import { z } from "zod";

const nonEmptyString = (field: string) => z.string().trim().min(1, `${field} is required`);

const blankStringToUndefined = (value: unknown) => {
  if (value === null || value === undefined) {
    return undefined;
  }

  if (typeof value !== "string") {
    return value;
  }

  const trimmedValue = value.trim();
  return trimmedValue.length > 0 ? trimmedValue : undefined;
};

export const postIdSchema = nonEmptyString("Post ID");

export const listPostsInputSchema = z.object({
  limit: z.coerce.number().int().min(1).max(50).optional(),
});

export const getPostByIdInputSchema = z.object({
  postId: postIdSchema,
});

export const createPostInputSchema = z.object({
  title: nonEmptyString("Title").max(160, "Title must be 160 characters or fewer"),
  body: nonEmptyString("Body").max(10_000, "Body must be 10000 characters or fewer"),
});

export const createCommentInputSchema = z.object({
  postId: postIdSchema,
  body: z.preprocess(blankStringToUndefined, nonEmptyString("Comment").max(4_000, "Comment must be 4000 characters or fewer")),
});

export type ListPostsInput = z.infer<typeof listPostsInputSchema>;
export type CreatePostInput = z.infer<typeof createPostInputSchema>;
export type CreateCommentInput = z.infer<typeof createCommentInputSchema>;