/*
 * Copyright (C) 2018,2021 Purism SPC
 *
 * This file is part of Calls.
 *
 * Calls is free software: you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Calls 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
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Calls.  If not, see <http://www.gnu.org/licenses/>.
 *
 * Author: Bob Ham <bob.ham@puri.sm>
 *
 * SPDX-License-Identifier: GPL-3.0-or-later
 *
 */

#define G_LOG_DOMAIN "CallsProvider"

#include "calls-provider.h"
#include "calls-origin.h"
#include "calls-message-source.h"
#include "calls-config.h"
#include "calls-util.h"

#include <glib/gi18n.h>
#include <libpeas/peas.h>

/**
 * SECTION:calls-provider
 * @short_description: An abstraction of call providers, such as
 * oFono, Telepathy or some SIP library.
 * @Title: CallsProvider
 *
 * The #CallsProvider abstract class is the root of the class tree that
 * needs to be implemented by a call provider.  A #CallsProvider
 * provides access to a list of #CallsOrigin interfaces, through the
 * #calls_provider_get_origins function and the #origin-added and
 * #origin-removed signals.
 */


G_DEFINE_ABSTRACT_TYPE (CallsProvider, calls_provider, G_TYPE_OBJECT)

enum {
  PROP_0,
  PROP_STATUS,
  PROP_LAST_PROP,
};
static GParamSpec *props[PROP_LAST_PROP];

static const char *
calls_provider_real_get_name (CallsProvider *self)
{
  return NULL;
}

static const char *
calls_provider_real_get_status (CallsProvider *self)
{
  return NULL;
}

static GListModel *
calls_provider_real_get_origins (CallsProvider *self)
{
  return NULL;
}

static const char * const *
calls_provider_real_get_protocols (CallsProvider *self)
{
  g_assert_not_reached ();
}

static gboolean
calls_provider_real_is_modem (CallsProvider *self)
{
  return FALSE;
}

static gboolean
calls_provider_real_is_operational (CallsProvider *self)
{
  GListModel *origins;

  origins = calls_provider_get_origins (self);

  if (origins)
    return !!g_list_model_get_n_items (origins);

  return FALSE;
}


static void
calls_provider_get_property (GObject    *object,
                             guint       prop_id,
                             GValue     *value,
                             GParamSpec *pspec)
{
  CallsProvider *self = CALLS_PROVIDER (object);

  switch (prop_id) {
  case PROP_STATUS:
    g_value_set_string (value, calls_provider_get_status (self));
    break;

  default:
    G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
  }
}

static void
calls_provider_class_init (CallsProviderClass *klass)
{
  GObjectClass *object_class = G_OBJECT_CLASS (klass);

  object_class->get_property = calls_provider_get_property;

  klass->get_name = calls_provider_real_get_name;
  klass->get_status = calls_provider_real_get_status;
  klass->get_origins = calls_provider_real_get_origins;
  klass->get_protocols = calls_provider_real_get_protocols;
  klass->is_modem = calls_provider_real_is_modem;
  klass->is_operational = calls_provider_real_is_operational;

  props[PROP_STATUS] =
    g_param_spec_string ("status",
                         "Status",
                         "A text string describing the status for display to the user",
                         "",
                         G_PARAM_READABLE | G_PARAM_STATIC_STRINGS);

  g_object_class_install_properties (object_class, PROP_LAST_PROP, props);
}

static void
calls_provider_init (CallsProvider *self)
{
}

/**
 * calls_provider_get_name:
 * @self: a #CallsProvider
 *
 * Get the user-presentable name of the provider.
 *
 * Returns: A string containing the name.
 */
const char *
calls_provider_get_name (CallsProvider *self)
{
  g_return_val_if_fail (CALLS_IS_PROVIDER (self), NULL);

  return CALLS_PROVIDER_GET_CLASS (self)->get_name (self);
}

const char *
calls_provider_get_status (CallsProvider *self)
{
  g_return_val_if_fail (CALLS_IS_PROVIDER (self), NULL);

