/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/***************************************************************************
 *            server.cc
 *
 *  Wed Aug 22 12:16:03 CEST 2007
 *  Copyright 2007 Bent Bisballe Nyeng
 *  deva@aasimon.org
 ****************************************************************************/

/*
 *  This file is part of Pracro.
 *
 *  Pracro is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  Pracro is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with Pracro; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA.
 */
#include "server.h"

#include <config.h>

#include "tcpsocket.h"
#include <errno.h>

#include <stdlib.h>

// For fork
#include <sys/types.h>
#include <unistd.h>
#include <string.h>

#include <microhttpd.h>

#include "configuration.h"
#include "transaction.h"
#include "transactionparser.h"
#include "templateparser.h"
#include "macroparser.h"

#include "queryhandler.h"
#include "queryhandlerpracro.h"
#include "queryhandlerpentominos.h"

#include "queryparser.h"
#include "luaquerymapper.h"
#include "database.h"
#include "widgetgenerator.h"
#include "resumeparser.h"
#include "journal_commit.h"
#include "xml_encode_decode.h"

#include "macrolist.h"
#include "templatelist.h"
#include "versionstr.h"
#include "mutex.h"
#include "log.h"

#include "transactionhandler.h"

typedef long long unsigned int sessionid_t;

typedef struct {
   JournalWriter *journalwriter;
} session_t;

struct conn_t {
  Database *db;
  Mutex mutex;
  std::map<sessionid_t, session_t> sessions;
};

static std::string error_box(std::string message)
{
  std::string errorbox =
    "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n"
    "<pracro version=\"1.0\">\n"
    "  <error>" + message + "</error>\n"
    "</pracro>\n";
  return errorbox;
}

static std::string handleConnection(const char *buf, size_t size, struct conn_t *conn,
                                    sessionid_t sid, bool commitsession)
{
  /*
  if(size == 0) 
    return error_box(xml_encode("Empty document received."));
  */
  TCPSocket pentominos_socket;
#ifndef WITHOUT_PENTOMINOS
  pentominos_socket.connect(Conf::pentominos_addr, Conf::pentominos_port);
#endif/*WITHOUT_PENTOMINOS*/

  JournalWriter *journalwriter = NULL;
  conn->mutex.lock();
  if(conn->sessions.find(sid) == conn->sessions.end()) {
    conn->sessions[sid].journalwriter =
      new JournalWriter(Conf::journal_commit_addr.c_str(), Conf::journal_commit_port);
  }
  journalwriter = conn->sessions[sid].journalwriter;
  conn->mutex.unlock();

  MacroList macrolist(Conf::xml_basedir + "/macros");
  TemplateList templatelist(Conf::xml_basedir + "/templates");

  Transaction transaction;
  TransactionParser parser(&transaction);
  
  PRACRO_DEBUG(server, "Read %d bytes from network\n", size);

  std::string res;
  if(size) {
    if(parser.parse(buf, size)) {
      PRACRO_DEBUG(server, "Got complete XML document, %d bytes in current buffer.\n", size);
      
      res = handleTransaction(&transaction, pentominos_socket,
                              *conn->db, *journalwriter, macrolist, templatelist);
    } else {
      PRACRO_ERR(server, "Failed to parse data!\n");
      res = error_box(xml_encode("XML Parse error."));
    }
  }

  if(commitsession) {
    journalwriter->commit();
    delete journalwriter;
    conn->mutex.lock();
    conn->sessions.erase(sid);
    conn->mutex.unlock();
  }

  return res;
}

static int handle_request(void *cls,
                          struct MHD_Connection *con,
                          const char *url,
                          const char *method,
                          const char *version,
                          const char *data,
                          unsigned int *data_size,
                          void **ptr)
{
  struct conn_t *conn = (struct conn_t*)cls;

  PRACRO_DEBUG(httpd,
               "handle_request(url=\"%s\", method=\"%s\","
               " version=\"%s\", data_size=\"%d\")\n",
               url, method, version, *data_size);
  sessionid_t sessionid;
  bool commitsession = false;
  bool sid_ok = true;

  const char *sessionids = MHD_lookup_connection_value(con, MHD_HEADER_KIND, "SessionID");
  if(sessionids == NULL) {
    sessionid = 42;//newSessionID(conn);
  } else {
    sessionid = atoll(sessionids);
    conn->mutex.lock();
    sid_ok = conn->sessions.find(sessionid) != conn->sessions.end();
    conn->mutex.unlock();
  }
  PRACRO_DEBUG(httpd, "SessionID: %llu\n", sessionid);

  const char *session_commit = MHD_lookup_connection_value(con, MHD_HEADER_KIND, "SessionCommit");
  if(session_commit) {
    PRACRO_DEBUG(httpd, "COMMIT: sessionid %llu\n", sessionid);
    commitsession = true;
  }

