/*
  The oSIP library implements the Session Initiation Protocol (SIP -rfc3261-)
  Copyright (C) 2001-2020 Aymeric MOIZARD amoizard@antisip.com

  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 <osip2/osip_dialog.h>

void osip_dialog_set_state(osip_dialog_t *dialog, state_t state) {
  if (dialog == NULL)
    return;

  dialog->state = state;
}

int osip_dialog_update_route_set_as_uas(osip_dialog_t *dialog, osip_message_t *invite) {
  osip_contact_t *contact;
  int i;

  if (dialog == NULL)
    return OSIP_BADPARAMETER;

  if (invite == NULL)
    return OSIP_BADPARAMETER;

  if (osip_list_eol(&invite->contacts, 0)) {
    OSIP_TRACE(osip_trace(__FILE__, __LINE__, OSIP_WARNING, NULL, "missing a contact in invite!\n"));

  } else {
    if (dialog->remote_contact_uri != NULL) {
      osip_contact_free(dialog->remote_contact_uri);
    }

    dialog->remote_contact_uri = NULL;
    contact = osip_list_get(&invite->contacts, 0);
    i = osip_contact_clone(contact, &(dialog->remote_contact_uri));

    if (i != 0)
      return i;
  }

  return OSIP_SUCCESS;
}

int osip_dialog_update_osip_cseq_as_uas(osip_dialog_t *dialog, osip_message_t *invite) {
  if (dialog == NULL)
    return OSIP_BADPARAMETER;

  if (invite == NULL || invite->cseq == NULL || invite->cseq->number == NULL)
    return OSIP_BADPARAMETER;

  dialog->remote_cseq = osip_atoi(invite->cseq->number);
  return OSIP_SUCCESS;
}

int osip_dialog_update_route_set_as_uac(osip_dialog_t *dialog, osip_message_t *response) {
  /* only the remote target URI is updated here... */
  osip_contact_t *contact;
  int i;

  if (dialog == NULL)
    return OSIP_BADPARAMETER;

  if (response == NULL)
    return OSIP_BADPARAMETER;

  if (osip_list_eol(&response->contacts, 0)) { /* no contact header in response? */
    OSIP_TRACE(osip_trace(__FILE__, __LINE__, OSIP_WARNING, NULL, "missing a contact in response!\n"));

  } else {
    /* I personally think it's a bad idea to keep the old
       value in case the new one is broken... */
    if (dialog->remote_contact_uri != NULL) {
      osip_contact_free(dialog->remote_contact_uri);
    }

    dialog->remote_contact_uri = NULL;
    contact = osip_list_get(&response->contacts, 0);
    i = osip_contact_clone(contact, &(dialog->remote_contact_uri));

    if (i != 0)
      return i;
  }

  if (dialog->state == DIALOG_EARLY && osip_list_size(&dialog->route_set) > 0) {
    osip_list_special_free(&dialog->route_set, (void (*)(void *)) & osip_record_route_free);
    osip_list_init(&dialog->route_set);
  }

  if (dialog->state == DIALOG_EARLY && osip_list_size(&dialog->route_set) == 0) { /* update the route set */
    int pos = 0;

    while (!osip_list_eol(&response->record_routes, pos)) {
      osip_record_route_t *rr;
      osip_record_route_t *rr2;

      rr = (osip_record_route_t *) osip_list_get(&response->record_routes, pos);
      i = osip_record_route_clone(rr, &rr2);

      if (i != 0)
        return i;

      osip_list_add(&dialog->route_set, rr2, 0);
      pos++;
    }
  }

  if (MSG_IS_STATUS_2XX(response))
    dialog->state = DIALOG_CONFIRMED;

  return OSIP_SUCCESS;
}

int osip_dialog_update_tag_as_uac(osip_dialog_t *dialog, osip_message_t *response) {
  osip_generic_param_t *tag;
  int i;

  if (dialog == NULL)
    return OSIP_BADPARAMETER;

  if (response == NULL || response->to == NULL)
    return OSIP_BADPARAMETER;

  if (dialog->remote_tag != NULL) {
    OSIP_TRACE(osip_trace(__FILE__, __LINE__, OSIP_WARNING, NULL, "This dialog already have a remote tag: it can't be changed!\n"));
    return OSIP_WRONG_STATE;
  }

  i = osip_to_get_tag(response->to, &tag);

  if (i != 0 || tag == NULL || tag->gvalue == NULL) {
    OSIP_TRACE(osip_trace(__FILE__, __LINE__, OSIP_WARNING, NULL, "Remote UA is not compliant: missing a tag in response!\n"));
    dialog->remote_tag = NULL;

