import { filterByNodeName } from './filter-by-nodename';
import { getAttributeProxy } from './get-attribute-proxy';
import { LanguageFactory } from './../../outputLanguages/LanguageFactory';
import { yarleOptions } from './../../yarle';

const isCodeBlock = (node: any)  => {
    const nodeProxy = getAttributeProxy(node);
    const codeBlockFlag = '-en-codeblock:true';

    return nodeProxy.style && nodeProxy.style.value.indexOf(codeBlockFlag) >= 0;
};

const getIntendNumber = (node: any): number => {
    const nodeProxy = getAttributeProxy(node);
    const paddingAttr = 'padding-left:';
    let intendNumber = 0;
    if (nodeProxy.style && nodeProxy.style.value.indexOf(paddingAttr) >= 0) {
        intendNumber = Math.floor(nodeProxy.style.value.split(paddingAttr)[1].split('px')[0] / 20);
    }

    return intendNumber;
};

export const unescapeMarkdown = (s: string): string => s.replace(/\\(.)/g, '$1');

export const codeBlockRule = {
    filter: filterByNodeName('DIV'),
    replacement: (content: string, node: any) => {
        return replaceCodeBlock(content, node);
    },
};

export const replaceCodeBlock = (content: string, node: any): any => {
    const nodeProxy = getAttributeProxy(node);
    const intend = getIntendNumber(node);
    content = `${'\t'.repeat(intend)}${content}`;
    if (isCodeBlock(node)) {
        // turndown has already escaped markdown chars (and all '\') in content;
        // reverse that to avoid extraneous backslashes in code block.
        content = unescapeMarkdown(content);
        const langaugeFactory = new LanguageFactory();
        const targetLanguage = langaugeFactory.createLanguage(yarleOptions.outputFormat)
        return `${targetLanguage.codeBlock}${content}${targetLanguage.codeBlock}`;
    }

    if (node.parentElement && isCodeBlock(node.parentElement) && node.parentElement.firstElementChild === node) {
        return `${content}`;
    }

    if (node.parentElement && isCodeBlock(node.parentElement)) {
        return `\n${content}`;
    }
    const childHtml = node.innerHTML;
    /*return node.isBlock
        ? childHtml !== '<br>'
            ? `\n${content}\n`
            : `${content}`
        : `${content}`;
    */

    return node.isBlock ? `\n${content}\n` : content;
};