#include "world.h"

#include <ctype.h>
#include <dlfcn.h>
#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <unistd.h>

/* Utility function for showing the marshalled states as hex code */
static void shx(uint8_t *state, uint32_t sz)
{
  uint32_t i = 0;
  while (i < sz) {
    for (int j = 0; j < 16; ++j) {
      if (i < sz) {
        printf("%02x ", (unsigned int)state[i]);
      }
      else {
        printf("   ");
      }
      ++i;
    }

    i -= 16;

    printf("   ");

    for (int j = 0; j < 16; ++j) {
      if (i < sz) {
        if (isprint(state[i]) && !isspace(state[i])) {
          printf("%c", state[i]);
        }
        else {
          printf(".");
        }
      }
      else {
        printf(" ");
      }
      ++i;
    }
    printf("\n");
  }
}

int load_world_from_dl_(dlhandle_t dl, world_t *world);

static void lock(world_t *world) { pthread_mutex_lock(&world->lock); };

static void unlock(world_t *world) { pthread_mutex_unlock(&world->lock); };

static int load_world_from_file_(int argc, char **argv, const char *filename,
                                 world_t *world)
{
  dlhandle_t lib = dlopen(filename, RTLD_NOW | RTLD_GLOBAL);
  int ec = 0;

  if (!lib) {
    fprintf(stderr, "Failed to open library: %s: %s\n", filename, dlerror());
    ec = 1;
    goto end;
  }

  printf("Loading file.\n");
  ec = load_world_from_dl_(lib, world);

  if (ec) {
    goto end;
  }

  strncpy(world->filename, filename, sizeof(world->filename));
  world->argc = argc;
  world->argv = argv;

  world->arkworld_export_load(world->argc, world->argv);
end:
  return ec;
}

static void maybe_run_metaload(int argc, char **argv, world_t *world)
{
  static char *loaded_worlds[12];
  int i;
  for (i = 0; i < 12 && loaded_worlds[i]; ++i) {
    if (strcmp(loaded_worlds[i], world->world_name) == 0) {
      return; // World is already loaded
    }
  }
  loaded_worlds[i] = strdup(world->world_name);

  printf("First time loading %s, running metaload.\n", world->world_name);
  if (world->arkworld_export_metaload) {
    world->arkworld_export_metaload(argc, argv);
  }
}

int load_world_from_file(int argc, char **argv, const char *filename,
                         world_t *world)
{
  memset(world, 0, sizeof(*world));

  pthread_mutexattr_t attr;
  if (pthread_mutexattr_init(&attr)) {
    perror("pthread_mutexattr_init");
    return 1;
  }

  if (pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE)) {
    perror("pthread_mutexattr_settype");
    return 1;
  }

  if (pthread_mutex_init(&world->lock, &attr)) {
    pthread_mutexattr_destroy(&attr);
    perror("pthread_mutexattr_init");
    return 1;
  }
  pthread_mutexattr_destroy(&attr);
  int rc = load_world_from_file_(argc, argv, filename, world);

  if (rc == 0) {
    maybe_run_metaload(argc, argv, world);
  }

  return rc;
}

int world_hot_reload_same_state(world_t *world)
{
  char filename_cpy[PATH_MAX];
  strncpy(filename_cpy, world->filename, sizeof(filename_cpy));
  return world_hot_reload(world->argc, world->argv, filename_cpy, world);
}

int world_hot_reload(int argc, char **argv, const char *filepath,
                     world_t *world)
{
  int ec = 0;
  uint32_t sz = 0;
  uint8_t *marshalled_state = NULL;

  printf("Hot Reloading %s\n", world->world_name);
  lock(world);

  printf("Marshalling state ...\n");
  marshalled_state = world->arkworld_export_preserve(world->state, &sz);

  printf("Calling teardown ...\n");
  world->arkworld_export_release(world->state);

  printf("State Marshalled:\n");
  shx(marshalled_state, sz);

  printf("Unloading old library handle.\n");
  if (dlclose(world->library_handle)) {
    printf("Could not close library handle: %s\n", dlerror());
  }

  if ((ec = load_world_from_file_(argc, argv, filepath, world))) {
    goto fail;
  }

  printf("Hot starting world ...\n");
  world->state = world->arkworld_export_rebirth(world, marshalled_state, sz);

fail:
  free(marshalled_state);
  unlock(world);
  return ec;
}

void world_run_requested_actions(world_t *world)
{
  lock(world);
  requested_action_t requested_actions[MAX_QUEUED_ACTIONS];
  size_t n_requested_actions = world->n_requested_actions;
  memcpy(&requested_actions, world->requested_actions,
         sizeof(requested_actions));
  world->n_requested_actions = 0;
  unlock(world);

  size_t i;
  for (i = 0; i < n_requested_actions; ++i) {
    requested_actions[i].action(world, requested_actions[i].str_arg);
    if (requested_actions[i].arg_dtor) {
      requested_actions[i].arg_dtor(requested_actions[i].ptr_arg);
    }
  }
}

void world_cold_start(world_t *world)
{
  lock(world);
  world->state = world->arkworld_export_enworld(world);
  unlock(world);
}