var TCP = process.binding("tcp_wrap").TCP;
var Buffer = process.binding("buffer").SlowBuffer;
var HTTPParser = process.binding("http_parser").HTTPParser;

function setupSocket(peer) {
  function shutdownHandler(status, handle, req) {
    // TODO: ensure we only shutdown once
    if(status != 0) {
      if(peer.onerror) {
        var err = new Error("shutdown");
        err.errno = errno;
        peer.onerror(err);
      }
    }
    handle.close();
    if(peer.onclose) peer.onclose();
  }
  function kill() {
    if(!peer.closed) {
      peer.readStop();
      peer.onread = function() {};
      var r = peer.shutdown();
      peer.closed = true;
      r.oncomplete = shutdownHandler;
    }
  }
  function send(buff, cb) {
    var wr = peer.write(buff);
    if (!wr) {
      if(peer.onerror) {
        var err = new Error("write");
        err.errno = errno;
        peer.onerror(err);
      }
      peer.kill();
      return false;
    }
    wr.oncomplete = cb;
    return true;
  }
  peer.closed = false;
  peer.kill = kill;
  peer.send = send;
}

var responses = {
  keepalive: "HTTP/1.1 200 OK\r\nServer: node-/0.6.10\r\nDate: Thu, 09 Feb 2012 00:46:42 GMT\r\nContent-Type: text/html\r\nContent-Length: 0\r\nLast-Modified: Tue, 06 Dec 2011 17:29:28 GMT\r\nConnection: keep-alive\r\nAccept-Ranges: bytes\r\n\r\n",
  close: "HTTP/1.1 200 OK\r\nServer: nginx/0.7.67\r\nDate: Thu, 09 Feb 2012 00:46:42 GMT\r\nContent-Type: text/html\r\nContent-Length: 0\r\nLast-Modified: Tue, 06 Dec 2011 17:29:28 GMT\r\nConnection: close\r\nAccept-Ranges: bytes\r\n\r\n"
}

for (name in responses) {
  var b = new Buffer(responses[name].length);
  b.asciiWrite(responses[name]);
  responses[name] = b;
}

var FreeList = function(name, max, constructor) {
  this.name = name;
  this.constructor = constructor;
  this.max = max;
  this.list = [];
};

FreeList.prototype.alloc = function() {
  return this.list.length ? this.list.shift() : this.constructor.apply(this, arguments);
};

FreeList.prototype.free = function(obj) {
  if (this.list.length < this.max) this.list.push(obj);
};

var HTTPParsers = new FreeList("HTTPParsers", 1024, function() {
  var parser = new HTTPParser(HTTPParser.REQUEST);
  parser.onHeadersComplete = function(info) {
    var peer = this.peer;
    peer.info = info
  };
  parser.onMessageComplete = function() {
    var peer = this.peer;
    peer.send(peer.info.shouldKeepAlive?responses.keepalive:responses.close, function(status, handle, req) {
      if(status != 0) {
        var err = new Error("write");
        err.errno = errno;
        console.error(err);
        peer.kill();
        return;
      }
      if(!peer.info.shouldKeepAlive) peer.kill();
    });
  };
  return parser;
});

function onConnection(peer) {
  if(!peer) {
    var err = new Error("accept");
    err.errno = errno;
    console.error(err);
    return;
  }
  setupSocket(peer);
  var parser = HTTPParsers.alloc();
  parser.peer = peer;
  peer.onread = function(buf, start, len) {
    if(!buf) {
      var err = new Error("EOF");
      err.errno = errno;
      console.error(err);
      peer.kill();
      return;
    }
    var r = parser.execute(buf, start, len);
    if(r < 0) {
      var err = new Error("parse");
      console.error(err);
      peer.kill();
      return;
    }
  }
  peer.onerror = function(err) {
    console.error(err);
  }
  peer.onclose = function() {
    HTTPParsers.free(parser);
  }
  peer.readStart();
}

var sock = new TCP();
sock.bind("0.0.0.0", 80);
sock.onconnection = onConnection;
sock.listen();