'use strict';

var v4 = require('aws-signature-v4');
var xml2js = require('xml2js');
var parseString = xml2js.parseString;
parseString = require('util').promisify(parseString);
var builder = new xml2js.Builder();
var request;

var defaults = {
	baseUri: '/2013-04-01/'
};

function setWeightedPolicy(XmlObject, isWildcard) {
	if (isWildcard) {
		XmlObject.ChangeResourceRecordSetsRequest.ChangeBatch[0].Changes[0].Change[0].ResourceRecordSet[0].SetIdentifier = [
			'wildcard'
		];
	} else {
		XmlObject.ChangeResourceRecordSetsRequest.ChangeBatch[0].Changes[0].Change[0].ResourceRecordSet[0].SetIdentifier = [
			'subdomain'
		];
	}

	XmlObject.ChangeResourceRecordSetsRequest.ChangeBatch[0].Changes[0].Change[0].ResourceRecordSet[0].Weight = [
		1
	];
}

// used to build XML payload
var XmlParameters = {
	ChangeResourceRecordSetsRequest: {
		$: {
			xmlns: ''
		},
		ChangeBatch: [
			{
				Changes: [
					{
						Change: [
							{
								Action: [''],
								ResourceRecordSet: [
									{
										Type: ['TXT'],
										Name: [''],
										ResourceRecords: [
											{
												ResourceRecord: [
													{
														Value: ['']
													}
												]
											}
										],
										TTL: [300]
									}
								]
							}
						]
					}
				]
			}
		]
	}
};

module.exports.create = function(config) {
	var baseUri = defaults.baseUri.replace(/\/$/, '');
	var key = config.key;
	var secret = config.secret;

	function api(method, path, body, query) {
		var body = body || '';
		var query = query || {};
		var options = {
			key: key,
			secret: secret,
			query: query
		};
		var parameters = {
			method: method
		};

		if (method === 'POST') {
			options.headers = { 'Content-Type': 'application/xml' };
			parameters.headers = { 'Content-Type': 'application/xml' };
		}

		if (body) {
			parameters.body = body;
		}

		var url = v4.createPresignedURL(
			method,
			'route53.amazonaws.com',
			path,
			'route53',
			body,
			options
		);

		parameters.url = url;

		return request(parameters).then(function(response) {
			if (response.statusCode < 200 || response.statusCode >= 300) {
				console.error(response.statusCode, options.url);
				console.error();
				console.error('Request:');
				console.error(options);
				console.error();
				console.error('Response:');
				console.error(response.body);
				console.error();
				throw new Error(
					'Error response. Check token, baseUri, domains, etc.'
				);
			}
			return response;
		});
	}

	return {
		init: function(options) {
			request = options.request;
			return null;
		},
		zones: function(data) {
			return api('GET', baseUri + '/' + 'hostedzone').then(function(
				response
			) {
				return parseString(response.body).then(function(body) {
					var zones = body.ListHostedZonesResponse.HostedZones[0].HostedZone.map(
						function(element) {
							return element.Name[0].replace(/\.$/, ''); // all route 53 domains terminate with a dot
						}
					);

					return zones;
				});
			});
		},
		set: function(data) {
			var challenge = data.challenge;

			if (!challenge.dnsZone) {
				throw new Error('No matching zone for ' + challenge.dnsHost);
			}

			return api(
				'GET',
				baseUri + '/' + 'hostedzonesbyname',
				null,
				'dnsname=' + challenge.dnsZone + '&maxitems=1'
			)
				.then(function(response) {
					return parseString(response.body).then(function(body) {
						return body;
					});
				})
				.then(function(body) {
					var zoneID =
						body.ListHostedZonesByNameResponse.HostedZones[0]
							.HostedZone[0].Id[0];
					var xmlns = body.ListHostedZonesByNameResponse.$.xmlns;

					var parameters = JSON.parse(JSON.stringify(XmlParameters));
					parameters.ChangeResourceRecordSetsRequest.$.xmlns = xmlns;
					parameters.ChangeResourceRecordSetsRequest.ChangeBatch[0].Changes[0].Change[0].Action[0] =
						'CREATE';
					parameters.ChangeResourceRecordSetsRequest.ChangeBatch[0].Changes[0].Change[0].ResourceRecordSet[0].Name[0] =
						challenge.dnsHost; // AWS requires FQDN
					parameters.ChangeResourceRecordSetsRequest.ChangeBatch[0].Changes[0].Change[0].ResourceRecordSet[0].ResourceRecords[0].ResourceRecord[0].Value[0] =
						'"' + challenge.dnsAuthorization + '"'; // value must be surrounded by double quotes

