import { ok, err, type CommandContext } from "@tailor-platform/erp-kit/core";
import { stockAdjustmentLifecycle } from "../db/stockAdjustment.lifecycle.generated";
import type { Transaction } from "../generated/kysely-tailordb";
import { StockAdjustmentNotFoundError, InvalidStatusError } from "../lib/errors.generated";

export interface RejectStockAdjustmentInput {
  id: string;
  rejectionReason?: string;
}

/**
 * Function: rejectStockAdjustment
 *
 * Transitions a stock adjustment from SUBMITTED to REJECTED status.
 * An optional rejection reason can be provided.
 * No inventory or ledger changes occur.
 */
export async function run(
  db: Transaction,
  input: RejectStockAdjustmentInput,
  _ctx: CommandContext,
) {
  const { id, rejectionReason } = input;

  // 1. Fetch adjustment
  const adjustment = await db
    .selectFrom("StockAdjustment")
    .selectAll()
    .where("id", "=", id)
    .forUpdate()
    .executeTakeFirst();

  if (!adjustment) {
    return err(new StockAdjustmentNotFoundError(id));
  }

  // 2. Validate transition is allowed
  const nextStatus = stockAdjustmentLifecycle.tryTransition(adjustment.status, "reject");
  if (!nextStatus) {
    return err(new InvalidStatusError(id));
  }

  // 3. Transition to REJECTED
  const stockAdjustment = await db
    .updateTable("StockAdjustment")
    .set({
      status: nextStatus,
      rejectionReason: rejectionReason ?? null,
    })
    .where("id", "=", id)
    .returningAll()
    .executeTakeFirstOrThrow();

  return ok({ stockAdjustment });
}