/*
 * The default account manager storage pseudo-plugin
 *
 * Copyright © 2010 Nokia Corporation
 * Copyright © 2010-2012 Collabora Ltd.
 *
 * 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., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

#include "config.h"

#include <errno.h>
#include <string.h>

#include <glib/gstdio.h>

#include <telepathy-glib/telepathy-glib.h>

#include "mcd-account-manager-default.h"
#include "mcd-debug.h"
#include "mcd-storage.h"
#include "mcd-misc.h"

#define PLUGIN_NAME "default"
#define PLUGIN_PRIORITY MCP_ACCOUNT_STORAGE_PLUGIN_PRIO_DEFAULT
#define PLUGIN_DESCRIPTION "Default account storage backend"

typedef struct {
    /* owned string, attribute => owned GVariant, value
     * attributes to be stored in the variant-file */
    GHashTable *attributes;
    /* owned string, parameter (without "param-") => owned GVariant, value
     * parameters of known type to be stored in the variant-file */
    GHashTable *parameters;
    /* owned string, parameter (without "param-") => owned string, value
     * parameters of unknwn type to be stored in the variant-file */
    GHashTable *untyped_parameters;
    /* TRUE if the account doesn't really exist, but is here to stop us
     * loading it from a lower-priority file */
    gboolean absent;
    /* TRUE if this account needs saving */
    gboolean dirty;
} McdDefaultStoredAccount;

static GVariant *
variant_ref0 (GVariant *v)
{
  return (v == NULL ? NULL : g_variant_ref (v));
}

static McdDefaultStoredAccount *
lookup_stored_account (McdAccountManagerDefault *self,
    const gchar *account)
{
  return g_hash_table_lookup (self->accounts, account);
}

static McdDefaultStoredAccount *
ensure_stored_account (McdAccountManagerDefault *self,
    const gchar *account)
{
  McdDefaultStoredAccount *sa = lookup_stored_account (self, account);

  if (sa == NULL)
    {
      sa = g_slice_new0 (McdDefaultStoredAccount);
      sa->attributes = g_hash_table_new_full (g_str_hash, g_str_equal,
          g_free, (GDestroyNotify) g_variant_unref);
      sa->parameters = g_hash_table_new_full (g_str_hash, g_str_equal,
          g_free, (GDestroyNotify) g_variant_unref);
      sa->untyped_parameters = g_hash_table_new_full (g_str_hash, g_str_equal,
          g_free, g_free);
      g_hash_table_insert (self->accounts, g_strdup (account), sa);
    }

  sa->absent = FALSE;
  return sa;
}

static void
stored_account_free (gpointer p)
{
  McdDefaultStoredAccount *sa = p;

  g_hash_table_unref (sa->attributes);
  g_hash_table_unref (sa->parameters);
  g_hash_table_unref (sa->untyped_parameters);
  g_slice_free (McdDefaultStoredAccount, sa);
}

static void account_storage_iface_init (McpAccountStorageIface *,
    gpointer);

G_DEFINE_TYPE_WITH_CODE (McdAccountManagerDefault, mcd_account_manager_default,
    G_TYPE_OBJECT,
    G_IMPLEMENT_INTERFACE (MCP_TYPE_ACCOUNT_STORAGE,
        account_storage_iface_init));

static gchar *
get_old_filename (void)
{
  const gchar *base;

  base = g_getenv ("MC_ACCOUNT_DIR");

  if (!base)
    base = ACCOUNTS_DIR;

  if (!base)
    return NULL;

  if (base[0] == '~')
    return g_build_filename (g_get_home_dir(), base + 1, "accounts.cfg", NULL);
  else
    return g_build_filename (base, "accounts.cfg", NULL);
}

static gchar *
accounts_cfg_in (const gchar *dir,
    const gchar *tp_dir)
{
  return g_build_filename (dir, tp_dir, "mission-control",
      "accounts.cfg", NULL);
}

static gchar *
account_directory_in (const gchar *dir,
    const gchar *tp_dir)
{
  return g_build_filename (dir, tp_dir, "mission-control", NULL);
}

static gchar *
account_file_in (const gchar *dir,
    const gchar *account)
{
  gchar *basename = g_strdup_printf ("%s.account", account);
  gchar *ret;

  g_strdelimit (basename, "/", '-');
  ret = g_build_filename (dir, "telepathy-1", "mission-control",
      basename, NULL);
  g_free (basename);
  return ret;
}

