/* -*- 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, Lars Bisballe Jensen and Peter Skaarup
 *  deva@aasimon.org, elsenator@gmail.com and piparum@piparum.dk
 ****************************************************************************/

/*
 *  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"

// For XML
#include <config.h>

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

#include <stdlib.h>

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

#include "configuration.h"

// For open, read and close
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>

#include "transaction.h"
#include "xmlparser.h"

/**
\section{Data transmission}
En transmission består af en række deltransmissioner som afhænger af
brugerens handling.
\begin{itemize}
\item Klienten beder om en XMLMakro by-name.
\item Serveren genererer makroen og sender den til klienten i en XML
      stream. Forbindelsen lukkes efter end overførsel.
\item Brugeren udfylder input felterne og trykker på ``commit'' eller
      ``abort'' knappen.
\item Hvis der blev trykket ``abort'' lukkes vinduet.
\item Hvis der blev trykket ``commit'' genereres et XML dokument på
      klienten indeholdene alle input felternes navne og deres tilhørende
      værdier.
\item Dette XML dokument sendes til serveren via en nyoprettet forbindelse.
\item Serveren producerer en plaintext klump som repræsenterer
\item Teksten sendes til klienten som appender til den PC-Praxis
      journalfilen.
\item Klienten svarer til serveren at alt gik godt (eller det modsatte) og
      makrovinduet lukkes.
\item Serveren lagrer dataene i en database hvis det gik godt.
\end{itemize}
*/
static void connection(TCPSocket &socket)
{
  printf("Got connection...\n");

  Transaction transaction;
  parse(socket, transaction);

  socket.write("<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n");
  socket.write("<pracro version=\"1.0\">\n");

  // Handle requests
  Requests::iterator i = transaction.requests.begin();
  while(i != transaction.requests.end()) {
    Request request = *i;

    printf("Handling request for \"%s\"...", request.macro.c_str());
    
    // Now handle the request.
    char outbuf[3];
    int bytes;

    std::string macro = std::string(XML) + "/" + request.macro + ".xml";

    int fd = open(macro.c_str(), O_RDONLY);
    if(fd == -1) {
      printf("Cannot open file \"%s\"...", macro.c_str());
      printf("failed!\n");
      i++;
      continue;
    }

    while((bytes = read(fd, outbuf, sizeof(outbuf))) ) {
      socket.write(outbuf, bytes);
    }
    close(fd);

    printf("done.\n");
    
    i++;
  }

  // Handle commits
  Commits::iterator j = transaction.commits.begin();
  while(j != transaction.commits.end()) {
    Commit commit = *j;
    printf("Commit %s\n", commit.macro.c_str());

    CommitValues::iterator k = commit.values.begin();
    while(k != commit.values.end()) {
      CommitValue val = *k;
      printf("\t%s=%s\n", val.name.c_str(), val.value.c_str());
      k++;
    }

    j++;
  }

  socket.write("</pracro>\n");

  printf("Done with connection.\n");
}

void server()
{
  int port;
  try {
    port = config()->lookup("port");
  } catch( ... ) {
    fprintf(stderr, "Could not read port.");
    return;
  }

  TCPSocket *socket;
  
  try {
    socket = new TCPSocket();
    socket->listen(port);
  } catch (Exception &e) {
    fprintf(stderr, "Error during parsing:\n%s\n",
            e.what());
    delete socket;
    return;
  }

  while(socket->connected()) {

    { // Reload if new port i assigned.
      int old_port = port;
      try {
        port = config()->lookup("port");
      } catch( ... ) {
        fprintf(stderr, "Could not read port.");
        return;
      }

      if(port != old_port) {
        // Start listening on the new port
        delete socket;
        socket = new TCPSocket();
        socket->listen(port);
      }
    }

    TCPSocket child = socket->accept();
    if(child.connected()) {
      switch(fork()) {
      case -1: // error
        fprintf(stderr, "Could not fork: %s\n", strerror(errno));
        break;
        
      case 0: // child
        socket->disconnect();
        connection(child);
        delete socket;
        return;
        
      default: // parent
        break;
      }
    }
  }

  delete socket;
  fprintf(stderr, "Oups... dropped out of the main loop\n");
}