/**
 * Checks the comment request bodies, for the comment routes to answer a 400.
 *
 * @module
 */

import type {
  CreateCommentRequest,
  UpdateCommentRequest,
} from "../../shared/comment.ts";
import { VALIDATION } from "../../shared/validation.ts";

/**
 * Checks whether `obj` is a {@link CreateCommentRequest} whose body isn't
 * blank and fits `VALIDATION.COMMENT_BODY_MAX`. A null `parentId` passes, as a
 * top-level comment.
 */
export function isCreateCommentRequest(
  obj: unknown,
): obj is CreateCommentRequest {
  if (!obj || typeof obj !== "object") return false;
  const o = obj as Record<string, unknown>;
  return typeof o.body === "string" &&
    (o.body as string).trim().length > 0 &&
    (o.body as string).length <= VALIDATION.COMMENT_BODY_MAX &&
    (!("parentId" in o) || typeof o.parentId === "string" ||
      o.parentId === null);
}

/**
 * Checks whether `obj` is an {@link UpdateCommentRequest} whose body isn't
 * blank and fits `VALIDATION.COMMENT_BODY_MAX`.
 */
export function isUpdateCommentRequest(
  obj: unknown,
): obj is UpdateCommentRequest {
  if (!obj || typeof obj !== "object") return false;
  const o = obj as Record<string, unknown>;
  return typeof o.body === "string" &&
    (o.body as string).trim().length > 0 &&
    (o.body as string).length <= VALIDATION.COMMENT_BODY_MAX;
}