// Main unit test compilation unit
// boost mandates that exactly one compilation unit contains the following two lines:
#define BOOST_TEST_MODULE webserver_test
#include <boost/test/included/unit_test.hpp>

// Support both boost in Debian unstable (BOOST_LATEST) and in stable (boost 1.67)
#if BOOST_VERSION >= 107100
#define BOOST_LATEST
#endif

#include <boost/test/data/dataset.hpp>
#include <boost/test/data/monomorphic.hpp>
#include <boost/test/data/test_case.hpp>

#include <boost/algorithm/string.hpp>
#include <boost/beast/core.hpp>
#include <boost/beast/http.hpp>
#ifdef BOOST_LATEST
#include <boost/beast/ssl.hpp>
#endif
#include <boost/beast/version.hpp>
#include <boost/asio/connect.hpp>
#include <boost/asio/ip/tcp.hpp>
#include <boost/asio/ssl/error.hpp>
#include <boost/asio/ssl/stream.hpp>
#include <boost/property_tree/ptree.hpp>
#include <boost/property_tree/xml_parser.hpp>

#include <fmt/core.h>

#include <chrono>
#include <filesystem>
#include <iostream>
#include <sstream>
#include <string>
#include <thread>

#include <ext/stdio_filebuf.h>
#include <signal.h>
#include <sys/wait.h>
#include <unistd.h>

#include <libreichwein/file.h>

#include "webserver.h"

using namespace std::string_literals;
namespace fs = std::filesystem;
namespace pt = boost::property_tree;
using namespace boost::unit_test;
using namespace Reichwein;

class WebserverProcess
{
public:
 const fs::path testConfigFilename{"./webserver.conf"};
 WebserverProcess(): m_pid{}
 {
  File::setFile(testConfigFilename, R"CONFIG(<webserver>
 <user>www-data</user>
 <group>www-data</group>
 <threads>10</threads>
 <plugin-directory>../plugins</plugin-directory>
 <sites>
  <site>
   <name>localhost</name>
   <host>ip6-localhost</host>
   <host>localhost</host>
   <host>127.0.0.1</host>
   <host>[::1]</host>
   <path requested="/">
    <plugin>static-files</plugin>
    <target>.</target>
   </path>
   <certpath>../fullchain.pem</certpath>
   <keypath>../privkey.pem</keypath>
  </site>
 </sites>
 <sockets>
  <socket>
   <address>127.0.0.1</address>
   <port>8080</port>
   <protocol>http</protocol>
   <site>localhost</site>
  </socket>
  <socket>
   <address>::1</address>
   <port>8080</port>
   <protocol>http</protocol>
   <site>localhost</site>
  </socket>
  <socket>
   <address>127.0.0.1</address>
   <port>8081</port>
   <protocol>https</protocol>
   <site>localhost</site>
  </socket>
  <socket>
   <address>::1</address>
   <port>8081</port>
   <protocol>https</protocol>
   <site>localhost</site>
  </socket>
 </sockets>
</webserver>

)CONFIG");

  start();
 }

 ~WebserverProcess()
 {
  stop();
  fs::remove(testConfigFilename);
 }

 void start()
 {
  if (m_pid != 0)
   throw std::runtime_error("Process already running, so it can't be started");

  // connect stdout of new child process to stream of parent, via pipe
  int filedes[2];
  if (pipe(filedes) == -1)
   throw std::runtime_error("Pipe error");

  m_pid = fork();
  if (m_pid < 0)
   throw std::runtime_error("Fork unsuccessful.");

  if (m_pid == 0) { // child process branch
                    //
   if (close(filedes[0]) == -1)
    throw std::runtime_error("Child can't close read end of pipe");

   // Replace stdout of child with pipe input (next 2 commands)
   if (close(1) == -1)
    throw std::runtime_error("Child can't close stdout");
   if (dup(filedes[1]) == -1)
    throw std::runtime_error("Child replace stdout w/ pipe input");

   char* argv[] = {(char*)"webserver", (char*)"-c", (char*)"./webserver.conf"};
   webserver(sizeof(argv) / sizeof(char*), argv);
   exit(0);
  }

  if (close(filedes[1]) == -1)
   throw std::runtime_error("Parent can't close read end of pipe");
  m_filebuf = std::make_shared<__gnu_cxx::stdio_filebuf<char>>(filedes[0], std::ios::in);
  m_is = std::make_shared<std::istream>(&(*m_filebuf));