  } else
    dialog->remote_tag = osip_strdup(tag->gvalue);

  return OSIP_SUCCESS;
}

int osip_dialog_match_as_uac(osip_dialog_t *dlg, osip_message_t *answer) {
  osip_generic_param_t *tag_param_local;
  osip_generic_param_t *tag_param_remote;
  char *tmp;
  int i;

  if (dlg == NULL || dlg->call_id == NULL)
    return OSIP_BADPARAMETER;

  if (answer == NULL || answer->call_id == NULL || answer->from == NULL || answer->to == NULL)
    return OSIP_BADPARAMETER;

  OSIP_TRACE(osip_trace(__FILE__, __LINE__, OSIP_WARNING, NULL, "Using this method is discouraged. See source code explanations!\n"));
  /*
     When starting a new transaction and when receiving several answers,
     you must be prepared to receive several answers from different sources.
     (because of forking).

     Because some UAs are not compliant (a to tag is missing!), this method
     may match the wrong dialog when a dialog has been created with an empty
     tag in the To header.

     Personnaly, I would recommend to discard 1xx>=101 answers without To tags!
     Just my own feelings.
   */
  i = osip_call_id_to_str(answer->call_id, &tmp);

  if (i != 0)
    return i;

  if (0 != strcmp(dlg->call_id, tmp)) {
    osip_free(tmp);
    return OSIP_UNDEFINED_ERROR;
  }

  osip_free(tmp);

  /* for INCOMING RESPONSE:
     To: remote_uri;remote_tag
     From: local_uri;local_tag           <- LOCAL TAG ALWAYS EXIST
   */
  i = osip_from_get_tag(answer->from, &tag_param_local);

  if (i != 0)
    return OSIP_SYNTAXERROR;

  if (dlg->local_tag == NULL)
    /* NOT POSSIBLE BECAUSE I MANAGE REMOTE_TAG AND I ALWAYS ADD IT! */
    return OSIP_SYNTAXERROR;

  if (0 != strcmp(tag_param_local->gvalue, dlg->local_tag))
    return OSIP_UNDEFINED_ERROR;

  i = osip_to_get_tag(answer->to, &tag_param_remote);

  if (i != 0 && dlg->remote_tag != NULL) /* no tag in response but tag in dialog */
    return OSIP_SYNTAXERROR;             /* impossible... */

  if (i != 0 && dlg->remote_tag == NULL) { /* no tag in response AND no tag in dialog */
    if (0 == osip_from_compare((osip_from_t *) dlg->local_uri, (osip_from_t *) answer->from) && 0 == osip_from_compare(dlg->remote_uri, answer->to))
      return OSIP_SUCCESS;

    return OSIP_UNDEFINED_ERROR;
  }

  if (dlg->remote_tag == NULL) { /* tag in response BUT no tag in dialog */
    OSIP_TRACE(osip_trace(__FILE__, __LINE__, OSIP_WARNING, NULL, "Remote UA is not compliant: missing a tag in To fields!\n"));

    if (0 == osip_from_compare((osip_from_t *) dlg->local_uri, (osip_from_t *) answer->from) && 0 == osip_from_compare(dlg->remote_uri, answer->to))
      return OSIP_SUCCESS;

    return OSIP_UNDEFINED_ERROR;
  }

  /* we don't have to compare
     remote_uri with from
     && local_uri with to.    ----> we have both tag recognized, it's enough..
   */
  if (0 == strcmp(tag_param_remote->gvalue, dlg->remote_tag))
    return OSIP_SUCCESS;

  return OSIP_UNDEFINED_ERROR;
}

int osip_dialog_match_as_uas(osip_dialog_t *dlg, osip_message_t *request) {
  osip_generic_param_t *tag_param_remote;
  int i;
  char *tmp;

  if (dlg == NULL || dlg->call_id == NULL)
    return OSIP_BADPARAMETER;

  if (request == NULL || request->call_id == NULL || request->from == NULL || request->to == NULL)
    return OSIP_BADPARAMETER;

  i = osip_call_id_to_str(request->call_id, &tmp);

  if (i != 0)
    return i;

  if (0 != strcmp(dlg->call_id, tmp)) {
    osip_free(tmp);
    return OSIP_UNDEFINED_ERROR;
  }

  osip_free(tmp);

  /* for INCOMING REQUEST:
     To: local_uri;local_tag           <- LOCAL TAG ALWAYS EXIST
     From: remote_uri;remote_tag
   */

  if (dlg->local_tag == NULL)
    /* NOT POSSIBLE BECAUSE I MANAGE REMOTE_TAG AND I ALWAYS ADD IT! */
    return OSIP_SYNTAXERROR;

