db.ts

import Dexie from "dexie";
import "fake-indexeddb/auto";
import browser from "webextension-polyfill";
import type { Allowance, Payment, Blocklist, Metadata } from "~/types";

class DB extends Dexie {

  metadata: Dexie.Table<Metadata, number>

  constructor() {
    super("LBE");
    
    this.version(x).stores({
      metadata:
        "++id,allowanceId,host,metadata,paymentHash,createdAt,type,contentUrl",
    });
    this.on("ready", this.loadFromStorage.bind(this));
    this.metadata = this.table("metadata");
  }

  async saveToStorage() {
    const metadataArray = await this.metadata.toArray();
    await browser.storage.local.set({
      allowances: allowanceArray,
      payments: paymentsArray,
      blocklist: blocklistArray,
      metadata: metadataArray
    });
    return true;
  }

  // Loads the data from the browser.storage and adds the data to the IndexedDB.
  // This is needed because the IndexedDB is not necessarily persistent,
  // BUT maybe there are already entries in the IndexedDB (that depends on the browser).
  // In that case we don't do anything as this would cause conflicts and errors.
  // (this could use some DRY-up)
  async loadFromStorage() {
    console.info("Loading DB data from storage");
    return browser.storage.local
      .get(["allowances", "payments", "blocklist", "metadata"])
      .then((result) => {
        
        const metadataPromise = this.metadata.count().then((count) => {
          // if the DB already has entries we do not need to add the data from the browser storage. We then already have the data in the indexeddb
          if (count > 0) {
            console.info(`Found ${count} metadata's already in the DB`);
            return;
          } else if (result.metadata && result.metadata.length > 0) {
            // adding the data from the browser storage
            return this.metadata
              .bulkAdd(result.metadata)
              .catch(Dexie.BulkError, function (e) {
                console.error("Failed to add metadata; ignoring", e);
              });
          }
        });

        // wait for all allowances and payments to be loaded
        return Promise.all([
          metadataPromise
        ]);
      })
      .catch((e) => {
        console.error("Failed to load DB data from storage", e);
      });
  }
}

const db = new DB();

export default db;