/* GStreamer
 *
 * Copyright (C) 2013 Collabora Ltd.
 *  Author: Thiago Sousa Santos <thiago.sousa.santos@collabora.com>
 *
 * validate.c - Validate generic functions
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library 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
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library 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.
 */
/**
 * SECTION:validate
 * @short_description: Initialize GstValidate
 */

#ifdef HAVE_CONFIG_H
#  include "config.h"
#endif /* HAVE_CONFIG_H */

#include <string.h>
/* For g_stat () */
#include <glib/gstdio.h>
#include <sys/types.h>
#include <sys/stat.h>

#include "validate.h"
#include "gst-validate-utils.h"
#include "gst-validate-internal.h"

#ifdef G_OS_WIN32
#define WIN32_LEAN_AND_MEAN     /* prevents from including too many things */
#include <windows.h>            /* GetStdHandle, windows console */
HMODULE _priv_gstvalidate_dll_handle = NULL;
#endif /* G_OS_WIN32 */

GST_DEBUG_CATEGORY (gstvalidate_debug);

static GMutex _gst_validate_registry_mutex;
static GstRegistry *_gst_validate_registry_default = NULL;

static GList *core_config = NULL;
static gboolean validate_initialized = FALSE;
GstClockTime _priv_start_time;

#ifdef G_OS_WIN32
BOOL WINAPI DllMain (HINSTANCE hinstDLL, DWORD fdwReason, LPVOID lpvReserved);
BOOL WINAPI
DllMain (HINSTANCE hinstDLL, DWORD fdwReason, LPVOID lpvReserved)
{
  if (fdwReason == DLL_PROCESS_ATTACH)
    _priv_gstvalidate_dll_handle = (HMODULE) hinstDLL;

  return TRUE;
}
#endif /* G_OS_WIN32 */

static GstRegistry *
gst_validate_registry_get (void)
{
  GstRegistry *registry;

  g_mutex_lock (&_gst_validate_registry_mutex);
  if (G_UNLIKELY (!_gst_validate_registry_default)) {
    _gst_validate_registry_default = g_object_new (GST_TYPE_REGISTRY, NULL);
    gst_object_ref_sink (GST_OBJECT_CAST (_gst_validate_registry_default));
  }
  registry = _gst_validate_registry_default;
  g_mutex_unlock (&_gst_validate_registry_mutex);

  return registry;
}

#define GST_VALIDATE_PLUGIN_CONFIG "gst-validate-plugin-config"

static void
_free_plugin_config (gpointer data)
{
  g_list_free_full (data, (GDestroyNotify) gst_structure_free);
}

static GList *
create_config (const gchar * path, const gchar * suffix)
{
  GList *structures = NULL, *tmp, *result = NULL;

  if (!suffix)
    return NULL;

  structures = gst_validate_utils_structs_parse_from_filename (path);

  for (tmp = structures; tmp; tmp = tmp->next) {
    GstStructure *structure = tmp->data;

    if (gst_structure_has_name (structure, suffix))
      result = g_list_append (result, structure);
    else
      gst_structure_free (structure);
  }

  g_list_free (structures);
  return result;
}

/* Copied from gststructure.c to avoid assertion */
static gboolean
gst_structure_validate_name (const gchar * name)
{
  const gchar *s;

  g_return_val_if_fail (name != NULL, FALSE);

  if (G_UNLIKELY (!g_ascii_isalpha (*name))) {
    GST_INFO ("Invalid character '%c' at offset 0 in structure name: %s",
        *name, name);
    return FALSE;
  }

  /* FIXME: test name string more */
  s = &name[1];
  while (*s && (g_ascii_isalnum (*s) || strchr ("/-_.:+", *s) != NULL))
    s++;
  if (*s == ',')
    return TRUE;

  if (G_UNLIKELY (*s != '\0')) {
    GST_INFO ("Invalid character '%c' at offset %" G_GUINTPTR_FORMAT " in"
        " structure name: %s", *s, ((guintptr) s - (guintptr) name), name);
    return FALSE;
  }

  return TRUE;
}

/**
 * gst_validate_plugin_get_config:
 * @plugin, a #GstPlugin, or #NULL
 *
 * Return the configuration specific to @plugin, or the "core" one if @plugin
 * is #NULL
 *
 * Returns: (transfer none) (element-type GstStructure): a list of #GstStructure
 */
GList *
gst_validate_plugin_get_config (GstPlugin * plugin)
{
  GList *plugin_conf = NULL;
  const gchar *suffix;
  const gchar *config;
  GStrv tmp;
  guint i;

  if (plugin) {
    if ((plugin_conf =
            g_object_get_data (G_OBJECT (plugin), GST_VALIDATE_PLUGIN_CONFIG)))
      return plugin_conf;

