// to include an npm module/package into clojurescript:
// https://figwheel.org/docs/npm.html

// to reduce the bundle size:
// https://mathjs.org/docs/custom_bundling.html

import { parse, evaluate } from 'mathjs';

function getVariables(expression) {
    if( !expression || typeof expression !== 'string' ) {
        console.log('not correct input', expression, typeof expression);
        return [];
    }
    try {
        const expressionObject = parse(expression);
        console.log('now returning', expressionObject);
        return expressionObject
            .filter(x => x.isSymbolNode)
            .map(x => x.name)
            .map(x => x.toUpperCase())
            .filter(x => /^[A-Z]+[0-9]+$/.test(x));
    }
    catch(e) {
        console.error('error in parsing or filtering for variables', e.message || e);
        return [];
    }
}

function customEval(...args) {
    try {
        return evaluate(...args);
    }
    catch(e) {
        console.error('error in evaluating expression', e.message || e);
        return {error: e.message};
    }
}

window.mathjs = {parse, evaluate: customEval, getVariables};