'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 = {
		getDomain: function(identifier) {
			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;
					});
				})
				.then(function(domains) {
					for (var i = 0; i < domains.length; i++) {
						var domain = domains[i];
						var pattern = new RegExp(domain.replace('.', '.') + '$');
						if (pattern.test(identifier)) {
							return domain;
						}
					}
					throw new Error('Domain not found for: ' + identifier);
				});
		},
		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 {
		set: function(data) {
			var ch = data.challenge;
			var domainRecord = ch.identifier.value;

			// Note: zone != domain
			// example.com, foo.example.com, and bar.foo.example.com are all in the example.com zone!!
			// Need to get list of "domains" (zones) and *then* set "subdomains" (domain records)
			// https://developers.digitalocean.com/documentation/v2/#domains
			return helpers.getDomain(domainRecord).then(function(zone) {
				// Note: dnsPrefix != dnsHost.split('.')[0]
				// _greenlock-dryrun-2277.bar.foo.example.com => _greenlock-dryrun-2277.bar.foo
				var dnsPrefix = ch.dnsHost.replace(new RegExp('.' + zone + '$'), '');
				var txt = ch.dnsAuthorization;
				var url = baseUrl + '/v2/domains/' + zone + '/records';

				// console.info('Adding TXT', data);
				return request({
					method: 'POST',
					url: url,
					headers: {
						Authorization: 'Bearer ' + authtoken,
						'Content-Type': 'application/json'
					},
					json: {
						type: 'TXT',
						name: 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;
			var domainRecord = ch.identifier.value;

			// Digital ocean provides the api to remove records by ID. So we first get the recordId and use it to remove the domain record
			return helpers.getDomain(domainRecord).then(function(zone) {
				var dnsPrefix = ch.dnsHost.replace(new RegExp('.' + zone + '$'), '');

				// console.info('Removing TXT', data);
				var payload = {
					dnsPrefix: dnsPrefix,
					zone: zone,
					txt: ch.dnsAuthorization
				};

				return helpers.getTXTRecord(payload).then(function(txtRecord) {
					if (txtRecord) {
						var url =
							baseUrl + '/v2/domains/' + zone + '/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;
			var domainRecord = ch.identifier.value;

			return helpers.getDomain(domainRecord).then(function(zone) {
				var dnsPrefix = domainRecord.replace(new RegExp('.' + zone + '$'), '');

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