    suffix = gst_plugin_get_name (plugin);
  } else {
    if (core_config)
      return core_config;

    suffix = "core";
  }

  config = g_getenv ("GST_VALIDATE_CONFIG");
  if (!config)
    return NULL;

  tmp = g_strsplit (config, G_SEARCHPATH_SEPARATOR_S, -1);
  for (i = 0; tmp[i] != NULL; i++) {
    GList *l;

    l = create_config (tmp[i], suffix);
    if (l)
      plugin_conf = g_list_concat (plugin_conf, l);
  }
  g_strfreev (tmp);

  if (!plugin_conf) {
    GstCaps *confs = NULL;

    if (gst_structure_validate_name (config))
      confs = gst_caps_from_string (config);

    if (confs) {
      gint i;

      for (i = 0; i < gst_caps_get_size (confs); i++) {
        GstStructure *structure = gst_caps_get_structure (confs, i);

        if (gst_structure_has_name (structure, suffix))
          plugin_conf =
              g_list_append (plugin_conf, gst_structure_copy (structure));
      }

      gst_caps_unref (confs);
    }
  }

  if (plugin)
    g_object_set_data_full (G_OBJECT (plugin), GST_VALIDATE_PLUGIN_CONFIG,
        plugin_conf, _free_plugin_config);
  else
    core_config = plugin_conf;

  return plugin_conf;
}

static void
gst_validate_init_plugins (void)
{
  GstRegistry *registry;
  const gchar *plugin_path;

  gst_registry_fork_set_enabled (FALSE);
  registry = gst_validate_registry_get ();

  plugin_path = g_getenv ("GST_VALIDATE_PLUGIN_PATH");
  if (plugin_path) {
    char **list;
    int i;

    GST_DEBUG ("GST_VALIDATE_PLUGIN_PATH set to %s", plugin_path);
    list = g_strsplit (plugin_path, G_SEARCHPATH_SEPARATOR_S, 0);
    for (i = 0; list[i]; i++) {
      gst_registry_scan_path (registry, list[i]);
    }
    g_strfreev (list);
  } else {
    GST_DEBUG ("GST_VALIDATE_PLUGIN_PATH not set");
  }

  if (plugin_path == NULL) {
    char *home_plugins;

    /* plugins in the user's home directory take precedence over
     * system-installed ones */
    home_plugins = g_build_filename (g_get_user_data_dir (),
        "gstreamer-" GST_API_VERSION, "plugins", NULL);

    GST_DEBUG ("scanning home plugins %s", home_plugins);
    gst_registry_scan_path (registry, home_plugins);
    g_free (home_plugins);

    /* add the main (installed) library path */

#ifdef G_OS_WIN32
    {
      char *base_dir;
      char *dir;

      base_dir =
          g_win32_get_package_installation_directory_of_module
          (_priv_gstvalidate_dll_handle);

      dir = g_build_filename (base_dir,
          "lib", "gstreamer-" GST_API_VERSION, "validate", NULL);

      GST_DEBUG ("scanning DLL dir %s", dir);

      gst_registry_scan_path (registry, dir);

      g_free (dir);
      g_free (base_dir);
    }
#else
    gst_registry_scan_path (registry, VALIDATEPLUGINDIR);
#endif
  }
  gst_registry_fork_set_enabled (TRUE);
}

/**
 * gst_validate_init:
 *
 * Initializes GstValidate. Call this before any usage of GstValidate.
 * You should take care of initializing GStreamer before calling this
 * function.
 */
void
gst_validate_init (void)
{
  if (validate_initialized) {
    return;
  }

  GST_DEBUG_CATEGORY_INIT (gstvalidate_debug, "validate", 0,
      "Validation library");

  _priv_start_time = gst_util_get_timestamp ();

  /* init the report system (can be called multiple times) */
  gst_validate_report_init ();

  /* Init the scenario system */
  init_scenarios ();

  /* Ensure we load overrides before any use of a monitor */
  gst_validate_override_registry_preload ();

  validate_initialized = TRUE;

  gst_validate_init_plugins ();
  gst_validate_init_runner ();
}

void
gst_validate_deinit (void)
{
  g_mutex_lock (&_gst_validate_registry_mutex);
  _free_plugin_config (core_config);
  gst_validate_deinit_runner ();

  gst_validate_scenario_deinit ();

  g_clear_object (&_gst_validate_registry_default);

  _priv_validate_override_registry_deinit ();
  core_config = NULL;
  validate_initialized = FALSE;
  gst_validate_report_deinit ();

  g_mutex_unlock (&_gst_validate_registry_mutex);
  g_mutex_clear (&_gst_validate_registry_mutex);
}

gboolean
gst_validate_is_initialized (void)
{
  return validate_initialized;
}