/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License. You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied. See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

var constants = require("constants");
var net = require("net");
var tls = require("tls");

var TBufferedTransport = require("./buffered_transport");
var TBinaryProtocol = require("./binary_protocol");
var THeaderProtocol = require("./header_protocol");
var InputBufferUnderrunError = require("./input_buffer_underrun_error");

/**
 * Create a Thrift server which can serve one or multiple services.
 * @param {object} processor - A normal or multiplexedProcessor (must
 *                             be preconstructed with the desired handler).
 * @param {ServerOptions} options - Optional additional server configuration.
 * @returns {object} - The Apache Thrift Multiplex Server.
 */
exports.createMultiplexServer = function (processor, options) {
  var transport =
    options && options.transport ? options.transport : TBufferedTransport;
  var protocol =
    options && options.protocol ? options.protocol : TBinaryProtocol;

  function serverImpl(stream) {
    var self = this;
    stream.on("error", function (err) {
      self.emit("error", err);
    });
    stream.on(
      "data",
      transport.receiver(function (transportWithData) {
        var input = new protocol(transportWithData);
        var outputCb = function (buf) {
          try {
            stream.write(buf);
          } catch (err) {
            self.emit("error", err);
            stream.end();
          }
        };

        var output = new protocol(new transport(undefined, outputCb));
        // Read and write need to be performed on the same transport
        // for THeaderProtocol because we should only respond with
        // headers if the request contains headers
        if (protocol === THeaderProtocol) {
          output = input;
          output.trans.onFlush = outputCb;
        }

        try {
          do {
            processor.process(input, output);
            transportWithData.commitPosition();
          } while (true);
        } catch (err) {
          if (err instanceof InputBufferUnderrunError) {
            //The last data in the buffer was not a complete message, wait for the rest
            transportWithData.rollbackPosition();
          } else if (err.message === "Invalid type: undefined") {
            //No more data in the buffer
            //This trap is a bit hackish
            //The next step to improve the node behavior here is to have
            //  the compiler generated process method throw a more explicit
            //  error when the network buffer is empty (regardles of the
            //  protocol/transport stack in use) and replace this heuristic.
            //  Also transports should probably not force upper layers to
            //  manage their buffer positions (i.e. rollbackPosition() and
            //  commitPosition() should be eliminated in lieu of a transport
            //  encapsulated buffer management strategy.)
            transportWithData.rollbackPosition();
          } else {
            //Unexpected error
            self.emit("error", err);
            stream.end();
          }
        }
      }),
    );

    stream.on("end", function () {
      stream.end();
    });
  }

  if (options && options.tls) {
    if (
      !("secureProtocol" in options.tls) &&
      !("secureOptions" in options.tls)
    ) {
      options.tls.secureProtocol = "SSLv23_method";
      options.tls.secureOptions =
        constants.SSL_OP_NO_SSLv2 | constants.SSL_OP_NO_SSLv3;
    }
    return tls.createServer(options.tls, serverImpl);
  } else {
    return net.createServer(serverImpl);
  }
};

/**
 * Create a single service Apache Thrift server.
 * @param {object} processor - A service class or processor function.
 * @param {ServerOptions} options - Optional additional server configuration.
 * @returns {object} - The Apache Thrift Multiplex Server.
 */
exports.createServer = function (processor, handler, options) {
  if (processor.Processor) {
    processor = processor.Processor;
  }
  return exports.createMultiplexServer(new processor(handler), options);
};
