/*
  The oSIP library implements the Session Initiation Protocol (SIP -rfc3261-)
  Copyright (C) 2001,2002,2003  Aymeric MOIZARD jack@atosc.org
  
  This library is free software; you can redistribute it and/or
  modify it under the terms of the GNU Lesser General Public
  License as published by the Free Software Foundation; either
  version 2.1 of the License, or (at your option) any later version.
  
  This library 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
  Lesser General Public License for more details.
  
  You should have received a copy of the GNU Lesser General Public
  License along with this library; if not, write to the Free Software
  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/

#include <osip2/internal.h>

#include <osip2/osip.h>
#include "fsm.h"
#include "xixt.h"

osip_statemachine_t *ict_fsm;

osip_statemachine_t *
__ict_get_fsm ()
{
  return ict_fsm;
}


void
__ict_unload_fsm ()
{
  transition_t *transition;
  osip_statemachine_t *statemachine = __ict_get_fsm ();

  for (transition = statemachine->transitions; transition != NULL; transition = statemachine->transitions)
    {
      REMOVE_ELEMENT(statemachine->transitions, transition);
      osip_free (transition);
    }

  osip_free (statemachine->transitions);
  osip_free (statemachine);
}


void
__ict_load_fsm ()
{
  transition_t *transition;

  ict_fsm = (osip_statemachine_t *) osip_malloc (sizeof (osip_statemachine_t));
  ict_fsm->transitions = NULL;

  /* a new state is needed because a race can happen between
     the timer and the timeout event!
     One day to find out this bug  ;-)
   */
  transition = (transition_t *) osip_malloc (sizeof (transition_t));
  transition->state = ICT_PRE_CALLING;
  transition->type = SND_REQINVITE;
  transition->method = (void (*)(void *, void *)) &ict_snd_invite;
  ADD_ELEMENT (ict_fsm->transitions, transition);
  /*
     transition         = (transition_t *) osip_malloc(sizeof(transition_t));
     transition->state  = ICT_CALLING;
     transition->type   = SND_REQINVITE;
     transition->method = (void(*)(void *,void *))&ict_snd_invite;
     osip_list_add(ict_fsm->transitions,transition,-1);
   */
  transition = (transition_t *) osip_malloc (sizeof (transition_t));
  transition->state = ICT_CALLING;
  transition->type = TIMEOUT_A;
  transition->method = (void (*)(void *, void *)) &osip_ict_timeout_a_event;
  ADD_ELEMENT (ict_fsm->transitions, transition);

  transition = (transition_t *) osip_malloc (sizeof (transition_t));
  transition->state = ICT_CALLING;
  transition->type = TIMEOUT_B;
  transition->method = (void (*)(void *, void *)) &osip_ict_timeout_b_event;
  ADD_ELEMENT (ict_fsm->transitions, transition);

  transition = (transition_t *) osip_malloc (sizeof (transition_t));
  transition->state = ICT_CALLING;
  transition->type = RCV_STATUS_1XX;
  transition->method = (void (*)(void *, void *)) &ict_rcv_1xx;
  ADD_ELEMENT (ict_fsm->transitions, transition);

  transition = (transition_t *) osip_malloc (sizeof (transition_t));
  transition->state = ICT_CALLING;
  transition->type = RCV_STATUS_2XX;
  transition->method = (void (*)(void *, void *)) &ict_rcv_2xx;
  ADD_ELEMENT (ict_fsm->transitions, transition);

  transition = (transition_t *) osip_malloc (sizeof (transition_t));
  transition->state = ICT_CALLING;
  transition->type = RCV_STATUS_3456XX;
  transition->method = (void (*)(void *, void *)) &ict_rcv_3456xx;
  ADD_ELEMENT (ict_fsm->transitions, transition);

  transition = (transition_t *) osip_malloc (sizeof (transition_t));
  transition->state = ICT_PROCEEDING;
  transition->type = RCV_STATUS_1XX;
  transition->method = (void (*)(void *, void *)) &ict_rcv_1xx;
  ADD_ELEMENT (ict_fsm->transitions, transition);

