'use strict';

const katex = require('katex');
const pandoc = require('pandoc-filter');
const filterSync = require('./filter.js');
const printMessage = require('./message.js');

function katexProcess(data, config, filePath) {
  function action({ t: type, c: value }, fotmat, meta) {
    if (type !== 'Math') {
      return null;
    }

    let options = config;
    if (config['strict'] === 'warn') {
      options['strict'] = (errorCode, errorMsg, token) => {
        printMessage('WARNING', filePath, errorMsg);
      };
    }
    if (value[0]['t'] === 'InlineMath') {
      options['displayMode'] = false;
    } else {
      options['displayMode'] = true;
    }
    
    try {
      return pandoc.RawInline('html', katex.renderToString(value[1], options));
    } catch (err) {
      printMessage('ERROR', filePath, err.toString());
      throw err;
    }
  }
  return JSON.stringify(filterSync(JSON.parse(data), action, ''));
}

module.exports = katexProcess;