Adding upstream version 43.5.upstream/43.5upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

5 files changed, 2401 insertions, 0 deletions

diff --git a/plugins/snap/gs-plugin-snap.c b/plugins/snap/gs-plugin-snap.c
new file mode 100644
index 0000000..460641c
--- /dev/null
+++ b/plugins/snap/gs-plugin-snap.c
@@ -0,0 +1,1924 @@
+/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*-
+ * vi:set noexpandtab tabstop=8 shiftwidth=8:
+ *
+ * Copyright (C) 2015-2018 Canonical Ltd
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <config.h>
+
+#include <gio/gdesktopappinfo.h>
+#include <glib/gi18n.h>
+#include <json-glib/json-glib.h>
+#include <snapd-glib/snapd-glib.h>
+#include <gnome-software.h>
+
+#include "gs-plugin-snap.h"
+
+/*
+ * SECTION:
+ * Lists and allows installation/uninstallation of snaps from the snap store.
+ *
+ * Since snapd is a daemon accessible via HTTP calls on a Unix socket, this
+ * plugin basically translates every job into one or more HTTP request, and all
+ * the real work is done in the snapd daemon. FIXME: This means the plugin can
+ * therefore execute entirely in the main thread, making asynchronous calls,
+ * once all the vfuncs have been ported.
+ */
+
+struct _GsPluginSnap {
+	GsPlugin		 parent;
+
+	gchar			*store_name;
+	gchar			*store_hostname;
+	SnapdSystemConfinement	 system_confinement;
+
+	GMutex			 store_snaps_lock;
+	GHashTable		*store_snaps;
+};
+
+G_DEFINE_TYPE (GsPluginSnap, gs_plugin_snap, GS_TYPE_PLUGIN)
+
+typedef struct {
+	SnapdSnap *snap;
+	gboolean full_details;
+} CacheEntry;
+
+static CacheEntry *
+cache_entry_new (SnapdSnap *snap, gboolean full_details)
+{
+	CacheEntry *entry = g_slice_new (CacheEntry);
+	entry->snap = g_object_ref (snap);
+	entry->full_details = full_details;
+	return entry;
+}
+
+static void
+cache_entry_free (CacheEntry *entry)
+{
+	g_object_unref (entry->snap);
+	g_slice_free (CacheEntry, entry);
+}
+
+static SnapdAuthData *
+get_auth_data (GsPluginSnap *self)
+{
+	g_autofree gchar *path = NULL;
+	g_autoptr(JsonParser) parser = NULL;
+	JsonNode *root;
+	JsonObject *object;
+	const gchar *macaroon;
+	g_autoptr(GPtrArray) discharges = NULL;
+	g_autoptr(GError) error = NULL;
+
+	path = g_build_filename (g_get_home_dir (), ".snap", "auth.json", NULL);
+	parser = json_parser_new ();
+	if (!json_parser_load_from_file (parser, path, &error)) {
+		if (!g_error_matches (error, G_FILE_ERROR, G_FILE_ERROR_NOENT))
+			g_warning ("Failed to load snap auth data: %s", error->message);
+		return NULL;
+	}
+
+	root = json_parser_get_root (parser);
+	if (root == NULL)
+		return NULL;
+
+	if (json_node_get_node_type (root) != JSON_NODE_OBJECT) {
+		g_warning ("Ignoring invalid snap auth data in %s", path);
+		return NULL;
+	}
+	object = json_node_get_object (root);
+	if (!json_object_has_member (object, "macaroon")) {
+		g_warning ("Ignoring invalid snap auth data in %s", path);
+		return NULL;
+	}
+	macaroon = json_object_get_string_member (object, "macaroon");
+	discharges = g_ptr_array_new ();
+	if (json_object_has_member (object, "discharges")) {
+		JsonArray *discharge_array;
+
+		discharge_array = json_object_get_array_member (object, "discharges");
+		for (guint i = 0; i < json_array_get_length (discharge_array); i++)
+			g_ptr_array_add (discharges, (gpointer) json_array_get_string_element (discharge_array, i));
+	}
+	g_ptr_array_add (discharges, NULL);
+
+	return snapd_auth_data_new (macaroon, (GStrv) discharges->pdata);
+}
+
+static SnapdClient *
+get_client (GsPluginSnap  *self,
+            gboolean       interactive,
+            GError       **error)
+{
+	g_autoptr(SnapdClient) client = NULL;
+	const gchar *old_user_agent;
+	g_autofree gchar *user_agent = NULL;
+	g_autoptr(SnapdAuthData) auth_data = NULL;
+
+	client = snapd_client_new ();
+	snapd_client_set_allow_interaction (client, interactive);
+	old_user_agent = snapd_client_get_user_agent (client);
+	user_agent = g_strdup_printf ("%s %s", gs_user_agent (), old_user_agent);
+	snapd_client_set_user_agent (client, user_agent);
+
+	auth_data = get_auth_data (self);
+	snapd_client_set_auth_data (client, auth_data);
+
+	return g_steal_pointer (&client);
+}
+
+static void
+gs_plugin_snap_init (GsPluginSnap *self)
+{
+	g_autoptr(SnapdClient) client = NULL;
+	g_autoptr (GError) error = NULL;
+
+	g_mutex_init (&self->store_snaps_lock);
+
+	client = get_client (self, FALSE, &error);
+	if (client == NULL) {
+		gs_plugin_set_enabled (GS_PLUGIN (self), FALSE);
+		return;
+	}
+
+	self->store_snaps = g_hash_table_new_full (g_str_hash, g_str_equal,
+						   g_free, (GDestroyNotify) cache_entry_free);
+
+	gs_plugin_add_rule (GS_PLUGIN (self), GS_PLUGIN_RULE_BETTER_THAN, "packagekit");
+	gs_plugin_add_rule (GS_PLUGIN (self), GS_PLUGIN_RULE_RUN_BEFORE, "icons");
+
+	/* set name of MetaInfo file */
+	gs_plugin_set_appstream_id (GS_PLUGIN (self), "org.gnome.Software.Plugin.Snap");
+}
+
+void
+gs_plugin_adopt_app (GsPlugin *plugin, GsApp *app)
+{
+	if (gs_app_get_bundle_kind (app) == AS_BUNDLE_KIND_SNAP)
+		gs_app_set_management_plugin (app, plugin);
+
+	if (gs_app_get_id (app) != NULL && g_str_has_prefix (gs_app_get_id (app), "io.snapcraft.")) {
+		g_autofree gchar *name_and_id = NULL;
+		gchar *divider, *snap_name;/*, *id;*/
+
+		name_and_id = g_strdup (gs_app_get_id (app) + strlen ("io.snapcraft."));
+		divider = strrchr (name_and_id, '-');
+		if (divider != NULL) {
+			*divider = '\0';
+			snap_name = name_and_id;
+			/*id = divider + 1;*/ /* NOTE: Should probably validate ID */
+
+			gs_app_set_management_plugin (app, plugin);
+			gs_app_set_metadata (app, "snap::name", snap_name);
+			gs_app_set_bundle_kind (app, AS_BUNDLE_KIND_SNAP);
+		}
+	}
+}
+
+static void
+snapd_error_convert (GError **perror)
+{
+	GError *error = perror != NULL ? *perror : NULL;
+
+	/* not set */
+	if (error == NULL)
+		return;
+
+	/* this are allowed for low-level errors */
+	if (gs_utils_error_convert_gio (perror))
+		return;
+
+	/* custom to this plugin */
+	if (error->domain == SNAPD_ERROR) {
+		switch (error->code) {
+		case SNAPD_ERROR_AUTH_DATA_REQUIRED:
+			error->code = GS_PLUGIN_ERROR_AUTH_REQUIRED;
+			g_free (error->message);
+			error->message = g_strdup ("Requires authentication with @snapd");
+			break;
+		case SNAPD_ERROR_AUTH_DATA_INVALID:
+		case SNAPD_ERROR_TWO_FACTOR_INVALID:
+			error->code = GS_PLUGIN_ERROR_AUTH_INVALID;
+			break;
+		case SNAPD_ERROR_AUTH_CANCELLED:
+			error->code = GS_PLUGIN_ERROR_CANCELLED;
+			break; 
+		case SNAPD_ERROR_CONNECTION_FAILED:
+		case SNAPD_ERROR_WRITE_FAILED:
+		case SNAPD_ERROR_READ_FAILED:
+		case SNAPD_ERROR_BAD_REQUEST:
+		case SNAPD_ERROR_BAD_RESPONSE:
+		case SNAPD_ERROR_PERMISSION_DENIED:
+		case SNAPD_ERROR_FAILED:
+		case SNAPD_ERROR_TERMS_NOT_ACCEPTED:
+		case SNAPD_ERROR_PAYMENT_NOT_SETUP:
+		case SNAPD_ERROR_PAYMENT_DECLINED:
+		case SNAPD_ERROR_ALREADY_INSTALLED:
+		case SNAPD_ERROR_NOT_INSTALLED:
+		case SNAPD_ERROR_NO_UPDATE_AVAILABLE:
+		case SNAPD_ERROR_PASSWORD_POLICY_ERROR:
+		case SNAPD_ERROR_NEEDS_DEVMODE:
+		case SNAPD_ERROR_NEEDS_CLASSIC:
+		case SNAPD_ERROR_NEEDS_CLASSIC_SYSTEM:
+		default:
+			error->code = GS_PLUGIN_ERROR_FAILED;
+			break;
+		}
+	} else {
+		g_warning ("can't reliably fixup error from domain %s",
+			   g_quark_to_string (error->domain));
+		error->code = GS_PLUGIN_ERROR_FAILED;
+	}
+	error->domain = GS_PLUGIN_ERROR;
+}
+
+static void get_system_information_cb (GObject      *source_object,
+                                       GAsyncResult *result,
+                                       gpointer      user_data);
+
+static void get_store_snap_async (GsPluginSnap        *self,
+                                  SnapdClient         *client,
+                                  const gchar         *name,
+                                  gboolean             need_details,
+                                  GCancellable        *cancellable,
+                                  GAsyncReadyCallback  callback,
+                                  gpointer             user_data);
+static SnapdSnap *get_store_snap_finish (GsPluginSnap  *self,
+                                         GAsyncResult  *result,
+                                         GError       **error);
+static void add_channels (GsPluginSnap *self,
+                          SnapdSnap    *snap,
+                          GsAppList    *list);
+
+static void
+gs_plugin_snap_setup_async (GsPlugin            *plugin,
+                            GCancellable        *cancellable,
+                            GAsyncReadyCallback  callback,
+                            gpointer             user_data)
+{
+	GsPluginSnap *self = GS_PLUGIN_SNAP (plugin);
+	g_autoptr(SnapdClient) client = NULL;
+	g_autoptr(GTask) task = NULL;
+	gboolean interactive = gs_plugin_has_flags (plugin, GS_PLUGIN_FLAGS_INTERACTIVE);
+	g_autoptr(GError) local_error = NULL;
+
+	task = g_task_new (plugin, cancellable, callback, user_data);
+	g_task_set_source_tag (task, gs_plugin_snap_setup_async);
+
+	client = get_client (self, interactive, &local_error);
+	if (client == NULL) {
+		g_task_return_error (task, g_steal_pointer (&local_error));
+		return;
+	}
+
+	snapd_client_get_system_information_async (client, cancellable,
+						   get_system_information_cb, g_steal_pointer (&task));
+}
+
+static void
+get_system_information_cb (GObject      *source_object,
+                           GAsyncResult *result,
+                           gpointer      user_data)
+{
+	SnapdClient *client = SNAPD_CLIENT (source_object);
+	g_autoptr(GTask) task = g_steal_pointer (&user_data);
+	GsPluginSnap *self = g_task_get_source_object (task);
+	g_autoptr(SnapdSystemInformation) system_information = NULL;
+	g_autoptr(GError) local_error = NULL;
+
+	system_information = snapd_client_get_system_information_finish (client, result, &local_error);
+	if (system_information == NULL) {
+		g_task_return_error (task, g_steal_pointer (&local_error));
+		return;
+	}
+
+	self->store_name = g_strdup (snapd_system_information_get_store (system_information));
+	if (self->store_name == NULL) {
+		self->store_name = g_strdup (/* TRANSLATORS: default snap store name */
+					     _("Snap Store"));
+		self->store_hostname = g_strdup ("snapcraft.io");
+	}
+	self->system_confinement = snapd_system_information_get_confinement (system_information);
+
+	g_debug ("Version '%s' on OS %s %s",
+		snapd_system_information_get_version (system_information),
+		snapd_system_information_get_os_id (system_information),
+		snapd_system_information_get_os_version (system_information));
+
+	/* success */
+	g_task_return_boolean (task, TRUE);
+}
+
+static gboolean
+gs_plugin_snap_setup_finish (GsPlugin      *plugin,
+                             GAsyncResult  *result,
+                             GError       **error)
+{
+	return g_task_propagate_boolean (G_TASK (result), error);
+}
+
+static SnapdSnap *