  transition = (transition_t *) osip_malloc (sizeof (transition_t));
  transition->state = ICT_PROCEEDING;
  transition->type = RCV_STATUS_2XX;
  transition->method = (void (*)(void *, void *)) &ict_rcv_2xx;
  ADD_ELEMENT (ict_fsm->transitions, transition);

  transition = (transition_t *) osip_malloc (sizeof (transition_t));
  transition->state = ICT_PROCEEDING;
  transition->type = RCV_STATUS_3456XX;
  transition->method = (void (*)(void *, void *)) &ict_rcv_3456xx;
  ADD_ELEMENT (ict_fsm->transitions, transition);

  transition = (transition_t *) osip_malloc (sizeof (transition_t));
  transition->state = ICT_COMPLETED;
  transition->type = RCV_STATUS_3456XX;
  transition->method = (void (*)(void *, void *)) &ict_retransmit_ack;
  ADD_ELEMENT (ict_fsm->transitions, transition);

  transition = (transition_t *) osip_malloc (sizeof (transition_t));
  transition->state = ICT_COMPLETED;
  transition->type = TIMEOUT_D;
  transition->method = (void (*)(void *, void *)) &osip_ict_timeout_d_event;
  ADD_ELEMENT (ict_fsm->transitions, transition);

}

static void
ict_handle_transport_error (osip_transaction_t * ict, int err)
{
  __osip_transport_error_callback (OSIP_ICT_TRANSPORT_ERROR, ict, err);
  __osip_transaction_set_state (ict, ICT_TERMINATED);
  __osip_kill_transaction_callback (OSIP_ICT_KILL_TRANSACTION, ict);
  /* TODO: MUST BE DELETED NOW */
}

void
ict_snd_invite (osip_transaction_t * ict, osip_event_t * evt)
{
  int i;
  osip_t *osip = (osip_t *) ict->config;

  /* Here we have ict->orig_request == NULL */
  ict->orig_request = evt->sip;

  i = osip->cb_send_message (ict, evt->sip, ict->ict_context->destination,
                             ict->ict_context->port, ict->out_socket);

  if (i == 0)
    {
      __osip_message_callback (OSIP_ICT_INVITE_SENT, ict, ict->orig_request);
      __osip_transaction_set_state (ict, ICT_CALLING);
  } else
    {
      ict_handle_transport_error (ict, i);
    }
}

void
osip_ict_timeout_a_event (osip_transaction_t * ict, osip_event_t * evt)
{
  osip_t *osip = (osip_t *) ict->config;
  int i;

  /* reset timer */
  ict->ict_context->timer_a_length = ict->ict_context->timer_a_length * 2;
  osip_gettimeofday (&ict->ict_context->timer_a_start, NULL);
  add_gettimeofday (&ict->ict_context->timer_a_start,
                    ict->ict_context->timer_a_length);

  /* retransmit REQUEST */
  i =
    osip->cb_send_message (ict, ict->orig_request,
                           ict->ict_context->destination,
                           ict->ict_context->port, ict->out_socket);
  if (i != 0)
    {
      ict_handle_transport_error (ict, i);
      return;
    }

  __osip_message_callback (OSIP_ICT_INVITE_SENT_AGAIN, ict, ict->orig_request);
}

void
osip_ict_timeout_b_event (osip_transaction_t * ict, osip_event_t * evt)
{
  ict->ict_context->timer_b_length = -1;
  ict->ict_context->timer_b_start.tv_sec = -1;

  __osip_message_callback (OSIP_ICT_STATUS_TIMEOUT, ict, evt->sip);
  __osip_transaction_set_state (ict, ICT_TERMINATED);
  __osip_kill_transaction_callback (OSIP_ICT_KILL_TRANSACTION, ict);
}

void
ict_rcv_1xx (osip_transaction_t * ict, osip_event_t * evt)
{
  /* leave this answer to the core application */

  if (ict->last_response != NULL)
    {
      osip_message_free (ict->last_response);
    }
  ict->last_response = evt->sip;
  __osip_message_callback (OSIP_ICT_STATUS_1XX_RECEIVED, ict, evt->sip);
  __osip_transaction_set_state (ict, ICT_PROCEEDING);
}

void
ict_rcv_2xx (osip_transaction_t * ict, osip_event_t * evt)
{
  /* leave this answer to the core application */

  if (ict->last_response != NULL)
    {
      osip_message_free (ict->last_response);
    }
  ict->last_response = evt->sip;