#if 0

  /* VR-2785: use line param to distinguish between two registrations by the same user */
  if (dlg->line_param) {
    osip_uri_param_t *line_param;

    i = osip_uri_param_get_byname(&request->req_uri->url_params, "line", &line_param);

    if (i == 0 && strcmp(dlg->line_param, line_param->gvalue))
      return OSIP_UNDEFINED_ERROR;      /* both dlg and req_uri have line params and they do not match */
  }

#endif

  i = osip_from_get_tag(request->from, &tag_param_remote);

  if (i != 0 && dlg->remote_tag != NULL) /* no tag in request but tag in dialog */
    return OSIP_SYNTAXERROR;             /* impossible... */

  if (i != 0 && dlg->remote_tag == NULL) { /* no tag in request AND no tag in dialog */
    if (0 == osip_from_compare((osip_from_t *) dlg->remote_uri, (osip_from_t *) request->from) && 0 == osip_from_compare(dlg->local_uri, request->to))
      return OSIP_SUCCESS;

    return OSIP_UNDEFINED_ERROR;
  }

  if (dlg->remote_tag == NULL) { /* tag in response BUT no tag in dialog */
    OSIP_TRACE(osip_trace(__FILE__, __LINE__, OSIP_WARNING, NULL, "Remote UA is not compliant: missing a tag in To feilds!\n"));

    if (0 == osip_from_compare((osip_from_t *) dlg->remote_uri, (osip_from_t *) request->from) && 0 == osip_from_compare(dlg->local_uri, request->to))
      return OSIP_SUCCESS;

    return OSIP_UNDEFINED_ERROR;
  }

  /* we don't have to compare
     remote_uri with from
     && local_uri with to.    ----> we have both tag recognized, it's enough..
   */
  if (0 == strcmp(tag_param_remote->gvalue, dlg->remote_tag))
    return OSIP_SUCCESS;

  return OSIP_UNDEFINED_ERROR;
}

static int __osip_dialog_init(osip_dialog_t **dialog, osip_message_t *invite, osip_message_t *response, osip_from_t *local, osip_to_t *remote, osip_message_t *remote_msg) {
  int i;
  int pos;
  osip_generic_param_t *tag;

  *dialog = NULL;

  if (response == NULL)
    return OSIP_BADPARAMETER;

  if (response->cseq == NULL || local == NULL || remote == NULL)
    return OSIP_SYNTAXERROR;

  (*dialog) = (osip_dialog_t *) osip_malloc(sizeof(osip_dialog_t));

  if (*dialog == NULL)
    return OSIP_NOMEM;

  memset(*dialog, 0, sizeof(osip_dialog_t));
  (*dialog)->your_instance = NULL;

  if (MSG_IS_STATUS_2XX(response))
    (*dialog)->state = DIALOG_CONFIRMED;

  else /* 1XX */
    (*dialog)->state = DIALOG_EARLY;

  i = osip_call_id_to_str(response->call_id, &((*dialog)->call_id));

  if (i != 0) {
    OSIP_TRACE(osip_trace(__FILE__, __LINE__, OSIP_ERROR, NULL, "Could not establish dialog!\n"));
    osip_dialog_free(*dialog);
    *dialog = NULL;
    return i;
  }

  i = osip_to_get_tag(local, &tag);

  if (i != 0) {
    OSIP_TRACE(osip_trace(__FILE__, __LINE__, OSIP_ERROR, NULL, "Could not establish dialog!\n"));
    osip_dialog_free(*dialog);
    *dialog = NULL;
    return i;
  }

  (*dialog)->local_tag = osip_strdup(tag->gvalue);

  i = osip_from_get_tag(remote, &tag);

  if (i == 0)
    (*dialog)->remote_tag = osip_strdup(tag->gvalue);