static void
mcd_account_manager_default_init (McdAccountManagerDefault *self)
{
  DEBUG ("mcd_account_manager_default_init");
  self->directory = account_directory_in (g_get_user_data_dir (),
      "telepathy-1");
  self->accounts = g_hash_table_new_full (g_str_hash, g_str_equal, g_free,
      stored_account_free);
  self->loaded = FALSE;
}

static void
mcd_account_manager_default_class_init (McdAccountManagerDefaultClass *cls)
{
  DEBUG ("mcd_account_manager_default_class_init");
}

static McpAccountStorageSetResult
set_parameter (McpAccountStorage *self,
    McpAccountManager *am,
    const gchar *account,
    const gchar *parameter,
    GVariant *val,
    McpParameterFlags flags)
{
  McdAccountManagerDefault *amd = MCD_ACCOUNT_MANAGER_DEFAULT (self);
  McdDefaultStoredAccount *sa;

  sa = lookup_stored_account (amd, account);
  g_return_val_if_fail (sa != NULL, MCP_ACCOUNT_STORAGE_SET_RESULT_FAILED);
  g_return_val_if_fail (!sa->absent, MCP_ACCOUNT_STORAGE_SET_RESULT_FAILED);

  if (val == NULL)
    {
      gboolean changed = FALSE;

      changed = g_hash_table_remove (sa->parameters, parameter);
      /* deliberately not ||= - if we removed it from parameters, we
       * still want to remove it from untyped_parameters if it was there */
      changed |= g_hash_table_remove (sa->untyped_parameters, parameter);

      if (!changed)
        return MCP_ACCOUNT_STORAGE_SET_RESULT_UNCHANGED;
    }
  else
    {
      GVariant *old;

      old = g_hash_table_lookup (sa->parameters, parameter);

      if (old != NULL && g_variant_equal (old, val))
        {
          return MCP_ACCOUNT_STORAGE_SET_RESULT_UNCHANGED;
        }

      /* We haven't checked whether it's in untyped_parameters with the
       * same value - but if it is, we want to migrate it to parameters
       * anyway (in order to record its type), so treat it as having
       * actually changed. */

      g_hash_table_remove (sa->untyped_parameters, parameter);
      g_hash_table_insert (sa->parameters, g_strdup (parameter),
          g_variant_ref (val));
    }

  sa->dirty = TRUE;
  return MCP_ACCOUNT_STORAGE_SET_RESULT_CHANGED;
}

static McpAccountStorageSetResult
set_attribute (McpAccountStorage *self,
    McpAccountManager *am,
    const gchar *account,
    const gchar *attribute,
    GVariant *val,
    McpAttributeFlags flags)
{
  McdAccountManagerDefault *amd = MCD_ACCOUNT_MANAGER_DEFAULT (self);
  McdDefaultStoredAccount *sa;

  sa = lookup_stored_account (amd, account);
  g_return_val_if_fail (sa != NULL, MCP_ACCOUNT_STORAGE_SET_RESULT_FAILED);
  g_return_val_if_fail (!sa->absent, MCP_ACCOUNT_STORAGE_SET_RESULT_FAILED);

  if (val == NULL)
    {
      if (!g_hash_table_remove (sa->attributes, attribute))
        return MCP_ACCOUNT_STORAGE_SET_RESULT_UNCHANGED;
    }
  else
    {
      GVariant *old;

      old = g_hash_table_lookup (sa->attributes, attribute);

      if (old != NULL && g_variant_equal (old, val))
        return MCP_ACCOUNT_STORAGE_SET_RESULT_UNCHANGED;

      g_hash_table_insert (sa->attributes, g_strdup (attribute),
          g_variant_ref (val));
    }

  sa->dirty = TRUE;
  return MCP_ACCOUNT_STORAGE_SET_RESULT_CHANGED;
}

static GVariant *
get_attribute (McpAccountStorage *self,
    McpAccountManager *am,
    const gchar *account,
    const gchar *attribute,
    const GVariantType *type,
    McpAttributeFlags *flags)
{
  McdAccountManagerDefault *amd = MCD_ACCOUNT_MANAGER_DEFAULT (self);
  McdDefaultStoredAccount *sa = lookup_stored_account (amd, account);

  if (flags != NULL)
    *flags = 0;

  g_return_val_if_fail (sa != NULL, NULL);
  g_return_val_if_fail (!sa->absent, NULL);