+store_snap_cache_lookup (GsPluginSnap *self,
+                         const gchar  *name,
+                         gboolean      need_details)
+{
+	CacheEntry *entry;
+	g_autoptr(GMutexLocker) locker = g_mutex_locker_new (&self->store_snaps_lock);
+
+	entry = g_hash_table_lookup (self->store_snaps, name);
+	if (entry == NULL)
+		return NULL;
+
+	if (need_details && !entry->full_details)
+		return NULL;
+
+	return g_object_ref (entry->snap);
+}
+
+static void
+store_snap_cache_update (GsPluginSnap *self,
+                         GPtrArray    *snaps,
+                         gboolean      full_details)
+{
+	g_autoptr(GMutexLocker) locker = g_mutex_locker_new (&self->store_snaps_lock);
+	guint i;
+
+	for (i = 0; i < snaps->len; i++) {
+		SnapdSnap *snap = snaps->pdata[i];
+		g_debug ("Caching '%s' by '%s' version %s revision %s",
+			snapd_snap_get_title (snap),
+			snapd_snap_get_publisher_display_name (snap),
+			snapd_snap_get_version (snap),
+			snapd_snap_get_revision (snap));
+		g_hash_table_insert (self->store_snaps, g_strdup (snapd_snap_get_name (snap)), cache_entry_new (snap, full_details));
+	}
+}
+
+static GPtrArray *
+find_snaps (GsPluginSnap    *self,
+            SnapdClient     *client,
+            SnapdFindFlags   flags,
+            const gchar     *section,
+            const gchar     *query,
+            GCancellable    *cancellable,
+            GError         **error)
+{
+	g_autoptr(GPtrArray) snaps = NULL;
+
+	snaps = snapd_client_find_section_sync (client, flags, section, query, NULL, cancellable, error);
+	if (snaps == NULL) {
+		snapd_error_convert (error);
+		return NULL;
+	}
+
+	store_snap_cache_update (self, snaps, flags & SNAPD_FIND_FLAGS_MATCH_NAME);
+
+	return g_steal_pointer (&snaps);
+}
+
+static gchar *
+get_appstream_id (SnapdSnap *snap)
+{
+	GStrv common_ids;
+
+	/* Get the AppStream ID from the snap, or generate a fallback one */
+	common_ids = snapd_snap_get_common_ids (snap);
+	if (g_strv_length (common_ids) == 1)
+		return g_strdup (common_ids[0]);
+	else
+		return g_strdup_printf ("io.snapcraft.%s-%s", snapd_snap_get_name (snap), snapd_snap_get_id (snap));
+}
+
+static AsComponentKind
+snap_guess_component_kind (SnapdSnap *snap)
+{
+	switch (snapd_snap_get_snap_type (snap)) {
+	case SNAPD_SNAP_TYPE_APP:
+		return AS_COMPONENT_KIND_DESKTOP_APP;
+	case SNAPD_SNAP_TYPE_KERNEL:
+	case SNAPD_SNAP_TYPE_GADGET:
+	case SNAPD_SNAP_TYPE_OS:
+		return AS_COMPONENT_KIND_RUNTIME;
+	default:
+	case SNAPD_SNAP_TYPE_UNKNOWN:
+		return AS_COMPONENT_KIND_UNKNOWN;
+	}
+}
+
+static GsApp *
+snap_to_app (GsPluginSnap *self, SnapdSnap *snap, const gchar *branch)
+{
+	g_autofree gchar *cache_id = NULL;
+	g_autoptr(GsApp) app = NULL;
+
+	cache_id = g_strdup_printf ("%s:%s", snapd_snap_get_name (snap), branch != NULL ? branch : "");
+
+	app = gs_plugin_cache_lookup (GS_PLUGIN (self), cache_id);
+	if (app == NULL) {
+		g_autofree gchar *appstream_id = NULL;
+
+		appstream_id = get_appstream_id (snap);
+		app = gs_app_new (appstream_id);
+		gs_app_set_kind (app, snap_guess_component_kind (snap));
+		gs_app_set_bundle_kind (app, AS_BUNDLE_KIND_SNAP);
+		gs_app_set_branch (app, branch);
+		gs_app_set_metadata (app, "snap::name", snapd_snap_get_name (snap));
+		gs_app_set_metadata (app, "GnomeSoftware::PackagingIcon", "snap-symbolic");
+		gs_plugin_cache_add (GS_PLUGIN (self), cache_id, app);
+	}
+
+	gs_app_set_management_plugin (app, GS_PLUGIN (self));
+	gs_app_add_quirk (app, GS_APP_QUIRK_DO_NOT_AUTO_UPDATE);
+	if (gs_app_get_kind (app) != AS_COMPONENT_KIND_DESKTOP_APP)
+		gs_app_add_quirk (app, GS_APP_QUIRK_NOT_LAUNCHABLE);
+	if (gs_plugin_check_distro_id (GS_PLUGIN (self), "ubuntu"))
+		gs_app_add_quirk (app, GS_APP_QUIRK_PROVENANCE);
+	if (branch != NULL && (g_str_has_suffix (branch, "/beta") || g_str_has_suffix (branch, "/edge")))
+		gs_app_add_quirk (app, GS_APP_QUIRK_DEVELOPMENT_SOURCE);
+
+	return g_steal_pointer (&app);
+}
+
+gboolean
+gs_plugin_url_to_app (GsPlugin *plugin,
+		      GsAppList *list,
+		      const gchar *url,
+		      GCancellable *cancellable,
+		      GError **error)
+{
+	GsPluginSnap *self = GS_PLUGIN_SNAP (plugin);
+	g_autoptr(SnapdClient) client = NULL;
+	g_autofree gchar *scheme = NULL;
+	g_autofree gchar *path = NULL;
+	g_autoptr(GPtrArray) snaps = NULL;
+	g_autoptr(GsApp) app = NULL;
+	gboolean interactive = gs_plugin_has_flags (plugin, GS_PLUGIN_FLAGS_INTERACTIVE);
+
+	/* not us */
+	scheme = gs_utils_get_url_scheme (url);
+	if (g_strcmp0 (scheme, "snap") != 0 &&
+	    g_strcmp0 (scheme, "appstream") != 0)
+		return TRUE;
+
+	/* Create client. */
+	client = get_client (self, interactive, error);
+	if (client == NULL)
+		return FALSE;
+
+	/* create app */
+	path = gs_utils_get_url_path (url);
+	snaps = find_snaps (self, client,
+			    SNAPD_FIND_FLAGS_SCOPE_WIDE | SNAPD_FIND_FLAGS_MATCH_NAME,
+			    NULL, path, cancellable, NULL);
+	if (snaps == NULL || snaps->len < 1) {
+		g_clear_pointer (&snaps, g_ptr_array_unref);
+		/* This works for the appstream:// URL-s */
+		snaps = find_snaps (self, client,
+				    SNAPD_FIND_FLAGS_SCOPE_WIDE | SNAPD_FIND_FLAGS_MATCH_COMMON_ID,
+				    NULL, path, cancellable, NULL);
+	}
+	if (snaps == NULL || snaps->len < 1)
+		return TRUE;
+
+	app = snap_to_app (self, g_ptr_array_index (snaps, 0), NULL);
+	gs_app_list_add (list, app);
+
+	return TRUE;
+}
+
+static void
+gs_plugin_snap_dispose (GObject *object)
+{
+	GsPluginSnap *self = GS_PLUGIN_SNAP (object);
+
+	g_clear_pointer (&self->store_name, g_free);
+	g_clear_pointer (&self->store_hostname, g_free);
+	g_clear_pointer (&self->store_snaps, g_hash_table_unref);
+
+	G_OBJECT_CLASS (gs_plugin_snap_parent_class)->dispose (object);
+}
+
+static void
+gs_plugin_snap_finalize (GObject *object)
+{
+	GsPluginSnap *self = GS_PLUGIN_SNAP (object);
+
+	g_mutex_clear (&self->store_snaps_lock);
+
+	G_OBJECT_CLASS (gs_plugin_snap_parent_class)->finalize (object);
+}
+
+static gboolean
+is_banner_image (const gchar *filename)
+{
+	/* Check if this screenshot was uploaded as "banner.png" or "banner.jpg".
+	 * The server optionally adds a 7 character suffix onto it if it would collide with
+	 * an existing name, e.g. "banner_MgEy4MI.png"
+	 * See https://forum.snapcraft.io/t/improve-method-for-setting-featured-snap-banner-image-in-store/
+	 */
+	return g_regex_match_simple ("^banner(?:_[a-zA-Z0-9]{7})?\\.(?:png|jpg)$", filename, 0, 0);
+}
+
+static gboolean
+is_banner_icon_image (const gchar *filename)
+{
+	/* Check if this screenshot was uploaded as "banner-icon.png" or "banner-icon.jpg".
+	 * The server optionally adds a 7 character suffix onto it if it would collide with
+	 * an existing name, e.g. "banner-icon_Ugn6pmj.png"
+	 * See https://forum.snapcraft.io/t/improve-method-for-setting-featured-snap-banner-image-in-store/
+	 */
+	return g_regex_match_simple ("^banner-icon(?:_[a-zA-Z0-9]{7})?\\.(?:png|jpg)$", filename, 0, 0);
+}
+
+/* Build a string representation of the IDs of a category and its parents.
+ * For example, `develop/featured`. */
+static gchar *
+category_build_full_path (GsCategory *category)
+{
+	g_autoptr(GString) id = g_string_new ("");
+	GsCategory *c;
+
+	for (c = category; c != NULL; c = gs_category_get_parent (c)) {
+		if (c != category)
+			g_string_prepend (id, "/");
+		g_string_prepend (id, gs_category_get_id (c));
+	}
+
+	return g_string_free (g_steal_pointer (&id), FALSE);
+}
+
+typedef struct {
+	/* In-progress data. */
+	guint n_pending_ops;
+	GError *saved_error;  /* (owned) (nullable) */
+	GsAppList *results_list;  /* (owned) (nullable) */
+} ListAppsData;
+
+static void
+list_apps_data_free (ListAppsData *data)
+{
+	/* Error should have been propagated by now, and all pending ops completed. */
+	g_assert (data->saved_error == NULL);
+	g_assert (data->n_pending_ops == 0);
+	g_assert (data->results_list == NULL);
+
+	g_free (data);
+}
+
+G_DEFINE_AUTOPTR_CLEANUP_FUNC (ListAppsData, list_apps_data_free)
+
+static void list_installed_apps_cb (GObject      *source_object,
+                                    GAsyncResult *result,
+                                    gpointer      user_data);
+static void list_alternate_apps_snap_cb (GObject      *source_object,
+                                         GAsyncResult *result,
+                                         gpointer      user_data);
+static void list_alternate_apps_nonsnap_cb (GObject      *source_object,
+                                            GAsyncResult *result,
+                                            gpointer      user_data);
+static void list_alternative_apps_nonsnap_get_store_snap_cb (GObject      *source_object,
+                                                             GAsyncResult *result,
+                                                             gpointer      user_data);
+static void list_apps_cb (GObject      *source_object,
+                          GAsyncResult *result,
+                          gpointer      user_data);
+static void finish_list_apps_op (GTask  *task,
+                                 GError *error);
+
+static void
+gs_plugin_snap_list_apps_async (GsPlugin              *plugin,
+                                GsAppQuery            *query,
+                                GsPluginListAppsFlags  flags,
+                                GCancellable          *cancellable,
+                                GAsyncReadyCallback    callback,
+                                gpointer               user_data)
+{
+	GsPluginSnap *self = GS_PLUGIN_SNAP (plugin);
+	g_autoptr(GTask) task = NULL;
+	g_autoptr(ListAppsData) owned_data = NULL;
+	ListAppsData *data;
+	g_autoptr(SnapdClient) client = NULL;
+	gboolean interactive = (flags & GS_PLUGIN_LIST_APPS_FLAGS_INTERACTIVE);
+	GsAppQueryTristate is_curated = GS_APP_QUERY_TRISTATE_UNSET;
+	GsCategory *category = NULL;
+	GsAppQueryTristate is_installed = GS_APP_QUERY_TRISTATE_UNSET;
+	const gchar * const *keywords = NULL;
+	GsApp *alternate_of = NULL;
+	const gchar * const *sections = NULL;
+	const gchar * const curated_sections[] = { "featured", NULL };
+	g_autoptr(GError) local_error = NULL;
+
+	task = g_task_new (plugin, cancellable, callback, user_data);
+	data = owned_data = g_new0 (ListAppsData, 1);
+	g_task_set_task_data (task, g_steal_pointer (&owned_data), (GDestroyNotify) list_apps_data_free);
+	g_task_set_source_tag (task, gs_plugin_snap_list_apps_async);
+
+	client = get_client (self, interactive, &local_error);
+	if (client == NULL) {
+		g_task_return_error (task, g_steal_pointer (&local_error));
+		return;
+	}
+
+	if (query != NULL) {
+		is_curated = gs_app_query_get_is_curated (query);
+		category = gs_app_query_get_category (query);
+		is_installed = gs_app_query_get_is_installed (query);
+		keywords = gs_app_query_get_keywords (query);
+		alternate_of = gs_app_query_get_alternate_of (query);
+	}
+
+	/* Currently only support a subset of query properties, and only one set at once.