  /* VR-2785: remember line value */
  if (invite) {
    osip_uri_param_t *line_param;

    i = osip_uri_param_get_byname(&invite->req_uri->url_params, "line", &line_param);

    if (i == 0 && line_param != NULL && line_param->gvalue != NULL)
      (*dialog)->line_param = osip_strdup(line_param->gvalue);
  }

  osip_list_init(&(*dialog)->route_set);

  pos = 0;

  while (!osip_list_eol(&response->record_routes, pos)) {
    osip_record_route_t *rr;
    osip_record_route_t *rr2;

    rr = (osip_record_route_t *) osip_list_get(&response->record_routes, pos);
    i = osip_record_route_clone(rr, &rr2);

    if (i != 0) {
      OSIP_TRACE(osip_trace(__FILE__, __LINE__, OSIP_ERROR, NULL, "Could not establish dialog!\n"));
      osip_dialog_free(*dialog);
      *dialog = NULL;
      return i;
    }

    if (invite == NULL)
      osip_list_add(&(*dialog)->route_set, rr2, 0);

    else
      osip_list_add(&(*dialog)->route_set, rr2, -1);

    pos++;
  }

  /* local_cseq is set to response->cseq->number for better
     handling of bad UA */
  (*dialog)->local_cseq = osip_atoi(response->cseq->number);

  i = osip_from_clone(remote, &((*dialog)->remote_uri));

  if (i != 0) {
    OSIP_TRACE(osip_trace(__FILE__, __LINE__, OSIP_ERROR, NULL, "Could not establish dialog!\n"));
    osip_dialog_free(*dialog);
    *dialog = NULL;
    return i;
  }

  i = osip_to_clone(local, &((*dialog)->local_uri));

  if (i != 0) {
    OSIP_TRACE(osip_trace(__FILE__, __LINE__, OSIP_ERROR, NULL, "Could not establish dialog!\n"));
    osip_dialog_free(*dialog);
    *dialog = NULL;
    return i;
  }

  {
    osip_contact_t *contact;

    if (!osip_list_eol(&remote_msg->contacts, 0)) {
      contact = osip_list_get(&remote_msg->contacts, 0);
      i = osip_contact_clone(contact, &((*dialog)->remote_contact_uri));

      if (i != 0) {
        OSIP_TRACE(osip_trace(__FILE__, __LINE__, OSIP_ERROR, NULL, "Could not establish dialog!\n"));
        osip_dialog_free(*dialog);
        *dialog = NULL;
        return i;
      }

    } else {
      (*dialog)->remote_contact_uri = NULL;
      OSIP_TRACE(osip_trace(__FILE__, __LINE__, OSIP_WARNING, NULL, "Remote UA is not compliant: missing a contact in remote message!\n"));
    }
  }

  (*dialog)->secure = -1; /* non secure */

  return OSIP_SUCCESS;
}

int osip_dialog_init_as_uac(osip_dialog_t **dialog, osip_message_t *response) {
  int i;

  i = __osip_dialog_init(dialog, NULL, response, response->from, response->to, response);

  if (i != 0) {
    *dialog = NULL;
    return i;
  }

  (*dialog)->type = CALLER;
  (*dialog)->remote_cseq = -1;

  return OSIP_SUCCESS;
}

/* SIPIT13 */
int osip_dialog_init_as_uac_with_remote_request(osip_dialog_t **dialog, osip_message_t *next_request, int local_cseq) {
  int i;

  *dialog = NULL;

  if (next_request->cseq == NULL)
    return OSIP_BADPARAMETER;

  i = __osip_dialog_init(dialog, next_request, next_request, next_request->to, next_request->from, next_request);

  if (i != 0) {
    *dialog = NULL;
    return i;
  }

  (*dialog)->type = CALLER;
  (*dialog)->state = DIALOG_CONFIRMED;

  (*dialog)->local_cseq = local_cseq; /* -1 osip_atoi (xxx->cseq->number); */
  (*dialog)->remote_cseq = osip_atoi(next_request->cseq->number);

  return OSIP_SUCCESS;
}

int osip_dialog_init_as_uas(osip_dialog_t **dialog, osip_message_t *invite, osip_message_t *response) {
  int i;

  *dialog = NULL;

  if (response->cseq == NULL)
    return OSIP_SYNTAXERROR;

  i = __osip_dialog_init(dialog, invite, response, response->to, response->from, invite);

  if (i != 0) {
    *dialog = NULL;
    return i;
  }

  (*dialog)->type = CALLEE;
  (*dialog)->remote_cseq = osip_atoi(response->cseq->number);

  return OSIP_SUCCESS;
}

void osip_dialog_free(osip_dialog_t *dialog) {
  if (dialog == NULL)
    return;

  osip_contact_free(dialog->remote_contact_uri);
  osip_from_free(dialog->local_uri);
  osip_to_free(dialog->remote_uri);
  osip_list_special_free(&dialog->route_set, (void (*)(void *)) & osip_record_route_free);
  osip_free(dialog->line_param);
  osip_free(dialog->remote_tag);
  osip_free(dialog->local_tag);
  osip_free(dialog->call_id);
  osip_free(dialog);
}