mini_cocopi/ya-webadb/apps/book/scripts/plantuml.js

const encoder = require('plantuml-encoder');
const svgToDataUri = require('mini-svg-data-uri');
const fetch = require('node-fetch');
const visit = require('unist-util-visit');

async function umlToSvgDataUri(uml) {
    const encoded = encoder.encode(uml);
    const response = await fetch(`https://www.plantuml.com/plantuml/svg/${encoded}`);
    let svg = await response.text();
    return svgToDataUri(svg);
}

module.exports = () => {
    return async syntaxTree => {
        const matches = [];
        visit(syntaxTree, 'code', node => {
            if (node.lang === 'uml' && !!node.value) {
                matches.push(node);
            }
        });
        if (!matches.length) {
            return;
        }

        const id = Math.random().toString().substring(2);
        syntaxTree.children.unshift({ type: 'import', value: `import ThemedImage${id} from '@theme/ThemedImage'` });

        await Promise.all(matches.map(async node => {
            const lightSvg = await umlToSvgDataUri(node.value.replace('@startuml', '@startuml\n!theme bluegray'));
            // Workaround https://github.com/bschwarz/puml-themes/issues/15
            const darkSvg = await umlToSvgDataUri(node.value.replace('@startuml', '@startuml\n!theme cyborg\nskinparam SequenceDelayFontColor $FGCOLOR'));
            node.type = 'jsx';
            node.value = `<ThemedImage${id} sources={{ light: "${lightSvg}", dark: "${darkSvg}" }} />`;
        }));
    }
}