  return CALLS_PROVIDER_GET_CLASS (self)->get_status (self);
}

/**
 * calls_provider_get_origins:
 * @self: a #CallsProvider
 *
 * Get the list of #CallsOrigin interfaces offered by this provider.
 *
 * Returns: (transfer none): A #GListModel of origins
 */
GListModel *
calls_provider_get_origins (CallsProvider *self)
{
  g_return_val_if_fail (CALLS_IS_PROVIDER (self), NULL);

  return CALLS_PROVIDER_GET_CLASS (self)->get_origins (self);
}

/**
 * calls_provider_load_plugin:
 * @name: The name of the provider plugin to load
 *
 * Get a #CallsProvider plugin by name
 *
 * Returns: (transfer full): A #CallsProvider
 */
CallsProvider *
calls_provider_load_plugin (const char *name)
{
  g_autoptr (GError) error = NULL;
  PeasEngine *plugins;
  PeasPluginInfo *info;
  PeasExtension *extension;

  plugins = peas_engine_get_default ();

  // Find the plugin
  info = peas_engine_get_plugin_info (plugins, name);
  if (!info) {
    g_debug ("Could not find plugin `%s'", name);
    return NULL;
  }

  // Possibly load the plugin
  if (!peas_plugin_info_is_loaded (info)) {
    peas_engine_load_plugin (plugins, info);

    if (!peas_plugin_info_is_available (info, &error)) {
      g_debug ("Error loading plugin `%s': %s", name, error->message);
      return NULL;
    }

    g_debug ("Loaded plugin `%s'", name);
  }

  // Check the plugin provides CallsProvider
  if (!peas_engine_provides_extension (plugins, info, CALLS_TYPE_PROVIDER)) {
    g_debug ("Plugin `%s' does not have a provider extension", name);
    return NULL;
  }

  // Get the extension
  extension = peas_engine_create_extensionv (plugins, info, CALLS_TYPE_PROVIDER, 0, NULL);
  if (!extension) {
    g_debug ("Could not create provider from plugin `%s'", name);
    return NULL;
  }

  g_debug ("Created provider from plugin `%s'", name);
  return CALLS_PROVIDER (extension);
}

void
calls_provider_unload_plugin (const char *name)
{
  PeasEngine *engine = peas_engine_get_default ();
  PeasPluginInfo *plugin = peas_engine_get_plugin_info (engine, name);

  if (plugin)
    peas_engine_unload_plugin (engine, plugin);
  else
    g_warning ("Can't unload plugin: No plugin with name %s found", name);
}

/**
 * calls_provider_get_protocols:
 * @self: A #CallsProvider
 *
 * Returns: (transfer none): A null-terminated array of strings
 */
const char * const *
calls_provider_get_protocols (CallsProvider *self)
{
  g_return_val_if_fail (CALLS_IS_PROVIDER (self), NULL);

  return CALLS_PROVIDER_GET_CLASS (self)->get_protocols (self);
}

/**
 * calls_provider_is_modem:
 * @self: A #CallsProvider
 *
 * Returns: %TRUE is this provider handles modems, %FALSE otherwise
 */
gboolean
calls_provider_is_modem (CallsProvider *self)
{
  g_return_val_if_fail (CALLS_IS_PROVIDER (self), FALSE);

  return CALLS_PROVIDER_GET_CLASS (self)->is_modem (self);
}

/**
 * calls_provider_is_operational:
 * @self: A #CallsProvider
 *
 * Returns: %TRUE is this provider is operational, %FALSE otherwise
 *
 * If not subclassed this method will simply test if there are any
 * origins available.
 */
gboolean
calls_provider_is_operational (CallsProvider *self)
{
  g_return_val_if_fail (CALLS_IS_PROVIDER (self), FALSE);

  return CALLS_PROVIDER_GET_CLASS (self)->is_operational (self);
}