import { currentUser } from "@clerk/nextjs/server";
import type { IDatabase, User } from "./database/types";
import log from "./logger";

export async function ensureUserSynced(
  userId: string,
  db: IDatabase,
): Promise<User | null> {
  const existingUser = await db.getUserById(userId);
  if (existingUser) return existingUser;

  log.debug("User not found in DB by ID, checking Clerk", { userId });
  const clerkUser = await currentUser();

  if (!clerkUser || clerkUser.id !== userId) {
    // If we can't get the user from Clerk (e.g. running locally without full auth sync),
    // we might want to fail gracefully or throw.
    // For now, throw to be safe.
    throw new Error("Could not fetch Clerk user details");
  }

  const email = clerkUser.emailAddresses[0]?.emailAddress;
  if (!email) throw new Error("User has no email");

  // Check if user exists by email (e.g. seeded user)
  const existingByEmail = await db.getUserByEmail(email);
  if (existingByEmail) {
    log.debug("User found by email but ID mismatch, migrating ID", {
      oldId: existingByEmail.id,
      newId: userId,
    });

    // Update the ID to match Clerk ID
    // We need to do this manually via SQL because IDatabase interface might not expose a direct ID update method easily
    // But we can use a raw query if we had access, or add a method.
    // Since we don't have direct access to `db.db` here (it's hidden behind IDatabase),
    // we should add a method to IDatabase or use a workaround.
    // Actually, `SQLiteDatabase` is what we have at runtime.
    // Let's assume we can cast it or add `updateUserId` to the interface.

    // For now, let's try to update it using `updateUser` but `updateUser` usually updates fields based on ID.
    // We can't update the ID itself using `updateUser(id, { id: newId })` because `updateUser` implementation filters out `id` from updates.

    // We need to add a method to migrate user ID in IDatabase.
    // Or, strictly for this prototype, we can delete the old user and create a new one (DATA LOSS RISK).
    // But since it's a seeded super admin with no data, it's fine.
    // However, if they had clients, we'd lose the link.

    // Let's add `migrateUserId(oldId, newId)` to IDatabase.
    await db.migrateUserId(existingByEmail.id, userId);
    return db.getUserById(userId);
  }

  log.debug("Creating new user from Clerk data", { userId, email });
  const user = await db.createUser({
    id: userId,
    email,
    firstName: clerkUser.firstName || "",
    lastName: clerkUser.lastName || "",
    password: "", // Managed by Clerk
    phone: clerkUser.phoneNumbers[0]?.phoneNumber || undefined,
    gymId: (clerkUser.publicMetadata.gymId as string | undefined) || undefined,
    role: (() => {
      const r = clerkUser.publicMetadata.role as string | undefined;
      const validRoles = ["superAdmin", "admin", "trainer", "client"] as const;
      return r && validRoles.includes(r as (typeof validRoles)[number])
        ? (r as (typeof validRoles)[number])
        : "client";
    })(),
  });

  return user;
}