					// By default AWS creates record sets with simple routing policy, so duplicates are not allowed.
					// A workaround is put the record sets in different weighted policies.
					if (challenge.identifier.value.startsWith('foo')) {
						setWeightedPolicy(parameters, challenge.wildcard);
					}

					var xml = builder.buildObject(parameters);
					return api('POST', baseUri + zoneID + '/rrset/', xml);
				});
		},
		get: function(data) {
			var challenge = data.challenge;

			return api(
				'GET',
				baseUri + '/' + 'hostedzonesbyname',
				null,
				'dnsname=' + challenge.dnsZone + '&maxitems=1'
			)
				.then(function(response) {
					return parseString(response.body).then(function(body) {
						return body;
					});
				})
				.then(function(body) {
					var zoneID =
						body.ListHostedZonesByNameResponse.HostedZones[0]
							.HostedZone[0].Id[0];
					return zoneID;
				})
				.then(function(zoneID) {
					return api(
						'GET',
						baseUri + '/' + zoneID + '/rrset',
						null,
						'name=' +
							challenge.dnsPrefix +
							'.' +
							challenge.dnsZone +
							'.' +
							'&type=TXT'
					).then(function(response) {
						return parseString(response.body).then(function(body) {
							if (
								body.ListResourceRecordSetsResponse
									.ResourceRecordSets[0] === ''
							) {
								return null;
							}

							var record = body.ListResourceRecordSetsResponse.ResourceRecordSets[0].ResourceRecordSet.filter(
								function(element) {
									return (
										element.ResourceRecords[0].ResourceRecord[0].Value[0].replace(
											/\"/g,
											''
										) === challenge.dnsAuthorization &&
										element.Name[0].includes(
											challenge.dnsPrefix
										)
									);
								}
							)[0];

							if (record) {
								return {
									dnsAuthorization: record.ResourceRecords[0].ResourceRecord[0].Value[0].replace(
										/\"/g,
										''
									)
								};
							}

							return null;
						});
					});
				});
		},
		remove: function(data) {
			var challenge = data.challenge;

			return api(
				'GET',
				baseUri + '/' + 'hostedzonesbyname',
				null,
				'dnsname=' + challenge.dnsZone + '&maxitems=1'
			)
				.then(function(response) {
					return parseString(response.body).then(function(body) {
						return body;
					});
				})
				.then(function(body) {
					var zoneID =
						body.ListHostedZonesByNameResponse.HostedZones[0]
							.HostedZone[0].Id[0];
					var xmlns = body.ListHostedZonesByNameResponse.$.xmlns;

					var parameters = JSON.parse(JSON.stringify(XmlParameters));
					parameters.ChangeResourceRecordSetsRequest.$.xmlns = xmlns;
					parameters.ChangeResourceRecordSetsRequest.ChangeBatch[0].Changes[0].Change[0].Action[0] =
						'DELETE';
					parameters.ChangeResourceRecordSetsRequest.ChangeBatch[0].Changes[0].Change[0].ResourceRecordSet[0].Name[0] =
						challenge.dnsHost; // AWS requires FQDN
					parameters.ChangeResourceRecordSetsRequest.ChangeBatch[0].Changes[0].Change[0].ResourceRecordSet[0].ResourceRecords[0].ResourceRecord[0].Value[0] =
						'"' + challenge.dnsAuthorization + '"'; // value must be surrounded by double quotes

					// need to add weight and setidentifier to delete record set
					if (challenge.identifier.value.startsWith('foo')) {
						setWeightedPolicy(parameters, challenge.wildcard);
					}

					var xml = builder.buildObject(parameters);
					return api('POST', baseUri + zoneID + '/rrset/', xml);
				});
		}
	};
};