/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*-
 * vi:set noexpandtab tabstop=8 shiftwidth=8:
 *
 * Copyright (C) 2024 Red Hat <www.redhat.com>
 *
 * SPDX-License-Identifier: GPL-2.0-or-later
 */

/**
 * SECTION:gs-plugin-job-cancel-offline-update
 * @short_description: A plugin job to cancel a pending offline update
 *
 * #GsPluginJobCancelOfflineUpdate is a #GsPluginJob to cancel a pending offline
 * update.
 *
 * See https://github.com/PackageKit/PackageKit/blob/main/docs/offline-updates.txt
 * and https://www.freedesktop.org/software/systemd/man/latest/systemd.offline-updates.html
 * for details of how offline updates work.
 *
 * This class is a wrapper around #GsPluginClass.cancel_offline_update_async
 * calling it for all loaded plugins.
 *
 * Since: 47
 */

#include "config.h"

#include <glib.h>
#include <glib-object.h>

#include "gs-enums.h"
#include "gs-plugin-job.h"
#include "gs-plugin-job-cancel-offline-update.h"
#include "gs-plugin-job-private.h"
#include "gs-plugin-types.h"

struct _GsPluginJobCancelOfflineUpdate
{
	GsPluginJob parent;

	/* Input arguments. */
	GsPluginCancelOfflineUpdateFlags flags;

	/* In-progress data. */
	GError *saved_error;  /* (owned) (nullable) */
	guint n_pending_ops;
};

G_DEFINE_TYPE (GsPluginJobCancelOfflineUpdate, gs_plugin_job_cancel_offline_update, GS_TYPE_PLUGIN_JOB)

typedef enum {
	PROP_FLAGS = 1,
} GsPluginJobCancelOfflineUpdateProperty;

static GParamSpec *props[PROP_FLAGS + 1] = { NULL, };

static void
gs_plugin_job_cancel_offline_update_dispose (GObject *object)
{
	GsPluginJobCancelOfflineUpdate *self = GS_PLUGIN_JOB_CANCEL_OFFLINE_UPDATE (object);

	g_assert (self->saved_error == NULL);
	g_assert (self->n_pending_ops == 0);

	G_OBJECT_CLASS (gs_plugin_job_cancel_offline_update_parent_class)->dispose (object);
}

static void
gs_plugin_job_cancel_offline_update_get_property (GObject    *object,
                                                  guint       prop_id,
                                                  GValue     *value,
                                                  GParamSpec *pspec)
{
	GsPluginJobCancelOfflineUpdate *self = GS_PLUGIN_JOB_CANCEL_OFFLINE_UPDATE (object);

	switch ((GsPluginJobCancelOfflineUpdateProperty) prop_id) {
	case PROP_FLAGS:
		g_value_set_flags (value, self->flags);
		break;
	default:
		G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
		break;
	}
}

static void
gs_plugin_job_cancel_offline_update_set_property (GObject      *object,
                                                  guint         prop_id,
                                                  const GValue *value,
                                                  GParamSpec   *pspec)
{
	GsPluginJobCancelOfflineUpdate *self = GS_PLUGIN_JOB_CANCEL_OFFLINE_UPDATE (object);

	switch ((GsPluginJobCancelOfflineUpdateProperty) prop_id) {
	case PROP_FLAGS:
		/* Construct only. */
		g_assert (self->flags == 0);
		self->flags = g_value_get_flags (value);
		g_object_notify_by_pspec (object, props[prop_id]);
		break;
	default:
		G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
		break;
	}
}

static void plugin_func_cb (GObject      *source_object,
			    GAsyncResult *result,
			    gpointer      user_data);
static void finish_op (GTask  *task,
                       GError *error);

static void
gs_plugin_job_cancel_offline_update_run_async (GsPluginJob         *job,
                                               GsPluginLoader      *plugin_loader,
                                               GCancellable        *cancellable,
                                               GAsyncReadyCallback  callback,
                                               gpointer             user_data)
{
	GsPluginJobCancelOfflineUpdate *self = GS_PLUGIN_JOB_CANCEL_OFFLINE_UPDATE (job);
	g_autoptr(GTask) task = NULL;
	GPtrArray *plugins;  /* (element-type GsPlugin) */
	gboolean anything_ran = FALSE;
	g_autoptr(GError) local_error = NULL;

	task = g_task_new (job, cancellable, callback, user_data);
	g_task_set_source_tag (task, gs_plugin_job_cancel_offline_update_run_async);
	g_task_set_task_data (task, g_object_ref (plugin_loader), (GDestroyNotify) g_object_unref);

	/* run each plugin, keeping a counter of pending operations which is
	 * initialised to 1 until all the operations are started */
	self->n_pending_ops = 1;
	plugins = gs_plugin_loader_get_plugins (plugin_loader);

	for (guint i = 0; i < plugins->len; i++) {
		GsPlugin *plugin = g_ptr_array_index (plugins, i);
		GsPluginClass *plugin_class = GS_PLUGIN_GET_CLASS (plugin);

		if (!gs_plugin_get_enabled (plugin))
			continue;
		if (plugin_class->cancel_offline_update_async == NULL)
			continue;

