import { ok, err, type CommandContext } from "@tailor-platform/erp-kit/core";
import { productionOrderLifecycle } from "../db/productionOrder.lifecycle.generated";
import type { Transaction } from "../generated/kysely-tailordb";
import {
  ProductionOrderNotFoundError,
  ProductionOrderNotUnreleasableError,
  ExecutionAlreadyStartedError,
  InventoryHandoffExistsError,
} from "../lib/errors.generated";

export interface UnreleaseProductionOrderInput {
  id: string;
}

/**
 * Function: unreleaseProductionOrder
 *
 * Returns a released order to DRAFT when execution has not meaningfully
 * started. Removes release artifacts so the planner can safely revise
 * the order.
 */
export async function run(
  db: Transaction,
  input: UnreleaseProductionOrderInput,
  _ctx: CommandContext,
) {
  const { id } = input;

  // 1. Fetch production order with lock
  const order = await db
    .selectFrom("ProductionOrder")
    .selectAll()
    .where("id", "=", id)
    .forUpdate()
    .executeTakeFirst();

  if (!order) {
    return err(new ProductionOrderNotFoundError(id));
  }

  // 2. Validate status is unreleasable
  const nextStatus = productionOrderLifecycle.tryTransition(order.status, "unrelease");
  if (!nextStatus) {
    return err(new ProductionOrderNotUnreleasableError(id));
  }

  // 3. Check no work order has execution evidence
  const workOrders = await db
    .selectFrom("WorkOrder")
    .selectAll()
    .where("productionOrderId", "=", id)
    .execute();

  const hasExecution = workOrders.some(
    (wo) =>
      wo.status === "IN_PROGRESS" ||
      wo.status === "PAUSED" ||
      wo.status === "COMPLETE" ||
      wo.completedQuantity > 0 ||
      wo.actualStartDate != null,
  );

  if (hasExecution) {
    return err(new ExecutionAlreadyStartedError(id));
  }

  // 4. Check no irreversible inventory handoff
  const _materialRequirements = await db
    .selectFrom("ProductionOrderMaterialRequirement")
    .selectAll()
    .where("productionOrderId", "=", id)
    .execute();

  // Check if any cost summary has actual costs recorded (inventory handoff evidence)
  const costSummary = await db
    .selectFrom("ManufacturingCostSummary")
    .selectAll()
    .where("productionOrderId", "=", id)
    .executeTakeFirst();

  if (
    costSummary &&
    (costSummary.actualMaterialCost > 0 ||
      costSummary.actualLaborCost > 0 ||
      costSummary.actualMachineCost > 0 ||
      costSummary.actualOverheadCost > 0)
  ) {
    return err(new InventoryHandoffExistsError(id));
  }

  // 5. Remove release artifacts - delete work orders
  await db.deleteFrom("WorkOrder").where("productionOrderId", "=", id).execute();

  // 6. Remove material requirements
  await db
    .deleteFrom("ProductionOrderMaterialRequirement")
    .where("productionOrderId", "=", id)
    .execute();

  // 7. Remove BOM snapshot
  await db.deleteFrom("ProductionOrderBomSnapshot").where("productionOrderId", "=", id).execute();

  // 8. Remove routing snapshot
  await db
    .deleteFrom("ProductionOrderRoutingSnapshot")
    .where("productionOrderId", "=", id)
    .execute();

  // 9. Remove cost baseline
  await db.deleteFrom("ProductionOrderCostBaseline").where("productionOrderId", "=", id).execute();

  // 10. Remove cost summary
  await db.deleteFrom("ManufacturingCostSummary").where("productionOrderId", "=", id).execute();

  // 11. Set status to DRAFT
  const draftOrder = await db
    .updateTable("ProductionOrder")
    .set({
      selectedBomVersionId: null,
      selectedRoutingRevisionId: null,
      status: nextStatus,
    })
    .where("id", "=", id)
    .returningAll()
    .executeTakeFirstOrThrow();

  return ok({ productionOrder: draftOrder });
}