'use strict';
require('./compat.js');

var path = require('path');
var homeRe = new RegExp('^~(\\/|\\\\|\\' + path.sep + ')');
// very basic check. Allows *.example.com.
var re = /^(\*\.)?[a-zA-Z0-9\.\-]+$/;
var punycode = require('punycode');
var dnsResolveMxAsync = require('util').promisify(require('dns').resolveMx);

module.exports.attachCertInfo = function(results) {
	var certInfo = require('cert-info').info(results.cert);

	// subject, altnames, issuedAt, expiresAt
	Object.keys(certInfo).forEach(function(key) {
		results[key] = certInfo[key];
	});

	return results;
};

module.exports.certHasDomain = function(certInfo, _domain) {
	var names = (certInfo.altnames || []).slice(0);
	names.push(certInfo.subject);
	return names.some(function(name) {
		var domain = _domain.toLowerCase();
		name = name.toLowerCase();
		if ('*.' === name.substr(0, 2)) {
			name = name.substr(2);
			domain = domain
				.split('.')
				.slice(1)
				.join('.');
		}
		return name === domain;
	});
};

module.exports.isValidDomain = function(domain) {
	if (re.test(domain)) {
		return domain;
	}

	domain = punycode.toASCII(domain);

	if (re.test(domain)) {
		return domain;
	}

	return '';
};

module.exports.merge = function(/*defaults, args*/) {
	var allDefaults = Array.prototype.slice.apply(arguments);
	var args = allDefaults.shift();
	var copy = {};

	allDefaults.forEach(function(defaults) {
		Object.keys(defaults).forEach(function(key) {
			/*
      if ('challenges' === key && copy[key] && defaults[key]) {
        Object.keys(defaults[key]).forEach(function (k) {
          copy[key][k] = defaults[key][k];
        });
      } else {
        copy[key] = defaults[key];
      }
    */
			copy[key] = defaults[key];
		});
	});

	Object.keys(args).forEach(function(key) {
		/*
    if ('challenges' === key && copy[key] && args[key]) {
        Object.keys(args[key]).forEach(function (k) {
          copy[key][k] = args[key][k];
        });
    } else {
      copy[key] = args[key];
    }
    */
		copy[key] = args[key];
	});

	return copy;
};

module.exports.tplCopy = function(copy) {
	var homedir = require('os').homedir();
	var tplKeys;

	copy.hostnameGet = function(copy) {
		return copy.subject || (copy.domains || [])[0] || copy.domain;
	};

	Object.keys(copy).forEach(function(key) {
		var newName;
		if (!/Get$/.test(key)) {
			return;
		}

		newName = key.replace(/Get$/, '');
		copy[newName] = copy[newName] || copy[key](copy);
	});

	tplKeys = Object.keys(copy);
	tplKeys.sort(function(a, b) {
		return b.length - a.length;
	});

	tplKeys.forEach(function(key) {
		if ('string' !== typeof copy[key]) {
			return;
		}

		copy[key] = copy[key].replace(homeRe, homedir + path.sep);
	});

	tplKeys.forEach(function(key) {
		if ('string' !== typeof copy[key]) {
			return;
		}

		tplKeys.forEach(function(tplname) {
			if (!copy[tplname]) {
				// what can't be templated now may be templatable later
				return;
			}
			copy[key] = copy[key].replace(':' + tplname, copy[tplname]);
		});
	});

	return copy;
};

module.exports.testEmail = function(email) {
	var parts = (email || '').split('@');
	var err;

	if (2 !== parts.length || !parts[0] || !parts[1]) {
		err = new Error("malformed email address '" + email + "'");
		err.code = 'E_EMAIL';
		return Promise.reject(err);
	}

	return dnsResolveMxAsync(parts[1]).then(
		function(records) {
			// records only returns when there is data
			if (!records.length) {
				throw new Error(
					'sanity check fail: success, but no MX records returned'
				);
			}
			return email;
		},
		function(err) {
			if ('ENODATA' === err.code) {
				err = new Error("no MX records found for '" + parts[1] + "'");
				err.code = 'E_EMAIL';
				return Promise.reject(err);
			}
		}
	);
};