  // wait for server to start up
  std::this_thread::sleep_for(std::chrono::milliseconds(100));
 }

 void stop()
 {
  if (m_pid == 0)
   throw std::runtime_error("Process not running, so it can't be stopped");
  
  if (kill(m_pid, SIGTERM) != 0)
   throw std::runtime_error("Unable to kill process");

  if (int result = waitpid(m_pid, NULL, 0); result != m_pid)
   throw std::runtime_error("waitpid returned "s + std::to_string(result));

  m_pid = 0;
  m_is = 0;
  m_filebuf = 0;
 }

 bool isRunning()
 {
  if (m_pid == 0)
   return false;

  fs::path pid_file{fmt::format("/proc/{}/stat", m_pid)};
  if (!fs::exists(pid_file))
   return false;

  std::string s{File::getFile(pid_file)};

  auto pos0{s.find(' ', 0)};
  pos0 = s.find(' ', pos0 + 1);
  pos0++;

  auto pos1{s.find(' ', pos0 + 1)};

  std::string state{s.substr(pos0, pos1 - pos0)};

  return state == "R" || state == "S";
 }

 std::string output()
 {
  if (!isRunning())
   throw std::runtime_error("No output/stdout available from webserver since it is not running");

  if (!m_is)
   throw std::runtime_error("Webserver stdout stream not initialized.");

  std::stringstream result;
  std::string buffer(static_cast<std::string::size_type>(1024), '\0');
  int size{};
  while ((size = m_is->readsome(buffer.data(), buffer.size())) > 0)
   result << buffer.substr(0, size);
  return result.str();
 }

private:
 pid_t m_pid;

 // child stdout
 std::shared_ptr<__gnu_cxx::stdio_filebuf<char>> m_filebuf;
 std::shared_ptr<std::istream> m_is;
};

std::pair<std::string,std::string> HTTPGet(const std::string& target, bool ipv6 = true, bool HTTP11 = true)
{
 auto const host = ipv6 ? "::1" : "127.0.0.1"; 
 auto const port = "8080";
 int version = HTTP11 ? 11 : 10;

 // The io_context is required for all I/O
 boost::asio::io_context ioc;

 // These objects perform our I/O
 boost::asio::ip::tcp::resolver resolver(ioc);
 boost::beast::tcp_stream stream(ioc);

 // Look up the domain name
 auto const results = resolver.resolve(host, port);

 // Make the connection on the IP address we get from a lookup
 stream.connect(results);

 // Set up an HTTP GET request message
 boost::beast::http::request<boost::beast::http::string_body> req{boost::beast::http::verb::get, target, version};
 req.set(boost::beast::http::field::host, ipv6 && host == "::1"s ? "["s + host + "]"s : host);
 req.set(boost::beast::http::field::user_agent, "Webserver Testsuite");

 // Send the HTTP request to the remote host
 boost::beast::http::write(stream, req);

 // This buffer is used for reading and must be persisted
 boost::beast::flat_buffer buffer;

 // Declare a container to hold the response
 boost::beast::http::response<boost::beast::http::dynamic_body> res;

 // Receive the HTTP response
 boost::beast::http::read(stream, buffer, res);

 // Return value
 std::ostringstream header_stream;
 header_stream << res.base();
 std::ostringstream body_stream;
 body_stream << boost::beast::buffers_to_string(res.body().data());

 // Gracefully close the socket
 boost::beast::error_code ec;
 stream.socket().shutdown(boost::asio::ip::tcp::socket::shutdown_both, ec);

 // not_connected happens sometimes
 // so don't bother reporting it.
 //
 if (ec && ec != boost::beast::errc::not_connected)
     throw boost::beast::system_error{ec};

 return {header_stream.str(), body_stream.str()};
}

std::pair<std::string,std::string> HTTPSGet(const std::string& target, bool ipv6 = true, bool HTTP11 = true)
{
 auto const host = ipv6 ? "::1" : "127.0.0.1"; 
 auto const port = "8081";
 int version = HTTP11 ? 11 : 10;

 // The io_context is required for all I/O
 boost::asio::io_context ioc;

 // The SSL context is required, and holds certificates
 boost::asio::ssl::context ctx(
#ifdef BOOST_LATEST
                               boost::asio::ssl::context::tlsv13_client
#else
                               boost::asio::ssl::context::tlsv12_client
#endif
                               );

 // This holds the root certificate used for verification
 //load_root_certificates(ctx);

