Add support for client-side watch history. (#370)

* Add support for client-side watch history.

* Update watched videos more often.

src/App.vue

@@ -41,6 +41,23 @@ export default {
                 default:
                     break;
             }
+
+        if (this.getPreferenceBoolean("watchHistory", false))
+            if ("indexedDB" in window) {
+                const request = indexedDB.open("piped-db", 1);
+                request.onupgradeneeded = function() {
+                    const db = request.result;
+                    console.log("Upgrading object store.");
+                    if (!db.objectStoreNames.contains("watch_history")) {
+                        const store = db.createObjectStore("watch_history", { keyPath: "videoId" });
+                        store.createIndex("video_id_idx", "videoId", { unique: true });
+                        store.createIndex("id_idx", "id", { unique: true, autoIncrement: true });
+                    }
+                };
+                request.onsuccess = e => {
+                    window.db = e.target.result;
+                };
+            } else console.log("This browser doesn't support IndexedDB");
     },
 };
 </script>