'use strict';

var defaults = {
	baseUrl: 'https://api.digitalocean.com/v2/domains'
};

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

	function api(method, path, form) {
		var req = {
			method: method,
			url: baseUrl + path,
			headers: {
				Authorization: 'Bearer ' + authtoken,
				'Content-Type': 'application/json'
			},
			json: true,
			form: form
		};
		return request(req).then(function(resp) {
			if (2 !== Math.floor(resp.statusCode / 100)) {
				console.error(resp.statusCode, req.url);
				console.error();
				console.error('Request:');
				console.error(req);
				console.error();
				console.error('Response:');
				console.error(resp.body);
				console.error();
				throw new Error('Error response. Check token, baseUrl, domains, etc.');
			}
			return resp;
		});
	}

	var helpers = {
		getZonenames: function(/*opts*/) {
			// { dnsHosts: [ xxxx.foo.example.com ] }
			return api('GET', '/').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;

			// 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 api('GET', '/' + data.zone + '/records').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 {
		init: function(opts) {
			request = opts.request;
			return null;
		},
		zones: function(data) {
			//console.info('Get zones');
			return helpers.getZonenames(data);
		},
		set: function(data) {
			var ch = data.challenge;
			var txt = ch.dnsAuthorization;

			// console.info('Adding TXT', data);
			return api('POST', '/' + ch.dnsZone + '/records', {
				type: 'TXT',
				name: ch.dnsPrefix,
				data: txt,
				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 + '/' + ch.dnsZone + '/records/' + txtRecord.id;

					return api(
						'DELETE',
						'/' + ch.dnsZone + '/records/' + txtRecord.id
					).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;
				}
			});
		}
	};
};