var _ = require('lodash');
var kramed = require('kramed');

// Get all the pairs of header + paragraph in a list of nodes
function groups(nodes) {
    // A list of next nodes
    var next = nodes.slice(1).concat(null);

    return _.reduce(nodes, function(accu, node, idx) {
        // Skip
        if(!(
            node.type === 'heading' &&
            (next[idx] && next[idx].type === 'paragraph')
        )) {
            return accu;
        }

        // Add group
        accu.push([
            node,
            next[idx]
        ]);

        return accu;
    }, []);
}

function parseGlossary(src) {
    var nodes = kramed.lexer(src);

    var entries = groups(nodes);

    return entries;
}

module.exports = parseGlossary;