CREATE OR REPLACE PROCEDURE public."Prc_P_PurchaseOrderSetStatus"(p_id uuid, p_action varchar, p_user_id uuid DEFAULT NULL)
LANGUAGE plpgsql AS $$
DECLARE v_status varchar(16);
BEGIN
  SELECT "Status" INTO v_status FROM "Prc_T_PurchaseOrder" WHERE "Id" = p_id;
  UPDATE "Prc_T_PurchaseOrder" SET "PendingAction" = NULL WHERE "Id" = p_id;

  IF p_action = 'Send' THEN
    IF v_status = 'Cancelled' THEN RAISE EXCEPTION 'İptal edilmiş belge gönderilemez.'; END IF;
    CALL public."Prc_P_PurchaseOrderSend"(p_id, p_user_id);
  ELSIF p_action = 'Confirm' THEN
    IF v_status NOT IN ('Draft', 'Sent') THEN RAISE EXCEPTION 'Yalnız teklif aşamasındaki belge siparişe çevrilebilir.'; END IF;
    IF NOT EXISTS (SELECT 1 FROM "Prc_T_PurchaseOrderLine" WHERE "PurchaseOrderId" = p_id AND "IsDeleted" = false) THEN
      RAISE EXCEPTION 'Kalemi olmayan teklif onaylanamaz.';
    END IF;
    UPDATE "Prc_T_PurchaseOrder" SET "Status" = 'Purchase', "ConfirmDate" = CURRENT_TIMESTAMP WHERE "Id" = p_id;
  ELSIF p_action = 'Cancel' THEN
    UPDATE "Prc_T_PurchaseOrder" SET "Status" = 'Cancelled' WHERE "Id" = p_id;
  ELSIF p_action = 'Draft' THEN
    IF v_status <> 'Cancelled' THEN RAISE EXCEPTION 'Yalnız iptal edilmiş belge taslağa alınabilir.'; END IF;
    UPDATE "Prc_T_PurchaseOrder" SET "Status" = 'Draft', "ConfirmDate" = NULL WHERE "Id" = p_id;
  END IF;
END;
$$;