 // Verify the remote server's certificate
 ctx.set_verify_mode(boost::asio::ssl::verify_none); // TODO: ssl::verify_peer w/ load_root_certificates() (above)

 // These objects perform our I/O
 boost::asio::ip::tcp::resolver resolver(ioc);
 boost::beast::ssl_stream<boost::beast::tcp_stream> stream(ioc, ctx);

 // Set SNI Hostname (many hosts need this to handshake successfully)
 if (!SSL_set_tlsext_host_name(stream.native_handle(), host))
 {
  boost::beast::error_code ec{static_cast<int>(::ERR_get_error()), boost::asio::error::get_ssl_category()};
  throw boost::beast::system_error{ec};
 }

 // Look up the domain name
 auto const results = resolver.resolve(host, port);

 // Make the connection on the IP address we get from a lookup
 boost::beast::get_lowest_layer(stream).connect(results);

 // Perform the SSL handshake
 stream.handshake(boost::asio::ssl::stream_base::client);

 // Set up an HTTP GET request message
 boost::beast::http::request<boost::beast::http::string_body> req{boost::beast::http::verb::get, target, version};
 req.set(boost::beast::http::field::host,  ipv6 && host == "::1"s ? "["s + host + "]"s : host);
 req.set(boost::beast::http::field::user_agent, "Webserver Testsuite");

 // Send the HTTP request to the remote host
 boost::beast::http::write(stream, req);

 // This buffer is used for reading and must be persisted
 boost::beast::flat_buffer buffer;

 // Declare a container to hold the response
 boost::beast::http::response<boost::beast::http::dynamic_body> res;

 // Receive the HTTP response
 boost::beast::http::read(stream, buffer, res);

 // Return value
 std::ostringstream header_stream;
 header_stream << res.base();
 std::ostringstream body_stream;
 body_stream << boost::beast::buffers_to_string(res.body().data());

 // Gracefully close the stream
 boost::beast::error_code ec;
 stream.shutdown(ec);
 if (ec == boost::asio::error::eof)
 {
  // Rationale:
  // http://stackoverflow.com/questions/25587403/boost-asio-ssl-async-shutdown-always-finishes-with-an-error
  ec = {};
 }
 if (ec)
  throw boost::beast::system_error{ec};
 
 return {header_stream.str(), body_stream.str()};
}

class Fixture
{
public:
 Fixture(){}
 ~Fixture(){}
};

BOOST_DATA_TEST_CASE_F(Fixture, http_get, data::make({false, true}) * data::make({false, true}) * data::make({false, true}), ipv6, http11, https)
{
 WebserverProcess serverProcess;

 BOOST_REQUIRE(serverProcess.isRunning());
 auto response{(https ? HTTPSGet("/webserver.conf") : HTTPGet("/webserver.conf"))};
 BOOST_REQUIRE(serverProcess.isRunning());
 BOOST_REQUIRE_EQUAL(response.first, "HTTP/1.1 200 OK\r\nServer: Reichwein.IT Webserver " VERSION "\r\nContent-Type: application/text\r\nContent-Length: 1021\r\n\r\n");
 BOOST_REQUIRE_EQUAL(response.second, File::getFile(serverProcess.testConfigFilename));
 auto output{serverProcess.output()};
 BOOST_REQUIRE_MESSAGE(boost::algorithm::contains(output, "Serving"), "Bad output: "s + output);
}

BOOST_DATA_TEST_CASE_F(Fixture, http_get_file_not_found, data::make({false, true}) * data::make({false, true}) * data::make({false, true}), ipv6, http11, https)
{
 WebserverProcess serverProcess;

 BOOST_REQUIRE(serverProcess.isRunning());
 BOOST_REQUIRE(!fs::exists("./webserver.confSUFFIX"));
 auto response{(https ? HTTPSGet("/webserver.confSUFFIX") : HTTPGet("/webserver.confSUFFIX"))};
 BOOST_REQUIRE(serverProcess.isRunning());
 BOOST_REQUIRE_EQUAL(response.first, "HTTP/1.1 404 Not Found\r\nServer: Reichwein.IT Webserver " VERSION "\r\nContent-Type: text/html\r\nContent-Length: 36\r\n\r\n");
 BOOST_REQUIRE_EQUAL(response.second, "404 Not found: /webserver.confSUFFIX");
 auto output{serverProcess.output()};
 BOOST_REQUIRE_MESSAGE(boost::algorithm::contains(output, "Serving"), "Bad output: "s + output);
}