/*
 * This file is part of Cockpit.
 *
 * Copyright (C) 2015 Red Hat, Inc.
 *
 * Cockpit 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.
 *
 * Cockpit 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 Cockpit; If not, see <http://www.gnu.org/licenses/>.
 */

#include "config.h"

#include "cockpitconf.h"

#include "cockpithash.h"

#include "errno.h"

static GHashTable *cockpit_conf = NULL;
static GHashTable *cached_strvs = NULL;

const gchar *cockpit_config_file = "cockpit.conf";
const gchar *cockpit_config_dirs[] = { PACKAGE_SYSCONF_DIR, NULL };

static gboolean
load_key_file (const gchar *file_path)
{
  GKeyFile *key_file = NULL;
  GHashTable *section;
  GError *error = NULL;
  gchar **groups;
  gint i;
  gint j;
  gboolean ret = TRUE;

  key_file = g_key_file_new ();

  if (!g_key_file_load_from_file (key_file, file_path, G_KEY_FILE_NONE, &error))
    {
      if (g_error_matches (error, G_FILE_ERROR, G_FILE_ERROR_NOENT))
        goto out;

      g_message ("couldn't load configuration file: %s: %s", file_path, error->message);
      ret = FALSE;
      goto out;
    }

  groups = g_key_file_get_groups (key_file, NULL);
  for (i = 0; groups[i] != NULL; i++)
    {
      gchar **keys;
      section = g_hash_table_lookup (cockpit_conf, groups[i]);
      if (section == NULL)
        {
          section = g_hash_table_new_full (cockpit_str_case_hash, cockpit_str_case_equal, g_free, g_free);
          g_hash_table_insert (cockpit_conf, g_strdup (groups[i]), section);
        }

      keys = g_key_file_get_keys (key_file, groups[i], NULL, &error);
      g_return_val_if_fail (error == NULL, FALSE);

      for (j = 0; keys[j] != NULL; j++)
        {
          gchar *value = g_key_file_get_value (key_file, groups[i], keys[j], &error);
          g_return_val_if_fail (error == NULL, FALSE);
          g_hash_table_insert (section, g_strdup (keys[j]), value);
        }
      g_strfreev (keys);
    }
  g_strfreev (groups);

  g_debug ("Loaded configuration from: %s", file_path);

out:
  g_clear_error (&error);
  g_key_file_free (key_file);
  return ret;
}

void
cockpit_conf_init (void)
{
  const gchar *const *dirs;
  gchar *file = NULL;
  gchar *dir = NULL;

  cockpit_conf = g_hash_table_new_full (cockpit_str_case_hash, cockpit_str_case_equal, g_free,
                                        (GDestroyNotify)g_hash_table_unref);
  cached_strvs = g_hash_table_new_full (cockpit_str_case_hash, cockpit_str_case_equal, g_free,
                                        (GDestroyNotify)g_strfreev);


  if (!cockpit_config_file)
    {
      g_debug ("No configuration to load");
      return;
    }

  dir = g_path_get_dirname (cockpit_config_file);
  if (dir && g_strcmp0 (dir, ".") != 0)
    {
      load_key_file (cockpit_config_file);
    }
  else
    {
      dirs = cockpit_conf_get_dirs ();
      while (dirs && dirs[0])
        {
          file = g_build_filename (dirs[0], "cockpit", cockpit_config_file, NULL);
          load_key_file (file);
          g_free (file);

          dirs++;
        }
    }

  g_free (dir);
}


void
cockpit_conf_cleanup (void)
{
  if (cockpit_conf)
    {
      g_hash_table_destroy (cockpit_conf);
      cockpit_conf = NULL;
    }

  if (cached_strvs)
    {
      g_hash_table_destroy (cached_strvs);
      cached_strvs = NULL;
    }
}


static void
ensure_cockpit_conf (void)
{
  if (cockpit_conf == NULL)
    cockpit_conf_init ();
}