  /* ignore @type, we store every attribute with its type anyway; MC will
   * coerce values to an appropriate type if needed */
  return variant_ref0 (g_hash_table_lookup (sa->attributes, attribute));
}

static GVariant *
get_parameter (McpAccountStorage *self,
    McpAccountManager *am,
    const gchar *account,
    const gchar *parameter,
    const GVariantType *type,
    McpParameterFlags *flags)
{
  McdAccountManagerDefault *amd = MCD_ACCOUNT_MANAGER_DEFAULT (self);
  McdDefaultStoredAccount *sa = lookup_stored_account (amd, account);
  GVariant *variant;
  gchar *str;

  if (flags != NULL)
    *flags = 0;

  g_return_val_if_fail (sa != NULL, NULL);
  g_return_val_if_fail (!sa->absent, NULL);

  variant = g_hash_table_lookup (sa->parameters, parameter);

  if (variant != NULL)
    return g_variant_ref (variant);

  if (type == NULL)
    return NULL;

  str = g_hash_table_lookup (sa->untyped_parameters, parameter);

  if (str == NULL)
    return NULL;

  return mcp_account_manager_unescape_variant_from_keyfile (am,
      str, type, NULL);
}

static gchar **
list_typed_parameters (McpAccountStorage *self,
    McpAccountManager *am,
    const gchar *account)
{
  McdAccountManagerDefault *amd = MCD_ACCOUNT_MANAGER_DEFAULT (self);
  McdDefaultStoredAccount *sa = lookup_stored_account (amd, account);
  GPtrArray *arr;
  GHashTableIter iter;
  gpointer k;

  g_return_val_if_fail (sa != NULL, NULL);
  g_return_val_if_fail (!sa->absent, NULL);

  arr = g_ptr_array_sized_new (g_hash_table_size (sa->parameters) + 1);

  g_hash_table_iter_init (&iter, sa->parameters);

  while (g_hash_table_iter_next (&iter, &k, NULL))
    g_ptr_array_add (arr, g_strdup (k));

  g_ptr_array_add (arr, NULL);

  return (gchar **) g_ptr_array_free (arr, FALSE);
}

static gchar **
list_untyped_parameters (McpAccountStorage *self,
    McpAccountManager *am,
    const gchar *account)
{
  McdAccountManagerDefault *amd = MCD_ACCOUNT_MANAGER_DEFAULT (self);
  McdDefaultStoredAccount *sa = lookup_stored_account (amd, account);
  GPtrArray *arr;
  GHashTableIter iter;
  gpointer k;

  g_return_val_if_fail (sa != NULL, NULL);
  g_return_val_if_fail (!sa->absent, NULL);

  arr = g_ptr_array_sized_new (g_hash_table_size (sa->untyped_parameters) + 1);

  g_hash_table_iter_init (&iter, sa->untyped_parameters);

  while (g_hash_table_iter_next (&iter, &k, NULL))
    g_ptr_array_add (arr, g_strdup (k));

  g_ptr_array_add (arr, NULL);

  return (gchar **) g_ptr_array_free (arr, FALSE);
}

static gchar *
_create (McpAccountStorage *self,
    McpAccountManager *am,
    const gchar *manager,
    const gchar *protocol,
    const gchar *identification,
    GError **error)
{
  McdAccountManagerDefault *amd = MCD_ACCOUNT_MANAGER_DEFAULT (self);
  gchar *unique_name;

  unique_name = mcp_account_manager_get_unique_name (MCP_ACCOUNT_MANAGER (am),
                                                     manager, protocol,
                                                     identification);
  g_return_val_if_fail (unique_name != NULL, NULL);

  ensure_stored_account (amd, unique_name);
  return unique_name;
}

static void
delete_async (McpAccountStorage *self,
    McpAccountManager *am,
    const gchar *account,
    GCancellable *cancellable,
    GAsyncReadyCallback callback,
    gpointer user_data)
{
  McdAccountManagerDefault *amd = MCD_ACCOUNT_MANAGER_DEFAULT (self);
  McdDefaultStoredAccount *sa = lookup_stored_account (amd, account);
  GTask *task;
  gchar *filename = NULL;
  const gchar * const *iter;

  task = g_task_new (amd, cancellable, callback, user_data);

  g_return_if_fail (sa != NULL);
  g_return_if_fail (!sa->absent);

  filename = account_file_in (g_get_user_data_dir (), account);

  DEBUG ("Deleting account %s from %s", account, filename);

  if (g_unlink (filename) != 0)
    {
      int e = errno;