  std::string reply;
  if(sid_ok) {
    reply = handleConnection(data, *data_size, conn, sessionid, commitsession);
  } else {
    PRACRO_ERR(httpd, "No such sessionid %llu\n", sessionid);
    reply = error_box("No such session ID!");
  }
  
  struct MHD_Response *rsp;
  rsp = MHD_create_response_from_data(reply.length(), (char*)reply.c_str(), MHD_NO, MHD_YES);
  MHD_add_response_header(rsp, MHD_HTTP_HEADER_CONTENT_TYPE, "text/plain; charset=UTF-8");

  char idbuf[32];
  snprintf(idbuf, sizeof(idbuf), "%llu", sessionid);
  MHD_add_response_header(rsp, "SessionID", idbuf);

  int ret = MHD_queue_response(con, MHD_HTTP_OK, rsp);
  MHD_destroy_response(rsp);

  *data_size = 0;

  return ret;
}

static void httpderr(void *arg, const char *fmt, va_list ap)
{
  PRACRO_ERR_VA(server, fmt, ap);
}

extern bool pracro_is_running;
void server()
{
  srand(time(NULL));

  bool forceshutdown = false;
  port_t port = Conf::server_port;

  int flags = MHD_USE_DEBUG | MHD_USE_SELECT_INTERNALLY; // | MHD_USE_PEDANTIC_CHECKS
#ifndef WITHOUT_SSL
  if(Conf::use_ssl) flags |= MHD_USE_SSL;
#endif

  PRACRO_DEBUG(server, "Server running on port %d.\n", port);

  struct conn_t conn;
  conn.db = new Database(Conf::database_backend, Conf::database_addr,
                         "", Conf::database_user, Conf::database_passwd, "");

  struct MHD_Daemon *d;
  d = MHD_start_daemon(flags, port, NULL, NULL,
                       handle_request, &conn,
                       MHD_OPTION_NOTIFY_COMPLETED, NULL, NULL,
                       MHD_OPTION_CONNECTION_LIMIT, Conf::connection_limit,
#ifndef WITHOUT_SSL
                       MHD_OPTION_HTTPS_MEM_KEY, Conf::ssl_key.c_str(),
                       MHD_OPTION_HTTPS_MEM_CERT, Conf::ssl_cert.c_str(),
#endif
                       MHD_OPTION_CONNECTION_TIMEOUT, Conf::connection_timeout,
                       MHD_OPTION_EXTERNAL_LOGGER, httpderr, NULL,
                       MHD_OPTION_END);

  if(!d) {
    PRACRO_ERR(server, "Failed to initialise MHD_start_daemon!\n");
    return;
  }
 again:
  while(pracro_is_running) sleep(1);

  if(!forceshutdown && conn.sessions.size() != 0) {
    char *errbuf;
    if(asprintf(&errbuf, "There are %d live sessions."
                " Kill again to force shutdown.\n",
                conn.sessions.size()) != -1) {
      PRACRO_ERR_LOG(server, "%s", errbuf);
      log(errbuf);
      free(errbuf);
    }
    pracro_is_running = true;
    forceshutdown = true;
    goto again;
  }
  delete conn.db;

  MHD_stop_daemon(d);

  PRACRO_DEBUG(server, "Server gracefully shut down.\n");
}


#ifdef TEST_SERVER

#include <sys/types.h>
#include <signal.h>

bool pracro_is_running = true;

char request[] = 
  "<?xml version='1.0' encoding='UTF-8'?>\n"
  "<pracro cpr=\"2003791613\" version=\"1.0\">\n"
  "  <request macro=\"example\" template=\"example\"/>\n"
  "</pracro>\n";

int main()
{
  Conf::xml_basedir = "../xml/";
  Conf::server_port = 32100; // Make sure wo don't interrupt an already running server.
  Conf::database_backend = "testdb";
  pid_t pid = fork();
  
  switch(pid) {
  case -1: // error
    perror("fork() failed!\n");
    return 1;
    
  case 0: // child
    try {
      server();
    } catch(Exception &e) {
      printf(e.what());
      return 1;
    }
    return 0;
    
  default: // parent
    try {
      //      sleep(1); // Make sure the server is started.
      TCPSocket socket;
      socket.connect("localhost", Conf::server_port);
      
      socket.write(request);

      //      sleep(1); // Make sure the server has handled the request.
      char buf[32];
      memset(buf, 0, sizeof(buf));
      //      while(socket.read(buf, 31, 1000)) {
      while(socket.read(buf, 31, 1000000)) {
        printf(buf); fflush(stdout);
        memset(buf, 0, sizeof(buf));
      }
    } catch(Exception &e) {
      printf(e.what());
      kill(pid, SIGKILL); // Kill the server again.
      return 1;
    }
    kill(pid, SIGKILL); // Kill the server again.
    return 0;
  }
  
  return 1;
}

#endif/*TEST_SERVER*/