import type { RuntimeMode } from "../shared/api";

import { createApiError, jsonResponse } from "./helpers";

const MAX_PAGE_SIZE = 200;

export function validatePagination(
  pageParam: null | string,
  pageSizeParam: null | string,
  mode: RuntimeMode,
): Response | { page: number; pageSize: number } {
  let page = 1;
  let pageSize = 20;

  if (pageParam !== null) {
    page = Number(pageParam);
    if (!Number.isInteger(page) || page <= 0) {
      return jsonResponse(createApiError("Invalid page parameter", 400), { mode, status: 400 });
    }
  }

  if (pageSizeParam !== null) {
    pageSize = Number(pageSizeParam);
    if (!Number.isInteger(pageSize) || pageSize <= 0) {
      return jsonResponse(createApiError("Invalid pageSize parameter", 400), { mode, status: 400 });
    }
    if (pageSize > MAX_PAGE_SIZE) {
      return jsonResponse(createApiError(`pageSize must not exceed ${MAX_PAGE_SIZE}`, 400), { mode, status: 400 });
    }
  }

  return { page, pageSize };
}

export function validateTargetId(idStr: string, mode: RuntimeMode): Response | { id: number } {
  const id = Number(idStr);
  if (!Number.isInteger(id) || id <= 0) {
    return jsonResponse(createApiError("Invalid target ID", 400), { mode, status: 400 });
  }
  return { id };
}

export function validateTimeRange(
  from: null | string,
  to: null | string,
  mode: RuntimeMode,
): Response | { from: string; to: string } {
  if (!from || !to) {
    return jsonResponse(createApiError("from and to parameters are required", 400), { mode, status: 400 });
  }

  if (isNaN(new Date(from).getTime()) || isNaN(new Date(to).getTime())) {
    return jsonResponse(createApiError("Invalid from or to parameter format", 400), { mode, status: 400 });
  }

  return { from, to };
}