[gnome-software/wip/hughsie/alternatives-pkgname] Suggest alternatives based on the package name

[Richard Hughes <rhughes src gnome org>]

commit ae5e7affd5775a8e4f5273d8b3dd48c7e2ebf259
Author: Richard Hughes <richard hughsie com>
Date:   Wed Sep 26 11:23:51 2018 +0100

    Suggest alternatives based on the package name
    
    This allows us to double click on a local RPM file and then get alternate
    results for a distribution package that may be more up to date.

 plugins/core/gs-appstream.c | 100 ++++++++++++++++++++++++++++++++++----------
 1 file changed, 78 insertions(+), 22 deletions(-)
---
diff --git a/plugins/core/gs-appstream.c b/plugins/core/gs-appstream.c
index 0ce2d9a9..5af9abad 100644
--- a/plugins/core/gs-appstream.c
+++ b/plugins/core/gs-appstream.c
@@ -1055,6 +1055,64 @@ gs_appstream_add_recent (GsPlugin *plugin,
        return TRUE;
 }
 
+static void
+_g_ptr_array_add_str_uniq (GPtrArray *array, const gchar *str)
+{
+       if (str == NULL)
+               return;
+       for (guint i = 0; i < array->len; i++) {
+               const gchar *str_tmp = g_ptr_array_index (array, i);
+               if (g_strcmp0 (str, str_tmp) == 0)
+                       return;
+       }
+       g_ptr_array_add (array, g_strdup (str));
+}
+
+/* add the component ID for any matching <provide><id/></provide> value */
+static void
+gs_appstream_add_alternates_new_id (GPtrArray *array, AsApp *item, const gchar *id)
+{
+       GPtrArray *provides = as_app_get_provides (item);
+       for (guint i = 0; i < provides->len; i++) {
+               AsProvide *provide = g_ptr_array_index (provides, i);
+               if (as_provide_get_kind (provide) == AS_PROVIDE_KIND_ID &&
+                   g_strcmp0 (as_provide_get_value (provide), id) == 0) {
+                       _g_ptr_array_add_str_uniq (array, as_app_get_id (item));
+                       break;
+               }
+       }
+
+}
+
+/* add all <provide><id/></provide> values for a matching component ID */
+static void
+gs_appstream_add_alternates_old_id (GPtrArray *array, AsApp *item, const gchar *id)
+{
+       GPtrArray *provides;
+       if (g_strcmp0 (as_app_get_id (item), id) != 0)
+               return;
+       provides = as_app_get_provides (item);
+       for (guint i = 0; i < provides->len; i++) {
+               AsProvide *provide = g_ptr_array_index (provides, i);
+               if (as_provide_get_kind (provide) == AS_PROVIDE_KIND_ID)
+                       _g_ptr_array_add_str_uniq (array, as_provide_get_value (provide));
+       }
+}
+
+/* find any matching package names */
+static void
+gs_appstream_add_alternates_source (GPtrArray *array, AsApp *item, const gchar *source)
+{
+       GPtrArray *item_pkgnames = as_app_get_pkgnames (item);
+       for (guint i = 0; i < item_pkgnames->len; i++) {
+               const gchar *pkgname = g_ptr_array_index (item_pkgnames, i);
+               if (g_strcmp0 (pkgname, source) == 0) {
+                       _g_ptr_array_add_str_uniq (array, as_app_get_id (item));
+                       break;
+               }
+       }
+}
+
 gboolean
 gs_appstream_add_alternates (GsPlugin *plugin,
                             AsStore *store,
@@ -1064,35 +1122,33 @@ gs_appstream_add_alternates (GsPlugin *plugin,
                             GError **error)
 {
        GPtrArray *apps = as_store_get_apps (store);
+       GPtrArray *ids = g_ptr_array_new_with_free_func (g_free);
 
        /* find apps that provide the new name */
        for (guint i = 0; i < apps->len; i++) {
                AsApp *item = g_ptr_array_index (apps, i);
-               GPtrArray *provides = as_app_get_provides (item);
-               if (g_strcmp0 (as_app_get_id (item), gs_app_get_id (app)) == 0) {
-                       for (guint j = 0; j < provides->len; j++) {
-                               AsProvide *tmp = g_ptr_array_index (provides, j);
-                               if (as_provide_get_kind (tmp) == AS_PROVIDE_KIND_ID) {
-                                       g_autoptr(GsApp) app2 = NULL;
-                                       app2 = gs_app_new (as_app_get_id (item));
-                                       gs_app_add_quirk (app2, AS_APP_QUIRK_MATCH_ANY_PREFIX);
-                                       gs_app_list_add (list, app2);
-                               }
-                       }
-               } else if (as_app_get_id (item) != NULL) {
-                       for (guint j = 0; j < provides->len; j++) {
-                               AsProvide *tmp = g_ptr_array_index (provides, j);
-                               if (as_provide_get_kind (tmp) == AS_PROVIDE_KIND_ID &&
-                                   g_strcmp0 (as_provide_get_value (tmp), gs_app_get_id (app)) == 0) {
-                                       g_autoptr(GsApp) app2 = NULL;
-                                       app2 = gs_app_new (as_app_get_id (item));
-                                       gs_app_add_quirk (app2, AS_APP_QUIRK_MATCH_ANY_PREFIX);
-                                       gs_app_list_add (list, app2);
-                               }
-                       }
+               GPtrArray *sources = gs_app_get_sources (app);
+
+               /* new ID -> old ID */
+               gs_appstream_add_alternates_old_id (ids, item, gs_app_get_id (app));
+
+               /* old ID -> new ID */
+               gs_appstream_add_alternates_new_id (ids, item, gs_app_get_id (app));
+
+               /* find apps that use the same pkgname */
+               for (guint j = 0; j < sources->len; j++) {
+                       const gchar *source = g_ptr_array_index (sources, j);
+                       gs_appstream_add_alternates_source (ids, item, source);
                }
        }
 
+       /* add all results */
+       for (guint i = 0; i < ids->len; i++) {
+               const gchar *id = g_ptr_array_index (ids, i);
+               g_autoptr(GsApp) app2 = gs_app_new (id);
+               gs_app_add_quirk (app2, AS_APP_QUIRK_MATCH_ANY_PREFIX);
+               gs_app_list_add (list, app2);
+       }
        return TRUE;
 }