		/* at least one plugin supports this vfunc */
		anything_ran = TRUE;

		/* Handle cancellation */
		if (g_cancellable_set_error_if_cancelled (cancellable, &local_error))
			break;

		/* run the plugin */
		self->n_pending_ops++;
		plugin_class->cancel_offline_update_async (plugin, self->flags, cancellable, plugin_func_cb, g_object_ref (task));
	}

	if (!anything_ran)
		g_debug ("no plugin could handle cancel-offline-update operation");

	finish_op (task, g_steal_pointer (&local_error));
}

static void
plugin_func_cb (GObject      *source_object,
		GAsyncResult *result,
		gpointer      user_data)
{
	GsPlugin *plugin = GS_PLUGIN (source_object);
	GsPluginClass *plugin_class = GS_PLUGIN_GET_CLASS (plugin);
	g_autoptr(GTask) task = G_TASK (user_data);
	gboolean success;
	g_autoptr(GError) local_error = NULL;

	success = plugin_class->cancel_offline_update_finish (plugin, result, &local_error);
	gs_plugin_status_update (plugin, NULL, GS_PLUGIN_STATUS_FINISHED);

	g_assert (success || local_error != NULL);

	finish_op (task, g_steal_pointer (&local_error));
}

/* @error is (transfer full) if non-%NULL */
static void
finish_op (GTask  *task,
           GError *error)
{
	GsPluginJobCancelOfflineUpdate *self = g_task_get_source_object (task);
	g_autoptr(GError) error_owned = g_steal_pointer (&error);
	g_autofree gchar *job_debug = NULL;

	if (error_owned != NULL && self->saved_error == NULL)
		self->saved_error = g_steal_pointer (&error_owned);
	else if (error_owned != NULL)
		g_debug ("Additional error while cancelling offline update: %s", error_owned->message);

	g_assert (self->n_pending_ops > 0);
	self->n_pending_ops--;

	if (self->n_pending_ops > 0)
		return;

	/* show elapsed time */
	job_debug = gs_plugin_job_to_string (GS_PLUGIN_JOB (self));
	g_debug ("%s", job_debug);

	if (self->saved_error != NULL)
		g_task_return_error (task, g_steal_pointer (&self->saved_error));
	else
		g_task_return_boolean (task, TRUE);
	g_signal_emit_by_name (G_OBJECT (self), "completed");
}

static gboolean
gs_plugin_job_cancel_offline_update_run_finish (GsPluginJob   *self,
                                                GAsyncResult  *result,
                                                GError       **error)
{
	return g_task_propagate_boolean (G_TASK (result), error);
}

static void
gs_plugin_job_cancel_offline_update_class_init (GsPluginJobCancelOfflineUpdateClass *klass)
{
	GObjectClass *object_class = G_OBJECT_CLASS (klass);
	GsPluginJobClass *job_class = GS_PLUGIN_JOB_CLASS (klass);

	object_class->dispose = gs_plugin_job_cancel_offline_update_dispose;
	object_class->get_property = gs_plugin_job_cancel_offline_update_get_property;
	object_class->set_property = gs_plugin_job_cancel_offline_update_set_property;

	job_class->run_async = gs_plugin_job_cancel_offline_update_run_async;
	job_class->run_finish = gs_plugin_job_cancel_offline_update_run_finish;

	/**
	 * GsPluginJobCancelOfflineUpdate:flags:
	 *
	 * Flags affecting how the operation runs.
	 *
	 * Since: 47
	 */
	props[PROP_FLAGS] =
		g_param_spec_flags ("flags", "Flags",
				    "Flags affecting how the operation runs.",
				    GS_TYPE_PLUGIN_CANCEL_OFFLINE_UPDATE_FLAGS,
				    GS_PLUGIN_CANCEL_OFFLINE_UPDATE_FLAGS_NONE,
				    G_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY |
				    G_PARAM_STATIC_STRINGS | G_PARAM_EXPLICIT_NOTIFY);

	g_object_class_install_properties (object_class, G_N_ELEMENTS (props), props);
}

static void
gs_plugin_job_cancel_offline_update_init (GsPluginJobCancelOfflineUpdate *self)
{
}

/**
 * gs_plugin_job_cancel_offline_update_new:
 * @flags: flags affecting how the operation runs
 *
 * Create a new #GsPluginJobCancelOfflineUpdate to cancel offline update.
 *
 * Returns: (transfer full): a new #GsPluginJobCancelOfflineUpdate
 * Since: 47
 */
GsPluginJob *
gs_plugin_job_cancel_offline_update_new (GsPluginCancelOfflineUpdateFlags flags)
{
	return g_object_new (GS_TYPE_PLUGIN_JOB_CANCEL_OFFLINE_UPDATE,
			     "flags", flags,
			     NULL);
}