      /* ENOENT is OK, anything else is more upsetting */
      if (e != ENOENT)
        {
          WARNING ("Unable to delete %s: %s", filename,
              g_strerror (e));
          g_task_return_new_error (task, G_IO_ERROR, g_io_error_from_errno (e),
              "Unable to delete %s: %s", filename, g_strerror (e));
          goto finally;
        }
    }

  for (iter = g_get_system_data_dirs ();
      iter != NULL && *iter != NULL;
      iter++)
    {
      gchar *other = account_file_in (*iter, account);
      gboolean other_exists = g_file_test (other, G_FILE_TEST_EXISTS);

      g_free (other);

      if (other_exists)
        {
          GError *error = NULL;

          /* There is a lower-priority file that would provide this
           * account. We can't delete a file from XDG_DATA_DIRS which
           * are conceptually read-only, but we can mask it with an
           * empty file (prior art: systemd) */
          if (!g_file_set_contents (filename, "", 0, &error))
            {
              g_prefix_error (&error,
                  "Unable to save empty account file to %s: ", filename);
              WARNING ("%s", error->message);
              g_task_return_error (task, error);
              g_free (filename);
              goto finally;
            }

          break;
        }
    }

  /* clean up the mess */
  g_hash_table_remove (amd->accounts, account);
  mcp_account_storage_emit_deleted (self, account);

  g_task_return_boolean (task, TRUE);

finally:
  g_free (filename);
  g_object_unref (task);
}

static gboolean
delete_finish (McpAccountStorage *storage,
    GAsyncResult *res,
    GError **error)
{
  return g_task_propagate_boolean (G_TASK (res), error);
}

static gboolean
am_default_commit_one (McdAccountManagerDefault *self,
    const gchar *account_name,
    McdDefaultStoredAccount *sa)
{
  gchar *filename;
  GHashTableIter inner;
  gpointer k, v;
  GVariantBuilder params_builder;
  GVariantBuilder attrs_builder;
  GVariant *content;
  gchar *content_text;
  gboolean ret;
  GError *error = NULL;

  DEBUG ("%s", account_name);

  g_return_val_if_fail (sa != NULL, FALSE);
  g_return_val_if_fail (!sa->absent, FALSE);

  if (!sa->dirty)
    return TRUE;

  if (!mcd_ensure_directory (self->directory, &error))
    {
      g_warning ("%s", error->message);
      g_error_free (error);
      return FALSE;
    }

  filename = account_file_in (g_get_user_data_dir (), account_name);

  DEBUG ("Saving account %s to %s", account_name, filename);

  g_variant_builder_init (&attrs_builder, G_VARIANT_TYPE_VARDICT);

  g_hash_table_iter_init (&inner, sa->attributes);

  while (g_hash_table_iter_next (&inner, &k, &v))
    {
      g_variant_builder_add (&attrs_builder, "{sv}", k, v);
    }

  g_variant_builder_init (&params_builder, G_VARIANT_TYPE ("a{sv}"));
  g_hash_table_iter_init (&inner, sa->parameters);

  while (g_hash_table_iter_next (&inner, &k, &v))
    {
      g_variant_builder_add (&params_builder, "{sv}", k, v);
    }

  g_variant_builder_add (&attrs_builder, "{sv}",
      "Parameters", g_variant_builder_end (&params_builder));

  g_variant_builder_init (&params_builder, G_VARIANT_TYPE ("a{ss}"));
  g_hash_table_iter_init (&inner, sa->untyped_parameters);

  while (g_hash_table_iter_next (&inner, &k, &v))
    {
      g_variant_builder_add (&params_builder, "{ss}", k, v);
    }

  g_variant_builder_add (&attrs_builder, "{sv}",
      "KeyFileParameters", g_variant_builder_end (&params_builder));

  content = g_variant_ref_sink (g_variant_builder_end (&attrs_builder));
  content_text = g_variant_print (content, TRUE);
  DEBUG ("%s", content_text);
  g_variant_unref (content);

  if (g_file_set_contents (filename, content_text, -1, &error))
    {
      sa->dirty = FALSE;
      ret = TRUE;
    }
  else
    {
      WARNING ("Unable to save account to %s: %s", filename,
          error->message);
      g_clear_error (&error);
      ret = FALSE;
    }

  g_free (filename);
  g_free (content_text);
  return ret;
}

static gboolean
_commit (McpAccountStorage *self,
    McpAccountManager *am,
    const gchar *account)
{
  McdAccountManagerDefault *amd = MCD_ACCOUNT_MANAGER_DEFAULT (self);
  McdDefaultStoredAccount *sa = lookup_stored_account (amd, account);

  g_return_val_if_fail (sa != NULL, FALSE);
  g_return_val_if_fail (!sa->absent, FALSE);

