var URL = require('url');
var request = require('request');
var UError = require('./error').UserError;
var mystreams = require('./streams');

//
// Implements Storage interface
// (same for storage.js, local-storage.js, up-storage.js)
//
function Storage(config, mainconfig) {
	if (!(this instanceof Storage)) return new Storage(config);
	this.config = config;
   this.is_alive = false;
	this.userAgent = mainconfig.user_agent;
	this.ca = config.ca;

	this.url = URL.parse(this.config.url);
	if (this.url.hostname === 'registry.npmjs.org') {
		this.ca = this.ca || require('./npmsslkeys');

		// npm registry is too slow working with ssl :(
		/*if (this.config._autogenerated) {
			// encrypt all the things!
			this.url.protocol = 'https';
			this.config.url = URL.format(this.url);
		}*/
	}

	this.config.url = this.config.url.replace(/\/$/, '');
	return this;
}

Storage.prototype.request = function(options, cb) {
	var self = this;
	var headers = options.headers || {};
	headers.accept = headers.accept || 'application/json';
	headers['user-agent'] = headers['user-agent'] || this.userAgent;
	var req = request({
		url: this.config.url + options.uri,
		method: options.method || 'GET',
		headers: headers,
		json: options.json || true,
		ca: this.ca,
	}, function(err) {
		if (cb) cb.apply(self, arguments);
	});
	req.on('response', function() {
		self.status_check(true);
	});
	req.on('error', function() {
		self.status_check(false);
	});
	return req;
}

Storage.prototype.status_check = function(alive) {
	if (arguments.length === 0) {
		if (!this.is_alive && Math.abs(Date.now() - this.is_alive_time()) > 60*1000) {
			return false;
		} else {
			return true;
		}
	} else {
		this.is_alive = alive;
		this.is_alive_time = Date.now();
	}
}

Storage.prototype.can_fetch_url = function(url) {
	url = URL.parse(url);

	return url.protocol === this.url.protocol
	    && url.host === this.url.host
	    && url.path.indexOf(this.url.path) === 0
}

Storage.prototype.add_package = function(name, metadata, callback) {
	this.request({
		uri: '/' + escape(name),
		method: 'PUT',
		json: metadata,
	}, function(err, res, body) {
		if (err) return callback(err);
		if (!(res.statusCode >= 200 && res.statusCode < 300)) {
			return callback(new Error('bad status code: ' + res.statusCode));
		}
		callback(null, body);
	});
}

Storage.prototype.add_version = function(name, version, metadata, tag, callback) {
	this.request({
		uri: '/' + escape(name) + '/' + escape(version) + '/-tag/' + escape(tag),
		method: 'PUT',
		json: metadata,
	}, function(err, res, body) {
		if (err) return callback(err);
		if (!(res.statusCode >= 200 && res.statusCode < 300)) {
			return callback(new Error('bad status code: ' + res.statusCode));
		}
		callback(null, body);
	});
}

Storage.prototype.add_tarball = function(name, filename) {
	var stream = new mystreams.UploadTarballStream();
	var self = this;

	var wstream = this.request({
		uri: '/' + escape(name) + '/-/' + escape(filename) + '/whatever',
		method: 'PUT',
		headers: {
			'content-type': 'application/octet-stream'
		},
	});

	wstream.on('response', function(res) {
		if (!(res.statusCode >= 200 && res.statusCode < 300)) {
			return stream.emit('error', new UError({
				msg: 'bad uplink status code: ' + res.statusCode,
				status: 500,
			}));
		}
		stream.emit('success');
	});

	wstream.on('error', function(err) {
		stream.emit('error', err);
	});

	stream.abort = function() {
		process.nextTick(function() {
			if (wstream.req) {
				wstream.req.abort();
			}
		});
	};
	stream.done = function() {};
	stream.pipe(wstream);

	return stream;
}

Storage.prototype.get_package = function(name, callback) {
	this.request({
		uri: '/' + escape(name),
		json: true,
	}, function(err, res, body) {
		if (err) return callback(err);
		if (res.statusCode === 404) {
			return callback(new UError({
				msg: 'package doesn\'t exist on uplink',
				status: 404,
			}));
		}
		if (!(res.statusCode >= 200 && res.statusCode < 300)) {
			return callback(new Error('bad status code: ' + res.statusCode));
		}
		callback(null, body);
	});
}

Storage.prototype.get_tarball = function(name, filename) {
	return this.get_url(this.config.url + '/' + name + '/-/' + filename);
}

Storage.prototype.get_url = function(url) {
	url = URL.parse(url);
	var stream = new mystreams.ReadTarballStream();
	stream.abort = function() {};

	var rstream = this.request({
		uri: url.path,
		encoding: null,
	});

	rstream.on('response', function(res) {
		if (res.statusCode === 404) {
			return stream.emit('error', new UError({
				msg: 'file doesn\'t exist on uplink',
				status: 404,
			}));
		}
		if (!(res.statusCode >= 200 && res.statusCode < 300)) {
			return stream.emit('error', new UError({
				msg: 'bad uplink status code: ' + res.statusCode,
				status: 500,
			}));
		}

		rstream.pipe(stream);
	});

	rstream.on('error', function(err) {
		stream.emit('error', err);
	});
	return stream;
}

module.exports = Storage;