bring back sqlite3 and migrations.

app/lib/db.ts

@@ -1,11 +1,26 @@
-import config from "@/knexfile";
-import Knex from "knex";
+import * as SQLite from "expo-sqlite";
+import { MIGRATE_UP, MIGRATE_DOWN } from "./migrations";
 
-export async function getDb(
-  environment: "development" | "staging" | "production" = "production",
-  automigrate = true
-) {
-  const k = Knex(config[environment]);
-  if (automigrate) await k.migrate.up();
-  return k;
+export async function getDb() {
+  return await SQLite.openDatabaseAsync("translation_terrace");
 }
+
+
+export async function migrateDb(direction: "up" | "down" = "up") {
+
+  const db = await getDb();
+
+  const m = direction === "up" ? MIGRATE_UP : MIGRATE_DOWN;
+
+  for (let [migration, statements] of Object.entries(m)) {
+    for (let statement of statements) {
+      console.log(statement);
+      try {
+        const result = await db.runAsync(statement);
+        console.log(result);
+      } catch (err) {
+        console.error(err);
+      }
+    }
+  }
+}

app/lib/migrations.ts

@@ -0,0 +1,23 @@
+
+export const MIGRATE_UP = {
+    1: [
+      `CREATE TABLE IF NOT EXISTS settings (
+              host_language TEXT,
+              libretranslate_base_url TEXT,
+              ui_direction INTEGER,
+              whisper_model TEXT
+          )`,
+    ],
+    2: [
+      `CREATE TABLE IF NOT EXISTS whisper_models (
+              model TEXT PRIMARY KEY,
+              bytes_done INTEGER,
+              bytes_total INTEGER
+          )`,
+    ],
+  };
+  
+  export const MIGRATE_DOWN = {
+    1: [`DROP TABLE IF EXISTS settings`],
+    2: [`DROP TABLE IF EXISTS whisper_models`],
+  };