/*
 * src/instance.c
 *
 * Copyright (C) 2019 Ilja Kartašov <ik@lowenware.com>
 *
 * Project homepage: https://lowenware.com/aisl/
 *
 */

#include <stdlib.h>
#include <stdarg.h>
#include <stdio.h>
#include <string.h>
#include <time.h>
#include <sys/select.h>
#include <sys/time.h>

#ifndef AISL_WITHOUT_SSL
#include <openssl/err.h>
#endif

#include "debug.h"
#include "str-utils.h"
#include "buffer.h"

#include "client.h"
#include "server.h"
//#include "globals.h"
#include "stream.h"
#include "instance.h"


#ifndef AISL_WITHOUT_SSL

static uint32_t m_instances = 0;


static const aisl_ssl_t
aisl_new_ssl( aisl_t instance, const aisl_cfg_ssl_t cfg_ssl)
{
  SSL_CTX * ssl_ctx = NULL;
  aisl_ssl_t * list = instance->ssl,
               ssl;

  /* lookup for existing contexts */
  while( (ssl = *list) )
  {
    if (ssl->key_file && strcmp(ssl->key_file, cfg_ssl->key_file)==0 &&
        ssl->crt_file && strcmp(ssl->crt_file, cfg_ssl->crt_file)==0 )
    {
      ssl_ctx = ssl->ctx;
      break;
    }

    list++;
  }

  ssl = aisl_ssl_new( cfg_ssl->host,
                      cfg_ssl->key_file,
                      cfg_ssl->crt_file,
                      ssl_ctx );

  if (ssl)
  {
    if ( !ssl_ctx && !aisl_ssl_get_ctx(ssl, (void*) instance))
    {
      aisl_ssl_free(ssl);
      ssl = NULL;
    }
  }

  return ssl;
}

#endif


/* Initialization functions */

__attribute__ ((visibility ("default") ))
aisl_t
aisl_new( aisl_cfg_t cfg )
{
  aisl_t instance;

  /* allocate root structure */
  if ( !(instance = calloc(1, sizeof(struct aisl))) )
    goto finally;

  /* allocate servers */
  if ( !(instance->srv = calloc(cfg->srv_cnt+1, sizeof(aisl_server_t))) )
    goto release;

  for (int i=0; i<cfg->srv_cnt; i++)
  {
    DPRINTF("new srv %d", i);
    if (!(instance->srv[i] = aisl_server_new(&cfg->srv[i], instance)))
      goto release;
  }

  #ifndef AISL_WITHOUT_SSL
  if ((m_instances++) == 0)
  {
    SSL_load_error_strings();
    OpenSSL_add_ssl_algorithms();
  }

  if ( !(instance->ssl = calloc(cfg->ssl_cnt+1, sizeof(aisl_ssl_t))) )
    goto release;

  for (int i=0; i<cfg->ssl_cnt; i++)
  {
    DPRINTF("new ssl %d", i);
    if (!(instance->ssl[i] = aisl_new_ssl(instance, &cfg->ssl[i])))
      goto release;
  }
  #endif

  if ( list_init(&instance->client_spool, cfg->client_spool_size) == -1 )
    goto release;

  instance->accept_limit = cfg->client_accept_limit;
  instance->silence_timeout = cfg->client_silence_timeout;
  instance->callback = cfg->callback;
  instance->p_ctx = cfg->p_ctx;

  goto finally;

release:
  aisl_free(instance);
  instance = NULL;

finally:
  return instance;
}


__attribute__ ((visibility ("default") ))
void
aisl_free( aisl_t instance )
{
  if (instance->srv)
  {
    aisl_server_t * srv = instance->srv;

    while (*srv)
    {
      aisl_server_free(*srv);
      srv++;
    }

    free(instance->srv);
  }

  list_release(&instance->client_spool, (list_destructor_t) aisl_client_free );