+	 * Also don’t currently support GS_APP_QUERY_TRISTATE_FALSE. */
+	if ((is_curated == GS_APP_QUERY_TRISTATE_UNSET &&
+	     category == NULL &&
+	     is_installed == GS_APP_QUERY_TRISTATE_UNSET &&
+	     keywords == NULL &&
+	     alternate_of == NULL) ||
+	    is_curated == GS_APP_QUERY_TRISTATE_FALSE ||
+	    is_installed == GS_APP_QUERY_TRISTATE_FALSE ||
+	    gs_app_query_get_n_properties_set (query) != 1) {
+		g_task_return_new_error (task, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
+					 "Unsupported query");
+		return;
+	}
+
+	data->results_list = gs_app_list_new ();
+
+	/* Listing installed apps requires calling a different libsnapd method,
+	 * so check that first. */
+	if (is_installed != GS_APP_QUERY_TRISTATE_UNSET) {
+		data->n_pending_ops++;
+		snapd_client_get_snaps_async (client, SNAPD_GET_SNAPS_FLAGS_NONE, NULL,
+					      cancellable, list_installed_apps_cb, g_steal_pointer (&task));
+		return;
+	}
+
+	/* Listing alternates also requires special handling. */
+	if (alternate_of != NULL) {
+		/* If it is a snap, find the channels that snap provides, otherwise find snaps that match on common id */
+		if (gs_app_has_management_plugin (alternate_of, plugin)) {
+			const gchar *snap_name;
+
+			snap_name = gs_app_get_metadata_item (alternate_of, "snap::name");
+
+			data->n_pending_ops++;
+			get_store_snap_async (self, client, snap_name, TRUE, cancellable, list_alternate_apps_snap_cb, g_steal_pointer (&task));
+		/* The id can be NULL for example for local package files */
+		} else if (gs_app_get_id (alternate_of) != NULL) {
+			data->n_pending_ops++;
+			snapd_client_find_section_async (client,
+							 SNAPD_FIND_FLAGS_SCOPE_WIDE | SNAPD_FIND_FLAGS_MATCH_COMMON_ID,
+							 NULL, gs_app_get_id (alternate_of),
+							 cancellable,
+							 list_alternate_apps_nonsnap_cb, g_steal_pointer (&task));
+		} else {
+			g_clear_object (&data->results_list);
+			g_task_return_new_error (task, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
+						 "Unsupported app without id");
+		}
+
+		return;
+	}
+
+	/* Querying with keywords also requires calling the method differently.
+	 * snapd will tokenise and stem @query internally. */
+	if (keywords != NULL) {
+		g_autofree gchar *query_str = NULL;
+
+		query_str = g_strjoinv (" ", (gchar **) keywords);
+		data->n_pending_ops++;
+		snapd_client_find_section_async (client, SNAPD_FIND_FLAGS_SCOPE_WIDE, NULL, query_str,
+						 cancellable, list_apps_cb, g_steal_pointer (&task));
+		return;
+	}
+
+	/* Work out which sections we’re querying for. */
+	if (is_curated != GS_APP_QUERY_TRISTATE_UNSET) {
+		sections = curated_sections;
+	} else if (category != NULL) {
+		g_autofree gchar *category_path = NULL;
+
+		/*
+		 * Unused categories:
+		 *
+		 * health-and-fitness
+		 * personalisation
+		 * devices-and-iot
+		 * security
+		 * server-and-cloud
+		 * entertainment
+		 */
+		const struct {
+			const gchar *category_path;
+			const gchar *sections[4];
+		} category_to_sections_map[] = {
+			{ "play/featured", { "games", NULL, }},
+			{ "create/featured", { "photo-and-video", "art-and-design", "music-and-video", NULL, }},
+			{ "socialize/featured", { "social", "news-and-weather", NULL, }},
+			{ "work/featured", { "productivity", "finance", "utilities", NULL, }},
+			{ "develop/featured", { "development", NULL, }},
+			{ "learn/featured", { "education", "science", "books-and-reference", NULL, }},
+		};
+
+		category_path = category_build_full_path (category);
+
+		for (gsize i = 0; i < G_N_ELEMENTS (category_to_sections_map); i++) {
+			if (g_str_equal (category_to_sections_map[i].category_path, category_path)) {
+				sections = category_to_sections_map[i].sections;
+				break;
+			}
+		}
+	}
+
+	/* Start a query for each of the sections we’re interested in, keeping a
+	 * counter of pending operations which is initialised to 1 until all
+	 * the operations are started. */
+	data->n_pending_ops = 1;
+
+	for (gsize i = 0; sections != NULL && sections[i] != NULL; i++) {
+		data->n_pending_ops++;
+		snapd_client_find_section_async (client, SNAPD_FIND_FLAGS_SCOPE_WIDE, sections[i], NULL,
+						 cancellable, list_apps_cb, g_object_ref (task));
+	}
+
+	finish_list_apps_op (task, NULL);
+}
+
+static void
+list_installed_apps_cb (GObject      *source_object,
+                        GAsyncResult *result,
+                        gpointer      user_data)
+{
+	SnapdClient *client = SNAPD_CLIENT (source_object);
+	g_autoptr(GTask) task = G_TASK (user_data);
+	GsPluginSnap *self = g_task_get_source_object (task);
+	ListAppsData *data = g_task_get_task_data (task);
+	g_autoptr(GPtrArray) snaps = NULL;
+	g_autoptr(GError) local_error = NULL;
+
+	snaps = snapd_client_get_snaps_finish (client, result, &local_error);
+
+	if (snaps == NULL) {
+		snapd_error_convert (&local_error);
+	}
+
+	for (guint i = 0; snaps != NULL && i < snaps->len; i++) {
+		SnapdSnap *snap = g_ptr_array_index (snaps, i);
+		g_autoptr(GsApp) app = NULL;
+
+		app = snap_to_app (self, snap, NULL);
+		gs_app_list_add (data->results_list, app);
+	}
+
+	finish_list_apps_op (task, g_steal_pointer (&local_error));
+}
+
+static void
+list_alternate_apps_snap_cb (GObject      *source_object,
+                             GAsyncResult *result,
+                             gpointer      user_data)
+{
+	GsPluginSnap *self = GS_PLUGIN_SNAP (source_object);
+	g_autoptr(GTask) task = G_TASK (user_data);
+	ListAppsData *data = g_task_get_task_data (task);
+	g_autoptr(SnapdSnap) snap = NULL;
+	g_autoptr(GError) local_error = NULL;
+
+	snap = get_store_snap_finish (self, result, &local_error);
+
+	if (snap != NULL)
+		add_channels (self, snap, data->results_list);
+
+	finish_list_apps_op (task, g_steal_pointer (&local_error));
+}
+
+static void
+list_alternate_apps_nonsnap_cb (GObject      *source_object,
+                                GAsyncResult *result,
+                                gpointer      user_data)
+{
+	SnapdClient *client = SNAPD_CLIENT (source_object);
+	g_autoptr(GTask) task = G_TASK (user_data);
+	GsPluginSnap *self = g_task_get_source_object (task);
+	GCancellable *cancellable = g_task_get_cancellable (task);
+	ListAppsData *data = g_task_get_task_data (task);
+	g_autoptr(GPtrArray) snaps = NULL;
+	g_autoptr(GError) local_error = NULL;
+
+	snaps = snapd_client_find_section_finish (client, result, NULL, &local_error);
+
+	if (snaps == NULL) {
+		snapd_error_convert (&local_error);
+		finish_list_apps_op (task, g_steal_pointer (&local_error));
+		return;
+	}
+
+	store_snap_cache_update (self, snaps, FALSE);
+
+	for (guint i = 0; snaps != NULL && i < snaps->len; i++) {
+		SnapdSnap *snap = g_ptr_array_index (snaps, i);
+
+		data->n_pending_ops++;
+		get_store_snap_async (self, client, snapd_snap_get_name (snap),
+				      TRUE, cancellable, list_alternative_apps_nonsnap_get_store_snap_cb, g_object_ref (task));
+	}
+
+	finish_list_apps_op (task, NULL);
+}
+
+static void
+list_alternative_apps_nonsnap_get_store_snap_cb (GObject      *source_object,
+                                                 GAsyncResult *result,
+                                                 gpointer      user_data)
+{
+	GsPluginSnap *self = GS_PLUGIN_SNAP (source_object);
+	g_autoptr(GTask) task = G_TASK (user_data);
+	ListAppsData *data = g_task_get_task_data (task);
+	g_autoptr(SnapdSnap) store_snap = NULL;
+	g_autoptr(GError) local_error = NULL;
+
+	store_snap = get_store_snap_finish (self, result, &local_error);
+
+	if (store_snap != NULL)
+		add_channels (self, store_snap, data->results_list);
+
+	finish_list_apps_op (task, g_steal_pointer (&local_error));
+}
+
+static void
+list_apps_cb (GObject      *source_object,
+              GAsyncResult *result,
+              gpointer      user_data)
+{
+	SnapdClient *client = SNAPD_CLIENT (source_object);
+	g_autoptr(GTask) task = G_TASK (user_data);
+	GsPluginSnap *self = g_task_get_source_object (task);
+	ListAppsData *data = g_task_get_task_data (task);
+	g_autoptr(GPtrArray) snaps = NULL;
+	g_autoptr(GError) local_error = NULL;
+
+	snaps = snapd_client_find_section_finish (client, result, NULL, &local_error);
+
+	if (snaps != NULL) {
+		store_snap_cache_update (self, snaps, FALSE);
+
+		for (guint i = 0; i < snaps->len; i++) {
+			SnapdSnap *snap = g_ptr_array_index (snaps, i);
+			g_autoptr(GsApp) app = NULL;
+
+			app = snap_to_app (self, snap, NULL);
+			gs_app_list_add (data->results_list, app);
+		}
+	} else {
+		snapd_error_convert (&local_error);
+	}
+
+	finish_list_apps_op (task, g_steal_pointer (&local_error));
+}
+
+/* @error is (transfer full) if non-%NULL */
+static void
+finish_list_apps_op (GTask  *task,
+                     GError *error)
+{
+	ListAppsData *data = g_task_get_task_data (task);
+	g_autoptr(GsAppList) results_list = NULL;
+	g_autoptr(GError) error_owned = g_steal_pointer (&error);
+
+	if (error_owned != NULL && data->saved_error == NULL)
+		data->saved_error = g_steal_pointer (&error_owned);
+	else if (error_owned != NULL)
+		g_debug ("Additional error while listing apps: %s", error_owned->message);
+
+	g_assert (data->n_pending_ops > 0);
+	data->n_pending_ops--;
+
+	if (data->n_pending_ops > 0)
+		return;
+
+	/* Get the results of the parallel ops. */
+	results_list = g_steal_pointer (&data->results_list);
+
+	if (data->saved_error != NULL)
+		g_task_return_error (task, g_steal_pointer (&data->saved_error));
+	else
+		g_task_return_pointer (task, g_steal_pointer (&results_list), g_object_unref);
+}
+
+static GsAppList *
+gs_plugin_snap_list_apps_finish (GsPlugin      *plugin,
+                                 GAsyncResult  *result,
+                                 GError       **error)
+{
+	return g_task_propagate_pointer (G_TASK (result), error);
+}
+
+static SnapdSnap *
+get_store_snap (GsPluginSnap  *self,
+                SnapdClient   *client,
