/**
 * Guards for the dump request bodies. File dumps arrive as multipart forms
 * and are checked in their route.
 *
 * @module
 */

import type {
  CreateUrlDumpRequest,
  UpdateDumpRequest,
} from "../../shared/dump.ts";
import { VALIDATION } from "../../shared/validation.ts";

function isStringArray(value: unknown): value is string[] {
  return Array.isArray(value) && value.every((v) => typeof v === "string");
}

/**
 * Checks whether `obj` is a valid {@link CreateUrlDumpRequest}, its title and
 * comment within the `VALIDATION` limits.
 */
export function isCreateUrlDumpRequest(
  obj: unknown,
): obj is CreateUrlDumpRequest {
  if (
    !obj || typeof obj !== "object" ||
    !("url" in obj) || typeof obj.url !== "string"
  ) return false;
  const o = obj as Record<string, unknown>;
  if (
    "comment" in o && typeof o.comment !== "string" && o.comment !== null
  ) return false;
  if (
    typeof o.comment === "string" &&
    (o.comment as string).length > VALIDATION.DUMP_COMMENT_MAX
  ) return false;
  if ("title" in o && typeof o.title !== "string" && o.title !== null) {
    return false;
  }
  if (
    typeof o.title === "string" &&
    (o.title as string).length > VALIDATION.DUMP_TITLE_MAX
  ) return false;
  if ("isPrivate" in o && typeof o.isPrivate !== "boolean") return false;
  if ("categoryIds" in o && !isStringArray(o.categoryIds)) return false;
  return true;
}

/**
 * Checks whether `obj` is a valid {@link UpdateDumpRequest}: a title, when
 * given, that isn't blank, and title and comment within the `VALIDATION`
 * limits.
 */
export function isUpdateDumpRequest(obj: unknown): obj is UpdateDumpRequest {
  if (!obj || typeof obj !== "object") return false;
  const o = obj as Record<string, unknown>;
  if ("url" in o && typeof o.url !== "string" && o.url !== null) return false;
  if ("title" in o) {
    if (typeof o.title !== "string") return false;
    const trimmed = (o.title as string).trim();
    if (!trimmed || trimmed.length > VALIDATION.DUMP_TITLE_MAX) return false;
  }
  if (
    "comment" in o && typeof o.comment !== "string" && o.comment !== null
  ) return false;
  if (
    typeof o.comment === "string" &&
    (o.comment as string).length > VALIDATION.DUMP_COMMENT_MAX
  ) return false;
  if ("isPrivate" in o && typeof o.isPrivate !== "boolean") return false;
  if ("categoryIds" in o && !isStringArray(o.categoryIds)) return false;
  return true;
}