#include <botan/tls_server.h>
#include <botan/tls_client.h>
#include <botan/pkcs10.h>
#include <botan/x509self.h>
#include <botan/rsa.h>
#include <botan/x509_ca.h>
#include <botan/hex.h>

#include "validate.h"
#include <iostream>
#include <vector>
#include <memory>

using namespace Botan;

namespace {

class Credentials_Manager_Test : public Botan::Credentials_Manager
   {
   public:
      Credentials_Manager_Test(const X509_Certificate& server_cert,
                               const X509_Certificate& ca_cert,
                               Private_Key* server_key) :
         m_server_cert(server_cert),
         m_ca_cert(ca_cert),
         m_key(server_key)
         {
         }

      std::vector<X509_Certificate>
      trusted_certificate_authorities(const std::string&,
                                      const std::string&) override
         {
         std::vector<X509_Certificate> certs;
         certs.push_back(m_ca_cert);
         return certs;
         }

      std::vector<X509_Certificate> cert_chain(
         const std::vector<std::string>& cert_key_types,
         const std::string& type,
         const std::string&) override
         {
         std::vector<X509_Certificate> chain;

         if(type == "tls-server")
            {
            bool have_match = false;
            for(size_t i = 0; i != cert_key_types.size(); ++i)
               if(cert_key_types[i] == m_key->algo_name())
                  have_match = true;

            if(have_match)
               {
               chain.push_back(m_server_cert);
               chain.push_back(m_ca_cert);
               }
            }

         return chain;
         }

      void verify_certificate_chain(
         const std::string& type,
         const std::string& purported_hostname,
         const std::vector<Botan::X509_Certificate>& cert_chain) override
         {
         try
            {
            Credentials_Manager::verify_certificate_chain(type,
                                                          purported_hostname,
                                                          cert_chain);
            }
         catch(std::exception& e)
            {
            std::cout << "Certificate verification failed - " << e.what() << " - but will ignore\n";
            }
         }

      Private_Key* private_key_for(const X509_Certificate&,
                                   const std::string&,
                                   const std::string&) override
         {
         return m_key;
         }
   public:
      X509_Certificate m_server_cert, m_ca_cert;
      Private_Key* m_key;
   };

Credentials_Manager* create_creds(RandomNumberGenerator& rng)
   {
   std::auto_ptr<Private_Key> ca_key(new RSA_PrivateKey(rng, 1024));

   X509_Cert_Options ca_opts;
   ca_opts.common_name = "Test CA";
   ca_opts.country = "US";
   ca_opts.CA_key(1);

   X509_Certificate ca_cert =
      X509::create_self_signed_cert(ca_opts,
                                    *ca_key,
                                    "SHA-256",
                                    rng);

   Private_Key* server_key = new RSA_PrivateKey(rng, 1024);

   X509_Cert_Options server_opts;
   server_opts.common_name = "localhost";
   server_opts.country = "US";

   PKCS10_Request req = X509::create_cert_req(server_opts,
                                              *server_key,
                                              "SHA-256",
                                              rng);

   X509_CA ca(ca_cert, *ca_key, "SHA-256");

   auto now = std::chrono::system_clock::now();
   X509_Time start_time(now);
   typedef std::chrono::duration<int, std::ratio<31556926>> years;
   X509_Time end_time(now + years(1));

   X509_Certificate server_cert = ca.sign_request(req,
                                                  rng,
                                                  start_time,
                                                  end_time);

   return new Credentials_Manager_Test(server_cert, ca_cert, server_key);
   }


void test_handshake(RandomNumberGenerator& rng)
   {
   TLS::Policy default_policy;

   std::auto_ptr<Credentials_Manager> creds(create_creds(rng));

   TLS::Session_Manager_In_Memory server_sessions;
   TLS::Session_Manager_In_Memory client_sessions;

   std::vector<byte> c2s_q, s2c_q, c2s_data, s2c_data;

   auto handshake_complete = [](const TLS::Session& session) -> bool
   {
      std::cout << "Handshake complete, " << session.version().to_string()
      << " using " << session.ciphersuite().to_string() << "\n";

      if(!session.session_id().empty())
         std::cout << "Session ID " << hex_encode(session.session_id()) << "\n";

      if(!session.session_ticket().empty())
         std::cout << "Session ticket " << hex_encode(session.session_ticket()) << "\n";

      return true;
   };

   auto save_server_data = [&](const byte buf[], size_t sz, TLS::Alert alert)
   {
      c2s_data.insert(c2s_data.end(), buf, buf+sz);
      if(alert.is_valid())
         std::cout << "Server recvd alert " << alert.type_string() << "\n";
   };

   auto save_client_data = [&](const byte buf[], size_t sz, TLS::Alert alert)
   {
      s2c_data.insert(s2c_data.end(), buf, buf+sz);
      if(alert.is_valid())
         std::cout << "Client recvd alert " << alert.type_string() << "\n";
   };

   TLS::Server server([&](const byte buf[], size_t sz)
                      { s2c_q.insert(s2c_q.end(), buf, buf+sz); },
                      save_server_data,
                      handshake_complete,
                      server_sessions,
                      *creds,
                      default_policy,
                      rng);

   TLS::Client client([&](const byte buf[], size_t sz)
                      { c2s_q.insert(c2s_q.end(), buf, buf+sz); },
                      save_client_data,
                      handshake_complete,
                      client_sessions,
                      *creds,
                      default_policy,
                      rng);

   while(true)
      {
      if(client.is_active())
         client.send("1");
      if(server.is_active())
         server.send("2");

      /*
      * Use this as a temp value to hold the queues as otherwise they
      * might end up appending more in response to messages during the
      * handshake.
      */
      std::vector<byte> input;
      std::swap(c2s_q, input);

      try
         {
         server.received_data(&input[0], input.size());
         }
      catch(std::exception& e)
         {
         std::cout << "Server error - " << e.what() << "\n";
         break;
         }

      input.clear();
      std::swap(s2c_q, input);

      try
         {
         client.received_data(&input[0], input.size());
         }
      catch(std::exception& e)
         {
         std::cout << "Client error - " << e.what() << "\n";
         break;
         }

      if(c2s_data.size())
         {
         if(c2s_data[0] != '1')
            {
            std::cout << "Error\n";
            break;
            }
         }

      if(s2c_data.size())
         {
         if(s2c_data[0] != '2')
            {
            std::cout << "Error\n";
            break;
            }
         }

      if(s2c_data.size() && c2s_data.size())
         break;
      }
   }

}

size_t do_tls_tests(RandomNumberGenerator& rng)
   {
   size_t errors = 0;

   std::cout << "TLS tests: ";

   test_handshake(rng);

   std::cout << std::endl;

   return errors;
   }