(_pagination);
        }
        return _pagination;
    }
    /**
     * Paginated categories from page
     * @example
     * wiki().page('batman').then(page => page.categories()).then(console.log);
     * @method WikiPage#categories
     * @param  {Boolean} [aggregated] - return all categories (default is true)
     * @param  {Number} [limit] - number of categories per page
     * @return {Promise} - returns results if aggregated [and next function for more results if not aggregated]
     */
    function categories(aggregated = true, limit = 100) {
        const _pagination = pagination(apiOptions, chain()
            .categories(limit)
            .params(), res => (res.query.pages[raw.pageid].categories || []).map(category => category.title));
        if (aggregated) {
            return aggregatePagination(_pagination);
        }
        return _pagination;
    }
    /**
     * Geographical coordinates from page
     * @example
     * wiki().page('Texas').then(texas => texas.coordinates())
     * @method WikiPage#coordinates
     * @return {Promise}
     */
    function coordinates() {
        return chain()
            .direct('coordinates')
            .then(coords => {
            if (coords)
                return coords;
            // No coordinates for this page, check infobox for deprecated version
            return info().then(data => parseCoordinates(data));
        });
    }
    function rawInfo(title) {
        return api(apiOptions, {
            prop: 'revisions',
            rvprop: 'content',
            rvsection: 0,
            titles: title || raw.title
        }).then(res => get(res, 'query', 'pages', firstValue, 'revisions', 0, '*'));
    }
    /**
     * Fetch and parse tables within page
     * @method WikiPage#tables
     * @return {Promise} Resolves to a collection of tables
     */
    function tables() {
        return api(apiOptions, {
            prop: 'revisions',
            rvprop: 'content',
            titles: raw.title
        })
            .then(res => get(res, 'query', 'pages', firstValue, 'revisions', 0, '*'))
            .then(wikitext => infoboxParser(wikitext, apiOptions.parser).tables);
    }
    /**
     * Get general information from page, with optional specifc property
     * @deprecated This method will be dropped and replaced with the `fullInfo` implementation in v5
     * @example
     * wiki().page('Batman').then(page => page.info('alter_ego'));
     * @method WikiPage#info
     * @param  {String} [key] - Information key. Falsy keys are ignored
     * @return {Promise} - info Object contains key/value pairs of infobox data, or specific value if key given
     */
    function info(key) {
        return rawInfo()
            .then(wikitext => {
            // Use general data for now...
            const info = infoboxParser(wikitext, apiOptions.parser).general;
            if (Object.keys(info).length === 0) {
                // If empty, check to see if this page has a templated infobox
                return rawInfo(`Template:Infobox ${raw.title.toLowerCase()}`).then(_wikitext => infoboxParser(_wikitext || '', apiOptions.parser).general);
            }
            return info;
        })
            .then(metadata => {
            if (!key) {
                return metadata;
            }
            if (metadata.hasOwnProperty(key)) {
                return metadata[key];
            }
        });
    }
    /**
     * Get the full infobox data, parsed in a easy to use manner
     * @example
     * new Wiki().page('Batman').then(page => page.fullInfo()).then(info => info.general.aliases);
     * @method WikiPage#fullInfo
     * @return {Promise} - Parsed object of all infobox data
     */
    function fullInfo() {
        return rawInfo().then(wikitext => infoboxParser(wikitext, apiOptions.parser));
    }
    /**
     * Paginated backlinks from page
     * @method WikiPage#backlinks
     * @param  {Boolean} [aggregated] - return all backlinks (default is true)
     * @param  {Number} [limit] - number of backlinks per page
     * @return {Promise} - includes results [and next function for more results if not aggregated]
     */
    function backlinks(aggregated = true, limit = 100) {
        const _pagination = pagination(apiOptions, {
            list: 'backlinks',
            bllimit: limit,
            bltitle: raw.title
        }, res => (res.query.backlinks || []).map(link => link.title));
        if (aggregated) {
            return aggregatePagination(_pagination);
        }
        return _pagination;
    }
    /**
     * Get list of links to different translations
     * @method WikiPage#langlinks
     * @return {Promise} - includes link objects { lang, title, url }
     */
    function langlinks() {
        return chain().direct('langlinks');
    }
    /**
     * Get URL for wiki page
     * @method WikiPage#url
     * @return {String}
     */
    function url() {
        return raw.canonicalurl;
    }
    const page = Object.assign({}, raw);
    /**
     * Returns a QueryChain for the page
     * @method WikiPage#chain
     * @returns {QueryChain}
     */
    function chain() {
        return new QueryChain(apiOptions, raw.pageid);
    }
    Object.assign(page, {
        raw,
        html,
        rawContent,
        content,
        sections: content,
        summary,
        images,
        references,
        links,
        externalLinks,
        categories,
        coordinates,
        info,
        backlinks,
        rawImages,
        mainImage,
        langlinks,
        rawInfo,
        fullInfo,
        pageImage,
        tables,
        url,
        chain
    });
    return page;
}