refactor: replace signIn callback with signIn event, adjust getUserByEmail in adapter to check provider (#1223)

* refactor: replace signIn callback with signIn event, adjust getUserByEmail in adapter to check provider

* test: adjusting tests for adapter and events

* docs: add comments for unknown auth provider

* fix: missing dayjs import

packages/auth/adapter.ts

@@ -1,5 +1,45 @@
+import type { Adapter } from "@auth/core/adapters";
 import { DrizzleAdapter } from "@auth/drizzle-adapter";
 
-import { db } from "@homarr/db";
+import type { Database } from "@homarr/db";
+import { and, eq } from "@homarr/db";
+import { accounts, users } from "@homarr/db/schema/sqlite";
+import type { SupportedAuthProvider } from "@homarr/definitions";
 
-export const adapter = DrizzleAdapter(db);
+export const createAdapter = (db: Database, provider: SupportedAuthProvider | "unknown"): Adapter => {
+  const drizzleAdapter = DrizzleAdapter(db, { usersTable: users, accountsTable: accounts });
+
+  return {
+    ...drizzleAdapter,
+    // We override the default implementation as we want to have a provider
+    // flag in the user instead of the account to not intermingle users from different providers
+    // eslint-disable-next-line no-restricted-syntax
+    getUserByEmail: async (email) => {
+      if (provider === "unknown") {
+        throw new Error("Unable to get user by email for unknown provider");
+      }
+
+      const user = await db.query.users.findFirst({
+        where: and(eq(users.email, email), eq(users.provider, provider)),
+        columns: {
+          id: true,
+          name: true,
+          email: true,
+          emailVerified: true,
+          image: true,
+        },
+      });
+
+      if (!user) {
+        return null;
+      }
+
+      return {
+        ...user,
+        // We allow null as email for credentials provider
+        // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
+        email: user.email!,
+      };
+    },
+  };
+};