hide watched videos in the feed

src/components/VideoItem.vue

@@ -1,5 +1,5 @@
 <template>
-    <div>
+    <div v-if="showVideo">
         <router-link
             :to="{
                 path: '/watch',
@@ -141,6 +141,10 @@ export default {
                 return {};
             },
         },
+        isFeed: {
+            type: Boolean,
+            default: false,
+        },
         height: { type: String, default: "118" },
         width: { type: String, default: "210" },
         hideChannel: { type: Boolean, default: false },
@@ -151,8 +155,12 @@ export default {
     data() {
         return {
             showModal: false,
+            showVideo: true,
         };
     },
+    mounted() {
+        this.shouldShowVideo();
+    },
     methods: {
         removeVideo() {
             if (confirm(this.$t("actions.delete_playlist_video_confirm"))) {
@@ -173,6 +181,21 @@ export default {
                 });
             }
         },
+        shouldShowVideo() {
+            if (!this.isFeed || !this.getPreferenceBoolean("hideWatched", false)) return;
+
+            const objectStore = window.db.transaction("watch_history", "readonly").objectStore("watch_history");
+            objectStore.openCursor().onsuccess = event => {
+                const cursor = event.target.result;
+                if (cursor) {
+                    if (cursor.value.videoId === this.video.url.replace("/watch?v=", "")) {
+                        this.showVideo = false;
+                        return;
+                    }
+                    cursor.continue();
+                }
+            };
+        },
     },
     computed: {
         short() {