Refactor the db; move to *Manager classes

web/src/app/SubscriptionManager.js

@@ -0,0 +1,75 @@
+import db from "./db";
+
+class SubscriptionManager {
+    async all() {
+        return db.subscriptions.toArray();
+    }
+
+    async get(subscriptionId) {
+        return await db.subscriptions.get(subscriptionId)
+    }
+
+    async save(subscription) {
+        await db.subscriptions.put(subscription);
+    }
+
+    async remove(subscriptionId) {
+        await db.subscriptions.delete(subscriptionId);
+        await db.notifications
+            .where({subscriptionId: subscriptionId})
+            .delete();
+    }
+
+    async first() {
+        return db.subscriptions.toCollection().first(); // May be undefined
+    }
+
+    async getNotifications(subscriptionId) {
+        return db.notifications
+            .where({ subscriptionId: subscriptionId })
+            .toArray();
+    }
+
+    /** Adds notification, or returns false if it already exists */
+    async addNotification(subscriptionId, notification) {
+        const exists = await db.notifications.get(notification.id);
+        if (exists) {
+            return false;
+        }
+        await db.notifications.add({ ...notification, subscriptionId });
+        await db.subscriptions.update(subscriptionId, {
+            last: notification.id
+        });
+        return true;
+    }
+
+    /** Adds/replaces notifications, will not throw if they exist */
+    async addNotifications(subscriptionId, notifications) {
+        const notificationsWithSubscriptionId = notifications
+            .map(notification => ({ ...notification, subscriptionId }));
+        const lastNotificationId = notifications.at(-1).id;
+        await db.notifications.bulkPut(notificationsWithSubscriptionId);
+        await db.subscriptions.update(subscriptionId, {
+            last: lastNotificationId
+        });
+    }
+
+    async deleteNotification(notificationId) {
+        await db.notifications.delete(notificationId);
+    }
+
+    async deleteNotifications(subscriptionId) {
+        await db.notifications
+            .where({subscriptionId: subscriptionId})
+            .delete();
+    }
+
+    async pruneNotifications(thresholdTimestamp) {
+        await db.notifications
+            .where("time").below(thresholdTimestamp)
+            .delete();
+    }
+}
+
+const subscriptionManager = new SubscriptionManager();
+export default subscriptionManager;