// deleted/main.cc
// This file is part of Decimail; see http://decimail.org
// (C) 2004-2007 Philip Endecott
 
// This program 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
// any later version.
//
// This program 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 this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.


#include "DmDatabase.hh"
#include "Configuration.hh"

#include "select.hh"

#include <syslog.h>

using namespace std;
using namespace pbe;


static void delete_message(int msg_id)
{
  assert(msg_id<1000000);
  char numstr[7];
  sprintf(numstr,"%06d",msg_id);
  string fn = Configuration::singleton().get_str("message_backup_dir");
  fn += numstr[0];
  fn += numstr[1];
  fn += "/";
  fn += numstr[2];
  fn += numstr[3];
  fn += "/";
  fn += numstr[4];
  fn += numstr[5];

  syslog(LOG_INFO,"Deleting %s",fn.c_str());
  int rc = unlink(fn.c_str());
  if (rc) {
    throw_ErrnoException("unlink("+fn+")");
  }
}


static void wait_for_any_pending(DmDatabase& db)
{
  while (1) {
    bool timed_out = db.get_fd().wait_until_readable_or_timeout(1000.0);
    if (timed_out) {
      return;
    }
    string n = db.get_any_notification();
    if (n=="delete_log") {
      return;
    }
  }
}


static void delete_any_pending(DmDatabase& db)
{
  Transaction t(db);

  Query<int> delete_from_delete_log
    (db, "delete from delete_log where msg_id=$1");

  ColumnQuery<int> q(db, "select msg_id from delete_log for update");
  typedef ColumnResult<int> col_t;
  col_t r = q.runonce();

  for (col_t::const_iterator i=r.begin();
       i != r.end(); ++i) {
    int m = *i;
    delete_message(m);
    delete_from_delete_log(m);
  }

  t.commit();
}



int main(int argc, char* argv[])
{
  try { try {
  
    openlog("dmdeleted",LOG_PID,LOG_MAIL);
    syslog(LOG_INFO,"Decimail deleted starting");

    for (int i=1; i<argc; ++i) {
      string arg = argv[i];
      DmDatabase::add_connection_string(arg);
    }

    DmDatabase db;

    Configuration::singleton().load();

    Query<> listen
      (db,"listen delete_log");
    listen();
    
    while(1) {
      delete_any_pending(db);
      wait_for_any_pending(db);
    }

  } RETHROW_MISC_EXCEPTIONS }
  catch (Exception& E) {
    ostringstream err_msg;
    E.report(err_msg);
    syslog(LOG_CRIT,"Decimail deleted failed: %s",err_msg.str().c_str());
    exit(1);
  }
}