  DEBUG ("Saving account %s to %s", account, amd->directory);

  return am_default_commit_one (amd, account, sa);
}

static gboolean
am_default_load_keyfile (McdAccountManagerDefault *self,
    const gchar *filename)
{
  GError *error = NULL;
  GKeyFile *keyfile = g_key_file_new ();
  gsize i;
  gsize n = 0;
  GStrv account_tails;
  gboolean all_ok = TRUE;

  /* We shouldn't call this function without modification if we think we've
   * migrated to a newer storage format, because it doesn't check whether
   * each account has already been loaded. */
  g_assert (!self->loaded);
  g_assert (g_hash_table_size (self->accounts) == 0);

  if (g_key_file_load_from_file (keyfile, filename,
        G_KEY_FILE_KEEP_COMMENTS, &error))
    {
      DEBUG ("Loaded accounts from %s", filename);
    }
  else
    {
      DEBUG ("Failed to load accounts from %s: %s", filename, error->message);
      g_error_free (error);

      /* Start with a blank configuration. */
      g_key_file_load_from_data (keyfile, "", -1, 0, NULL);
      /* Don't delete the old file, which might be recoverable. */
      all_ok = FALSE;
    }

  account_tails = g_key_file_get_groups (keyfile, &n);

  for (i = 0; i < n; i++)
    {
      const gchar *account = account_tails[i];
      McdDefaultStoredAccount *sa = ensure_stored_account (self, account);
      gsize j;
      gsize m = 0;
      GStrv keys = g_key_file_get_keys (keyfile, account, &m, NULL);

      /* We're going to need to migrate this account. */
      sa->dirty = TRUE;

      for (j = 0; j < m; j++)
        {
          gchar *key = keys[j];

          if (g_str_has_prefix (key, "param-"))
            {
              gchar *raw = g_key_file_get_value (keyfile, account, key, NULL);

              /* steals ownership of raw */
              g_hash_table_insert (sa->untyped_parameters, g_strdup (key + 6),
                  raw);
            }
          else
            {
              const GVariantType *type = mcd_storage_get_attribute_type (key);
              GVariant *variant = NULL;

              if (type == NULL)
                {
                  /* go to the error code path */
                  g_set_error (&error, TP_ERROR, TP_ERROR_INVALID_ARGUMENT,
                      "unknown attribute");
                }
              else
                {
                  variant = mcd_keyfile_get_variant (keyfile,
                      account, key, type, &error);
                }

              if (variant == NULL)
                {
                  WARNING ("Unable to migrate %s.%s from keyfile: %s",
                      account, key, error->message);
                  g_clear_error (&error);
                  /* Don't delete the old file, which might be recoverable. */
                  all_ok = FALSE;
                }
              else
                {
                  g_hash_table_insert (sa->attributes, g_strdup (key),
                      g_variant_ref_sink (variant));
                }
            }
        }

      g_strfreev (keys);
    }

  g_strfreev (account_tails);
  g_key_file_unref (keyfile);
  return all_ok;
}

static void
am_default_load_variant_file (McdAccountManagerDefault *self,
    const gchar *account_tail,
    const gchar *full_name)
{
  McdDefaultStoredAccount *sa;
  gchar *text = NULL;
  gsize len;
  GVariant *contents = NULL;
  GVariantIter iter;
  const gchar *k;
  GVariant *v;
  GError *error = NULL;

  DEBUG ("%s from %s", account_tail, full_name);

  sa = lookup_stored_account (self, account_tail);

  if (sa != NULL)
    {
      DEBUG ("Ignoring %s: account %s already %s",
          full_name, account_tail, sa->absent ? "masked" : "loaded");
      goto finally;
    }

  if (!g_file_get_contents (full_name, &text, &len, &error))
    {
      WARNING ("Unable to read account %s from %s: %s",
          account_tail, full_name, error->message);
      g_error_free (error);
      goto finally;
    }

  if (len == 0)
    {
      DEBUG ("Empty file %s masks account %s", full_name, account_tail);
      ensure_stored_account (self, account_tail)->absent = TRUE;
      goto finally;
    }

  contents = g_variant_parse (G_VARIANT_TYPE_VARDICT,
      text, text + len, NULL, &error);

  if (contents == NULL)
    {
      WARNING ("Unable to parse account %s from %s: %s",
          account_tail, full_name, error->message);
      g_error_free (error);
      goto finally;
    }

  sa = ensure_stored_account (self, account_tail);

  g_variant_iter_init (&iter, contents);

  while (g_variant_iter_loop (&iter, "{sv}", &k, &v))
    {
      if (!tp_strdiff (k, "KeyFileParameters"))
        {
          GVariantIter param_iter;
          gchar *parameter;
          gchar *param_value;

          if (!g_variant_is_of_type (v, G_VARIANT_TYPE ("a{ss}")))
            {
              gchar *repr = g_variant_print (v, TRUE);

