Application

var _ = require('lodash');

module.exports.arrayDiffToHtmlTable = function () {
	var occurrences = _.flatten(_.toArray(arguments));
	var cache = {};
	var results = occurrences.reduce(function (stack, item) {
		var rewrite = {};
		var flatten = Object.assign(_.omit(item, ['meta']), item.meta);
		var data = rewrite[item._id] = flatten;
		cache[item._id] = (cache.hasOwnProperty(item._id) ? cache[item._id] : flatten);
		return Object.assign(stack, rewrite);
	}, {});
	var attributes = _.uniq(_.flatten(_.map(results, _.keys)));
	var head = '<tr>' + attributes.reduce(function (stack, attribute) {
		return stack.concat('<td>' + attribute + '</td>');
	}, []).join("\n") + '</tr>';
	var body = Object.keys(results).map(function (id) {
		var result = results[id];
		return '<tr>' + attributes.reduce(function (_stack, attribute) {
			var bolded = (_.values(cache)[0][attribute] !== result[attribute]);
			var bold = {
				begin: (bolded ? '**' : ''),
				end: (bolded ? '**' : '')
			};
			return _stack.concat('<td>' + bold.begin + (result[attribute] || '') + bold.end + '</td>');
		}, []).join("\n") + '</tr>';
	}).join("\n");
	return ('<table>' + head + body + '</table>');
}