  #ifndef AISL_WITHOUT_SSL
  if (instance->ssl)
  {
    aisl_ssl_t * ssl = instance->ssl;

    while (*ssl)
    {
      aisl_ssl_free(*ssl);
      ssl++;
    }

    free(instance->ssl);
  }

  if ((--m_instances) == 0)
  {
    EVP_cleanup();
  }

  #endif

  free(instance);
}


#ifndef AISL_WITHOUT_SSL

SSL_CTX *
aisl_get_ssl_ctx( aisl_t instance, const char * host )
{
  aisl_ssl_t * list = instance->ssl,
               ssl;

  if (host)
  {
    while ( (ssl = *list) )
    {
      if (str_cmpi(ssl->host, host) == 0)
      {
        return ssl->ctx;
      }

      list++;
    }
  }

  return NULL;
}

#endif


void
aisl_raise_evt( aisl_t instance, aisl_evt_t const evt )
{
  #ifdef AISL_WITHOUT_STRINGIFIERS
  DPRINTF("! %d", evt->code);
  #else
  DPRINTF("! %s", aisl_evt_code_to_string(evt->code));
  #endif

  if (instance->callback)
    instance->callback(evt, instance->p_ctx);
}


void
aisl_raise( aisl_t          instance,
            void          * source,
            aisl_evt_code_t code,
            aisl_status_t   status )
{
  struct aisl_evt evt;

  evt.source = source;
  evt.code   = code;
  evt.status = status;

  aisl_raise_evt(instance, &evt);
}


__attribute__ ((visibility ("default") ))
aisl_status_t
aisl_run_cycle( aisl_t instance )
{
  aisl_status_t result = AISL_IDLE;

  aisl_server_t * list = instance->srv,
                  srv;
  aisl_client_t cli;

  while ( (srv = *list) )
  {
    cli = NULL;

    if (aisl_server_touch(srv, &cli) != AISL_IDLE)
      result = AISL_SUCCESS;

    if (cli)
    {
      DPRINTF("Accepted %p", (void*)cli);
      if ( list_append(&instance->client_spool, cli) == -1 )
        aisl_client_free(cli);
    }

    list++;
  }

  for (int32_t i=0; i < instance->client_spool.count; i++)
  {
    cli = LIST_INDEX(instance->client_spool, i);

    if (aisl_client_touch(cli, instance->silence_timeout) != AISL_IDLE)
      result = AISL_SUCCESS;

    /* if (aisl_client_is_timed_out( c, instance->silence_timeout ) )
       aisl_raise( instance, c, AISL_EVENT_CLIENT_TIMEOUT );
       */

    if ( !aisl_client_is_online(cli) )
    {
      aisl_client_free( cli );
      list_remove_index(&instance->client_spool, i);
    }
  }

  return result;
}


__attribute__ ((visibility ("default") ))
aisl_status_t
aisl_sleep( aisl_t instance, uint32_t usec )
{
  int maxfd=0,
      sd;
  size_t i;
  struct timeval timeout = {0,usec};

  memset(&timeout, 0, sizeof(struct timeval));
  timeout.tv_usec = usec;

  fd_set  fs;
  FD_ZERO (&fs);

  aisl_server_t * list = instance->srv,
                  srv;

  while ( (srv = *list) )
  {
    sd = aisl_server_get_socket(srv);

    if (sd != -1)
    {
      FD_SET(sd, &fs);
      if (sd > maxfd) maxfd = sd;
    }

    list++;
  }

  for (i=0; i<instance->client_spool.count; i++)
  {
    aisl_client_t c = LIST_INDEX(instance->client_spool, i);
    sd = aisl_client_get_socket(c);
    if (sd != -1)
    {
      FD_SET(sd, &fs);
      if (sd > maxfd) maxfd = sd;
    }
  }

  switch ( select(maxfd+1, &fs, NULL, NULL, &timeout) )
  {
    case -1:
      return AISL_SYSCALL_ERROR;

    case 0:
      return AISL_IDLE;

    default:
      return AISL_SUCCESS;
  }
}