import { ok, err, type CommandContext } from "@tailor-platform/erp-kit/core";
import { accountLifecycle } from "../db/account.lifecycle.generated";
import type { Transaction } from "../generated/kysely-tailordb";
import {
  AccountNotFoundError,
  InvalidStateTransitionError,
  OpenBalancesExistError,
} from "../lib/errors.generated";

export interface DeactivateAccountInput {
  id: string;
  preDeactivationHook?: (accountId: string) => Promise<boolean>;
}

/**
 * Function: deactivateAccount
 *
 * Transitions a GL account from ACTIVE to INACTIVE status, preventing new
 * journal postings while preserving history.
 */
export async function run(db: Transaction, input: DeactivateAccountInput, _ctx: CommandContext) {
  const { id, preDeactivationHook } = input;

  // 1. Find account with forUpdate
  const account = await db
    .selectFrom("Account")
    .selectAll()
    .where("id", "=", id)
    .forUpdate()
    .executeTakeFirst();

  if (!account) {
    return err(new AccountNotFoundError(id));
  }

  const nextStatus = accountLifecycle.tryTransition(account.status, "deactivate");
  if (!nextStatus) {
    return err(new InvalidStateTransitionError(id));
  }

  // 3. Pre-deactivation hook (GL balance check)
  if (preDeactivationHook) {
    const canDeactivate = await preDeactivationHook(id);
    if (!canDeactivate) {
      return err(new OpenBalancesExistError(id));
    }
  }

  // 4. Update status.
  const updated = await db
    .updateTable("Account")
    .set({ status: nextStatus })
    .where("id", "=", id)
    .returningAll()
    .executeTakeFirstOrThrow();

  return ok({ account: updated });
}