'use strict';

var request = require('@root/request');
request = require('util').promisify(request);

var defaults = {
	baseUrl: 'https://api.digitalocean.com'
};

module.exports.create = function(config) {
	// config = { baseUrl, token }
	var baseUrl = config.baseUrl || defaults.baseUrl;
	var authtoken = config.token;

	var helpers = {
		getZonenames: function(/*opts*/) {
			// { dnsHosts: [ xxxx.foo.example.com ] }
			var url = baseUrl + '/v2/domains/';

			return request({
				method: 'GET',
				url: url,
				headers: {
					Authorization: 'Bearer ' + authtoken,
					'Content-Type': 'application/json'
				},
				json: true
			}).then(function(resp) {
				return resp.body.domains.map(function(x) {
					return x.name;
				});
			});
		},
		getTXTRecord: function(data) {
			// data:{dnsPrefix:"_88-acme-challenge-0e.foo",zone:"example.com",txt:"_cdZWaclIbkP1qYpMkZIURTK--ydQIK6d9axFmftWz0"}
			var dnsPrefix = data.dnsPrefix;
			var txt = data.txt;
			var url = baseUrl + '/v2/domains/' + data.zone + '/records';

			// Digital ocean provides the api to fetch records by ID. Since we do not have id, we fetch all the records,
			// filter the required TXT record

			return request({
				method: 'GET',
				url: url,
				json: true,
				headers: {
					Authorization: 'Bearer ' + authtoken,
					'Content-Type': 'application/json'
				}
			}).then(function(resp) {
				resp = resp.body;
				var entries =
					resp &&
					resp.domain_records &&
					resp.domain_records.filter(function(x) {
						return x.type === 'TXT' && x.name === dnsPrefix && x.data === txt;
					});
				return entries && entries[0];
			});
		}
	};

	return {
		zones: function(data) {
			//console.info('Get zones');
			return helpers.getZonenames(data);
		},
		set: function(data) {
			var ch = data.challenge;
			var txt = ch.dnsAuthorization;
			var url = baseUrl + '/v2/domains/' + ch.dnsZone + '/records';

			// console.info('Adding TXT', data);
			return request({
				method: 'POST',
				url: url,
				headers: {
					Authorization: 'Bearer ' + authtoken,
					'Content-Type': 'application/json'
				},
				json: {
					type: 'TXT',
					// Note: dnsPrefix != dnsHost.split('.')[0]
					// _greenlock-dryrun-2277.bar.foo.example.com => _greenlock-dryrun-2277.bar.foo
					name: ch.dnsPrefix,
					data: txt,
					// Note: set a LOW ttl so that responses are not cached so long
					ttl: 300
				}
			}).then(function(resp) {
				resp = resp.body;
				if (resp && resp.domain_record && resp.domain_record.data === txt) {
					return true;
				}
				throw new Error('record did not set. check subdomain, api key, etc');
			});
		},
		remove: function(data) {
			var ch = data.challenge;

			// Digital ocean provides the api to remove records by ID. So we first get the recordId and use it to remove the domain record
			// console.info('Removing TXT', data);
			var payload = {
				dnsPrefix: ch.dnsPrefix,
				zone: ch.dnsZone,
				txt: ch.dnsAuthorization
			};

			return helpers.getTXTRecord(payload).then(function(txtRecord) {
				if (txtRecord) {
					var url =
						baseUrl + '/v2/domains/' + ch.dnsZone + '/records/' + txtRecord.id;

					return request({
						method: 'DELETE',
						url: url,
						headers: {
							Authorization: 'Bearer ' + authtoken,
							'Content-Type': 'application/json'
						}
					}).then(function(resp) {
						resp = resp.body;
						return true;
					});
				} else {
					throw new Error('Txt Record not found for removal');
				}
			});
		},
		get: function(data) {
			var ch = data.challenge;

			// console.info('Fetching TXT', data);
			var payload = {
				dnsPrefix: ch.dnsPrefix,
				zone: ch.dnsZone,
				txt: ch.dnsAuthorization
			};
			return helpers.getTXTRecord(payload).then(function(txtRecord) {
				if (txtRecord) {
					return { dnsAuthorization: txtRecord.data };
				} else {
					return null;
				}
			});
		}
	};
};