              WARNING ("invalid KeyFileParameters found in %s, "
                  "ignoring: %s", full_name, repr);
              g_free (repr);
              continue;
            }

          g_variant_iter_init (&param_iter, v);

          while (g_variant_iter_next (&param_iter, "{ss}", &parameter,
                &param_value))
            {
              /* steals parameter, param_value */
              g_hash_table_insert (sa->untyped_parameters, parameter,
                  param_value);
            }
        }
      else if (!tp_strdiff (k, "Parameters"))
        {
          GVariantIter param_iter;
          gchar *parameter;
          GVariant *param_value;

          if (!g_variant_is_of_type (v, G_VARIANT_TYPE ("a{sv}")))
            {
              gchar *repr = g_variant_print (v, TRUE);

              WARNING ("invalid Parameters found in %s, "
                  "ignoring: %s", full_name, repr);
              g_free (repr);
              continue;
            }

          g_variant_iter_init (&param_iter, v);

          while (g_variant_iter_next (&param_iter, "{sv}", &parameter,
                &param_value))
            {
              /* steals parameter, param_value */
              g_hash_table_insert (sa->parameters, parameter, param_value);
            }
        }
      else
        {
          /* an ordinary attribute */
          g_hash_table_insert (sa->attributes,
              g_strdup (k), g_variant_ref (v));
        }
    }

finally:
  tp_clear_pointer (&contents, g_variant_unref);
  g_free (text);
}

static void
am_default_load_directory (McdAccountManagerDefault *self,
    const gchar *directory)
{
  GDir *dir_handle;
  const gchar *basename;
  GRegex *regex;
  GError *error = NULL;

  dir_handle = g_dir_open (directory, 0, &error);

  if (dir_handle == NULL)
    {
      /* We expect ENOENT. Anything else is a cause for (minor) concern. */
      if (g_error_matches (error, G_FILE_ERROR, G_FILE_ERROR_NOENT))
        DEBUG ("%s", error->message);
      else
        WARNING ("%s", error->message);

      g_error_free (error);
      return;
    }

  DEBUG ("Looking for accounts in %s", directory);

  regex = g_regex_new ("^[A-Za-z][A-Za-z0-9_]*-"  /* CM name */
      "[A-Za-z][A-Za-z0-9_]*-"                    /* protocol with s/-/_/ */
      "[A-Za-z_][A-Za-z0-9_]*\\.account$",        /* account-specific part */
      G_REGEX_DOLLAR_ENDONLY, 0, &error);
  g_assert_no_error (error);

  while ((basename = g_dir_read_name (dir_handle)) != NULL)
    {
      gchar *full_name;
      gchar *account_tail;

      /* skip it silently if it's obviously not an account */
      if (!g_str_has_suffix (basename, ".account"))
        continue;

      /* We consider ourselves to have migrated to the new storage format
       * as soon as we find something that looks as though it ought to be an
       * account. */
      self->loaded = TRUE;

      if (!g_regex_match (regex, basename, 0, NULL))
        {
          WARNING ("Ignoring %s/%s: not a syntactically valid account",
              directory, basename);
        }

      full_name = g_build_filename (directory, basename, NULL);
      account_tail = g_strdup (basename);
      g_strdelimit (account_tail, "-", '/');
      g_strdelimit (account_tail, ".", '\0');

      am_default_load_variant_file (self, account_tail, full_name);

      g_free (account_tail);
      g_free (full_name);
    }
}

static void mcd_account_manager_default_load (McdAccountManagerDefault *amd,
    gboolean telepathy0);

static void
maybe_import_from_tp0 (McdAccountManagerDefault *self)
{
  const gchar *user_data_dir = g_get_user_data_dir ();
  McdAccountManagerDefault *old = NULL;
  gchar *dir = NULL;
  gchar *stamp = NULL;
  gchar *old_accounts_cfg = NULL;
  gchar *accounts_cfg = NULL;
  GError *error = NULL;

  dir = account_directory_in (user_data_dir, "telepathy");
  stamp = g_build_filename (dir, "MIGRATED-TO-TELEPATHY-1.txt", NULL);
  accounts_cfg = accounts_cfg_in (user_data_dir, "telepathy");
  old_accounts_cfg = get_old_filename ();

