Add an option to get unread chapters of mangas

app/src/main/java/eu/kanade/mangafeed/data/managers/MangaManager.java

@@ -3,10 +3,12 @@ package eu.kanade.mangafeed.data.managers;
 import com.pushtorefresh.storio.sqlite.StorIOSQLite;
 import com.pushtorefresh.storio.sqlite.operations.put.PutResult;
 import com.pushtorefresh.storio.sqlite.queries.Query;
+import com.pushtorefresh.storio.sqlite.queries.RawQuery;
 
 import java.util.List;
 
 import eu.kanade.mangafeed.data.models.Manga;
+import eu.kanade.mangafeed.data.tables.ChaptersTable;
 import eu.kanade.mangafeed.data.tables.MangasTable;
 import rx.Observable;
 
@@ -16,6 +18,18 @@ public class MangaManager extends BaseManager {
         super(db);
     }
 
+    private final String mangasWithUnreadQuery = String.format(
+            "SELECT %1$s.*, COUNT(C.%4$s) AS %5$s FROM %1$s LEFT JOIN " +
+            "(SELECT %4$s FROM %2$s WHERE %6$s = 0) AS C ON %3$s = C.%4$s " +
+            "GROUP BY %3$s",
+            MangasTable.TABLE,
+            ChaptersTable.TABLE,
+            MangasTable.TABLE + "." + MangasTable.COLUMN_ID,
+            ChaptersTable.COLUMN_MANGA_ID,
+            MangasTable.COLUMN_UNREAD,
+            ChaptersTable.COLUMN_READ
+    );
+
     public Observable<List<Manga>> get() {
         return db.get()
                 .listOfObjects(Manga.class)
@@ -26,6 +40,17 @@ public class MangaManager extends BaseManager {
                 .createObservable();
     }
 
+    public Observable<List<Manga>> getWithUnread() {
+        return db.get()
+                .listOfObjects(Manga.class)
+                .withQuery(RawQuery.builder()
+                        .query(mangasWithUnreadQuery)
+                        .observesTables(MangasTable.TABLE, ChaptersTable.TABLE)
+                        .build())
+                .prepare()
+                .createObservable();
+    }
+
     public Observable<PutResult> insert(Manga manga) {
         return db.put()
                 .object(manga)
@@ -34,7 +59,15 @@ public class MangaManager extends BaseManager {
     }
 
     public void createDummyManga() {
+        insert(createDummyManga("One Piece")).subscribe();
+        insert(createDummyManga("Übel Blatt")).subscribe();
+        insert(createDummyManga("Berserk")).subscribe();
+        insert(createDummyManga("Horimiya")).subscribe();
+    }
+
+    private Manga createDummyManga(String title) {
         Manga m = new Manga();
+        m.title = title;
         m.url="http://example.com";
         m.artist="Eiichiro Oda";
         m.author="Eiichiro Oda";
@@ -42,8 +75,7 @@ public class MangaManager extends BaseManager {
         m.genre="Action, Drama";
         m.status="Ongoing";
         m.thumbnail_url="http://example.com/pic.png";
-        m.title="One Piece";
-        insert(m).subscribe();
+        return m;
     }
 
 }