+                const gchar   *name,
+                gboolean       need_details,
+                GCancellable  *cancellable,
+                GError       **error)
+{
+	SnapdSnap *snap = NULL;
+	g_autoptr(GPtrArray) snaps = NULL;
+
+	/* use cached version if available */
+	snap = store_snap_cache_lookup (self, name, need_details);
+	if (snap != NULL)
+		return g_object_ref (snap);
+
+	snaps = find_snaps (self, client,
+			    SNAPD_FIND_FLAGS_SCOPE_WIDE | SNAPD_FIND_FLAGS_MATCH_NAME,
+			    NULL, name, cancellable, error);
+	if (snaps == NULL || snaps->len < 1)
+		return NULL;
+
+	return g_object_ref (g_ptr_array_index (snaps, 0));
+}
+
+static void get_store_snap_cb (GObject      *source_object,
+                               GAsyncResult *result,
+                               gpointer      user_data);
+
+static void
+get_store_snap_async (GsPluginSnap        *self,
+                      SnapdClient         *client,
+                      const gchar         *name,
+                      gboolean             need_details,
+                      GCancellable        *cancellable,
+                      GAsyncReadyCallback  callback,
+                      gpointer             user_data)
+{
+	g_autoptr(GTask) task = NULL;
+	SnapdSnap *snap = NULL;
+
+	task = g_task_new (self, cancellable, callback, user_data);
+	g_task_set_source_tag (task, get_store_snap_async);
+
+	/* use cached version if available */
+	snap = store_snap_cache_lookup (self, name, need_details);
+	if (snap != NULL) {
+		g_task_return_pointer (task, g_object_ref (snap), (GDestroyNotify) g_object_unref);
+		return;
+	}
+
+	snapd_client_find_section_async (client,
+					 SNAPD_FIND_FLAGS_SCOPE_WIDE | SNAPD_FIND_FLAGS_MATCH_NAME,
+					 NULL, name,
+					 cancellable,
+					 get_store_snap_cb, g_steal_pointer (&task));
+}
+
+static void
+get_store_snap_cb (GObject      *source_object,
+                   GAsyncResult *result,
+                   gpointer      user_data)
+{
+	SnapdClient *client = SNAPD_CLIENT (source_object);
+	g_autoptr(GTask) task = g_steal_pointer (&user_data);
+	GsPluginSnap *self = g_task_get_source_object (task);
+	g_autoptr(GPtrArray) snaps = NULL;
+	g_autoptr(GError) local_error = NULL;
+
+	snaps = snapd_client_find_section_finish (client, result, NULL, &local_error);
+
+	if (snaps == NULL || snaps->len < 1) {
+		snapd_error_convert (&local_error);
+		g_task_return_error (task, g_steal_pointer (&local_error));
+	} else {
+		store_snap_cache_update (self, snaps, TRUE);
+		g_task_return_pointer (task, g_object_ref (g_ptr_array_index (snaps, 0)), (GDestroyNotify) g_object_unref);
+	}
+}
+
+static SnapdSnap *
+get_store_snap_finish (GsPluginSnap  *self,
+                       GAsyncResult  *result,
+                       GError       **error)
+{
+	return g_task_propagate_pointer (G_TASK (result), error);
+}
+
+static int
+track_value (const gchar *track, GStrv tracks)
+{
+	int r = 0;
+	while (tracks[r] != NULL && strcmp (track, tracks[r]) != 0)
+		r++;
+	return r;
+}
+
+static int
+risk_value (const gchar *risk)
+{
+	if (strcmp (risk, "stable") == 0)
+		return 0;
+	else if (strcmp (risk, "candidate") == 0)
+		return 1;
+	else if (strcmp (risk, "beta") == 0)
+		return 2;
+	else if (strcmp (risk, "edge") == 0)
+		return 3;
+	else
+		return 4;
+}
+
+static int
+compare_channel (gconstpointer a, gconstpointer b, gpointer user_data)
+{
+	SnapdChannel *channel_a = *(SnapdChannel **)a, *channel_b = *(SnapdChannel **)b;
+	GStrv tracks = user_data;
+	int r;
+
+	r = track_value (snapd_channel_get_track (channel_a), tracks) - track_value (snapd_channel_get_track (channel_b), tracks);
+	if (r != 0)
+		return r;
+
+	r = g_strcmp0 (snapd_channel_get_risk (channel_a), snapd_channel_get_risk (channel_b));
+	if (r != 0) {
+		int r2;
+
+		r2 = risk_value (snapd_channel_get_risk (channel_a)) - risk_value (snapd_channel_get_risk (channel_b));
+		if (r2 != 0)
+			return r2;
+		else
+			return r;
+	}
+
+	return g_strcmp0 (snapd_channel_get_branch (channel_a), snapd_channel_get_branch (channel_b));
+}
+
+static gchar *
+expand_channel_name (const gchar *name)
+{
+	g_auto(GStrv) tokens = NULL;
+	const gchar *risks[] = { "stable", "candidate", "beta", "edge", NULL };
+
+	if (name == NULL)
+		return NULL;
+
+	tokens = g_strsplit (name, "/", -1);
+	for (int i = 0; risks[i] != NULL; i++) {
+		if (strcmp (tokens[0], risks[i]) == 0)
+			return g_strconcat ("latest/", name, NULL);
+	}
+
+	return g_strdup (name);
+}
+
+static void
+add_channels (GsPluginSnap *self, SnapdSnap *snap, GsAppList *list)
+{
+	GStrv tracks;
+	GPtrArray *channels;
+	g_autoptr(GPtrArray) sorted_channels = NULL;
+
+	tracks = snapd_snap_get_tracks (snap);
+	channels = snapd_snap_get_channels (snap);
+	sorted_channels = g_ptr_array_new ();
+	for (guint i = 0; i < channels->len; i++) {
+		SnapdChannel *channel = g_ptr_array_index (channels, i);
+		g_ptr_array_add (sorted_channels, channel);
+	}
+	g_ptr_array_sort_with_data (sorted_channels, compare_channel, tracks);
+
+	for (guint i = 0; i < sorted_channels->len; i++) {
+		SnapdChannel *channel = g_ptr_array_index (sorted_channels, i);
+		g_autoptr(GsApp) app = NULL;
+		g_autofree gchar *expanded_name = NULL;
+
+		expanded_name = expand_channel_name (snapd_channel_get_name (channel));
+		app = snap_to_app (self, snap, expanded_name);
+
+		gs_app_list_add (list, app);
+	}
+}
+
+static gboolean
+app_name_matches_snap_name (SnapdSnap *snap, SnapdApp *app)
+{
+	return g_strcmp0 (snapd_snap_get_name (snap), snapd_app_get_name (app)) == 0;
+}
+
+static SnapdApp *
+get_primary_app (SnapdSnap *snap)
+{
+	GPtrArray *apps;
+	guint i;
+	SnapdApp *primary_app = NULL;
+
+	/* Pick the "main" app from the snap.  In order of
+	 * preference, we want to pick:
+	 *
+	 *   1. the main app, provided it has a desktop file
+	 *   2. the first app with a desktop file
+	 *   3. the main app
+	 *   4. the first app
+	 *
+	 * The "main app" is one whose name matches the snap name.
+	 */
+	apps = snapd_snap_get_apps (snap);
+	for (i = 0; i < apps->len; i++) {
+		SnapdApp *app = apps->pdata[i];
+
+		if (primary_app == NULL ||
+                    (snapd_app_get_desktop_file (primary_app) == NULL && snapd_app_get_desktop_file (app) != NULL) ||
+                    (!app_name_matches_snap_name (snap, primary_app) && app_name_matches_snap_name (snap, app)))
+			primary_app = app;
+	}
+
+	return primary_app;
+}
+
+static void
+refine_icons (GsApp        *app,
+              SnapdSnap    *snap)
+{
+	GPtrArray *media;
+	guint i;
+
+	media = snapd_snap_get_media (snap);
+	for (i = 0; i < media->len; i++) {
+		SnapdMedia *m = media->pdata[i];
+		g_autoptr(GIcon) icon = NULL;
+
+		if (g_strcmp0 (snapd_media_get_media_type (m), "icon") != 0)
+			continue;
+
+		icon = gs_remote_icon_new (snapd_media_get_url (m));
+		gs_icon_set_width (icon, snapd_media_get_width (m));
+		gs_icon_set_height (icon, snapd_media_get_height (m));
+		gs_app_add_icon (app, icon);
+	}
+}
+
+static void serialize_node (SnapdMarkdownNode *node, GString *text, guint indentation);
+
+static gboolean
+is_block_node (SnapdMarkdownNode *node)
+{
+	switch (snapd_markdown_node_get_node_type (node)) {
+	case SNAPD_MARKDOWN_NODE_TYPE_PARAGRAPH:
+	case SNAPD_MARKDOWN_NODE_TYPE_UNORDERED_LIST:
+	case SNAPD_MARKDOWN_NODE_TYPE_CODE_BLOCK:
+		return TRUE;
+	default:
+		return FALSE;
+	}
+}
+
+static void
+serialize_nodes (GPtrArray *nodes, GString *text, guint indentation)
+{
+	for (guint i = 0; i < nodes->len; i++) {
+		SnapdMarkdownNode *node = g_ptr_array_index (nodes, i);
+
+		if (i != 0) {
+			SnapdMarkdownNode *last_node = g_ptr_array_index (nodes, i - 1);
+			if (is_block_node (node) && is_block_node (last_node))
+				g_string_append (text, "\n");
+		}
+
+		serialize_node (node, text, indentation);
+	}
+}
+
+static void
+serialize_node (SnapdMarkdownNode *node, GString *text, guint indentation)
+{
+	GPtrArray *children = snapd_markdown_node_get_children (node);
+	g_autofree gchar *escaped_text = NULL;
+	g_autoptr(GString) url = NULL;
+
+	switch (snapd_markdown_node_get_node_type (node)) {
+	case SNAPD_MARKDOWN_NODE_TYPE_TEXT:
+		escaped_text = g_markup_escape_text (snapd_markdown_node_get_text (node), -1);
+		g_string_append (text, escaped_text);
+		return;
+
+	case SNAPD_MARKDOWN_NODE_TYPE_PARAGRAPH:
+		serialize_nodes (children, text, indentation);
+		g_string_append (text, "\n");
+		return;
+
+	case SNAPD_MARKDOWN_NODE_TYPE_UNORDERED_LIST:
+		serialize_nodes (children, text, indentation);
+		return;
+
+	case SNAPD_MARKDOWN_NODE_TYPE_LIST_ITEM:
+		for (guint i = 0; i < indentation; i++) {
+			g_string_append (text, "    ");
+		}
+		g_string_append_printf (text, " • ");
+		serialize_nodes (children, text, indentation + 1);
+		return;
+
+	case SNAPD_MARKDOWN_NODE_TYPE_CODE_BLOCK:
+	case SNAPD_MARKDOWN_NODE_TYPE_CODE_SPAN:
+		g_string_append (text, "<tt>");
+		serialize_nodes (children, text, indentation);
+		g_string_append (text, "</tt>");
+		return;
+
+	case SNAPD_MARKDOWN_NODE_TYPE_EMPHASIS:
+		g_string_append (text, "<i>");
+		serialize_nodes (children, text, indentation);
+		g_string_append (text, "</i>");
+		return;
+
+	case SNAPD_MARKDOWN_NODE_TYPE_STRONG_EMPHASIS:
+		g_string_append (text, "<b>");
+		serialize_nodes (children, text, indentation);
+		g_string_append (text, "</b>");
+		return;
+
+	case SNAPD_MARKDOWN_NODE_TYPE_URL:
+		url = g_string_new ("");
+		serialize_nodes (children, url, indentation);
+		g_string_append_printf (text, "<a href=\"%s\">%s</a>", url->str, url->str);
+		return;
+
+	default:
+		g_assert_not_reached();
+	}
+}
+
+static gchar *
+gs_plugin_snap_get_markup_description (SnapdSnap *snap)
+{
+	g_autoptr(SnapdMarkdownParser) parser = snapd_markdown_parser_new (SNAPD_MARKDOWN_VERSION_0);
+	g_autoptr(GPtrArray) nodes = NULL;
+	g_autoptr(GString) text = g_string_new ("");
