util.js

import {combineDefaults, combineWithMathJax} from '#js/components/global.js';
import {Package} from '#js/components/package.js';
import {hasWindow} from '#js/util/context.js';
import {mathjax} from '#js/mathjax.js'

export function configFont(font, jax, config, extension = '') {
  const version =
        (MathJax.config.loader?.paths?.fonts || '').substring(0, 24) === 'https://cdn.jsdelivr.net'
          ? `@%%VERSION%%` : '';
  const path = (config.fontPath || `[fonts]/%%FONT%%-font${extension}${version}`);
  const name = (font.match(/^[a-z]+:/) ? (font.match(/[^/:\\]*$/) || [jax])[0] : font);
  combineDefaults(MathJax.config.loader, 'paths', {
    [name+extension]: (
      name === font
        ? path.replace(/%%FONT%%/g, font).replace(/%%VERSION%%/g, mathjax.version)
        : font
    )
  });
  return `[${name}${extension}]`;
}

export function configExtensions(jax, config) {
  const extensions = [];
  for (const name of (config.fontExtensions || [])) {
    const font = configFont(name, jax, config, '-extension');
    const module = `${font}/${jax}`
    extensions.push(module);
  }
  return extensions;
}

export const OutputUtil = {
  config(jax, jaxClass, defaultFont, fontClass) {

    if (MathJax.loader) {

      combineDefaults(MathJax.config, jax, MathJax.config.output || {});

      let config = MathJax.config[jax];
      let font = config.font || config.fontData || defaultFont;
      if (typeof(font) !== 'string') {
        config.fontData = font;
        config.font = font = font.NAME;
      }

      if (font.charAt(0) !== '[') {
        font = configFont(font, jax, config);
      }
      const name = font.substring(1, font.length - 1);

      const extensions = configExtensions(jax, config);
      if (extensions.length) {
        MathJax.loader.addPackageData(`${font}/${jax}`, {extraLoads: extensions});
      }

      if (name !== defaultFont || !fontClass) {

        MathJax.loader.addPackageData(`output/${jax}`, {extraLoads: [`${font}/${jax}`]});

      } else {

        const extraLoads = MathJax.config.loader[`${font}/${jax}`]?.extraLoads;
        if (extraLoads) {
          MathJax.loader.addPackageData(`output/${jax}`, {extraLoads});
        }

        combineWithMathJax({_: {
          output: {
            fonts: {
              [name]: {
                [jax + '_ts']: {
                  [fontClass.NAME + 'Font']: fontClass
                }
              }
            }
          }
        }});

        combineDefaults(MathJax, 'config', {
          output: {
            font: font,
          },
          [jax]: {
            fontData: fontClass,
            dynamicPrefix: `${font}/${jax}/dynamic`
          }
        });
        if (jax === 'chtml') {
          combineDefaults(MathJax.config, jax, {
            fontURL: Package.resolvePath(`${font}/${jax}/woff2`, false),
          });
        }

      }
    }

    if (MathJax.startup) {
      MathJax.startup.registerConstructor(jax, jaxClass);
      MathJax.startup.useOutput(jax);
    }

  },

  loadFont(startup, jax, font, preloaded) {
    if (!MathJax.loader) {
      return startup;
    }
    if (preloaded) {
      MathJax.loader.preLoaded(`[${font}]/${jax}`);
    }
    return Package.loadPromise(`output/${jax}`).then(startup);
  }

};