'use strict';

var utils = require('./utils');

function _log(debug) {
	if (debug) {
		var args = Array.prototype.slice.call(arguments);
		args.shift();
		args.unshift('[greenlock/lib/middleware.js]');
		console.log.apply(console, args);
	}
}

module.exports.create = function(gl) {
	if (!gl.challenges['http-01'] || !gl.challenges['http-01'].get) {
		throw new Error('middleware requires challenge plugin with get method');
	}
	var log = gl.log || _log;

	log(gl.debug, 'created middleware');
	return function(_app) {
		if (_app && 'function' !== typeof _app) {
			throw new Error(
				'use greenlock.middleware() or greenlock.middleware(function (req, res) {})'
			);
		}
		var prefix = gl.acmeChallengePrefix || '/.well-known/acme-challenge/';

		return function(req, res, next) {
			if (0 !== req.url.indexOf(prefix)) {
				log(gl.debug, 'no match, skipping middleware');
				if ('function' === typeof _app) {
					_app(req, res, next);
				} else if ('function' === typeof next) {
					next();
				} else {
					res.statusCode = 500;
					res.end(
						"[500] Developer Error: app.use('/', greenlock.middleware()) or greenlock.middleware(app)"
					);
				}
				return;
			}

			log(gl.debug, "this must be tinder, 'cuz it's a match!");

			var token = req.url.slice(prefix.length);
			var hostname =
				req.hostname ||
				(req.headers.host || '').toLowerCase().replace(/:.*/, '');

			log(gl.debug, 'hostname', hostname, 'token', token);

			var copy = utils.merge({ domains: [hostname] }, gl);
			copy = utils.tplCopy(copy);
			copy.challenge = {};
			copy.challenge.type = 'http-01'; // obviously...
			copy.challenge.identifier = { type: 'dns', value: hostname };
			copy.challenge.wildcard = false;
			copy.challenge.token = token;
			copy.challenge.altname = hostname;

			function cb(opts) {
				var secret = opts.keyAuthorization || opts;
				if (secret && 'string' === typeof secret) {
					res.setHeader('Content-Type', 'text/plain; charset=utf-8');
					res.end(secret);
					return;
				}
				eb(new Error("couldn't retrieve keyAuthorization"));
				return;
			}
			function eb(/*err*/) {
				res.statusCode = 404;
				res.setHeader(
					'Content-Type',
					'application/json; charset=utf-8'
				);
				res.end(
					'{ "error": { "message": "Error: These aren\'t the tokens you\'re looking for. Move along." } }'
				);
				return;
			}
			function mb(err, result) {
				if (err) {
					eb(err);
					return;
				}
				cb(result);
			}

			var challenger = gl.challenges['http-01'].get;
			if (1 === challenger.length) {
				/*global Promise*/
				return Promise.resolve()
					.then(function() {
						return gl.challenges['http-01'].get(copy);
					})
					.then(cb)
					.catch(eb);
			} else if (2 === challenger.length) {
				gl.challenges['http-01'].get(copy, mb);
			} else {
				gl.challenges['http-01'].get(copy, hostname, token, mb);
			}
		};
	};
};