+
+	nodes = snapd_markdown_parser_parse (parser, snapd_snap_get_description (snap));
+	serialize_nodes (nodes, text, 0);
+	return g_string_free (g_steal_pointer (&text), FALSE);
+}
+
+static void
+refine_screenshots (GsApp *app, SnapdSnap *snap)
+{
+	GPtrArray *media;
+	guint i;
+
+	media = snapd_snap_get_media (snap);
+	for (i = 0; i < media->len; i++) {
+		SnapdMedia *m = media->pdata[i];
+		const gchar *url;
+		g_autofree gchar *filename = NULL;
+		g_autoptr(AsScreenshot) ss = NULL;
+		g_autoptr(AsImage) image = NULL;
+
+		if (g_strcmp0 (snapd_media_get_media_type (m), "screenshot") != 0)
+			continue;
+
+		/* skip screenshots used for banner when app is featured */
+		url = snapd_media_get_url (m);
+		filename = g_path_get_basename (url);
+		if (is_banner_image (filename) || is_banner_icon_image (filename))
+			continue;
+
+		ss = as_screenshot_new ();
+		as_screenshot_set_kind (ss, AS_SCREENSHOT_KIND_EXTRA);
+		image = as_image_new ();
+		as_image_set_url (image, snapd_media_get_url (m));
+		as_image_set_kind (image, AS_IMAGE_KIND_SOURCE);
+		as_image_set_width (image, snapd_media_get_width (m));
+		as_image_set_height (image, snapd_media_get_height (m));
+		as_screenshot_add_image (ss, image);
+		gs_app_add_screenshot (app, ss);
+	}
+}
+
+static gboolean
+gs_snap_file_size_include_cb (const gchar *filename,
+			      GFileTest file_kind,
+			      gpointer user_data)
+{
+	return file_kind != G_FILE_TEST_IS_SYMLINK &&
+	       g_strcmp0 (filename, "common") != 0 &&
+	       g_strcmp0 (filename, "current") != 0;
+}
+
+static guint64
+gs_snap_get_app_directory_size (const gchar *snap_name,
+				gboolean is_cache_size,
+				GCancellable *cancellable)
+{
+	g_autofree gchar *filename = NULL;
+
+	if (is_cache_size)
+		filename = g_build_filename (g_get_home_dir (), "snap", snap_name, "common", NULL);
+	else
+		filename = g_build_filename (g_get_home_dir (), "snap", snap_name, NULL);
+
+	return gs_utils_get_file_size (filename, is_cache_size ? NULL : gs_snap_file_size_include_cb, NULL, cancellable);
+}
+
+static SnapdSnap *
+find_snap_in_array (GPtrArray   *snaps,
+                    const gchar *snap_name)
+{
+	for (guint i = 0; i < snaps->len; i++) {
+		SnapdSnap *snap = SNAPD_SNAP (snaps->pdata[i]);
+		if (g_strcmp0 (snapd_snap_get_name (snap), snap_name) == 0)
+			return snap;
+	}
+
+	return NULL;
+}
+
+static void get_snaps_cb (GObject      *object,
+                          GAsyncResult *result,
+                          gpointer      user_data);
+
+static void
+gs_plugin_snap_refine_async (GsPlugin            *plugin,
+                             GsAppList           *list,
+                             GsPluginRefineFlags  flags,
+                             GCancellable        *cancellable,
+                             GAsyncReadyCallback  callback,
+                             gpointer             user_data)
+{
+	GsPluginSnap *self = GS_PLUGIN_SNAP (plugin);
+	g_autoptr(SnapdClient) client = NULL;
+	g_autoptr(GPtrArray) snap_names = g_ptr_array_new_with_free_func (NULL);
+	g_autoptr(GTask) task = NULL;
+	g_autoptr(GsAppList) snap_apps = NULL;
+	g_autoptr(GsPluginRefineData) data = NULL;
+	gboolean interactive = gs_plugin_has_flags (plugin, GS_PLUGIN_FLAGS_INTERACTIVE);
+	g_autoptr(GError) local_error = NULL;
+
+	task = g_task_new (plugin, cancellable, callback, user_data);
+	g_task_set_source_tag (task, gs_plugin_snap_refine_async);
+
+	/* Filter out apps that aren't managed by us */
+	snap_apps = gs_app_list_new ();
+	for (guint i = 0; i < gs_app_list_length (list); i++) {
+		GsApp *app = gs_app_list_index (list, i);
+
+		if (!gs_app_has_management_plugin (app, plugin))
+			continue;
+
+		gs_app_list_add (snap_apps, app);
+	}
+
+	data = gs_plugin_refine_data_new (snap_apps, flags);
+	g_task_set_task_data (task, g_steal_pointer (&data), (GDestroyNotify) gs_plugin_refine_data_free);
+
+	client = get_client (self, interactive, &local_error);
+	if (client == NULL) {
+		g_task_return_error (task, g_steal_pointer (&local_error));
+		return;
+	}
+
+	/* Get information from locally installed snaps */
+	for (guint i = 0; i < gs_app_list_length (snap_apps); i++) {
+		GsApp *app = gs_app_list_index (snap_apps, i);
+		g_ptr_array_add (snap_names, (gpointer) gs_app_get_metadata_item (app, "snap::name"));
+	}
+
+	g_ptr_array_add (snap_names, NULL);  /* NULL terminator */
+
+	snapd_client_get_snaps_async (client, SNAPD_GET_SNAPS_FLAGS_NONE, (gchar **) snap_names->pdata, cancellable, get_snaps_cb, g_steal_pointer (&task));
+}
+
+static void get_icon_cb (GObject      *object,
+                         GAsyncResult *result,
+                         gpointer      user_data);
+
+static void
+get_snaps_cb (GObject      *object,
+              GAsyncResult *result,
+              gpointer      user_data)
+{
+	SnapdClient *client = SNAPD_CLIENT (object);
+	g_autoptr(GTask) task = g_steal_pointer (&user_data);
+	GsPluginSnap *self = g_task_get_source_object (task);
+	GCancellable *cancellable = g_task_get_cancellable (task);
+	GsPluginRefineData *data = g_task_get_task_data (task);
+	GsAppList *list = data->list;
+	GsPluginRefineFlags flags = data->flags;
+	g_autoptr(GPtrArray) local_snaps = NULL;
+	g_autoptr(GError) local_error = NULL;
+
+	local_snaps = snapd_client_get_snaps_finish (client, result, &local_error);
+	if (local_snaps == NULL) {
+		g_task_return_error (task, g_steal_pointer (&local_error));
+		return;
+	}
+
+	for (guint i = 0; i < gs_app_list_length (list); i++) {
+		GsApp *app = gs_app_list_index (list, i);
+		const gchar *snap_name, *name, *website, *contact, *version;
+		g_autofree gchar *channel = NULL;
+		g_autofree gchar *store_channel = NULL;
+		g_autofree gchar *tracking_channel = NULL;
+		gboolean need_details = FALSE;
+		SnapdConfinement confinement = SNAPD_CONFINEMENT_UNKNOWN;
+		SnapdSnap *local_snap, *snap;
+		g_autoptr(SnapdSnap) store_snap = NULL;
+		const gchar *developer_name;
+		g_autofree gchar *description = NULL;
+		guint64 release_date = 0;
+
+		snap_name = gs_app_get_metadata_item (app, "snap::name");
+		channel = g_strdup (gs_app_get_branch (app));
+
+		/* get information from locally installed snaps and information we already have */
+		local_snap = find_snap_in_array (local_snaps, snap_name);
+		store_snap = store_snap_cache_lookup (self, snap_name, FALSE);
+		if (store_snap != NULL)
+			store_channel = expand_channel_name (snapd_snap_get_channel (store_snap));
+
+		/* check if requested information requires us to go to the Snap Store */
+		if (flags & GS_PLUGIN_REFINE_FLAGS_REQUIRE_SCREENSHOTS)
+			need_details = TRUE;
+		if (channel != NULL && g_strcmp0 (store_channel, channel) != 0)
+			need_details = TRUE;
+		if (need_details) {
+			g_clear_object (&store_snap);
+			store_snap = get_store_snap (self, client, snap_name, need_details,
+						     cancellable, NULL);
+		}
+
+		/* we don't know anything about this snap */
+		if (local_snap == NULL && store_snap == NULL)
+			continue;
+
+		if (local_snap != NULL)
+			tracking_channel = expand_channel_name (snapd_snap_get_tracking_channel (local_snap));
+
+		/* Get default channel to install */
+		if (channel == NULL) {
+			if (local_snap != NULL)
+				channel = g_strdup (tracking_channel);
+			else
+				channel = expand_channel_name (snapd_snap_get_channel (store_snap));
+
+			gs_app_set_branch (app, channel);
+		}
+
+		if (local_snap != NULL && g_strcmp0 (tracking_channel, channel) == 0) {
+			/* Do not set to installed state if app is updatable */
+			if (gs_app_get_state (app) != GS_APP_STATE_UPDATABLE_LIVE) {
+				gs_app_set_state (app, GS_APP_STATE_INSTALLED);
+			}
+		} else
+			gs_app_set_state (app, GS_APP_STATE_AVAILABLE);
+		gs_app_add_quirk (app, GS_APP_QUIRK_DO_NOT_AUTO_UPDATE);
+
+		/* use store information for basic metadata over local information */
+		snap = store_snap != NULL ? store_snap : local_snap;
+		name = snapd_snap_get_title (snap);
+		if (name == NULL || g_strcmp0 (name, "") == 0)
+			name = snapd_snap_get_name (snap);
+		gs_app_set_name (app, GS_APP_QUALITY_NORMAL, name);
+		website = snapd_snap_get_website (snap);
+		if (g_strcmp0 (website, "") == 0)
+			website = NULL;
+		gs_app_set_url (app, AS_URL_KIND_HOMEPAGE, website);
+		contact = snapd_snap_get_contact (snap);
+		if (g_strcmp0 (contact, "") == 0)
+			contact = NULL;
+		gs_app_set_url (app, AS_URL_KIND_CONTACT, contact);
+		gs_app_set_summary (app, GS_APP_QUALITY_NORMAL, snapd_snap_get_summary (snap));
+		description = gs_plugin_snap_get_markup_description (snap);
+		gs_app_set_description (app, GS_APP_QUALITY_NORMAL, description);
+		gs_app_set_license (app, GS_APP_QUALITY_NORMAL, snapd_snap_get_license (snap));
+		developer_name = snapd_snap_get_publisher_display_name (snap);
+		if (developer_name == NULL)
+			developer_name = snapd_snap_get_publisher_username (snap);
+		gs_app_set_developer_name (app, developer_name);
+		if (snapd_snap_get_publisher_validation (snap) == SNAPD_PUBLISHER_VALIDATION_VERIFIED)
+			gs_app_add_quirk (app, GS_APP_QUIRK_DEVELOPER_VERIFIED);
+
+		snap = local_snap != NULL ? local_snap : store_snap;
+		version = snapd_snap_get_version (snap);
+		confinement = snapd_snap_get_confinement (snap);
+
+		if (channel != NULL && store_snap != NULL) {
+			GPtrArray *channels = snapd_snap_get_channels (store_snap);
+
+			for (guint j = 0; j < channels->len; j++) {
+				SnapdChannel *c = channels->pdata[j];
+				g_autofree gchar *expanded_name = NULL;
+				GDateTime *dt;
+
+				expanded_name = expand_channel_name (snapd_channel_get_name (c));
+				if (g_strcmp0 (expanded_name, channel) != 0)
+					continue;
+
+				version = snapd_channel_get_version (c);
+				confinement = snapd_channel_get_confinement (c);
+
+				dt = snapd_channel_get_released_at (c);
+				if (dt)
+					release_date = (guint64) g_date_time_to_unix (dt);
+			}