  if (g_file_test (stamp, G_FILE_TEST_EXISTS))
    {
      DEBUG ("already migrated: %s exists", stamp);
      goto finally;
    }

  if (!g_file_test (dir, G_FILE_TEST_IS_DIR) &&
      !g_file_test (accounts_cfg, G_FILE_TEST_EXISTS) &&
      !g_file_test (old_accounts_cfg, G_FILE_TEST_EXISTS))
    {
      DEBUG ("nothing to import");
      goto finally;
    }

  if (!mcd_ensure_directory (dir, &error))
    {
      WARNING ("Unable to create %s: %s", dir, error->message);
      goto finally;
    }

  DEBUG ("loading old accounts");
  self->loaded = FALSE;
  mcd_account_manager_default_load (self, TRUE);

  if (!g_file_set_contents (stamp,
        "Accounts from this directory (if any) have been copied to "
        "XDG_DATA_DIRS/telepathy-1/mission-control. Migration will "
        "not be repeated while this file exists.",
        -1, &error))
    {
      WARNING ("Unable to write %s: %s", dir, error->message);
    }

finally:
  g_free (dir);
  g_free (stamp);
  g_free (old_accounts_cfg);
  g_free (accounts_cfg);
  g_clear_error (&error);
  g_clear_object (&old);
}

static GList *
_list (McpAccountStorage *self,
    McpAccountManager *am)
{
  GList *rval = NULL;
  McdAccountManagerDefault *amd = MCD_ACCOUNT_MANAGER_DEFAULT (self);
  GHashTableIter hash_iter;
  gpointer k, v;

  mcd_account_manager_default_load (amd, FALSE);

  if (g_hash_table_size (amd->accounts) == 0)
    {
      DEBUG ("no Telepathy 1 accounts, considering Telepathy 0 import");
      maybe_import_from_tp0 (amd);
    }

  g_hash_table_iter_init (&hash_iter, amd->accounts);

  while (g_hash_table_iter_next (&hash_iter, &k, &v))
    {
      McdDefaultStoredAccount *sa = v;

      if (!sa->absent)
        rval = g_list_prepend (rval, g_strdup (k));
    }

  return rval;
}

static void
mcd_account_manager_default_load (McdAccountManagerDefault *amd,
    gboolean telepathy0)
{
  GHashTableIter hash_iter;
  gchar *migrate_from = NULL;
  gpointer k, v;
  /* If we copied accounts from Telepathy 0, we want to save the
   * Telepathy 1 version */
  gboolean save = telepathy0;

  DEBUG ("loading Telepathy v%d accounts", telepathy0 ? 0 : 1);

  /* (XDG_DATA_HOME|XDG_DATA_DIRS)/telepathy(-1)?/mission-control/(.*).account,
   * used in MC5 >= 5.17, MC6 >= 0.99.6 */
  if (!amd->loaded)
    {
      const gchar * const *iter;

      if (telepathy0)
        {
          gchar *dir = account_directory_in (g_get_user_data_dir (),
              "telepathy");

          am_default_load_directory (amd, dir);
          g_free (dir);
        }
      else
        {
          am_default_load_directory (amd, amd->directory);
        }

      /* We do this even if am_default_load_directory() succeeded, and
       * do not stop when amd->loaded becomes true. If XDG_DATA_HOME
       * contains gabble-jabber-example_2eexample_40com.account, that doesn't
       * mean a directory in XDG_DATA_DIRS doesn't also contain
       * haze-msn-example_2ehotmail_40com.account or something, which
       * should also be loaded. */
      for (iter = g_get_system_data_dirs ();
          iter != NULL && *iter != NULL;
          iter++)
        {
          gchar *dir = account_directory_in (*iter,
              telepathy0 ? "telepathy" : "telepathy-1");

          am_default_load_directory (amd, dir);
          g_free (dir);
        }
    }

  /* XDG_DATA_HOME/telepathy(-1)?/mission-control/accounts.cfg,
   * used in 5.13.2 <= MC5 < 5.17 and MC6 < 5.99.6 */
  if (!amd->loaded)
    {
      migrate_from = accounts_cfg_in (g_get_user_data_dir (),
          telepathy0 ? "telepathy" : "telepathy-1");

      if (g_file_test (migrate_from, G_FILE_TEST_EXISTS))
        {
          if (!am_default_load_keyfile (amd, migrate_from))
            tp_clear_pointer (&migrate_from, g_free);

          amd->loaded = TRUE;
        }
      else
        {
          tp_clear_pointer (&migrate_from, g_free);
        }
    }