const gchar * const*
cockpit_conf_get_dirs (void)
{
  const gchar *env;

  env = g_getenv ("XDG_CONFIG_DIRS");
  if (env && env[0])
    return g_get_system_config_dirs ();
  else
    return cockpit_config_dirs;
}

const gchar *
cockpit_conf_string (const gchar *section,
                     const gchar *field)
{
  GHashTable *sect = NULL;
  ensure_cockpit_conf ();
  sect = g_hash_table_lookup (cockpit_conf, section);
  if (sect != NULL)
    return g_hash_table_lookup (sect, field);

  return NULL;
}

gboolean
cockpit_conf_bool (const gchar *section,
                   const gchar *field,
                   gboolean defawlt)
{
  GHashTable *sect = NULL;
  gchar *cmp = NULL;
  const gchar *value;
  gboolean ret = defawlt;

  ensure_cockpit_conf ();
  sect = g_hash_table_lookup (cockpit_conf, section);
  if (sect != NULL)
    {
      value = g_hash_table_lookup (sect, field);
      if (value)
        {
          cmp = g_ascii_strdown (value, -1);
          ret = g_strcmp0 (cmp, "yes") == 0 ||
                g_strcmp0 (cmp, "true") == 0 ||
                g_strcmp0 (cmp, "1") == 0;
        }
    }

  g_free (cmp);
  return ret;
}

static const gchar **
build_strv (const gchar *section,
            const gchar *field,
            gchar *delimiter)
{
  const gchar *string = NULL;
  const gchar **value = NULL;
  gchar *stripped = NULL;
  gchar **strv = NULL;

  string = cockpit_conf_string (section, field);

  if (string != NULL)
    {
      stripped = g_strstrip (g_strdup (string));
      strv = g_strsplit (stripped, delimiter, -1);
      if (strv)
        {
          guint n = g_strv_length (strv);
          guint i;
          value = g_new (const gchar *, n + 1);

          for (i = 0; i < n; i++)
            value[i] = g_strdup (strv[i]);

          value[i] = NULL;
          g_strfreev (strv);
        }
    }
  g_free (stripped);
  return value;
}

const gchar **
cockpit_conf_strv (const gchar *section,
                   const gchar *field,
                   gchar delimiter)
{
  const gchar **value = NULL;
  gchar *key = NULL;
  gchar delm[2] = {delimiter, '\0'};

  g_return_val_if_fail (section != NULL, NULL);
  g_return_val_if_fail (field != NULL, NULL);

  ensure_cockpit_conf ();
  key = g_strjoin (delm, section, field, NULL);

  if (!g_hash_table_contains (cached_strvs, key))
    {
      value = build_strv (section, field, delm);
      if (value)
        g_hash_table_insert (cached_strvs, g_strdup (key), value);
    }
  else
    {
      value = g_hash_table_lookup (cached_strvs, key);
    }

  g_free (key);
  return value;
}

guint
cockpit_conf_guint (const gchar *section,
                    const gchar *field,
                    guint default_value,
                    guint64 max,
                    guint64 min)
{
  guint val = default_value;
  guint64 conf_val;
  gchar *endptr = NULL;

  const gchar* conf = cockpit_conf_string (section, field);
  if (conf)
    {
      conf_val = g_ascii_strtoull (conf, &endptr, 10);
      if ((conf_val == G_MAXUINT64 || conf_val == 0) &&
          (errno == ERANGE || errno == EINVAL))
        val = default_value;
      else if (endptr && endptr[0] != '\0')
        val = default_value;
      else if (conf_val > max || conf_val > UINT_MAX)
        val = (max > UINT_MAX) ? UINT_MAX : max;
      else if (conf_val < min)
        val = min;
      else
        val = (guint)conf_val;

      if (conf_val != val)
        g_message ("Invalid %s %s value '%s', setting to %u", section, field, conf, val);
    }

  return val;
}