+		}
+
+		gs_app_set_version (app, version);
+		gs_app_set_release_date (app, release_date);
+
+		if (confinement != SNAPD_CONFINEMENT_UNKNOWN) {
+			GEnumClass *enum_class = g_type_class_ref (SNAPD_TYPE_CONFINEMENT);
+			gs_app_set_metadata (app, "snap::confinement", g_enum_get_value (enum_class, confinement)->value_nick);
+			g_type_class_unref (enum_class);
+		}
+
+		if (flags & GS_PLUGIN_REFINE_FLAGS_REQUIRE_KUDOS &&
+		    self->system_confinement == SNAPD_SYSTEM_CONFINEMENT_STRICT &&
+		    confinement == SNAPD_CONFINEMENT_STRICT)
+			gs_app_add_kudo (app, GS_APP_KUDO_SANDBOXED);
+
+		gs_app_set_kind (app, snap_guess_component_kind (snap));
+
+		/* add information specific to installed snaps */
+		if (local_snap != NULL) {
+			SnapdApp *snap_app;
+			GDateTime *install_date;
+			gint64 installed_size_bytes;
+
+			install_date = snapd_snap_get_install_date (local_snap);
+			installed_size_bytes = snapd_snap_get_installed_size (local_snap);
+
+			gs_app_set_size_installed (app, (installed_size_bytes > 0) ? GS_SIZE_TYPE_VALID : GS_SIZE_TYPE_UNKNOWN, (guint64) installed_size_bytes);
+			gs_app_set_install_date (app, install_date != NULL ? g_date_time_to_unix (install_date) : GS_APP_INSTALL_DATE_UNKNOWN);
+
+			snap_app = get_primary_app (local_snap);
+			if (snap_app != NULL) {
+				gs_app_set_metadata (app, "snap::launch-name", snapd_app_get_name (snap_app));
+				gs_app_set_metadata (app, "snap::launch-desktop", snapd_app_get_desktop_file (snap_app));
+			} else {
+				gs_app_add_quirk (app, GS_APP_QUIRK_NOT_LAUNCHABLE);
+			}
+		}
+
+		/* add information specific to store snaps */
+		if (store_snap != NULL) {
+			gint64 download_size_bytes;
+
+			gs_app_set_origin (app, self->store_name);
+			gs_app_set_origin_hostname (app, self->store_hostname);
+
+			download_size_bytes = snapd_snap_get_download_size (store_snap);
+			gs_app_set_size_download (app, (download_size_bytes > 0) ? GS_SIZE_TYPE_VALID : GS_SIZE_TYPE_UNKNOWN, (guint64) download_size_bytes);
+
+			if (flags & GS_PLUGIN_REFINE_FLAGS_REQUIRE_SCREENSHOTS && gs_app_get_screenshots (app)->len == 0)
+				refine_screenshots (app, store_snap);
+		}
+
+		/* load icon if requested */
+		if (flags & GS_PLUGIN_REFINE_FLAGS_REQUIRE_ICON)
+			refine_icons (app, snap);
+
+		if ((flags & GS_PLUGIN_REFINE_FLAGS_REQUIRE_SIZE_DATA) != 0 &&
+		    gs_app_is_installed (app) &&
+		    gs_app_get_kind (app) != AS_COMPONENT_KIND_RUNTIME) {
+			if (gs_app_get_size_cache_data (app, NULL) != GS_SIZE_TYPE_VALID)
+				gs_app_set_size_cache_data (app, GS_SIZE_TYPE_VALID, gs_snap_get_app_directory_size (snap_name, TRUE, cancellable));
+			if (gs_app_get_size_user_data (app, NULL) != GS_SIZE_TYPE_VALID)
+				gs_app_set_size_user_data (app, GS_SIZE_TYPE_VALID, gs_snap_get_app_directory_size (snap_name, FALSE, cancellable));
+
+			if (g_cancellable_is_cancelled (cancellable)) {
+				gs_app_set_size_cache_data (app, GS_SIZE_TYPE_UNKNOWABLE, 0);
+				gs_app_set_size_user_data (app, GS_SIZE_TYPE_UNKNOWABLE, 0);
+			}
+		}
+	}
+
+	/* Icons require async calls to get */
+	if (flags & GS_PLUGIN_REFINE_FLAGS_REQUIRE_ICON && gs_app_list_length (list) > 0) {
+		GsApp *app = gs_app_list_index (list, 0);
+		snapd_client_get_icon_async (client, gs_app_get_metadata_item (app, "snap::name"), cancellable, get_icon_cb, g_steal_pointer (&task));
+	} else {
+		g_task_return_boolean (task, TRUE);
+	}
+}
+
+static void
+get_icon_cb (GObject      *object,
+             GAsyncResult *result,
+             gpointer      user_data)
+{
+	SnapdClient *client = SNAPD_CLIENT (object);
+	g_autoptr(GTask) task = g_steal_pointer (&user_data);
+	GCancellable *cancellable = g_task_get_cancellable (task);
+	GsPluginRefineData *data = g_task_get_task_data (task);
+	GsApp *app;
+	g_autoptr(SnapdIcon) snap_icon = NULL;
+	g_autoptr(GError) local_error = NULL;
+
+	app = gs_app_list_index (data->list, 0);
+	snap_icon = snapd_client_get_icon_finish (client, result, &local_error);
+	if (snap_icon != NULL) {
+		g_autoptr(GIcon) icon = g_bytes_icon_new (snapd_icon_get_data (snap_icon));
+		gs_app_add_icon (app, icon);
+	}
+
+	/* Get next icon in the list or done */
+	gs_app_list_remove (data->list, app);
+	if (gs_app_list_length (data->list) > 0) {
+		app = gs_app_list_index (data->list, 0);
+		snapd_client_get_icon_async (client, gs_app_get_metadata_item (app, "snap::name"), cancellable, get_icon_cb, g_steal_pointer (&task));
+	} else {
+		g_task_return_boolean (task, TRUE);
+	}
+}
+
+static gboolean
+gs_plugin_snap_refine_finish (GsPlugin      *plugin,
+                              GAsyncResult  *result,
+                              GError       **error)
+{
+	return g_task_propagate_boolean (G_TASK (result), error);
+}
+
+static void
+progress_cb (SnapdClient *client, SnapdChange *change, gpointer deprecated, gpointer user_data)
+{
+	GsApp *app = user_data;
+	GPtrArray *tasks;
+	guint i;
+	gint64 done = 0, total = 0;
+
+	tasks = snapd_change_get_tasks (change);
+	for (i = 0; i < tasks->len; i++) {
+		SnapdTask *task = tasks->pdata[i];
+		done += snapd_task_get_progress_done (task);
+		total += snapd_task_get_progress_total (task);
+	}
+
+	gs_app_set_progress (app, (guint) (100 * done / total));
+}
+
+gboolean
+gs_plugin_app_install (GsPlugin *plugin,
+		       GsApp *app,
+		       GCancellable *cancellable,
+		       GError **error)
+{
+	GsPluginSnap *self = GS_PLUGIN_SNAP (plugin);
+	g_autoptr(SnapdClient) client = NULL;
+	const gchar *name, *channel;
+	SnapdInstallFlags flags = SNAPD_INSTALL_FLAGS_NONE;
+	gboolean result;
+	gboolean interactive = gs_plugin_has_flags (plugin, GS_PLUGIN_FLAGS_INTERACTIVE);
+	g_autoptr(GError) error_local = NULL;
+
+	/* We can only install apps we know of */
+	if (!gs_app_has_management_plugin (app, plugin))
+		return TRUE;
+
+	client = get_client (self, interactive, error);
+	if (client == NULL)
+		return FALSE;
+
+	name = gs_app_get_metadata_item (app, "snap::name");
+	channel = gs_app_get_branch (app);
+
+	gs_app_set_state (app, GS_APP_STATE_INSTALLING);
+
+	if (g_strcmp0 (gs_app_get_metadata_item (app, "snap::confinement"), "classic") == 0)
+		flags |= SNAPD_INSTALL_FLAGS_CLASSIC;
+	result = snapd_client_install2_sync (client, flags, name, channel, NULL, progress_cb, app, cancellable, &error_local);
+
+	/* if already installed then just try to switch channel */
+	if (!result && g_error_matches (error_local, SNAPD_ERROR, SNAPD_ERROR_ALREADY_INSTALLED)) {
+		g_clear_error (&error_local);
+		result = snapd_client_refresh_sync (client, name, channel, progress_cb, app, cancellable, &error_local);
+	}
+
+	if (!result) {
+		gs_app_set_state_recover (app);
+		g_propagate_error (error, g_steal_pointer (&error_local));
+		snapd_error_convert (error);
+		return FALSE;
+	}
+
+	gs_app_set_state (app, GS_APP_STATE_INSTALLED);
+
+	return TRUE;
+}
+
+// Check if an app is graphical by checking if it uses a known GUI interface.
+// This doesn't necessarily mean that every binary uses this interfaces, but is probably true.
+// https://bugs.launchpad.net/bugs/1595023
+static gboolean
+is_graphical (GsPluginSnap *self,
+              SnapdClient  *client,
+              GsApp        *app,
+              GCancellable *cancellable)
+{
+	g_autoptr(GPtrArray) plugs = NULL;
+	guint i;
+	g_autoptr(GError) error = NULL;
+
+	if (!snapd_client_get_connections2_sync (client,
+						 SNAPD_GET_CONNECTIONS_FLAGS_SELECT_ALL, NULL, NULL,
+						 NULL, NULL, &plugs, NULL,
+						 cancellable, &error)) {
+		g_warning ("Failed to get connections: %s", error->message);
+		return FALSE;
+	}
+
+	for (i = 0; i < plugs->len; i++) {
+		SnapdPlug *plug = plugs->pdata[i];
+		const gchar *interface;
+
+		// Only looks at the plugs for this snap
+		if (g_strcmp0 (snapd_plug_get_snap (plug), gs_app_get_metadata_item (app, "snap::name")) != 0)
+			continue;
+
+		interface = snapd_plug_get_interface (plug);
+		if (interface == NULL)
+			continue;
+
+		if (g_strcmp0 (interface, "unity7") == 0 || g_strcmp0 (interface, "x11") == 0 || g_strcmp0 (interface, "mir") == 0)
+			return TRUE;
+	}
+
+	return FALSE;
+}
+
+gboolean
+gs_plugin_launch (GsPlugin *plugin,
+		  GsApp *app,
+		  GCancellable *cancellable,
+		  GError **error)
+{
+	GsPluginSnap *self = GS_PLUGIN_SNAP (plugin);
+	const gchar *launch_name;
+	const gchar *launch_desktop;
+	g_autoptr(GAppInfo) info = NULL;
+	gboolean interactive = gs_plugin_has_flags (plugin, GS_PLUGIN_FLAGS_INTERACTIVE);
+
+	/* We can only launch apps we know of */
+	if (!gs_app_has_management_plugin (app, plugin))
+		return TRUE;
+
+	launch_name = gs_app_get_metadata_item (app, "snap::launch-name");
+	launch_desktop = gs_app_get_metadata_item (app, "snap::launch-desktop");
+	if (!launch_name)
+		return TRUE;
+
+	if (launch_desktop) {
+		info = (GAppInfo *)g_desktop_app_info_new_from_filename (launch_desktop);
+	} else {
+		g_autofree gchar *commandline = NULL;
+		g_autoptr(SnapdClient) client = NULL;
+		GAppInfoCreateFlags flags = G_APP_INFO_CREATE_NONE;
+
+		if (g_strcmp0 (launch_name, gs_app_get_metadata_item (app, "snap::name")) == 0)
+			commandline = g_strdup_printf ("snap run %s", launch_name);
+		else
+			commandline = g_strdup_printf ("snap run %s.%s", gs_app_get_metadata_item (app, "snap::name"), launch_name);
+
+		client = get_client (self, interactive, error);
+		if (client == NULL)
+			return FALSE;
+
+		if (!is_graphical (self, client, app, cancellable))
+			flags |= G_APP_INFO_CREATE_NEEDS_TERMINAL;
+		info = g_app_info_create_from_commandline (commandline, NULL, flags, error);
+	}
+
+	if (info == NULL)
+		return FALSE;
+
+	return g_app_info_launch (info, NULL, NULL, error);
+}
+
+gboolean
+gs_plugin_app_remove (GsPlugin *plugin,
+		      GsApp *app,
+		      GCancellable *cancellable,
+		      GError **error)
+{
+	GsPluginSnap *self = GS_PLUGIN_SNAP (plugin);
+	g_autoptr(SnapdClient) client = NULL;