  /* XDG_DATA_DIRS/telepathy(-1)?/mission-control/accounts.cfg,
   * used in 5.13.2 <= MC5 < 5.17 and MC6 < 5.99.6 */
  if (!amd->loaded)
    {
      const gchar * const *iter;

      for (iter = g_get_system_data_dirs ();
          iter != NULL && *iter != NULL;
          iter++)
        {
          /* not setting migrate_from here - XDG_DATA_DIRS are conceptually
           * read-only, so we don't want to delete these files */
          gchar *filename = accounts_cfg_in (*iter,
              telepathy0 ? "telepathy" : "telepathy-1");

          if (g_file_test (filename, G_FILE_TEST_EXISTS))
            {
              am_default_load_keyfile (amd, filename);
              amd->loaded = TRUE;
            }

          g_free (filename);

          if (amd->loaded)
            break;
        }
    }

  /* ~/.mission-control or something, used in MC < 5.13.2.
   * Telepathy 1 never used this. */
  if (!amd->loaded && telepathy0)
    {
      migrate_from = get_old_filename ();

      if (g_file_test (migrate_from, G_FILE_TEST_EXISTS))
        {
          if (!am_default_load_keyfile (amd, migrate_from))
            tp_clear_pointer (&migrate_from, g_free);
          amd->loaded = TRUE;
          save = TRUE;
        }
      else
        {
          tp_clear_pointer (&migrate_from, g_free);
        }
    }

  if (!amd->loaded)
    {
      DEBUG ("Creating initial account data");
      amd->loaded = TRUE;
      save = TRUE;
    }

  if (telepathy0)
    {
      g_hash_table_iter_init (&hash_iter, amd->accounts);

      while (g_hash_table_iter_next (&hash_iter, NULL, &v))
        {
          McdDefaultStoredAccount *sa = v;

          /* mark it as "dirty" so we save it in the Telepathy-1
           * location */
          sa->dirty = TRUE;
        }
    }
  else if (!save)
    {
      g_hash_table_iter_init (&hash_iter, amd->accounts);

      while (g_hash_table_iter_next (&hash_iter, NULL, &v))
        {
          McdDefaultStoredAccount *sa = v;

          if (sa->dirty)
            {
              save = TRUE;
              break;
            }
        }
    }

  if (save)
    {
      gboolean all_succeeded = TRUE;

      DEBUG ("Saving initial or migrated account data");

      g_hash_table_iter_init (&hash_iter, amd->accounts);

      while (g_hash_table_iter_next (&hash_iter, &k, &v))
        {
          McdDefaultStoredAccount *sa = v;

          if (sa->absent)
            continue;

          if (!am_default_commit_one (amd, k, v))
            all_succeeded = FALSE;
        }

      if (all_succeeded)
        {
          /* Never delete old Telepathy 0 accounts - leave them available
           * for parallel use of Telepathy 0 */
          if (migrate_from != NULL && !telepathy0)
            {
              DEBUG ("Migrated %s to new location: deleting old copy",
                  migrate_from);

              if (g_unlink (migrate_from) != 0)
                WARNING ("Unable to delete %s: %s", migrate_from,
                    g_strerror (errno));
            }
        }
    }

  tp_clear_pointer (&migrate_from, g_free);
}

static McpAccountStorageFlags
get_flags (McpAccountStorage *storage,
    const gchar *account)
{
  return MCP_ACCOUNT_STORAGE_FLAG_STORES_TYPES;
}

static void
account_storage_iface_init (McpAccountStorageIface *iface,
    gpointer unused G_GNUC_UNUSED)
{
  iface->name = PLUGIN_NAME;
  iface->desc = PLUGIN_DESCRIPTION;
  iface->priority = PLUGIN_PRIORITY;

  iface->get_flags = get_flags;
  iface->get_attribute = get_attribute;
  iface->get_parameter = get_parameter;
  iface->list_typed_parameters = list_typed_parameters;
  iface->list_untyped_parameters = list_untyped_parameters;
  iface->set_attribute = set_attribute;
  iface->set_parameter = set_parameter;
  iface->create = _create;
  iface->delete_async = delete_async;
  iface->delete_finish = delete_finish;
  iface->commit = _commit;
  iface->list = _list;

}

McdAccountManagerDefault *
mcd_account_manager_default_new (void)
{
  return g_object_new (MCD_TYPE_ACCOUNT_MANAGER_DEFAULT, NULL);
}