#include <boost/asio.hpp>

#define USING_SSL   //是否加密

#ifdef USING_SSL

#include <boost/asio/ssl.hpp>

#endif

using boost::asio::ip::tcp;

using std::string;

int post(const string& host, const string& port, const string& page, const string& data, string& reponse_data)

{

  try

  {

    boost::asio::io_service io_service;

    //如果io_service存在复用的情况

   // if(io_service.stopped())

   //   io_service.reset();

    // 从dns取得域名下的所有ip

    tcp::resolver resolver(io_service);

    tcp::resolver::query query(host, port);

    tcp::resolver::iterator endpoint_iterator = resolver.resolve(query);

	// 尝试连接到其中的某个ip直到成功

#ifdef USING_SSL

	boost::asio::ssl::context context(boost::asio::ssl::context::sslv23);

	context.set_default_verify_paths();

	boost::asio::ssl::stream<boost::asio::ip::tcp::socket> socket(io_service, context);

	socket.set_verify_mode(boost::asio::ssl::context::verify_none);

	boost::asio::connect(socket.lowest_layer(), endpoint_iterator);

	socket.handshake(boost::asio::ssl::stream_base::client);

#else

	tcp::socket socket(io_service);

	boost::asio::connect(socket, endpoint_iterator);

#endif

    // Form the request. We specify the "Connection: close" header so that the

    // server will close the socket after transmitting the response. This will

    // allow us to treat all data up until the EOF as the content.

    boost::asio::streambuf request;

    std::ostream request_stream(&request);

	request_stream << "POST " << page << " HTTP/1.1\r\n";

    request_stream << "Host: " << host << "\r\n";

    request_stream << "Content-Length: " << data.length() << "\r\n";

    // Content-Type: 视实际情况修改，or“application/octet-stream”

    request_stream << "Content-Type: application/json; charset=UTF-8\r\n";

	request_stream << "Accept: */*\r\n";

    request_stream << "Connection: close\r\n\r\n";

    request_stream << data;

    // Send the request.

    boost::asio::write(socket, request);

    // Read the response status line. The response streambuf will automatically

    // grow to accommodate the entire line. The growth may be limited by passing

    // a maximum size to the streambuf constructor.

    boost::asio::streambuf response;

    boost::asio::read_until(socket, response, "\r\n");

    // Check that response is OK.

    std::istream response_stream(&response);

    std::string http_version;

    response_stream >> http_version;

    unsigned int status_code;

    response_stream >> status_code;

    std::string status_message;

    std::getline(response_stream, status_message);

    if (!response_stream || http_version.substr(0, 5) != "HTTP/")

    {

      reponse_data = "Invalid response";

      return -2;

    }

    // 如果服务器返回非200都认为有错,不支持301/302等跳转

    if (status_code != 200)

    {

		std::stringstream oss;

		oss << "Response returned with status code" << " : " << status_code;

		reponse_data = oss.str();

        return -3;

    }

    // 传说中的包头可以读下来了

    std::string header;

    std::vector<string> headers;

//		string content_length_header("Content-Length: ");

//		size_t content_length = 0;

    while (std::getline(response_stream, header) && header != "\r")

	{

		/*	if(string::npos != header.find(content_length_header))

			{

				string tmp(header.substr(content_length_header.size()));

				stringstream ss;

				ss << tmp;

				ss >> content_length;

			}*/

      headers.push_back(header);

	  //std::cout << header << std::endl;

	}

    // 读取所有剩下的数据作为包体

    boost::system::error_code error;

    while (boost::asio::read(socket, response,

        boost::asio::transfer_at_least(1), error))

    {

    }

	// 返回值为eof,认为是正确的

	if (error != boost::asio::error::eof && error.value() != 0x140000db)

	{

		std::stringstream oss;

		oss << error.value() << " : " <<  error.message();

		reponse_data = oss.str();

		return -4;

	}

    //响应有数据

    if (response.size())

    {

      std::istream response_stream(&response);

      std::istreambuf_iterator<char> eos;

      reponse_data = string(std::istreambuf_iterator<char>(response_stream), eos);

    }

  }

  catch(std::exception& e)

  {

    reponse_data = e.what();

      return -1;

  }

  return 0;

}