  __osip_message_callback (OSIP_ICT_STATUS_2XX_RECEIVED, ict, evt->sip);

  __osip_transaction_set_state (ict, ICT_TERMINATED);
  __osip_kill_transaction_callback (OSIP_ICT_KILL_TRANSACTION, ict);
}

osip_message_t *
ict_create_ack (osip_transaction_t * ict, osip_message_t * response)
{
  int i;
  osip_message_t *ack;

  i = osip_message_init (&ack);
  if (i != 0)
    return NULL;

  /* Section 17.1.1.3: Construction of the ACK request: */
  i = osip_from_clone (response->from, &(ack->from));
  if (i != 0)
    goto ica_error;
  i = osip_to_clone (response->to, &(ack->to)); /* include the tag! */
  if (i != 0)
    goto ica_error;
  i = osip_call_id_clone (response->call_id, &(ack->call_id));
  if (i != 0)
    goto ica_error;
  i = osip_cseq_clone (response->cseq, &(ack->cseq));
  if (i != 0)
    goto ica_error;
  osip_free (ack->cseq->method);
  ack->cseq->method = osip_strdup ("ACK");

  ack->sip_method = (char *) osip_malloc (5);
  sprintf (ack->sip_method, "ACK");
  ack->sip_version = osip_strdup (ict->orig_request->sip_version);

  ack->status_code = 0;
  ack->reason_phrase = NULL;

  /* MUST copy REQUEST-URI from Contact header! */
  osip_uri_clone (ict->orig_request->req_uri, &(ack->req_uri));

  /* ACK MUST contain only the TOP Via field from original request */
  {
    osip_via_t *via;
    osip_via_t *orig_via;

    osip_message_get_via (ict->orig_request, 0, &orig_via);
    if (orig_via == NULL)
      goto ica_error;
    osip_via_clone (orig_via, &via);
    osip_list_add (&ack->vias, via, -1);
  }

  /* ack MUST contains the ROUTE headers field from the original request */
  /* IS IT TRUE??? */
  /* if the answers contains a set of route (or record route), then it */
  /* should be used instead?? ......May be not..... */
  {
    int pos = 0;
    osip_route_t *route;
    osip_route_t *orig_route;

    while (!osip_list_eol (&ict->orig_request->routes, pos))
      {
        orig_route =
          (osip_route_t *) osip_list_get (&ict->orig_request->routes, pos);
        osip_route_clone (orig_route, &route);
        osip_list_add (&ack->routes, route, -1);
        pos++;
      }
  }

  /* may be we could add some other headers: */
  /* For example "Max-Forward" */

  return ack;
ica_error:
  osip_message_free (ack);
  return NULL;
}

void
ict_rcv_3456xx (osip_transaction_t * ict, osip_event_t * evt)
{
  osip_route_t *route;
  int i;
  osip_t *osip = (osip_t *) ict->config;

  /* leave this answer to the core application */

  if (ict->last_response != NULL)
    osip_message_free (ict->last_response);

  ict->last_response = evt->sip;
  if (ict->state != ICT_COMPLETED)      /* not a retransmission */
    {
      /* automatic handling of ack! */
      osip_message_t *ack = ict_create_ack (ict, evt->sip);

      ict->ack = ack;

      if (ict->ack == NULL)
        {
          __osip_transaction_set_state (ict, ICT_TERMINATED);
          __osip_kill_transaction_callback (OSIP_ICT_KILL_TRANSACTION, ict);
          return;
        }

