[gnome-software] snap: Use same auth data as the command line client

[Richard Hughes <rhughes src gnome org>]

commit f0529f7c1fc008a1cf86c0c0846f367d05cfa298
Author: Robert Ancell <robert ancell canonical com>
Date:   Thu Jan 23 17:47:36 2020 +1300

    snap: Use same auth data as the command line client
    
    Previously we have a graphical means of logging into the snap store, but this
    was removed in 145bb82. This change means we now use the same auth data as
    the command line snap client where previously GNOME Software used it's own
    auth data store. For a user this requires them to have run 'snap login' from the
    command line at some point.

 plugins/snap/gs-plugin-snap.c | 43 ++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 40 insertions(+), 3 deletions(-)
---
diff --git a/plugins/snap/gs-plugin-snap.c b/plugins/snap/gs-plugin-snap.c
index 28392b79..8a055223 100644
--- a/plugins/snap/gs-plugin-snap.c
+++ b/plugins/snap/gs-plugin-snap.c
@@ -9,11 +9,11 @@
 
 #include <gio/gdesktopappinfo.h>
 #include <glib/gi18n.h>
+#include <json-glib/json-glib.h>
 #include <snapd-glib/snapd-glib.h>
 #include <gnome-software.h>
 
 struct GsPluginData {
-       SnapdAuthData           *auth_data;
        gchar                   *store_name;
        gchar                   *store_hostname;
        SnapdSystemConfinement   system_confinement;
@@ -43,20 +43,57 @@ cache_entry_free (CacheEntry *entry)
        g_slice_free (CacheEntry, entry);
 }
 
+static SnapdAuthData *
+get_auth_data (GsPlugin *plugin)
+{
+       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);
+       object = json_node_get_object (root);
+       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, 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 (GsPlugin *plugin, GError **error)
 {
-       GsPluginData *priv = gs_plugin_get_data (plugin);
        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, TRUE);
        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);
-       snapd_client_set_auth_data (client, priv->auth_data);
+
+       auth_data = get_auth_data (plugin);
+       snapd_client_set_auth_data (client, auth_data);
 
        return g_steal_pointer (&client);
 }