/* eslint-disable @typescript-eslint/no-unsafe-enum-comparison */
import { isHTMLTag, isMathMLTag, isSVGTag } from '@vue/shared';
import { load } from 'cheerio';
import matter from 'gray-matter';
import { isLinkHttp, removeEndingSlash } from 'vuepress/shared';
import { isArray, isLinkAbsolute, startsWith } from '../../shared/index.js';
const HEADING_TAGS = ['h1', 'h2', 'h3', 'h4', 'h5', 'h6'];
const handleNode = (node, { base, isCustomElement, keepFenceDom }) => {
    if (node.type === 'tag') {
        // image using relative urls shall be dropped
        if (node.tagName === 'img') {
            const { src } = node.attribs;
            // this is not a resolvable image link
            if (!isLinkHttp(src) && !isLinkAbsolute(src))
                return null;
        }
        // toc should be dropped
        if ([node.attribs.class, node.attribs.id].some((item) => ['table-of-contents', 'toc'].includes(item)))
            return null;
        // standard tags can be returned
        if (isHTMLTag(node.tagName) ||
            isSVGTag(node.tagName) ||
            isMathMLTag(node.tagName)) {
            // handing heading tags
            if (HEADING_TAGS.includes(node.tagName)) {
                // remove heading id tabindex
                delete node.attribs.id;
                delete node.attribs.tabindex;
                // extract heading tags and remove anchor
                if (node.children.length === 1 &&
                    node.children[0].type === 'tag' &&
                    node.children[0].tagName === 'a' &&
                    node.children[0].attribs.class === 'header-anchor')
                    node.children = node.children[0].children[0].children;
            }
            if (node.tagName === 'div' &&
                startsWith(node.attribs.class, 'language-')) {
                const pre = node.children.find((childNode) => childNode.type === 'tag' &&
                    childNode.tagName === 'pre' &&
                    startsWith(childNode.attribs.class, 'language-'));
                if (
                // we are sure this is a code fence
                pre &&
                    !keepFenceDom) {
                    node.attribs.class = node.attribs.class.replace(' line-numbers-mode', '');
                    node.children = [pre];
                }
            }
            // remove `v-pre` attribute on code
            if (node.tagName === 'code' || node.tagName === 'pre')
                delete node.attribs['v-pre'];
            // eslint-disable-next-line @typescript-eslint/no-use-before-define
            node.children = handleNodes(node.children, {
                base,
                isCustomElement,
                keepFenceDom,
            });
            return node;
        }
        // we shall convert `<RouteLink>` and `<RouterLink>` to `<a>` tag
        if (node.tagName === 'routelink' || node.tagName === 'routerlink') {
            node.tagName = 'a';
            node.attribs.href = `${removeEndingSlash(base)}${node.attribs.to}`;
            node.attribs.target = '_blank';
            delete node.attribs.to;
            // eslint-disable-next-line @typescript-eslint/no-use-before-define
            node.children = handleNodes(node.children, {
                base,
                isCustomElement,
                keepFenceDom,
            });
            return node;
        }
        // keep custom element as is
        if (isCustomElement(node.tagName))
            return node;
        // other tags are considered as vue components and dropped
        return null;
    }
    return node;
};
const handleNodes = (nodes, { base, isCustomElement, keepFenceDom }) => isArray(nodes)
    ? nodes
        .map((node) => handleNode(node, {
        base,
        isCustomElement,
        keepFenceDom,
    }))
        .filter((node) => node !== null)
    : [];
const $ = load('');
const isH1Tag = (node) => node.type === 'tag' && node.tagName === 'h1';
/**
 * Get raw content of excerpt from page content
 *
 * 从页面内容中获取摘要的原始内容
 *
 * @param content - Raw content of page / 页面的原始内容
 * @param separator - Excerpt separator / 摘要分隔符
 *
 * @returns Raw content of excerpt / 摘要的原始内容
 */
export const getPageRawExcerpt = (content, separator = '<!-- more -->') => matter(content, {
    excerpt: true,
    excerpt_separator: separator,
}).excerpt;
/**
 * Get excerpt content of a page
 *
 * 获取页面的摘要内容
 *
 * @param app - VuePress App / VuePress 应用
 * @param page - VuePress Page / VuePress 页面
 * @param excerptOptions - Excerpt behavior options / 摘要行为选项
 *
 * @returns Page excerpt / 页面摘要
 */
export const getPageExcerpt = ({ markdown, options: { base } }, { content, contentRendered, filePath, filePathRelative, frontmatter }, { isCustomElement = () => false, separator = '<!-- more -->', length = 300, keepPageTitle = false, keepFenceDom = false, } = {}) => {
    // get page content
    const rawExcerpt = getPageRawExcerpt(content, separator);
    if (rawExcerpt) {
        const renderedContent = markdown.render(rawExcerpt, 
        // markdown env
        {
            base,
            filePath,
            filePathRelative,
            frontmatter: { ...frontmatter },
        });
        const rootNodes = renderedContent ? $.parseHTML(renderedContent) : [];
        if (rootNodes[0] && !keepPageTitle && isH1Tag(rootNodes[0]))
            rootNodes.shift();
        return $.html(handleNodes(rootNodes, {
            base,
            isCustomElement,
            keepFenceDom,
        }));
    }
    if (length > 0) {
        let autoExcerpt = '';
        const rootNodes = contentRendered ? $.parseHTML(contentRendered) : [];
        if (rootNodes[0] && !keepPageTitle && isH1Tag(rootNodes[0]))
            rootNodes.shift();
        for (const node of rootNodes) {
            const resolvedNode = handleNode(node, {
                base,
                isCustomElement,
                keepFenceDom,
            });
            if (resolvedNode) {
                autoExcerpt += $.html(resolvedNode);
                if (autoExcerpt.length >= length)
                    break;
            }
        }
        return autoExcerpt;
    }
    return '';
};