"use strict";

const defaultValue = require("default-value");
const http = require("http");
const chalk = require("chalk");
const util = require("util");

module.exports = function errorHandler(error, _req, res, _next) {
	console.log(chalk.bold.red("Unhandled error:"), error.stack);

	/* This extracts any (nested) metadata from chained errors */
	let errorContext = (error.getAllContext != null)
		? error.getAllContext()
		: error;

	console.log(chalk.red("Error metadata:"), util.inspect(errorContext, { colors: true, depth: 5 }));

	let statusCode = (errorContext.isHttpError && errorContext.statusCode != null)
		? errorContext.statusCode
		: 500;

	let errorCode = (errorContext.isHttpError && errorContext.errorCode != null)
		? errorContext.errorCode
		: "M_UNKNOWN";

	let errorMessage = (statusCode !== 500)
		? defaultValue(error.message, http.STATUS_CODES[statusCode])
		: "An internal server error occurred. Please contact the server administrator for more information."
		/* TODO: Add contact details? */

	let errorMeta = (errorContext.errorMeta != null)
		? errorContext.errorMeta
		: {};

	let errorCodeData = (!errorContext.noErrorCode)
		? { errcode: errorCode, error: errorMessage }
		: {};

	res.status(statusCode).json(Object.assign({}, errorMeta, errorCodeData));
};