var Stream = require('stream').Stream,
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util = require('util'),
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driver = require('websocket-driver'),
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Headers = require('websocket-driver/lib/websocket/driver/headers'),
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API = require('./websocket/api'),
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EventTarget = require('./websocket/api/event_target'),
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Event = require('./websocket/api/event');
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var EventSource = function(request, response, options) {
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this.writable = true;
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options = options || {};
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this._stream = response.socket;
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this._ping = options.ping || this.DEFAULT_PING;
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this._retry = options.retry || this.DEFAULT_RETRY;
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var scheme = driver.isSecureRequest(request) ? 'https:' : 'http:';
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this.url = scheme + '//' + request.headers.host + request.url;
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this.lastEventId = request.headers['last-event-id'] || '';
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this.readyState = API.CONNECTING;
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var headers = new Headers(),
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self = this;
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if (options.headers) {
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for (var key in options.headers) headers.set(key, options.headers[key]);
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}
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if (!this._stream || !this._stream.writable) return;
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process.nextTick(function() { self._open() });
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this._stream.setTimeout(0);
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this._stream.setNoDelay(true);
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var handshake = 'HTTP/1.1 200 OK\r\n' +
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'Content-Type: text/event-stream\r\n' +
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'Cache-Control: no-cache, no-store\r\n' +
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'Connection: close\r\n' +
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headers.toString() +
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'\r\n' +
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'retry: ' + Math.floor(this._retry * 1000) + '\r\n\r\n';
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this._write(handshake);
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this._stream.on('drain', function() { self.emit('drain') });
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if (this._ping)
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this._pingTimer = setInterval(function() { self.ping() }, this._ping * 1000);
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['error', 'end'].forEach(function(event) {
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self._stream.on(event, function() { self.close() });
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});
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};
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util.inherits(EventSource, Stream);
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EventSource.isEventSource = function(request) {
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if (request.method !== 'GET') return false;
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var accept = (request.headers.accept || '').split(/\s*,\s*/);
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return accept.indexOf('text/event-stream') >= 0;
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};
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var instance = {
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DEFAULT_PING: 10,
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DEFAULT_RETRY: 5,
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_write: function(chunk) {
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if (!this.writable) return false;
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try {
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return this._stream.write(chunk, 'utf8');
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} catch (e) {
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return false;
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}
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},
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_open: function() {
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if (this.readyState !== API.CONNECTING) return;
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this.readyState = API.OPEN;
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var event = new Event('open');
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event.initEvent('open', false, false);
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this.dispatchEvent(event);
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},
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write: function(message) {
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return this.send(message);
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},
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end: function(message) {
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if (message !== undefined) this.write(message);
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this.close();
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},
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send: function(message, options) {
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if (this.readyState > API.OPEN) return false;
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message = String(message).replace(/(\r\n|\r|\n)/g, '$1data: ');
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options = options || {};
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var frame = '';
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if (options.event) frame += 'event: ' + options.event + '\r\n';
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if (options.id) frame += 'id: ' + options.id + '\r\n';
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frame += 'data: ' + message + '\r\n\r\n';
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return this._write(frame);
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},
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ping: function() {
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return this._write(':\r\n\r\n');
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},
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close: function() {
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if (this.readyState > API.OPEN) return false;
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this.readyState = API.CLOSED;
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this.writable = false;
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if (this._pingTimer) clearInterval(this._pingTimer);
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if (this._stream) this._stream.end();
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var event = new Event('close');
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event.initEvent('close', false, false);
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this.dispatchEvent(event);
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return true;
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}
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};
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for (var method in instance) EventSource.prototype[method] = instance[method];
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for (var key in EventTarget) EventSource.prototype[key] = EventTarget[key];
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module.exports = EventSource;
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