feat: implement TASK-WP1-05 account deletion

apps/worker/src/retention-cleanup.ts

@@ -0,0 +1,46 @@
+import { createRequire } from "node:module";
+
+import type BetterSqlite3 from "better-sqlite3";
+
+const require = createRequire(import.meta.url);
+const Database = require("better-sqlite3") as typeof BetterSqlite3;
+
+export class RetentionCleanup {
+  private readonly clock: () => number;
+  private readonly database: BetterSqlite3.Database;
+  private retentionPurgeActive = false;
+
+  constructor(input: { clock?: () => number; databasePath: string }) {
+    this.clock = input.clock ?? Date.now;
+    const nativeBinding = process.env.DADA_SQLITE_NATIVE_BINDING;
+    this.database = new Database(input.databasePath, nativeBinding ? { nativeBinding } : undefined);
+    this.database.pragma("foreign_keys = ON");
+    this.database.pragma("busy_timeout = 5000");
+    this.database.function("dada_allow_privacy_purge", { deterministic: false }, () => 0);
+    this.database.function("dada_allow_retention_purge", { deterministic: false }, () => this.retentionPurgeActive ? 1 : 0);
+  }
+
+  purgeExpired() {
+    const now = this.clock();
+    this.database.exec("BEGIN IMMEDIATE");
+    try {
+      this.retentionPurgeActive = true;
+      const privateAccess = this.database.prepare("DELETE FROM private_content_access_logs WHERE expires_at <= ?").run(now);
+      const anonymous = this.database.prepare("DELETE FROM anonymous_retained_events WHERE expires_at <= ?").run(now);
+      this.retentionPurgeActive = false;
+      this.database.exec("COMMIT");
+      return {
+        anonymous_events: anonymous.changes,
+        private_access_logs: privateAccess.changes,
+      };
+    } catch (error) {
+      this.retentionPurgeActive = false;
+      if (this.database.inTransaction) this.database.exec("ROLLBACK");
+      throw error;
+    }
+  }
+
+  close() {
+    this.database.close();
+  }
+}