+	gboolean interactive = gs_plugin_has_flags (plugin, GS_PLUGIN_FLAGS_INTERACTIVE);
+
+	/* We can only remove apps we know of */
+	if (!gs_app_has_management_plugin (app, plugin))
+		return TRUE;
+
+	client = get_client (self, interactive, error);
+	if (client == NULL)
+		return FALSE;
+
+	gs_app_set_state (app, GS_APP_STATE_REMOVING);
+	if (!snapd_client_remove2_sync (client, SNAPD_REMOVE_FLAGS_NONE, gs_app_get_metadata_item (app, "snap::name"), progress_cb, app, cancellable, error)) {
+		gs_app_set_state_recover (app);
+		snapd_error_convert (error);
+		return FALSE;
+	}
+	gs_app_set_state (app, GS_APP_STATE_AVAILABLE);
+	return TRUE;
+}
+
+gboolean
+gs_plugin_add_updates (GsPlugin *plugin,
+		       GsAppList *list,
+		       GCancellable *cancellable,
+		       GError **error)
+{
+	GsPluginSnap *self = GS_PLUGIN_SNAP (plugin);
+	g_autoptr(GPtrArray) apps = NULL;
+	g_autoptr(SnapdClient) client = NULL;
+	gboolean interactive = gs_plugin_has_flags (plugin, GS_PLUGIN_FLAGS_INTERACTIVE);
+	g_autoptr(GError) error_local = NULL;
+
+	client = get_client (self, interactive, &error_local);
+	if (client == NULL) {
+		g_debug ("Failed to get client to get updates: %s", error_local->message);
+		return TRUE;
+	}
+
+	/* Get the list of refreshable snaps */
+	apps = snapd_client_find_refreshable_sync (client, cancellable, &error_local);
+	if (apps == NULL) {
+		g_warning ("Failed to find refreshable snaps: %s", error_local->message);
+		return TRUE;
+	}
+
+	for (guint i = 0; i < apps->len; i++) {
+		SnapdSnap *snap = g_ptr_array_index (apps, i);
+		g_autoptr(GsApp) app = NULL;
+
+		/* Convert SnapdSnap to a GsApp */
+		app = snap_to_app (self, snap, NULL);
+
+		/* If for some reason the app is already getting updated, then
+		 * don't change its state */
+		if (gs_app_get_state (app) != GS_APP_STATE_INSTALLING)
+			gs_app_set_state (app, GS_APP_STATE_UPDATABLE_LIVE);
+
+		/* Add GsApp to updatable GsAppList */
+		gs_app_list_add (list, app);
+	}
+
+	return TRUE;
+}
+
+gboolean
+gs_plugin_update (GsPlugin *plugin,
+                  GsAppList *list,
+                  GCancellable *cancellable,
+                  GError **error)
+{
+	GsPluginSnap *self = GS_PLUGIN_SNAP (plugin);
+	g_autoptr(SnapdClient) client = NULL;
+	gboolean interactive = gs_plugin_has_flags (plugin, GS_PLUGIN_FLAGS_INTERACTIVE);
+
+	client = get_client (self, interactive, error);
+	if (client == NULL)
+		return FALSE;
+
+	for (guint i = 0; i < gs_app_list_length (list); i++) {
+		/* Get the name of the snap to refresh */
+		GsApp *app = gs_app_list_index (list, i);
+		const gchar *name = gs_app_get_metadata_item (app, "snap::name");
+
+		/* Refresh the snap */
+		gs_app_set_state (app, GS_APP_STATE_INSTALLING);
+
+		if (!snapd_client_refresh_sync (client, name, NULL, progress_cb, app, cancellable, error)) {
+			gs_app_set_state_recover (app);
+			snapd_error_convert (error);
+			return FALSE;
+		}
+
+		gs_app_set_state (app, GS_APP_STATE_INSTALLED);
+	}
+
+	return TRUE;
+}
+
+static void
+gs_plugin_snap_class_init (GsPluginSnapClass *klass)
+{
+	GObjectClass *object_class = G_OBJECT_CLASS (klass);
+	GsPluginClass *plugin_class = GS_PLUGIN_CLASS (klass);
+
+	object_class->dispose = gs_plugin_snap_dispose;
+	object_class->finalize = gs_plugin_snap_finalize;
+
+	plugin_class->setup_async = gs_plugin_snap_setup_async;
+	plugin_class->setup_finish = gs_plugin_snap_setup_finish;
+	plugin_class->refine_async = gs_plugin_snap_refine_async;
+	plugin_class->refine_finish = gs_plugin_snap_refine_finish;
+	plugin_class->list_apps_async = gs_plugin_snap_list_apps_async;
+	plugin_class->list_apps_finish = gs_plugin_snap_list_apps_finish;
+}
+
+GType
+gs_plugin_query_type (void)
+{
+	return GS_TYPE_PLUGIN_SNAP;
+}
diff --git a/plugins/snap/gs-plugin-snap.h b/plugins/snap/gs-plugin-snap.h
new file mode 100644
index 0000000..26702a9
--- /dev/null
+++ b/plugins/snap/gs-plugin-snap.h
@@ -0,0 +1,22 @@
+/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*-
+ * vi:set noexpandtab tabstop=8 shiftwidth=8:
+ *
+ * Copyright (C) 2021 Endless OS Foundation LLC
+ *
+ * Author: Philip Withnall <pwithnall@endlessos.org>
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#pragma once
+
+#include <glib.h>
+#include <glib-object.h>
+
+G_BEGIN_DECLS
+
+#define GS_TYPE_PLUGIN_SNAP (gs_plugin_snap_get_type ())
+
+G_DECLARE_FINAL_TYPE (GsPluginSnap, gs_plugin_snap, GS, PLUGIN_SNAP, GsPlugin)
+
+G_END_DECLS
diff --git a/plugins/snap/gs-self-test.c b/plugins/snap/gs-self-test.c
new file mode 100644
index 0000000..e748866
--- /dev/null
+++ b/plugins/snap/gs-self-test.c
@@ -0,0 +1,395 @@
+/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*-
+ * vi:set noexpandtab tabstop=8 shiftwidth=8:
+ *
+ * Copyright (C) 2017 Canonical Ltd
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <snapd-glib/snapd-glib.h>
+
+#include "config.h"
+
+#include "gnome-software-private.h"
+
+#include "gs-test.h"
+
+static gboolean snap_installed = FALSE;
+
+SnapdAuthData *
+snapd_login_sync (const gchar *username, const gchar *password, const gchar *otp,
+		  GCancellable *cancellable, GError **error)
+{
+	return snapd_auth_data_new ("macaroon", NULL);
+}
+
+SnapdClient *
+snapd_client_new (void)
+{
+	/* use a dummy object - we intercept all snapd-glib calls */
+	return g_object_new (G_TYPE_OBJECT, NULL);
+}
+
+void
+snapd_client_set_allow_interaction (SnapdClient *client, gboolean allow_interaction)
+{
+}
+
+void
+snapd_client_set_auth_data (SnapdClient *client, SnapdAuthData *auth_data)
+{
+}
+
+gboolean
+snapd_client_connect_sync (SnapdClient *client, GCancellable *cancellable, GError **error)
+{
+	/* skip connection */
+	return TRUE;
+}
+
+const gchar *
+snapd_client_get_user_agent (SnapdClient *client)
+{
+	return "snapd-glib/0.0.1";
+}
+
+void
+snapd_client_set_user_agent (SnapdClient *client, const gchar *user_agent)
+{
+}
+
+SnapdSystemInformation *
+snapd_client_get_system_information_sync (SnapdClient *client, GCancellable *cancellable, GError **error)
+{
+	g_autoptr(GHashTable) sandbox_features = g_hash_table_new (g_str_hash, g_str_equal);
+	return g_object_new (SNAPD_TYPE_SYSTEM_INFORMATION,
+			     "version", "2.31",
+			     "confinement", SNAPD_SYSTEM_CONFINEMENT_STRICT,
+			     "sandbox-features", sandbox_features,
+			     NULL);
+}
+
+static SnapdSnap *
+make_snap (const gchar *name, SnapdSnapStatus status)
+{
+	gchar *common_ids[] = { NULL };
+	g_autoptr(GDateTime) install_date = NULL;
+	g_autoptr(GPtrArray) apps = NULL;
+	g_autoptr(GPtrArray) media = NULL;
+	SnapdMedia *m;
+
+	install_date = g_date_time_new_utc (2017, 1, 2, 11, 23, 58);
+
+	apps = g_ptr_array_new_with_free_func (g_object_unref);
+
+	media = g_ptr_array_new_with_free_func (g_object_unref);
+	m = g_object_new (SNAPD_TYPE_MEDIA,
+			  "type", "screenshot",
+			  "url", "http://example.com/screenshot1.jpg",
+			  "width", 640,
+			  "height", 480,
+			  NULL);
+	g_ptr_array_add (media, m);
+	m = g_object_new (SNAPD_TYPE_MEDIA,
+			  "type", "screenshot",
+			  "url", "http://example.com/screenshot2.jpg",
+			  "width", 1024,
+			  "height", 768,
+			  NULL);
+	g_ptr_array_add (media, m);
+
+	return g_object_new (SNAPD_TYPE_SNAP,
+			     "apps", status == SNAPD_SNAP_STATUS_INSTALLED ? apps : NULL,
+			     "common-ids", common_ids,
+			     "description", "DESCRIPTION",
+			     "download-size", status == SNAPD_SNAP_STATUS_AVAILABLE ? 500 : 0,
+			     "icon", status == SNAPD_SNAP_STATUS_AVAILABLE ? NULL : "/icon",
+			     "id", name,
+			     "install-date", status == SNAPD_SNAP_STATUS_INSTALLED ? install_date : NULL,
+			     "installed-size", status == SNAPD_SNAP_STATUS_INSTALLED ? 1000 : 0,
+			     "media", status == SNAPD_SNAP_STATUS_AVAILABLE ? media : NULL,
+			     "name", name,
+			     "status", status,
+			     "snap-type", SNAPD_SNAP_TYPE_APP,
+			     "summary", "SUMMARY",
+			     "version", "VERSION",
+			     NULL);
+}
+
+GPtrArray *
+snapd_client_get_snaps_sync (SnapdClient *client,
+			     SnapdGetSnapsFlags flags, gchar **names,
+			     GCancellable *cancellable, GError **error)
+{
+	GPtrArray *snaps;
+
+	snaps = g_ptr_array_new_with_free_func (g_object_unref);
+	if (snap_installed)
+		g_ptr_array_add (snaps, make_snap ("snap", SNAPD_SNAP_STATUS_INSTALLED));
+
+	return snaps;
+}
+
+SnapdSnap *
+snapd_client_get_snap_sync (SnapdClient *client,
+			    const gchar *name,
+			    GCancellable *cancellable, GError **error)
+{
+	if (snap_installed) {
+		return make_snap ("snap", SNAPD_SNAP_STATUS_INSTALLED);
+	} else {
+		g_set_error_literal (error, SNAPD_ERROR, SNAPD_ERROR_NOT_INSTALLED, "not installed");
+		return NULL;
+	}
+}
+
+SnapdIcon *
+snapd_client_get_icon_sync (SnapdClient *client,
+			    const gchar *name,
+			    GCancellable *cancellable, GError **error)
+{
+	g_autoptr(GBytes) data = NULL;
+	/* apparently this is the smallest valid PNG file (1x1) */
+	const gchar png_data[67] = { 0x89, 0x50, 0x4E, 0x47, 0x0D, 0x0A, 0x1A, 0x0A,
+				     0x00, 0x00, 0x00, 0x0D, 0x49, 0x48, 0x44, 0x52,
+				     0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x01,
+				     0x08, 0x06, 0x00, 0x00, 0x00, 0x1F, 0x15, 0xC4,
+				     0x89, 0x00, 0x00, 0x00, 0x0A, 0x49, 0x44, 0x41,
+				     0x54, 0x78, 0x9C, 0x63, 0x00, 0x01, 0x00, 0x00,
+				     0x05, 0x00, 0x01, 0x0D, 0x0A, 0x2D, 0xB4, 0x00,
+				     0x00, 0x00, 0x00, 0x49, 0x45, 0x4E, 0x44, 0xAE,
+				     0x42, 0x60, 0x82 };
+
+	data = g_bytes_new (png_data, 67);
+	return g_object_new (SNAPD_TYPE_ICON,
+			     "mime-type", "image/png",
+			     "data", data,
+			     NULL);
+}
+
+gboolean
+snapd_client_get_connections_sync (SnapdClient *client,
+				   GPtrArray **established, GPtrArray **undesired,
+				   GPtrArray **plugs, GPtrArray **slots,
+				   GCancellable *cancellable, GError **error)
+{
+	if (plugs)
+		*plugs = g_ptr_array_new_with_free_func (g_object_unref);
