Improve search results by checking query against package id and name (#2232 - #1556)

src/Core/Package.vala

@@ -95,6 +95,8 @@ public class AppCenterCore.Package : Object {
     public const string RUNTIME_UPDATES_ID = "xxx-runtime-updates";
     public const string LOCAL_ID_SUFFIX = ".appcenter-local";
     public const string DEFAULT_PRICE_DOLLARS = "1";
+    public const uint EXACT_MATCH_SCORE = 100;
+    public const uint PARTIAL_MATCH_SCORE = 50;
 
     public string uid { get; construct; }
 
@@ -599,8 +601,27 @@ public class AppCenterCore.Package : Object {
             var query_score = component.search_matches (query);
 
             if (query_score == 0) {
-                score = 0;
-                break;
+                var id_down = component.id.down ();
+                var name_down = component.name.down ();
+                var query_down = query.down ();
+
+                /*
+                * Give extra score value if query is a substring, or if it
+                * matches exactly the component name or id.
+                * We multiply both by queries.length to negate the dilution made
+                * by cached_search_score when dividing by queries.length, thus
+                * making it a perfect EXACT_MATCH_SCORE or PARTIAL_MATCH_SCORE
+                * search value, since an exact or partial match should achieve
+                * the perfect score in any query token.
+                */
+                if (query_down == name_down || query_down == id_down) {
+                    query_score = EXACT_MATCH_SCORE * queries.length;
+                } else if (
+                    name_down.contains (query_down) ||
+                    id_down.contains (query_down)
+                ) {
+                    query_score = PARTIAL_MATCH_SCORE * queries.length;
+                }
             }
 
             score += query_score;

src/Core/SearchEngine.vala

@@ -57,6 +57,19 @@ public class AppCenterCore.SearchEngine : Object {
 
     public void search (string query, AppStream.Category? category) {
         this.query = pool.build_search_tokens (query);
+        /*
+        * If there are multiple tokens, add an additional joined query token.
+        * This is done because users tend to search queries for apps that have
+        * one name as separate with spaces. An example would be "LibreOffice",
+        * usually being searched as "Libre Office". Searching this shows the app
+        * as the 17th result instead of the first without a joined query. With 
+        * the joined query (e.g. the search being "Libre Office LibreOffice") it
+        * will show up as the first search result.
+        */
+        if (this.query.length > 1) {
+            var joined_query = query.replace (" ", "");
+            this.query += joined_query;
+        }
         this.category = category;
         packages.items_changed (0, packages.n_items, packages.n_items);
     }