      /* reset ict->ict_context->destination only if
         it is not yet set. */
      if (ict->ict_context->destination == NULL)
        {
          osip_message_get_route (ack, 0, &route);
          if (route != NULL && route->url != NULL)
            {
              osip_uri_param_t *lr_param;

              osip_uri_uparam_get_byname (route->url, "lr", &lr_param);
              if (lr_param == NULL)
                {
                  /* using uncompliant proxy: destination is the request-uri */
                  route = NULL;
                }
            }

          if (route != NULL && route->url != NULL)
            {
              int port = 5060;

              if (route->url->port != NULL)
                port = osip_atoi (route->url->port);
              osip_ict_set_destination (ict->ict_context,
                                        osip_strdup (route->url->host), port);
          } else
            {
              int port = 5060;

              if (ack->req_uri->port != NULL)
                port = osip_atoi (ack->req_uri->port);
              osip_ict_set_destination (ict->ict_context,
                                        osip_strdup (ack->req_uri->host), port);
            }
        }
      i = osip->cb_send_message (ict, ack, ict->ict_context->destination,
                                 ict->ict_context->port, ict->out_socket);
      if (i != 0)
        {
          ict_handle_transport_error (ict, i);
          return;
        }
      if (MSG_IS_STATUS_3XX (evt->sip))
        __osip_message_callback (OSIP_ICT_STATUS_3XX_RECEIVED, ict, evt->sip);
      else if (MSG_IS_STATUS_4XX (evt->sip))
        __osip_message_callback (OSIP_ICT_STATUS_4XX_RECEIVED, ict, evt->sip);
      else if (MSG_IS_STATUS_5XX (evt->sip))
        __osip_message_callback (OSIP_ICT_STATUS_5XX_RECEIVED, ict, evt->sip);
      else
        __osip_message_callback (OSIP_ICT_STATUS_6XX_RECEIVED, ict, evt->sip);

      __osip_message_callback (OSIP_ICT_ACK_SENT, ict, evt->sip);
    }

  /* TEST ME:
     sipevt = osip_fifo_tryget(ict->transactionff);
     if (sipevt==NULL)
     {}
     else if (sipevt->sip==NULL)
     osip_fifo_insert(ict->transactionff, sipevt);
     else if (MSG_IS_RESPONSE(sipevt->sip))
     {
     if (sipevt->sip->status_code==evt->sip->status_code)
     {
     OSIP_TRACE (osip_trace
     (__FILE__, __LINE__, OSIP_WARNING, NULL,
     "discard this clone of late response... callid:%s\n",
     evt->sip->call_id->number));
     osip_message_free(sipevt->sip);
     osip_free(sipevt);
     }
     else
     {
     osip_fifo_insert(ict->transactionff, sipevt);
     }
     }
     else
     osip_fifo_insert(ict->transactionff, sipevt);
   */

  /* start timer D (length is set to MAX (64*DEFAULT_T1 or 32000) */
  osip_gettimeofday (&ict->ict_context->timer_d_start, NULL);
  add_gettimeofday (&ict->ict_context->timer_d_start,
                    ict->ict_context->timer_d_length);
  __osip_transaction_set_state (ict, ICT_COMPLETED);
}

void
osip_ict_timeout_d_event (osip_transaction_t * ict, osip_event_t * evt)
{
  ict->ict_context->timer_d_length = -1;
  ict->ict_context->timer_d_start.tv_sec = -1;

  __osip_transaction_set_state (ict, ICT_TERMINATED);
  __osip_kill_transaction_callback (OSIP_ICT_KILL_TRANSACTION, ict);
}

void
ict_retransmit_ack (osip_transaction_t * ict, osip_event_t * evt)
{
  int i;
  osip_t *osip = (osip_t *) ict->config;

  /* this could be another 3456xx ??? */
  /* we should make a new ACK and send it!!! */
  /* TODO */

  __osip_message_callback (OSIP_ICT_STATUS_3456XX_RECEIVED_AGAIN, ict, evt->sip);

  osip_message_free (evt->sip);

  i = osip->cb_send_message (ict, ict->ack, ict->ict_context->destination,
                             ict->ict_context->port, ict->out_socket);

  if (i == 0)
    {
      __osip_message_callback (OSIP_ICT_ACK_SENT_AGAIN, ict, ict->ack);
      __osip_transaction_set_state (ict, ICT_COMPLETED);
  } else
    {
      ict_handle_transport_error (ict, i);
    }
}