Implement simple stats screen (#8068)

* Implement simple stats screen

* Review Changes

* Some other changes

* Remove unused

* Small changes

* Review Changes 2 + Cleanup

* Review Changes 3

* Cleanup leftovers

* Optimize imports

app/src/main/java/eu/kanade/tachiyomi/data/download/DownloadCache.kt

@@ -107,6 +107,19 @@ class DownloadCache(
         return false
     }
 
+    /**
+     * Returns the amount of downloaded chapters.
+     */
+    fun getTotalDownloadCount(): Int {
+        renewCache()
+
+        return rootDownloadsDir.sourceDirs.values.sumOf { sourceDir ->
+            sourceDir.mangaDirs.values.sumOf { mangaDir ->
+                mangaDir.chapterDirs.size
+            }
+        }
+    }
+
     /**
      * Returns the amount of downloaded chapters for a manga.
      *

app/src/main/java/eu/kanade/tachiyomi/data/download/DownloadManager.kt

@@ -205,6 +205,13 @@ class DownloadManager(
             .firstOrNull { it.chapter.id == chapter.id && it.chapter.manga_id == chapter.mangaId }
     }
 
+    /**
+     * Returns the amount of downloaded chapters.
+     */
+    fun getDownloadCount(): Int {
+        return cache.getTotalDownloadCount()
+    }
+
     /**
      * Returns the amount of downloaded chapters for a manga.
      *