'use strict';
var request = require('@root/request');
request = require('util').promisify(request);
var crypto = require('crypto');
var querystring = require('querystring');

var defaults = {
	region:'ovh-eu',
	basePath:'/1.0'
};

var recordsStore = {};

module.exports.create = function(config) {
	var applicationKey = config.applicationKey||null;
	var applicationSecret = config.applicationSecret||null;
	var consumerKey = config.consumerKey||null;
	// one of ovh-eu, ovh-ca, kimsufi-eu, kimsufi-ca, soyoustart-eu, soyoustart-ca, runabove-ca
	var region = config.region || defaults.region;
	var apiTimeDiff = config.apiTimeDiff || null;
	var basePath = config.basePath || defaults.basePath;

	if (typeof(applicationKey) !== 'string' || typeof(applicationSecret) !== 'string') {
		throw new Error('[OVH] You should precise an application key / secret');
	}

	var endpoints = {
		'ovh-eu': 'eu.api.ovh.com',
		'ovh-ca': 'ca.api.ovh.com',
		'kimsufi-eu': 'eu.api.kimsufi.com',
		'kimsufi-ca': 'ca.api.kimsufi.com',
		'soyoustart-eu': 'eu.api.soyoustart.com',
		'soyoustart-ca': 'ca.api.soyoustart.com',
		'runabove-ca': 'api.runabove.com'
	};

	var baseUrl = 'https://' + endpoints[region] + basePath;

	/**
	 * Signs an API request
	 *
	 * @param {String} httpMethod
	 * @param {String} url
	 * @param {String} body
	 * @param {Number|String} timestamp
	 * @return {String} The signature
	 */
	function signRequest(httpMethod, url, body, timestamp) {
		var s = [
			applicationSecret,
			consumerKey,
			httpMethod,
			url,
			body || '',
			timestamp
		];
		return '$1$' + crypto.createHash('sha1').update(s.join('+')).digest('hex');
	}

	function api(httpMethod, path, params) {
		// Time drift
		if (apiTimeDiff === null && path !== '/auth/time') {
			return api('GET', '/auth/time', {})
				.then(function(res) {

					apiTimeDiff = res.body - Math.round(Date.now() / 1000);
					return api(httpMethod, path, params);
				}).catch(function(err) {
					throw new Error('[OVH] Unable to fetch OVH API time');
				});
		}

		var headers = {
			'X-Ovh-Application': applicationKey
		};

		if (httpMethod === 'GET') {
			path += '?' + querystring.stringify(params);
		}

		var url = baseUrl + path;

		if (path.indexOf('/auth') < 0) {
			headers['X-Ovh-Timestamp'] = Math.round(Date.now() / 1000) + apiTimeDiff;
			// Sign request
			if (typeof(consumerKey) === 'string') {
				headers['X-Ovh-Consumer'] = consumerKey;
				headers['X-Ovh-Signature'] = signRequest(
					httpMethod, url, params, headers['X-Ovh-Timestamp']
				);
			}
		}

		console.debug(
			'[OVH] API call:',
			httpMethod,
			path,
			params || ''
		);

		return request({
			method: httpMethod,
			url: url,
			headers: headers,
			json: true,
			form: params
		});
	}

	return {
		init: function(deps) {
			request = deps.request;
			return null;
		},
		zones: function(data) {
			return api('GET', '/domain/zone')
				.then(function(resp) {
					if (200 !== resp.statusCode) {
						console.error(resp.statusCode);
						console.error(resp.body);
						throw new Error('Could not get list of zones.');
					}

					// list of zones
					return resp.body;

				}).catch(function(err) {

				});
		},
		set: function(data) {
			var ch = data.challenge;
			var txt = ch.dnsAuthorization;

			// record name received as argument : www.qwerty.sampledomain.com
			// received zone id : sampledomain.com required record name by OVH : www.qwerty
			//console.debug('adding txt', data);
			return api('POST', '/domain/zone/' + ch.dnsZone + '/record', {
				fieldType: 'TXT',
				subDomain: ch.dnsPrefix,
				target: txt,
				ttl: 1
			}).then(function(resp) {
				if (200 !== resp.statusCode) {
					console.error(resp.statusCode);
					console.error(resp.body);
					throw new Error('record did not set.');
				}
				// save id for remove
				recordsStore[ch.dnsPrefix] = resp.body['id']

			}).then(function() {
				// Apply zone modification on DNS servers
				return api('POST', '/domain/zone/' + ch.dnsZone + '/record', {})
					.then(function() {
						return true;
					});
			});
		},
		remove: function(data) {
			var ch = data.challenge;
			return api('DELETE', '/domain/zone/' + ch.dnsZone + '/record/'+recordsStore[ch.dnsPrefix])
				.then(function(resp) {
					if (200 !== resp.statusCode) {
						throw new Error('record did not remove.');
					}
				})
				.then(function() {
					return api('POST', '/domain/zone/' + ch.dnsZone + '/record', {})
						.then(function(resp) {
							if (200 !== resp.statusCode) {
								console.error(resp.statusCode);
								console.error(resp.body);
								throw new Error('record did not remove.');
							}
							return true;
						});
				});
		},
		get: function(data) {
			var ch = data.challenge;

			return api('GET', '/domain/zone/' + ch.dnsZone + '/record/'+recordsStore[ch.dnsPrefix])
				.then(function(resp) {
					if (200 !== resp.statusCode) {
						throw new Error('record did not remove.');
					}
					return {
						dnsAuthorization:resp.body.target
					};

			});
		}
	};
};