+	if (slots)
+		*slots = g_ptr_array_new_with_free_func (g_object_unref);
+	return TRUE;
+}
+
+GPtrArray *
+snapd_client_find_section_sync (SnapdClient *client,
+				SnapdFindFlags flags,
+				const gchar *section, const gchar *query,
+				gchar **suggested_currency,
+				GCancellable *cancellable, GError **error)
+{
+	GPtrArray *snaps;
+
+	snaps = g_ptr_array_new_with_free_func (g_object_unref);
+	g_ptr_array_add (snaps, make_snap ("snap", SNAPD_SNAP_STATUS_AVAILABLE));
+
+	return snaps;
+}
+
+gboolean
+snapd_client_install2_sync (SnapdClient *client,
+			    SnapdInstallFlags flags,
+			    const gchar *name, const gchar *channel, const gchar *revision,
+			    SnapdProgressCallback progress_callback, gpointer progress_callback_data,
+			    GCancellable *cancellable, GError **error)
+{
+	g_autoptr(SnapdChange) change = NULL;
+	g_autoptr(GPtrArray) tasks = NULL;
+	SnapdTask *task;
+
+	g_assert_cmpstr (name, ==, "snap");
+	g_assert (channel == NULL);
+
+	tasks = g_ptr_array_new_with_free_func (g_object_unref);
+	task = g_object_new (SNAPD_TYPE_TASK,
+			     "progress-done", 0,
+			     "progress-total", 1,
+			     NULL);
+	g_ptr_array_add (tasks, task);
+	change = g_object_new (SNAPD_TYPE_CHANGE,
+			       "tasks", tasks,
+			       NULL);
+	progress_callback (client, change, NULL, progress_callback_data);
+
+	snap_installed = TRUE;
+	return TRUE;
+}
+
+gboolean
+snapd_client_remove_sync (SnapdClient *client,
+			  const gchar *name,
+			  SnapdProgressCallback progress_callback, gpointer progress_callback_data,
+			  GCancellable *cancellable, GError **error)
+{
+	g_autoptr(SnapdChange) change = NULL;
+	g_autoptr(GPtrArray) tasks = NULL;
+	SnapdTask *task;
+
+	g_assert_cmpstr (name, ==, "snap");
+
+	tasks = g_ptr_array_new_with_free_func (g_object_unref);
+	task = g_object_new (SNAPD_TYPE_TASK,
+			     "progress-done", 0,
+			     "progress-total", 1,
+			     NULL);
+	g_ptr_array_add (tasks, task);
+	change = g_object_new (SNAPD_TYPE_CHANGE,
+			       "tasks", tasks,
+			       NULL);
+	progress_callback (client, change, NULL, progress_callback_data);
+
+	snap_installed = FALSE;
+	return TRUE;
+}
+
+static void
+gs_plugins_snap_test_func (GsPluginLoader *plugin_loader)
+{
+	g_autoptr(GsPluginJob) plugin_job = NULL;
+	g_autoptr(GsAppList) apps = NULL;
+	gboolean ret;
+	GsApp *app;
+	GPtrArray *screenshots, *images;
+	AsScreenshot *screenshot;
+	AsImage *image;
+	g_autoptr(GIcon) icon = NULL;
+	g_autoptr(GInputStream) icon_stream = NULL;
+	g_autoptr(GdkPixbuf) pixbuf = NULL;
+	g_autoptr(GError) error = NULL;
+	GsSizeType size_installed_type, size_download_type;
+	guint64 size_installed_bytes, size_download_bytes;
+	const gchar *keywords[] = { NULL, };
+	g_autoptr(GsAppQuery) query = NULL;
+
+	/* no snap, abort */
+	if (!gs_plugin_loader_get_enabled (plugin_loader, "snap")) {
+		g_test_skip ("not enabled");
+		return;
+	}
+
+	keywords[0] = "snap";
+	query = gs_app_query_new ("keywords", keywords,
+				  "refine-flags", GS_PLUGIN_REFINE_FLAGS_REQUIRE_ICON |
+						  GS_PLUGIN_REFINE_FLAGS_REQUIRE_SCREENSHOTS,
+				  "dedupe-flags", GS_PLUGIN_JOB_DEDUPE_FLAGS_DEFAULT,
+				  "sort-func", gs_utils_app_sort_match_value,
+				  NULL);
+	plugin_job = gs_plugin_job_list_apps_new (query, GS_PLUGIN_LIST_APPS_FLAGS_NONE);
+	apps = gs_plugin_loader_job_process (plugin_loader, plugin_job, NULL, &error);
+	g_assert_no_error (error);
+	g_assert (apps != NULL);
+	g_assert_cmpint (gs_app_list_length (apps), ==, 1);
+	app = gs_app_list_index (apps, 0);
+	g_assert_cmpint (gs_app_get_state (app), ==, GS_APP_STATE_AVAILABLE);
+	g_assert_cmpstr (gs_app_get_name (app), ==, "snap");
+	g_assert_cmpstr (gs_app_get_version (app), ==, "VERSION");
+	g_assert_cmpstr (gs_app_get_summary (app), ==, "SUMMARY");
+	g_assert_cmpstr (gs_app_get_description (app), ==, "DESCRIPTION");
+	screenshots = gs_app_get_screenshots (app);
+	g_assert_cmpint (screenshots->len, ==, 2);
+	screenshot = g_ptr_array_index (screenshots, 0);
+	images = as_screenshot_get_images (screenshot);
+	g_assert_cmpint (images->len, ==, 1);
+	image = g_ptr_array_index (images, 0);
+	g_assert_cmpstr (as_image_get_url (image), ==, "http://example.com/screenshot1.jpg");
+	g_assert_cmpint (as_image_get_width (image), ==, 640);
+	g_assert_cmpint (as_image_get_height (image), ==, 480);
+	screenshot = g_ptr_array_index (screenshots, 1);
+	images = as_screenshot_get_images (screenshot);
+	g_assert_cmpint (images->len, ==, 1);
+	image = g_ptr_array_index (images, 0);
+	g_assert_cmpstr (as_image_get_url (image), ==, "http://example.com/screenshot2.jpg");
+	g_assert_cmpint (as_image_get_width (image), ==, 1024);
+	g_assert_cmpint (as_image_get_height (image), ==, 768);
+	icon = gs_app_get_icon_for_size (app, 64, 1, NULL);
+	g_assert_null (icon);
+
+	size_installed_type = gs_app_get_size_installed (app, &size_installed_bytes);
+	g_assert_cmpint (size_installed_type, ==, GS_SIZE_TYPE_VALID);
+	g_assert_cmpuint (size_installed_bytes, ==, 0);
+
+	size_download_type = gs_app_get_size_download (app, &size_download_bytes);
+	g_assert_cmpint (size_download_type, ==, GS_SIZE_TYPE_VALID);
+	g_assert_cmpuint (size_download_bytes, ==, 500);
+
+	g_assert_cmpint (gs_app_get_install_date (app), ==, 0);
+
+	g_object_unref (plugin_job);
+	plugin_job = gs_plugin_job_newv (GS_PLUGIN_ACTION_INSTALL,
+					 "app", app,
+					 "refine-flags", GS_PLUGIN_REFINE_FLAGS_REQUIRE_ICON,
+					 NULL);
+	ret = gs_plugin_loader_job_action (plugin_loader, plugin_job, NULL, &error);
+	gs_test_flush_main_context ();
+	g_assert_no_error (error);
+	g_assert (ret);
+	g_assert_cmpint (gs_app_get_state (app), ==, GS_APP_STATE_INSTALLED);
+
+	size_installed_type = gs_app_get_size_installed (app, &size_installed_bytes);
+	g_assert_cmpint (size_installed_type, ==, GS_SIZE_TYPE_VALID);
+	g_assert_cmpuint (size_installed_bytes, ==, 1000);
+
+	g_assert_cmpint (gs_app_get_install_date (app), ==, g_date_time_to_unix (g_date_time_new_utc (2017, 1, 2, 11, 23, 58)));
+
+	icon = gs_app_get_icon_for_size (app, 128, 1, NULL);
+	g_assert_nonnull (icon);
+	g_assert_true (G_IS_LOADABLE_ICON (icon));
+	icon_stream = g_loadable_icon_load (G_LOADABLE_ICON (icon), 128, NULL, NULL, &error);
+	g_assert_no_error (error);
+	g_assert_nonnull (icon_stream);
+	pixbuf = gdk_pixbuf_new_from_stream (icon_stream, NULL, &error);
+	g_assert_no_error (error);
+	g_assert_nonnull (pixbuf);
+	g_assert_cmpint (gdk_pixbuf_get_width (pixbuf), ==, 128);
+	g_assert_cmpint (gdk_pixbuf_get_height (pixbuf), ==, 128);
+
+	g_object_unref (plugin_job);
+	plugin_job = gs_plugin_job_newv (GS_PLUGIN_ACTION_REMOVE,
+					 "app", app,
+					 NULL);
+	gs_test_flush_main_context ();
+	ret = gs_plugin_loader_job_action (plugin_loader, plugin_job, NULL, &error);
+	g_assert_no_error (error);
+	g_assert (ret);
+}
+
+int
+main (int argc, char **argv)
+{
+	gboolean ret;
+	g_autoptr(GError) error = NULL;
+	g_autoptr(GsPluginLoader) plugin_loader = NULL;
+	const gchar * const allowlist[] = {
+		"snap",
+		NULL
+	};
+
+	gs_test_init (&argc, &argv);
+
+	/* we can only load this once per process */
+	plugin_loader = gs_plugin_loader_new (NULL, NULL);
+	gs_plugin_loader_add_location (plugin_loader, LOCALPLUGINDIR);
+	gs_plugin_loader_add_location (plugin_loader, LOCALPLUGINDIR_CORE);
+	ret = gs_plugin_loader_setup (plugin_loader,
+				      allowlist,
+				      NULL,
+				      NULL,
+				      &error);
+	g_assert_no_error (error);
+	g_assert (ret);
+
+	/* plugin tests go here */
+	g_test_add_data_func ("/gnome-software/plugins/snap/test",
+			      plugin_loader,
+			      (GTestDataFunc) gs_plugins_snap_test_func);
+	return g_test_run ();
+}
diff --git a/plugins/snap/meson.build b/plugins/snap/meson.build
new file mode 100644
index 0000000..eceee1a
--- /dev/null
+++ b/plugins/snap/meson.build
@@ -0,0 +1,48 @@
+cargs = ['-DG_LOG_DOMAIN="GsPluginSnap"']
+
+shared_module(
+  'gs_plugin_snap',
+  sources : [
+    'gs-plugin-snap.c'
+  ],
+  include_directories : [
+    include_directories('../..'),
+    include_directories('../../lib'),
+  ],
+  install : true,
+  install_dir: plugin_dir,
+  c_args : cargs,
+  dependencies : [ plugin_libs, snap ],
+)
+metainfo = 'org.gnome.Software.Plugin.Snap.metainfo.xml'
+
+i18n.merge_file(
+  input: metainfo + '.in',
+  output: metainfo,
+  type: 'xml',
+  po_dir: join_paths(meson.project_source_root(), 'po'),
+  install: true,
+  install_dir: join_paths(get_option('datadir'), 'metainfo')
+)
+
+if get_option('tests')
+  cargs += ['-DLOCALPLUGINDIR="' + meson.current_build_dir() + '"']
+  cargs += ['-DLOCALPLUGINDIR_CORE="' + meson.current_build_dir() + '/../core"']
+  e = executable(
+    'gs-self-test-snap',
+    compiled_schemas,
+    sources : [
+      'gs-self-test.c'
+    ],
+    include_directories : [
+      include_directories('../..'),
+      include_directories('../../lib'),
+    ],
+    dependencies : [
+      plugin_libs,
+      snap
+    ],
+    c_args : cargs,
+  )
+  test('gs-self-test-snap', e, suite: ['plugins', 'snap'], env: test_env)
+endif
diff --git a/plugins/snap/org.gnome.Software.Plugin.Snap.metainfo.xml.in b/plugins/snap/org.gnome.Software.Plugin.Snap.metainfo.xml.in
new file mode 100644
index 0000000..2478778
--- /dev/null
+++ b/plugins/snap/org.gnome.Software.Plugin.Snap.metainfo.xml.in
@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!-- Copyright 2013-2016 Richard Hughes <richard@hughsie.com> -->
+<component type="addon">
+  <id>org.gnome.Software.Plugin.Snap</id>
+  <extends>org.gnome.Software.desktop</extends>
+  <name>Snap Support</name>
+  <summary>A snap is a universal Linux package</summary>
+  <url type="homepage">https://snapcraft.io/</url>
+  <metadata_license>CC0-1.0</metadata_license>
+  <project_license>GPL-2.0+</project_license>
+  <update_contact>richard_at_hughsie.com</update_contact>
+</component>